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Test Catalog
Explore MDL’s endocrinology hormone panels and individual analytes. Search by test name or code, and filter by type or method.
48 results
661 Adrenocorticotropic Hormone (ACTH) by Immunoassay Test
ACTH is a hormone from the pituitary gland that signals the adrenal glands to produce cortisol. Cortisol supports the stress response, metabolism, and blood pressure control. ACTH levels are highest in the early morning and decline through the day, so the time of collection matters. Testing helps diagnose adrenal disorders including Addison’s disease, Cushing’s syndrome, and tumors of the adrenal or pituitary gland. ACTH is interpreted together with a cortisol drawn at the same time to identify where the problem lies.
Download fact sheet (PDF)Limitations & disclaimers 6
- Plasma levels of ACTH exhibit a significant diurnal variation. It is important, therefore, to standardize the time of collection: reference ranges have typically been established for approximately 9 in the morning.
- ACTH measurement is not recommended for patients who have been administered cosyntropin (ACTH(1-24)) because the results may be falsely elevated or depressed.
- The presence of conjugated and unconjugated bilirubin in concentrations up to 200 mg/L has no effect on results, within the precision of the assay.
- Specimens that contain biotin at a concentration of 1500 ng/mL demonstrate a less than or equal to 10% change in results. Biotin concentrations greater than this may lead to incorrect results for patients samples.
- For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
621 Androstenedione by Immunoassay Test
Androstenedione is a steroid hormone produced by the adrenal glands, ovaries, and testes. It is a precursor that the body converts into testosterone and estrogen. Testing helps evaluate signs of excess androgen such as excessive hair growth, acne, and irregular periods. It also supports the diagnosis of congenital adrenal hyperplasia and polycystic ovary syndrome.
Download fact sheet (PDF)Limitations & disclaimers 13
- This assay is intended for the quantitative measurement of Δ4-androstenedione in human serum.
- Ensure that the time of specimen collection is noted; diurnal variation has been observed with a circadian amplitude equaling 42% of the mean in a sample size of 11 healthy men.
- Exercise can also increase androstenedione levels and should be avoided at least ninety minutes prior to sample collection or otherwise noted.
- The date of the last menstrual cycle should be noted at the time of collection as the growing graafian follicle secretes androstenedione, and a two-fold increase in its production occurs near the midcycle. Specimens drawn during this time may therefore yield androstenedione results which fall above the upper central 95% limit.
- Crossreactivity to all steroid metabolites cannot be ruled out.
- Androstenedione results may be falsely elevated in samples obtained from patients being treated with Spironolactone due to cross-reactivity. Use of this assay is not recommended for patients undergoing therapy with Spironolactone.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- Bilirubin may interfere with the assay, causing false elevations in androstenedione results.
- Hemolysis may interfere with the assay, causing false elevations in androstenedione results.
- Lipemia may interfere with the assay, causing a false depression of androstenedione values.
- Neither EDTA nor heparinized plasma are recommended for use with this assay.
653 Anti-Müllerian Hormone (AMH) by Immunoassay Test
Anti-Müllerian hormone is produced by small follicles in the ovaries and reflects a woman’s remaining egg supply, known as ovarian reserve. It is used to estimate fertility potential and to predict how the ovaries will respond to IVF stimulation. AMH also helps evaluate polycystic ovary syndrome, where levels are typically high, and primary ovarian insufficiency, where they are low. Unlike most reproductive hormones, AMH remains relatively stable across the menstrual cycle, so it can be drawn on any day.
Download fact sheet (PDF)Limitations & disclaimers 7
- The Access AMH results should be interpreted in light of the total clinical presentation of the patient, including: symptoms, clinical history, data from additional tests, and other appropriate information.
- The Access AMH assay is intended to be used for assessing the ovarian reserve in conjunction with other clinical and laboratory findings before starting any fertility therapy (including pre-treatment such as GnRH agonist down-regulation therapy) and should be used in conjunction with AFC.
- The Access AMH assay is not intended to be used for monitoring of women undergoing controlled ovarian stimulation in an Assisted Reproduction Technology program.
- Samples for AMH levels should be drawn on days 2-4 of the menstrual cycle.
- Compounds were tested for interference and their highest concentrations were Acetaminophen 20 mg/dL, Acetylsalicylic Acid 65 mg/dL, Ampicillin sodium salt 1000 mg/L, Ascorbic Acid 170 µmol/L, Bilirubin (conjugated) 43 mg/dL, Bilirubin (unconjugated) 40 mg/dL, Biotin 179 ng/mL, Cefoxitin sodium salt 2500 mg/L, Cyclosporin A 5 mg/L, doxycycline hyclate 50 mg/L, Folic Acid 0.4 mg/L, Gamma Globulin 60 mg/mL, Hemoglobin 1 g/dL, Heparin (low molecular weight) 3000 U/L, Ibuprofen 50 mg/dL, IgA 1.8 g/dL, IgG 2.5 g/dL, IgM 0.5 g/dL, Intralipids 37 mmol/L, Levodopa 20 mg/L, Levothyroxine sodium hydrate 0.2 mg/L, Metformin 2000 mg/L, Methyldopa 20 mg/L, Metronidazole 200 mg/L, N-Acetyl-L cysteine 150 mg/L, Phenylbutazone 400 mg/L, Rheumatoid Factor 1000 IU/mL, Rifampicin 60 mg/L, Theophyline 100 mg/L, Triptoreline (Gonapeptyl) 0.1 mg/L, Total protein (human serum albumin) 12 g/dL, Uric Acid 1.4 mmol/L, Inhibin A 100 ng/mL, Activin A 16.32 µg/mL, hLH 100 mIU/mL, hFSH 115 mIU/mL, TGF β-1 65 ng/mL and none were found to cause a bias of > 10%.
- For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
652 Anti-Thyroglobulin Antibody (Anti-Tg Ab) by Immunoassay Test
Thyroglobulin is a protein the thyroid gland uses to build and store its hormones. Anti-thyroglobulin antibodies attack that protein and are frequently present in autoimmune thyroid disease such as Hashimoto’s thyroiditis and Graves’ disease. A small proportion of healthy people also carry these antibodies. Testing is important whenever thyroglobulin is measured, because these antibodies interfere with the thyroglobulin assay and can make results unreliable.
Download fact sheet (PDF)Limitations & disclaimers 8
- This assay is intended for the quantitative measurement of autoantibodies to thyroglobulin (TG) in serum, as an aid in the clinical diagnosis of thyroid diseases.
- Use serum collection tubes without gel barriers or clot-promoting additives.
- For diagnostic purposes, anti-TG results should be used in conjunction with other test results, the overall clinical presentation to the physician, and all other appropriate information.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference potentially causing an anomalous result. These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- anti-TG determinations do not seem to add to the diagnostic information provided by anti-TPO results.
- TG autoantibodies can interfere with both competitive immunoassays and immunometric assays for thyroglobulin.
- Antibody and antigen testing detects the presence of antibodies or antigens in the blood when the body is responding to an infection, disease, or when exposure has occurred to the target. This test detects the body's immune response to the target the rather than detecting the target itself. Results from antibody or antigen testing should not be used as the sole basis to diagnose or exclude infection or disease; or to inform infection or disease status. A negative result does not rule out an infection or disease and a positive result may be due to past or present infection or disease.
