Antimicrosomal antibody

Synonyms and Related Keywords: Thyroid antimicrosomal antibody; Antimicrosomal antibody; Microsomal antibody; Thyroid peroxidase antibody; TPOAb

Overview
Antithyroid microsomal antibody is a test to measure antithyroid microsomal antibodies in the blood. Microsomes are found inside thyroid cells. The body produces antibodies to microsomes when there has been damage to thyroid cells.

Differential diagnoses
A negative test is normal. A positive test may be due to:


 * Autoimmune hemolytic anemia
 * Granulomatous thyroiditis
 * Hashimoto's thyroiditis
 * Nontoxic nodular goiter
 * Rheumatoid arthritis
 * Sjogren syndrome
 * Systemic lupus erythematosus
 * Thyroid cancer

High levels of these antibodies have also been linked to an increased risk of:


 * Miscarriage
 * Preeclampsia
 * Premature birth
 * In vitro fertilization failure

Other risks associated with having blood drawn are slight but may include:


 * Excessive bleeding
 * Fainting or feeling light-headed
 * Hematoma (blood accumulating under the skin)
 * Infection (a slight risk any time the skin is broken)