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Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

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Item Value
Approval req'd? No
Available Stat? No
Test code TPO
Performed by? Chemistry
Sendout? No
Price range $$
In House Availability Daily, Mon - Fri
Method Competitive immunoassay using chemiluminescent technology
Interpretation The determination of TPO antibody is the most sensitive test for detecting autoimmune thyroid disease (inlcuding Hashimoto's thyroiditis and Graves' Disease). The results of this test should be used in conjunction with clinical findings and other laboratory data (i.e., TSH and thyroid hormone levels) to make a diagnosis of autoimmune thyroid disease. Although anti-thyroperoxidase antibodies are a sensitive and specific indicator of autoimmune thyroid disease, a subset of normal individuals (up to 5%) may have low level antibodies that may not have clinical significance, yielding a false positive test result. Moderately increased levels of TPO antibodies may be found in patients with non-thyroid disease, such as type I diabetes, pernicious anemia, rheumatoid arthritis, lupus erythematosus, and other autoimmune disorders.

The antibody reactivity previously ascribed to the thyroid microsomes is now recognized to be primarily directed against thyroperoxidase, and is the antibody activity most commonly found in thyroid disease.
Container type gold top gel tube
Amount to Collect 2 mL
Sample type Serum
Preferred volume 1 mL serum
Min. Volume 0.5 mL serum
Units U/mL
Normal range
Negative < 60 U/mL
Positive ≥ 60 U/mL

Synonyms Anti-TPO Antibodies; ATMA; Anti-microsomal Antibody; Anti-Thryoid Microsomal Antibody; Thyroperoxidase
Stability 2 days at 4°C
1 month at -20°C
CPT coding 86376
Last Updated 10/23/2012 6:39:31 PM
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