638 Anti-Thyroid Peroxidase Antibody (Anti-TPO Ab) by Immunoassay Test
Thyroid peroxidase is the enzyme the thyroid uses to build its hormones. Anti-TPO antibodies attack that enzyme and are the most common marker of autoimmune thyroid disease. Testing helps diagnose Hashimoto’s disease, Graves’ disease, autoimmune thyroiditis, and goiter. High antibody levels in a patient with an underactive thyroid confirm Hashimoto’s disease.
Download fact sheet (PDF)Limitations & disclaimers 7
- This assay is intended for the quantitative measurement of antithyroid peroxidase (TPO) antibodies in serum, as an aid in the clinical diagnosis of thyroid diseases.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results for patient samples.
- For diagnostic purposes, anti-TPO results should be used in conjunction with other test results, the overall clinical presentation to the physician, and all other appropriate information. Autoantibodies may be found in less than 10% of the normal population at low levels and in patients with non-thyroidal illnesses, such as the inflammatory rheumatic diseases.
- Patient TPO autoantibodies and the antibodies used for calibrating the assay may differ in their binding properties. This may lead to deviations from strict dilutional parallelism for certain patient samples.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result. These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- Antibody and antigen testing detect the presence of antibodies or antigens in the blood when the body is responding to an infection, disease, or when exposure has occurred to the target. This test detects the body's immune response to the target rather than detecting the target itself. Results from antibody or antigen testing should not be used as the sole basis to diagnose or exclude infection or disease; or to inform infection or disease status. A negative result does not rule out an infection or disease and a positive result may be due to past or present infection or disease.
645 Bone Metabolism Disorder Panel Panel
This panel examines the hormones and nutrients that determine bone strength and turnover. It measures the hormones regulating how the body uses calcium, along with vitamin D and a marker of active bone formation. Because bone loss frequently originates outside the skeleton, the panel also evaluates thyroid, reproductive, adrenal, and growth hormones. The results help identify treatable causes of bone loss and establish a baseline for monitoring therapy.
663 C-Reactive Protein, High Sensitivity (hs-CRP) by Immunoassay Test
C-reactive protein is made by the liver and rises when there is inflammation anywhere in the body. Levels increase quickly with infection, injury, and chronic inflammatory conditions such as rheumatoid arthritis. The high-sensitivity version of the test, hs-CRP, detects much lower concentrations and is used primarily to assess cardiovascular risk. Results are most meaningful in a patient who is otherwise well, since a recent infection or injury can elevate levels temporarily.
Download fact sheet (PDF)Limitations & disclaimers 11
- CRP results should be used in conjunction with other test results, the overall clinical presentation to the physician, and all other appropriate information. Increases in CRP are non-specific and should not be interpreted without a complete clinical history. Screening the entire adult population is not recommended.
- CRP measurements are not a substitute for traditional cardiovascular risk factors. Acute coronary syndrome management should not depend on CRP measurements.
- Patients with persistently unexplained CRP levels above 10 mg/L should be evaluated for other non-cardiovascular origins.
- Testing for risk assessment should not be performed while there is an indication of infection, systemic inflammation, or trauma.
- Secondary prevention measures should be based on global risk assessment and not depend on CRP.
- Serial testing of CRP should not be used to monitor effects of treatment. The average of CRP results repeated optimally over two weeks should be used in performing risk assessment on metabolically stable patients.
- The presence of conjugated bilirubin in concentrations up to 200 mg/L has no effect on results, within the precision of the assay.
- Specimens that contain biotin at a concentration of 1500 ng/mL demonstrate a less than or equal to 10% change in results. Biotin concentrations greater than this may lead to incorrect results for patient samples.
- The presence of hemoglobin in concentrations up to 512 mg/dL has no effect on results, within the precision of the assay.
- For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
628 Calcitonin by Immunoassay Test
Calcitonin is a hormone produced by the C-cells of the thyroid gland that helps regulate calcium. It opposes parathyroid hormone and slows the breakdown of bone by blocking the cells responsible for bone resorption. Its principal clinical application is as a tumor marker for medullary thyroid carcinoma, in which levels are markedly elevated. Calcitonin may also be measured when evaluating a thyroid nodule or a family history of this cancer.
Download fact sheet (PDF)Limitations & disclaimers 11
- This assay is intended for the quantitative measurement of calcitonin (thyrocalcitonin) in human serum, as an aid in the diagnosis and treatment of diseases involving the thyroid and parathyroid glands, including carcinoma and hyperparathyroidism.
- Samples must be refrigerated after collection to prevent degradation.
- The time of collection should be noted.
- EDTA coated tubes are not recommended for sample collection as EDTA interferes with the assay.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results.
- Multiple forms of immunoreactive calcitonin are present in the circulation of healthy subjects, patients with medullary thyroid carcinoma, and patients with other malignancies. These different forms of calcitonin (polymers and/or glycosylated forms) can have molecular weights varying from 3.4 to 70 KDa. Therefore, samples may exhibit varied response in an immunoassay and non-linear dilution.
- Some healthy individuals may be encountered who have elevated immunoreactive calcitonin levels.
- Because calcitonin is highly labile, special attention must be paid to proper specimen collection and preservation.
- Where several samples are collected from a single patient, e.g. in pentagastrin stimulation testing or serial monitoring, all samples should be assayed by the same procedure.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays.
- Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference potentially causing an anomalous result. These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur. For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
647 Comprehensive Menopause Panel Panel
This panel helps confirm whether a woman is entering or has completed menopause and how her body is responding. It measures the ovarian and pituitary hormones that shift during this transition, plus testosterone and the proteins that carry them in the blood. Menopause symptoms can closely resemble thyroid disease or nutritional deficiency, so the panel evaluates those possibilities too. It also includes markers of bone health and inflammation, which become more important after menopause.
694 Comprehensive HRT Panel Panel
This panel guides doctors in starting and adjusting hormone replacement therapy. It measures estrogen and testosterone along with the proteins that bind them, indicating how much active hormone actually reaches the tissues. Hormone therapy can also affect thyroid function, inflammation, and nutrient levels, so the panel evaluates these as well. Results should be interpreted alongside the hormone prescribed, its dose, how it is taken, and when the last dose was given.
649 Comprehensive PMOS/PCOS Panel Panel
This panel evaluates the hormone patterns used to diagnose and manage polycystic ovary syndrome (PMOS/PCOS). It measures androgens, the protein that binds them, and calculated indices showing how much active androgen reaches the tissues. It also measures the pituitary and ovarian hormones that reflect disrupted ovulation, along with markers of inflammation and nutrition. Because diagnosis requires ruling out conditions with similar features, the panel checks thyroid function, prolactin, and cortisol as well.
691 Advanced Women’s Hormone & Healthy Aging Panel Panel
This panel provides a broad hormonal and nutritional assessment for older women. It evaluates thyroid function and thyroid autoimmunity in detail, since thyroid disease becomes more common with age and often produces vague symptoms. It also measures the hormones and markers of bone metabolism, the postmenopausal sex steroids and their binding protein, and the growth hormone axis. Nutritional and inflammatory markers complete the assessment, addressing the deficiencies and chronic inflammation that affect health and function in later life.
