Microsomal (TPO) antibody

Clinical definition of the Microsomal (TPO) antibody test
Microsomal antibody is a test that detects the presence and measures the quantity of   antithyroid microsomal antibodies in the blood. Microsomes are found inside thyroid cells. The body produces antibodies to microsomes when a person’s immune system mistakenly recognizes the components of the thyroid as foreign (not self). These antibodies interfere with thyroid hormone production leading to chronic inflammation of thyroid (thyroiditis), tissue damage, disruption of thyroid function and disorders such as hyperthyroidism and hypothyroidism

Why is the Microsomal (TPO) antibody test done?
Microsomal antibody test is carried out to monitor autoimmune thyroid diseases and to differentiate it from other forms of thyroiditis   and help find the cause of goiter and other thyroid dysfunctions.

What are the common signs/symptoms when the Microsomal (TPO) antibody test is done? 

  • Weight gain
  • Goiter
  • Dry skin
  • Hair loss
  • Intolerance to cold
  • Constipation
  • Excessive Sweating
  • Rapid heart rate
  • Anxiety
  • Tremors
  • Fatigue
  • Difficulty sleeping
  • Sudden weight loss
  • Potruding eyes

What should I do before the Microsomal (TPO) antibody test?

Specimen type

Specimen collection procedure

Preparatory instructions before the test *

Serum (Blood Sample)


Collection of blood from a vein, usually from the arm.

No Fasting Required.

No other special preparations required.

*Subjects suffering from any illness or on oral or injectable medications are advised to consult their physician prior to requesting any tests or procedures.

How do I interpret my Microsomal (TPO) antibody test results?

Reference Range*


Upto 5.61 IU/mL


‘*A Reference range is a set of values which helps the healthcare professional to interpret a medical test. It may vary with age, gender, and other factors. Reference ranges may also vary between labs, in value & units depending on instruments used and method of establishment of reference ranges’

Diseases/conditions related to the Microsomal (TPO) antibody test

  • Autoimmune Hemolytic Anemia
  • Granulomatous Thyroiditis
  • Hashimoto's Thyroiditis
  • Nontoxic Nodular Goiter
  • Rheumatoid Arthritis
  • Sjogren Syndrome
  • Systemic Lupus Erythematosus
  • Thyroid Cancer
  • Autoimmune Hepatitis
  • Pernicious Anemia

Other tests related to the Microsomal (TPO) antibody test

  • T3
  • T4
  • TSH
  • Thyroglobulin