Thyroid Peroxidase (TPO) Antibodies

TEST: 006676
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CPT: 86376
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Synonyms

  • Antimicrosomal Antibody
  • Antithyroid Microsomal Antibody

Special Instructions

This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.

Expected Turnaround Time

Within 1 day

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Documents

For more information, please view the literature below.

Thyroid Testing: Assessing Thyroid Disease in Your Patients

Thyroid Cascade Testing: Differential Laboratory Diagnosis of Thyroid Function

Specimen Requirements

Specimen

Serum (preferred) or plasma

Volume

1 mL

Minimum Volume

0.7 mL (Note: This volume does not allow for repeat testing.)

Container

Red-top tube, gel-barrier tube, or green-top (lithium heparin) tube. Do not use oxalate, EDTA, or citrate plasma.

Collection

If a red-top tube or plasma is used, transfer separated serum or plasma to a plastic transport tube.

Storage Instructions

Room temperature

Stability Requirements

Temperature

Period

Room temperature

14 days

Refrigerated

14 days

Frozen

14 days

Causes for Rejection

Citrate plasma specimen; improper labeling

Test Details

Use

Differential diagnosis of hypothyroidism and thyroiditis

Limitations

Should be used in conjunction with antithyroglobulin test, since autoimmune thyroiditis may demonstrate a response to antigens other than thyroid microsomes. To order both antithyroglobulin and antimicrosomal tests, use profile 006684. Other autoimmune disorders such as Sjögren's syndrome, lupus erythematosus, rheumatoid arthritis, pernicious anemia, and others may be positive for antimicrosomal and antithyroglobulin. Patients with myxedema, granulomatous thyroiditis, nontoxic nodular goiter, and thyroid carcinoma may occasionally produce thyroid antibodies.

Methodology

Electrochemiluminescence immunoassay (ECLIA)

Reference Interval

See table.1

Age

Range (IU/mL)

0 to 6 d

0−117

7 d to 3 m

0−47

4 to 11 m

0−32

1 to 5 y

0−13

6 to 10 y

0−18

11 to 19 y

0−26

>19 y

0−34

Additional Information

Antibodies to thyroid microsomes (thyroid peroxidase) are present in 70% to 90% of patients with chronic thyroiditis. They are also present in smaller percentages of patients of other thyroid diseases. Antibody production may be confined to lymphocytes within the thyroid, and serum may be negative. Small numbers (3%) of people with no evidence of disease may have antibody. This is more frequent in females and increases with age.

Footnotes

1. Reference Intervals for Children and Adults. Elecsys Thyroid Test. Manneheim, Germany: Roche Diagnostics Corporation; 2009.

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
006676 Thyroid Peroxidase (TPO) Ab 8099-4 006676 Thyroid Peroxidase (TPO) Ab IU/mL 8099-4

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