690 Core PMOS/PCOS Panel Panel
This panel is a focused first-line screen for polycystic ovary syndrome (PMOS/PCOS). It measures androgens, the protein that binds them, and calculated indices showing how much active androgen reaches the tissues. It also assesses the pituitary and ovarian hormones that reflect ovarian function and follicle reserve. Thyroid function and prolactin are included to help exclude common conditions that produce similar symptoms.
641 Cortisol by Immunoassay Test
Cortisol is the body’s primary stress hormone, produced by the adrenal glands from cholesterol. It regulates metabolism, maintains blood pressure, suppresses inflammation, and helps control the sleep-wake cycle. Cortisol follows a daily rhythm, peaking in the early morning and reaching its lowest point at night, so the collection time must be recorded. Testing evaluates the function of the adrenal glands, the pituitary gland, and the hypothalamus. Persistently high cortisol suggests Cushing’s syndrome, while persistently low cortisol suggests Addison’s disease.
Download fact sheet (PDF)Limitations & disclaimers 11
- This assay is intended for the quantitative measurement of cortisol (hydrocortisone, Compound F) in serum, as an aid in the clinical assessment of adrenal status.
- Time of specimen collection should be noted as cortisol exhibits a diurnal fluctuation pattern with levels at their highest upon waking and lowest in the evening prior to sleep.
- Anomalous cortisol concentrations have been shown to exist in patients with acute infections, severe pain, diabetes mellitus or heart failure, and in women either pregnant or on estrogen therapy. In addition, certain virilizing syndromes and iatrogenic conditions raise other naturally occurring steroid levels to high (nonphysiologic) concentrations that may interfere with assaying cortisol directly, unless a highly specific antiserum is used.
- Icteric or grossly contaminated samples may give erroneous results.
- Circulating cortisol results may be falsely elevated in samples obtained from patients being treated with prednisolone or prednisone (converted to prednisolone in vivo). Circulating cortisol results may also be falsely elevated due to cross-reactivity with 11-Deoxycortisol during metyrapone stimulation testing and therapy, potentially masking a hypoadrenalism. Caution must therefore be exercised with cortisol determinations for patients undergoing therapy with these and structurally related synthetic corticosteroids.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- There is an observed cross-reactivity of approximately 62% with prednisolone, 22-25% with methylprednisolone, 6.4% with corticosterone, and 6.1% with prednisone which must be considered for patients undergoing these therapies.
- Bilirubin may interfere with the assay.
- Biotin concentrations greater than 3,500ng/mL may lead to incorrect results for patient samples.
631 Dehydroepiandrosterone Sulfate (DHEA-SO₄) by Immunoassay Test
DHEA-sulfate is a steroid hormone produced almost entirely by the adrenal glands. It has little activity of its own but serves as a precursor the body converts into testosterone and estrogen. Because its source is almost exclusively adrenal, DHEA-S is a useful marker of adrenal androgen production. Elevated levels point toward an adrenal cause of excess androgen and are common in women with excessive hair growth. Testing supports the evaluation of polycystic ovary syndrome, congenital adrenal hyperplasia, and Cushing’s syndrome.
Download fact sheet (PDF)Limitations & disclaimers 5
- This assay is intended for the quantitative measurement of DHEA-SO4 in serum.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results for patient samples.
693 Endometriosis Panel Panel
This panel assesses hormone levels, inflammation, and nutrition in women with pelvic pain, heavy menstrual bleeding, or trouble conceiving. It measures the ovarian and pituitary hormones that control the menstrual cycle, plus ovarian reserve and androgen status. Thyroid tests and prolactin are included because these conditions cause similar symptoms. It also checks inflammation and the iron stores often depleted by heavy bleeding.
611 Estradiol (E2) by Immunoassay Test
Estradiol is the most potent form of estrogen and the main one produced by the ovaries before menopause. It regulates the menstrual cycle, drives ovulation, and prepares the uterus for pregnancy. Estradiol also helps maintain bone density, cardiovascular health, mood, and cognitive function in women and, in smaller amounts, in men. Levels decline naturally at menopause. Testing supports the evaluation of fertility, menstrual disorders, and menopausal status.
Download fact sheet (PDF)Limitations & disclaimers 13
- This assay is intended for the quantitative measurement of estradiol in serum, as an aid in the diagnosis and treatment of various sexual disorders.
- Exercise caution when testing pregnancy samples, as estriol levels may be high enough to interfere with the assay.
- The assay has not been validated for use on neonatal samples.
- Cross-reacting steroids, including estriol, circulating at high concentrations during this period may cause spuriously elevated results.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings. If estradiol results are inconsistent with clinical evidence, additional testing is suggested to confirm the result.
- The drug Fulvestrant (FASLODEX®, a registered trademark of AstraZeneca) may cause falsely elevated estradiol results in immunoassays. For patients being treated with Fulvestrant, an alternate method that is not expected to show cross-reactivity to Fulvestrant, such as Liquid Chromatography-Mass Spectrometry (LC-MS), should be used.
- With the advent of new steroid-based medications (analogues) with similar chemical structures to estradiol, there is the possibility of cross-reactivity and results that are inconsistent with the patients’ clinical history.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results for patient samples.
- The presence of triglycerides in concentrations up to 3,000 mg/dL may interfere with the assay; lipemic samples are not to be used.
- The date of the first day of the last menstrual period should be gathered at the time of sample collection as estradiol levels are expected to fluctuate throughout the menstrual cycle.
- Estradiol levels can exceed the expected normal values if oral contraceptives are taken.
657 Ferritin by Immunoassay Test
Ferritin is the protein that stores iron in the body and releases it as needed, chiefly for producing red blood cells. Measuring ferritin indicates how much iron is held in reserve. Low ferritin is the most reliable early indicator of iron deficiency and iron-deficiency anemia. High ferritin can indicate iron overload, but because ferritin also rises with inflammation, elevated results should be interpreted alongside other markers.
Download fact sheet (PDF)Limitations & disclaimers 7
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays.
- Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- The drug asfotase alfa (STRENSIQ®), a recombinant form of alkaline phosphatase, is expected to interfere with in vitro diagnostic assays utilizing an alkaline phosphatase detection system. Test samples from patients receiving asfotase alfa should be analyzed using a non-alkaline phosphatase methodology.
- For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
656 Folate by Immunoassay Test
Folate, also called vitamin B9, is a water-soluble vitamin required for DNA synthesis, cell division, and red blood cell formation. It occurs naturally in leafy greens and is added to fortified foods and supplements as folic acid. Testing assesses nutritional status and helps determine the cause of anemia. Folate deficiency produces a characteristic form of anemia and is a particular concern before and during pregnancy. Results are usually interpreted alongside vitamin B12.
Download fact sheet (PDF)Limitations & disclaimers 8
- Circulating folate levels are an unreliable indicator of tissue stores and inversely, tissue stores are unreliable in measuring circulating folate levels. Accordingly it is important to measure red cell folate levels whenever serum or plasma levels are measured.
