Test Details
Methodology
Electrochemiluminescence immunoassay (ECLIA)
Result 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.
Use
Differential diagnosis of hypothyroidism and thyroiditis
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.
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.
Footnotes
Custom 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.
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 Instructions
If a red-top tube or plasma is used, transfer separated serum or plasma to a plastic transport tube.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Reference Range
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 |
Storage Instructions
Room temperature
Causes for Rejection
Citrate plasma specimen; improper labeling
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 |
| Order Code | 006676 | |||||
| Order Code Name | Thyroid Peroxidase (TPO) Ab | |||||
| Order Loinc | 8099-4 | |||||
| Result Code | 006676 | |||||
| Result Code Name | Thyroid Peroxidase (TPO) Ab | |||||
| UofM | IU/mL | |||||
| Result LOINC | 8099-4 |