- Patients must be in a fasting state.
- Since high-dose infusions of methotrexate may result in circulating levels of 45,000 ng/mL initially and levels in the order of 2000 ng/mL 48 hours later, the kit should not be used for folic acid measurements on patients currently receiving the drug. Moreover, great caution must be exercised when interpreting folic acid levels on patients who have recently undergone therapy with methotrexate or any other drug with a similar structure.
- Folic acid results near the lower limit of normal should be interpreted with caution.
- The presence of bilirubin in concentrations up to 200 mg/L has no effect on results, within the precision of the assay.
- Specimens that contain biotin at a concentration of 500 ng/mL demonstrate a less than or equal to 10% change in results. Biotin concentrations greater than this may lead to falsely elevated results for patient samples.
- For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
610 Follicle Stimulating Hormone (FSH) by Immunoassay Test
Follicle-stimulating hormone is produced by the pituitary gland and works with luteinizing hormone to control the ovaries and testes. In women, FSH drives the growth of ovarian follicles and stimulates estrogen production, and levels rise substantially after menopause. In men, FSH supports sperm production and testicular function. Testing helps evaluate infertility in both sexes, assess ovarian reserve, and investigate disorders of the pituitary gland or hypothalamus.
Download fact sheet (PDF)Limitations & disclaimers 8
- This assay is intended for the quantitative measurement of FSH in serum, as an aid in the diagnosis and treatment of pituitary and gonadal disorders
- EDTA plasma specimens should not be used as a sample type.
- Caution should be exercised in populations undergoing fertility treatments. The administration of human gonadotropins can cause antibodies to FSH to be produced, causing direct interference with the assay.
- Due to the effects of pulsatile secretion, samples obtained within the same day from the same patient may fluctuate widely within the reference range, reflecting physiological variation rather than errors in technique or methodology.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- Samples containing biotin concentrations greater than 1,500 ng/mL may lead to incorrect results for patient samples.
696 Free Androgen Index (FAI) by Calculation Test
The free androgen index is a calculated ratio that estimates how much testosterone is biologically available. It is derived from total testosterone and sex hormone-binding globulin rather than measured directly. Because SHBG determines how much testosterone remains bound and inactive, the index provides a rapid picture of active androgen without a separate assay. An elevated free androgen index is a common finding in polycystic ovary syndrome and other conditions causing excess androgen in women. The index is most informative in women and has limited value in men.
Download fact sheet (PDF)662 Homocysteine by Immunoassay Test
Homocysteine is an amino acid formed when the body metabolizes methionine, a building block of protein. It is subsequently cleared using vitamins B6, B12, and folate. Elevated homocysteine can indicate a deficiency in one of these vitamins or impaired processing of them. Higher concentrations are also associated with increased risk of heart attack, stroke, blood clots, and cognitive decline.
Download fact sheet (PDF)Limitations & disclaimers 6
- It is important to separate the plasma or serum from the cells as soon as possible after collection, as synthesis of HCY will take place in red blood cells after sampling.
- Specimens from patients who are on drug therapy involving S-adenosyl-methionine may show falsely elevated levels of homocysteine.
- Presence of conjugated and unconjugated bilirubin in concentrations up to 200 mg/L has no effect on results, within the precision of the assay.
- Specimens that contain biotin at a concentration of 1500 ng/mL demonstrate a less than or equal to 10% change in results. Biotin concentrations greater than this may lead to incorrect results for patient samples.
- For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
695 Hormone Replacement Therapy (HRT) Panel Panel
This panel measures only the hormones directly involved in hormone replacement therapy. It covers the estrogens, progesterone, and androgens being replaced, plus the binding protein and calculated indices showing how much active hormone reaches the tissues. Pituitary hormones and ovarian reserve are included to gauge how the body is responding to treatment. Results should be interpreted alongside the hormone prescribed, its dose, how it is taken, and when the last dose was given.
640 Human Chorionic Gonadotropin (hCG) by Immunoassay Test
Human chorionic gonadotropin is a hormone produced by placental tissue and is normally detectable in blood only during pregnancy. It is the hormone identified by pregnancy tests. Concentrations rise rapidly following conception, peak near the end of the first trimester, and subsequently decline. Outside pregnancy, hCG serves as a tumor marker for certain cancers of the testes, ovaries, and placenta.
Download fact sheet (PDF)Limitations & disclaimers 5
- This assay is intended for the quantitative measurement of human chorionic gonadotropin (hCG) in serum, as an aid in the detection of pregnancy.
- Ectopic pregnancies and pregnancies terminating in spontaneous abortion tend to have lower than normal circulating hCG levels, while somewhat higher levels are often seen in multiple pregnancies.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results for patient samples.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result. These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
660 Insulin-like Growth Factor 1 (IGF-1) by Immunoassay Test
Insulin-like growth factor 1 is produced primarily by the liver in response to growth hormone. It stimulates the growth of bone, cartilage, and muscle, and it is the principal mechanism through which growth hormone exerts its effects. Because IGF-1 is considerably more stable in blood than growth hormone itself, it is the preferred measure of growth hormone status. Testing evaluates growth hormone deficiency and acromegaly. IGF-1 also contributes to the excess androgen production characteristic of polycystic ovary syndrome.
Download fact sheet (PDF)Limitations & disclaimers 1
- Acid treatment is necessary to release IGF-I to ensure accurate quantitation. Because EDTA would affect results, it should not be used as an anticoagulant. Presence of conjugated and unconjugated bilirubin in concentrations up to 200 mg/L has no effect on results, within the precision of the assay. Assessed per CLSI guideline EP07-A2. For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings. Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).”
620 Insulin-like Growth Factor Binding Protein 3 (IGFBP-3) by Immunoassay Test
Insulin-like growth factor binding protein 3 transports the majority of the IGF-1 circulating in the bloodstream. By binding IGF-1, it regulates how much remains biologically active and prolongs its persistence in circulation. IGFBP-3 concentrations respond directly to growth hormone, which makes the test valuable in evaluating growth disorders in children. It is generally interpreted together with IGF-1 and growth hormone.
Download fact sheet (PDF)Limitations & disclaimers 5
- This assay is intended for the quantitative measurement of insulin-like growth factor binding protein 3 (IGFBP-3) in serum, as an aid in the evaluation of growth disorders.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result.
- These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect patient results for patient samples.
618 Intact Parathyroid Hormone (iPTH) by Immunoassay Test
Parathyroid hormone is produced by the parathyroid glands and is the principal regulator of calcium in the body. It controls calcium, phosphorus, and vitamin D levels by acting on bone, the kidneys, and the intestine. The intact PTH test measures the biologically active form of the hormone. Testing is used to diagnose and monitor parathyroid disorders, chronic kidney disease, and abnormal calcium levels.
Download fact sheet (PDF)Limitations & disclaimers 13
- This assay is intended for the quantitative measurement of intact parathyroid hormone (parathyrin, PTH) in serum, as an aid in the differential diagnosis of hypercalcemia and hypocalcemia.
- The assay exhibits cross reactivity (44.8%) with a large fragment of PTH, 7-84. As such, positive results may be due to the presence of PTH 7-84, in addition to intact PTH.
- The presence of conjugated and unconjugated bilirubin in concentrations up to 200 mg/L may cause a depression of values.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results for patient samples.
- The presence of hemoglobin in concentrations up to 513 mg/dL may cause a depression of values.
- The presence of triglycerides in concentrations up to 3,000 mg/dL may cause a depression of values.
- The assay is intended strictly as an aid in the differential diagnosis of hypercalcemia and hypocalcemia, not for the diagnosis or management of malignancy.
- Because of the physiological relationship between circulating calcium and PTH, it is always important to interpret PTH results in the light of total or ionized calcium levels. The finding of a persistently high-normal calcium accompanied by a high-normal PTH (alternatively, a low-normal calcium accompanied by a low-normal PTH) warrants further investigation; for the PTH, though itself within normal limits, may still be inappropriately high (or inappropriately low) relative to the circulating calcium level.
- Indices of renal function, e.g. creatinine levels; measurement of albumin, as an adjunct to measurement of total calcium levels; and determinations of phosphorus, chloride, nephrogenous cyclic AMP, and possibly calcitonin, may also (in certain circumstances) aid in the interpretation of PTH and calcium results. It should also be remembered that hypercalcemia and hypocalcemia may be secondary to disordered vitamin D metabolism.
- Lipemic, hemolyzed, icteric or grossly contaminated samples may give erroneous results.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays.
- Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference potentially causing an anomalous result. These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
614 Luteinizing Hormone (LH) by Immunoassay Test
Luteinizing hormone is produced by the pituitary gland and works with follicle-stimulating hormone to control the ovaries and testes. In women, a mid-cycle surge of LH triggers ovulation and prompts the ovary to form the corpus luteum, which prepares the uterus for pregnancy. In men, LH stimulates the testes to produce testosterone and supports sperm production. Testing helps evaluate infertility, irregular periods, and polycystic ovary syndrome.
Download fact sheet (PDF)Limitations & disclaimers 8
- This assay is intended for the quantitative measurement of LH in serum, as an aid in clinical diagnosis.
- The time of collection should be noted as LH levels have been known to fluctuate following circadian rhythm.
- Because of pulsatile secretion, samples obtained within the same day from the same patient may fluctuate widely within the reference range, reflecting physiological variation rather than errors in technique or methodology.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results for patient samples.
- The assay exhibits mild cross reactivity to hCG. The level of cross-reactivity is low and should not impact test results under normal circumstances. However, for samples with very high levels of hCG, such as pregnancy samples, samples from trophoblastic disease or testicular cancer patients, LH may be falsely elevated due to cross reactivity to hCG.
651 Endocrinology Metabolism Panel Panel
This panel evaluates the hormones and nutrients that regulate metabolic rate and energy balance. Thyroid function is assessed in detail, since it sets the body's baseline metabolic rate. The panel also measures cortisol, growth hormone signaling, and the sex steroids that affect how energy is stored and used. Nutritional and inflammatory markers complete the assessment, since deficiency and chronic inflammation both disrupt metabolism.
658 Ostase (BSAP/BAP) by Immunoassay Test
Ostase measures bone-specific alkaline phosphatase, an enzyme found on the surface of the cells that build new bone. It is a sensitive marker of bone formation and overall bone turnover. Elevated levels indicate increased bone-building activity, seen in Paget’s disease, healing fractures, overactive parathyroid glands, and cancer that has spread to bone. Because this form of the enzyme originates specifically in bone, it helps determine whether an elevated total alkaline phosphatase comes from the skeleton or the liver.
Download fact sheet (PDF)Limitations & disclaimers 13
- The results should be interpreted in light of the total clinical presentation of the patient, including: symptoms, clinical history, data from additional tests, and other appropriate information.
- The immunoreactivity of liver ALP has been determined in the Access Ostase assay: 100 U/L of liver ALP activity gives a result of 2.5 to 5.8 µg/L in the Access Ostase assay.
- Serum samples with significant elevations of liver ALP activity may yield elevated results in the Access Ostase assay.
- Patients with metabolic bone disorders who have low levels of disease activity may have BAP levels that fall within the Access Ostase assay expected values.
- Access Ostase assay results should be used only in conjunction with information available from the clinical evaluation of the patient and other diagnostic procedures.
- Hemoglobin, tested at concentrations up to 500 mg/dL, does not interfere with the Access Ostase assay.
- Unconjugated and conjugated bilirubin, tested at concentrations up to 40 mg/dL and 20 mg/dL, respectively, do not interfere with the Access Ostase assay.
- Triglycerides, tested at concentrations up to 2,000 mg/dL, do not interfere with the Access Ostase assay.
- Total protein, tested at concentrations between 3.0 and 15.6 g/dL, does not interfere with the Access Ostase assay.
- 100 U/L intestinal ALP activity yields a result of 1.8 µg/L in the Access Ostase assay. 100 U/L placental ALP activity yields a result of 0.3 µg/L in the Access Ostase assay. Therefore, the Access Ostase assay is not recommended for use as a screening procedure to detect the presence of osteoporosis in the general population.
- Furthermore, the Access Ostase assay cannot be used to assess the rate of bone formation or bone remodeling.
- For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
692 Primary Ovarian Insufficiency (POI) Panel Panel
This panel supports the workup of premature ovarian insufficiency, the loss of ovarian function before age 40. It measures the pituitary and ovarian hormones used to make the diagnosis, including the rise in follicle-stimulating hormone and the fall in estradiol and ovarian reserve. The condition is often autoimmune, so the panel includes thyroid function and thyroid antibodies. Prolactin and adrenal hormones help rule out other causes of missed periods.
630 Progesterone by Immunoassay Test
Progesterone is a steroid hormone produced mainly by the ovaries after ovulation and by the placenta during pregnancy. It prepares the uterine lining for implantation and helps maintain an early pregnancy. A progesterone level drawn in the second half of the cycle is the standard way to confirm that ovulation has occurred. Progesterone is also a component of many oral contraceptives, where it helps prevent ovulation. Testing supports the evaluation of infertility, ovulation disorders, and pregnancy complications.
Download fact sheet (PDF)Limitations & disclaimers 10
- This assay is intended for use for the quantitative measurement of progesterone in serum, as an aid in the diagnosis and treatment of disorders of the ovaries or placenta.
- EDTA interferes with results and should not be used as an anticoagulant.
- Time-dependent decreases in progesterone levels have been reported when serum samples are collected and stored in gel barrier tubes.
- Lipemic samples have demonstrated reduced progesterone concentrations due to interference and should be avoided.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- The supplement Dehydroepiandrosterone (DHEA) may cause falsely elevated progesterone results in immunoassays. At an initial concentration of progesterone of 1.16 ng/mL, an 80.2% change in concentration was observed at the supraphysiologic level of DHEAS (DHEA metabolite) of 20,000 ng/mL. For patients being treated with DHEA, an alternate method that is not expected to show cross reactivity to DHEAS (DHEA metabolite), such as Liquid Chromatography-Mass Spectrometry (LC-MS), should be used.
- With the advent of new steroid based medications (analogues) with similar chemical structures to progesterone, there is the possibility of cross-reactivity and falsely elevated results.
- For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings. If the progesterone results are inconsistent with clinical evidence, additional testing is suggested to confirm the result.
654 Prolactin by Immunoassay Test
Prolactin is a hormone produced by the pituitary gland that starts and maintains breast milk production. It also influences the reproductive system, metabolism, and immune function. Testing helps evaluate infertility, irregular or absent periods, and unexplained breast milk production, and very high levels can indicate a pituitary tumor. Elevated prolactin suppresses ovulation and lowers reproductive hormone levels.
Download fact sheet (PDF)Limitations & disclaimers 10
- Prolactin is a stress hormone. Events no more distressing than venipuncture have been reported to cause a rise in prolactin levels. The release of prolactin is inherently episodic, and day-to-day fluctuations with CVs as high as 30% have been encountered. Sleep-related diurnal variation also occurs, with prolactin levels increasing during sleep and reaching their lowest a few hours after waking.
- Women taking oral contraceptives or under estrogen treatment may have higher than normal prolactin levels.
- Blood collection tubes from different manufacturers may yield differing values, depending on materials and additives, including gel or physical barriers, clot activators and/or anticoagulants.
- This assay has not been tested with all possible variations of tube types. Please consult the instructions for use for further information.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays.
- Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result.
- These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- Specimens that contain biotin at a concentration of 1,500 ng/mL demonstrate a less than or equal to 10% change in results. Biotin concentrations greater than this may lead to incorrect results for patient samples.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
639 Sex Hormone-Binding Globulin (SHBG) by Immunoassay Test
Sex hormone-binding globulin is a protein made by the liver that binds testosterone, dihydrotestosterone, and estradiol and carries them through the blood. Hormone bound to SHBG is unavailable to tissues, so SHBG determines how much active hormone the body can actually use. Measuring it allows a more accurate assessment of hormone status than total levels alone. SHBG is typically higher in women than in men. Levels rise with an overactive thyroid, pregnancy, and liver disease, and fall with obesity, type 2 diabetes, an underactive thyroid, and polycystic ovary syndrome.
Download fact sheet (PDF)Limitations & disclaimers 5
- This assay is intended for the quantitative measurement of SHBG in serum, as an aid in the differential diagnosis of hirsutism.
- SHBG results should be interpreted in conjunction with measures of the hormones with which it binds, notably testosterone. Combining such information in the form of a free androgen index (FAI) — computed as the ratio of total testosterone to SHBG — has been reported to yield better discrimination of women with hyperandrogenic hirsutism from healthy women than the use of SHBG levels on their own.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result.
- These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
685 Testosterone, Free (FT) by Calculation Test
Free testosterone is the small portion of circulating testosterone that is not bound to sex hormone-binding globulin or albumin. Because only this unbound fraction can enter cells and act on tissues, it often reflects androgen status more accurately than total testosterone. This is particularly true when SHBG is abnormal, as occurs with obesity, thyroid disease, and aging. At MDL, free testosterone is calculated from measured total testosterone, SHBG, and albumin rather than measured directly. It is most useful in evaluating women for polycystic ovary syndrome and excessive hair growth, and men for low testosterone.
Download fact sheet (PDF)622 Testosterone, Total (TT) by Immunoassay Test
Testosterone is the principal androgen, produced mainly by the testes in men and in smaller amounts by the ovaries and adrenal glands in women. In men it drives sexual development, sperm production, muscle mass, bone density, and libido. In women it contributes to bone strength, muscle, and libido. Low testosterone can cause fatigue, reduced libido, loss of muscle, and mood changes in both sexes. Testing supports the diagnosis of low testosterone in men and of polycystic ovary syndrome and congenital adrenal hyperplasia in women.
Download fact sheet (PDF)Limitations & disclaimers 6
- This assay is intended for the quantitative measurement of total testosterone in serum, as an aid in the diagnosis and management of conditions involving excess or deficiency of this androgen.
- EDTA tubes should not be used to collect specimens for this assay.
- Bilirubin may cause elevation of values.
- Presence of triglycerides in concentrations above 500 mg/dL may interfere with the assay.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference potentially causing an anomalous result. These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
623 Thyroglobulin (Tg) by Immunoassay Test
Thyroglobulin is a protein produced only by the thyroid gland, which uses it to build and store thyroid hormones. Healthy people have low but detectable levels that roughly reflect the size of the gland. Its principal use is as a tumor marker after treatment for thyroid cancer, since removing the thyroid should reduce thyroglobulin to very low or undetectable levels. A subsequent rise can signal residual or recurrent cancer. Results must be interpreted alongside anti-thyroglobulin antibodies, which interfere with the test.
Download fact sheet (PDF)Limitations & disclaimers 18
- This assay is intended for the quantitative measurement of thyroglobulin in serum, as an aid in monitoring patients who have undergone thyroidectomy.
- EDTA coated tubes should not be used to collect specimens as EDTA plasma has an effect on the measurement of thyroglobulin for this assay.
- Biotin concentrations greater than 5 ng/mL may lead to falsely depressed results.
- The presence of autoantibodies against thyroglobulin (anti-TG) can interfere with the determination of thyroglobulin in serum. Anti-TG antibodies can be quantitated by using Test No. 652, Anti-TG Ab.
- Thyroglobulin results must be interpreted with caution as the presence of thyroglobulin autoantibodies may cause underestimation of the thyroglobulin level as measured by immunometric assays.
- Results of this assay should not be reported for patients with renal impairment (eGFR <60), unless it is confirmed that the patient is not taking biotin, as this may lead to false results.
- When monitoring patients over time, TG values obtained with different methods cannot be used interchangeably due to the differences in methods and reagent specificity. Serial serum TG measurements should be made with the same method.
- Somewhat higher values are encountered in newborns and during the third trimester of pregnancy. Thyroglobulin levels also tend to be elevated in regions of endemic goiter.
- In patients who have undergone thyroidectomy, thyroglobulin concentrations should theoretically approach zero or approximate the sensitivity of the thyroglobulin assay. Any increase in the thyroglobulin level of such patients should be further interpreted in conjunction with other available diagnostic test results and the patient's clinical presentation.
- Because thyroglobulin autoantibodies (TgAb) can interfere with both competitive immunoassays and immunometric assays for thyroglobulin, all patients should be screened for TgAb by a sensitive immunoassay: recovery studies are not adequate for ruling out interference by TgAb.
- Thyroglobulin antibodies (TgAb) are present in the majority of patients with Hashimoto's thyroiditis, but also in approximately 5% of healthy individuals.
- At least 6 weeks should elapse after thyroidectomy or 131I treatment as thyroglobulin levels may remain elevated for several months following successful treatment. Serial determinations assessed relative to a post-treatment baseline established for the patient may still be of value in monitoring.
- It is important to obtain thyroglobulin measurements before administering 131I for scanning, since the scan may result in the release of large amounts of thyroglobulin from a relatively small number of cells. Likewise, samples for thyroglobulin assay should not be collected prematurely following procedures such as needle biopsy that are likely to cause a transient elevation in the thyroglobulin level.
- Although thyroglobulin measurements are of established value in the differential diagnosis of congenital hypothyroidism, they are not recommended for use in screening for this condition since a wide spectrum of thyroglobulin levels are obtained for this condition.
- Immunologically inactive thyroglobulin may not be determined by this assay.
- In patients receiving thyroid suppression therapy, thyroglobulin may not be reliably detected.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result. These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
644 Thyroid Disorder Panel Panel
This panel provides a complete assessment of thyroid function and the most common causes of thyroid disease. It measures thyroid-stimulating hormone along with the free and total forms of both thyroid hormones, giving a full picture of how the gland is working. Antibody testing identifies the autoimmune conditions behind most thyroid disorders, including Hashimoto's disease and Graves' disease. The panel also includes markers used to evaluate thyroid nodules and cancer, plus tests for nutritional deficiencies and bone effects that often accompany thyroid disease.
612 Thyroid-Stimulating Hormone (TSH) by Immunoassay Test
Thyroid-stimulating hormone is produced by the pituitary gland and tells the thyroid how much hormone to make. It is the primary screening test for thyroid function because it responds sensitively to small changes in thyroid hormone levels. An elevated TSH usually indicates an underactive thyroid, while a low TSH suggests an overactive one. TSH is generally interpreted alongside free T4 to determine the nature and severity of the problem.
Download fact sheet (PDF)Limitations & disclaimers 7
- This assay is intended for the quantitative measurement of thyrotropin (TSH) in serum, as an aid in the diagnosis of thyroid or pituitary disorders.
- Hyperthyroidism and hypothyroidism are graded conditions; not all patients in these disease categories can be expected to have TSH levels far outside the euthyroid range and TSH levels exit the euthyroid reference range in the very early phases of developing thyroid disease, while the patient’s disease is still subclinical and thyroid hormone levels remain within their euthyroid reference ranges.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results for patient samples.
- This assay is not indicated for use with neonatal blood spots for newborn screening.
- As with any immune-recognition measurement of a peptide, extremely rare genetic variants may exhibit varying degrees of detection.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result. These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
664 Thyroid-Stimulating Immunoglobulin (TSI) by Immunoassay Test
Thyroid-stimulating immunoglobulin is an antibody that mimics TSH, binding the same receptor and driving the thyroid to overproduce hormone. It is the antibody responsible for Graves’ disease, the most common cause of an overactive thyroid. Testing identifies the autoimmune basis of hyperthyroidism and helps assess the risk of Graves’ eye disease. In pregnancy, TSI is measured because the antibody can cross the placenta and affect the baby’s thyroid. A positive result strongly supports a diagnosis of Graves’ disease.
Download fact sheet (PDF)Limitations & disclaimers 8
- This assay has not been tested with all possible variations of tube types. Consult the IFU regarding alternate sample types for details on tubes that have been tested. Short drawn K2-EDTA plasma samples may result in under-recovery of TSI results.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays.
- Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- Certain patient samples may exhibit a non-linear dilution due to the heterogeneity of TSHR autoantibodies.
- The simultaneous occurrence of Hashimoto’s thyroiditis (HT) and Graves’ disease, although rare, has been reported in the literature and cannot be ruled out through this assay.
- For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
617 Thyroxine, Free (FT4) by Immunoassay Test
Thyroxine, or T4, is the principal hormone produced by the thyroid gland and establishes the body’s metabolic rate. It functions primarily as a reserve hormone that peripheral tissues convert into the more active T3. Most T4 in circulation is bound to carrier proteins and therefore unavailable to tissues. Free T4 measures only the unbound, biologically active portion, which makes it more reliable than total T4 when carrier protein concentrations are altered by pregnancy, estrogen therapy, or illness. It is generally interpreted together with TSH.
Download fact sheet (PDF)Limitations & disclaimers 9
- This assay is intended for the quantitative measurement of non-protein-bound thyroxine (free T4) in serum, as an aid in the diagnosis and treatment of thyroid disease.
- The interpretation of free T4 results is complicated by a variety of drugs which can affect the binding of T4 to the thyroid hormone-carrier proteins or interfere with its metabolism to T3.
- In severe nonthyroidal illness, the assessment of thyroid status becomes especially difficult. Since some patients in this category may suffer from concomitant primary hypothyroidism or from a compensatory secondary hypothyroidism, TSH immunoassay has been recommended as a confirmatory test in this context.
- In rare conditions associated with extreme variations in the albumin-binding capacity for T4 — such as familial dysalbuminemic hyperthyroxinemia (FDH) — direct free thyroid hormone assays may yield misleading results.
- Circulating autoantibodies to T4, and hormone-binding inhibitors may interfere with this assay.
- Heparin has been reported to have in vivo and in vitro effects on free T4 assays and samples should not be collected during or soon after the administration of this anticoagulant.
- EDTA should not be used as an anticoagulant as it would have a significant effect on results.
- Heterophilic antibodies in human serum or plasma can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result. These reagents have been formulated to minimize the risk of interference; however, potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
613 Thyroxine, Total (TT4) by Immunoassay Test
Thyroxine, or T4, is the principal hormone produced by the thyroid gland and establishes the body’s metabolic rate. It functions primarily as a reserve hormone that peripheral tissues convert into the more active T3. Thyroid hormones influence virtually every organ system, affecting heart rate, body temperature, digestion, brain development, and the rate at which the body replaces aging cells. Total T4 measures both the protein-bound and unbound hormone in circulation. Because carrier protein concentrations affect the result, free T4 is frequently preferred.
Download fact sheet (PDF)Limitations & disclaimers 8
- This assay is intended for the quantitative measurement of total circulating thyroxine (T4) in serum, as an aid in the diagnosis and treatment of thyroid disease.
- EDTA plasma should not be used as a sample type.
- Many physiological, pharmacological, pathological, and genetic factors affect the interpretation of total T4 results. More than 20% of patients with non-thyroidal disease who are critically ill have low serum T4 levels.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components, causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference, potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results in patient samples.
- This assay exhibits significant (50%) cross-reactivity with tetraiodothyroacetic acid. Positive results may be due to the presence of tetraiodothyroacetic acid in addition to total T4.
616 Triiodothyronine, Free (FT3) by Immunoassay Test
Triiodothyronine, or T3, is the more biologically active of the two thyroid hormones. Most of it is generated outside the thyroid, when tissues such as the liver, kidneys, and muscle convert T4 into T3. Only a very small fraction circulates unbound, with the remainder attached to carrier proteins and therefore unavailable to tissues. Free T3 measures that small active fraction directly. It is most useful in evaluating an overactive thyroid, including cases in which T3 is elevated but T4 remains normal.
Download fact sheet (PDF)Limitations & disclaimers 13
- This assay is intended for the quantitative measurement of free T3 in serum, as an aid in the diagnosis and treatment of thyroid disease.
- EDTA coated tubes should not be used as EDTA interferes with the results of the assay.
- Heparin has been reported to have both in vivo and in vitro effects on free thyroid hormones. Hence, samples should not be collected during or soon after the administration of this anticoagulant.
- The free T3 assay serves primarily as a confirmatory test for hyperthyroidism and is of very limited value in the context of hypothyroidism. There may be some overlap between the euthyroid and/or hyperthyroid ranges.
- The interpretation of free T3 results is complicated by a variety of drugs which can affect the binding of T3 to the thyroid hormone carrier proteins. In severe nonthyroidal illness, the assessment of thyroid status becomes especially difficult. Since some patients in this category may suffer from concomitant primary hypothyroidism or from a compensatory secondary hypothyroidism, TSH immunoassay (Test No. 612) has been recommended as a confirmatory test in this context.
- In rare conditions associated with extreme variations in the albumin-binding capacity — such as familial dysalbuminemic hyperthyroxinemia (FDH) — direct free thyroid hormone assays may yield misleading results.
- Circulating autoantibodies to T3, and hormone-binding inhibitors, may interfere with the assay.
- Since dilution shifts the equilibrium between free and protein-bound T3, the assay cannot be expected to maintain linearity.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur. For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results for patient samples
- The presence of nonsterified fatty acids in samples in concentration greater than 2.5 mmol/L may exhibit an inhibitory effect upon the assay.
- Lipemic samples may interfere with the performance of the assay and should be rejected.
615 Triiodothyronine, Total (TT3) by Immunoassay Test
Triiodothyronine, or T3, is the more active of the two thyroid hormones and helps regulate metabolic rate. Most of it is produced outside the thyroid, when tissues such as the liver, kidneys, and muscle convert T4 into T3. Thyroid hormones influence nearly every organ, affecting heart rate, body temperature, digestion, brain development, and the rate at which the body replaces aging cells. Total T3 measures both bound and unbound hormone and is used chiefly in evaluating an overactive thyroid.
Download fact sheet (PDF)Limitations & disclaimers 8
- This assay is intended for the quantitative measurement of total circulating triiodothyronin (T3) in serum, as an aid in diagnosis and treatment of thyroid disease.
- EDTA coated tubes are not recommended for sample collection as EDTA interferes with assay performance.
- Numerous conditions unrelated to thyroid disease may cause abnormal T3 values and T3 values should not be used on their own in establishing the thyroid status of an individual.
- Many physiological, pharmacological, pathological, and genetic factors affect the interpretation of total T3 results. More than 20% of patients with non-thyroidal disease who are critically ill have low serum total T3 levels.
- Heterophilic antibodies in human serum can react with the immunoglobulins included in the assay components causing interference with in vitro immunoassays. Samples from patients routinely exposed to animals or animal serum products can demonstrate this type of interference potentially causing an anomalous result.
- Potential interactions between rare sera and test components can occur.
- For diagnostic purposes, the results obtained from this assay should always be used in combination with the clinical examination, patient medical history, and other findings.
- Biotin concentrations greater than 1,500 ng/mL may lead to incorrect results for patient samples.
655 Vitamin B12 by Immunoassay Test
Vitamin B12, also called cobalamin, is essential for nerve function, brain health, DNA synthesis, and red blood cell formation. It is found almost entirely in animal foods such as meat, fish, eggs, and dairy. Deficiency causes anemia, fatigue, and nerve damage that can become permanent if untreated, and it may result from poor intake, pernicious anemia, or impaired absorption. Elevated levels can occur with liver or kidney disease. Vitamin B12 is usually interpreted alongside folate.
Download fact sheet (PDF)Limitations & disclaimers 11
- EDTA plasma is not recommended for use with this assay.
- Blocking antibodies specific for intrinsic factor are present in more than half of all patients with pernicious anemia and may interfere with accurate vitamin B12 measurement if not fully inactivated during sample pretreatment. Although alkaline hydrolysis has been shown to effectively inactivate high titers of intrinsic factor blocking antibodies, incomplete inactivation in rare specimens with extremely high antibody titers cannot be ruled out.
- When assay results are inconsistent with the clinical examination, patient medical history, or other laboratory findings, testing for intrinsic factor blocking antibodies should be considered.
- Heterophilic antibodies in human serum may react with assay immunoglobulins and interfere with in vitro immunoassays.
- Samples from patients routinely exposed to animals or animal serum products may demonstrate this type of interference and produce anomalous results.
- Potential interactions between rare sera and assay components may also occur.
- Blood collection tubes from different manufacturers may yield differing results depending on tube materials, additives, gel barriers, clot activators, and anticoagulants.
- Presence of bilirubin in concentrations up to 200 mg/L has no significant effect on assay performance within the precision limits of the assay.
- For diagnostic purposes, results obtained from this assay should always be interpreted in conjunction with the patient’s clinical presentation, medical history, and other laboratory findings.
- For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
659 Vitamin D, 25-OH by Immunoassay Test
Vitamin D is a fat-soluble vitamin obtained from sunlight, a small number of foods, and supplements. The body converts it in the liver to 25-hydroxyvitamin D, the main circulating form and the best measure of overall vitamin D status. The kidneys then activate it further into the form that acts on bone and calcium metabolism. This test measures total 25-hydroxyvitamin D, covering both the D2 and D3 forms. Low results indicate insufficiency or deficiency, which affects bone strength and calcium balance.
Download fact sheet (PDF)Limitations & disclaimers 5
- The results should be interpreted in light of the total clinical presentation of the patient, including: symptoms, clinical history, data from additional tests, and other appropriate information.
- Falsely elevated results may occur in patients being treated with Paricalcitol (Zemplar). 25(OH) Vitamin D levels should not be tested in patients who have received Paricalcitol within 24 hours of obtaining the sample.
- Compounds were tested for interference and their highest concentrations were Acetaminophen 20 mg/dL, Bilirubin conjugated and unconjugated 40 mg/dL, Biotin 180 ng/mL, Acetylsalicyclic Acid 65 mg/dL, Ascorbic Acid 3 mg/dL, Hemoglobin 50 mg/dL, Cholesterol 500 mg/dL, Heparin (low molecular weight) 3 U/mL, Ibuprofen 30 mg/dL, Rheumatoid Factor 200 U/mL, Protein (gamma globulin) 6 g/dL, Triglycerides 3280 mg/dL, Uric Acid 24 mg/dL and none were found to cause a bias of >10%.
- For diagnostic purposes, the results obtained from this assay should be used in combination with the clinical examination, patient medical history, and other findings.
- Additional assay limitations and interference information are described in the manufacturer’s instructions for use (IFU).
642 Women’s Comprehensive Hormone Panel Panel
This panel provides a broad assessment of the hormones governing women's reproductive, adrenal, and thyroid health. It measures the ovarian and pituitary hormones that control the menstrual cycle and ovarian reserve, plus androgens and the binding protein that determines how much reaches the tissues. Adrenal and thyroid hormones are included because problems with either can disrupt periods and mimic reproductive disease. Nutritional and inflammatory markers complete the assessment.
643 Women’s Fertility Panel Panel
This panel evaluates the hormonal and nutritional factors that affect a woman's ability to conceive. It measures ovarian reserve, the pituitary hormones that drive ovulation, and the progesterone rise that confirms ovulation has occurred. Thyroid function, thyroid antibodies, and prolactin are included because each is a common and treatable cause of infertility or miscarriage. Nutritional markers address the deficiencies that affect conception and early pregnancy
Need help ordering or interpreting a test? Call MDL at 877-269-0090 or contact us.