Medical Specialty >> Endocrinology

Doctors Lounge - Endocrinology Answers

Back to Endocrinology Answers List

If you think you may have a medical emergency, call your doctor or 911 immediately. Doctors Lounge ( does not recommend or endorse any specific tests, physicians, products, procedures, opinions, or other information that may be mentioned on the Site.

DISCLAIMER: The information provided on is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her physician. Please read our 'Terms and Conditions of Use' carefully before using this site.

Date of last update: 10/17/2017.

Forum Name: Endocrinology Topics

Question: High anti-thyroid antibodies, but no reference range given

 Peabold - Tue Aug 17, 2010 8:39 am

Hi there

I recently had a private thyroid screen due to miscarriages. My antimicrosomal antibodies came back at 1:102400 and I was told to see my doctor as these were high.

As my TSH is only 2.97, my doctor will not entertain even discussing my symptoms. It's so frustrating.

I believe the results I have been given (1:102400) are an 'old fashioned' way of reporting and I'm wondering if you'd be able to convert them into the newer way of reporting, so I'm able to arm myself with information before making another trip to see a doctor.

Thanks in advance.
 Dr.M.Aroon kamath - Sun Aug 29, 2010 1:36 am

User avatar Hi,
In the not so distant past, elevated TSH and Antithyroid microsomal antibodies (TMAb) were considered the gold standard for the diagnosis of chronic autoimmune (Hashimoto's) thyroiditis. despite the presence of contaminating antigens in the preparations. Thyroid peroxidase (TPO), a large, membrane-associated glycoprotein expressed only in the thyrocytes, is an important enzyme involved in the multistep thyroid hormone synthesis. It is the major autoantigen in the thyroid microsomal particle. Assays for Thyroid peroxidase antibody (TPOAb) are now available and this has rendered TMAb obsolete.

Antithyroid microsomal antibodies in titers greater than 1:6,400 are strongly suggestive of chronic autoimmune (Hashimoto) thyroiditis or Graves disease (GD). TPOAb in excess of 200 IU per mL, strongly suggests Hashimoto's thyroiditis. 57-74% of patients with Graves' disease also show high values.

TMAb titers >1:100 are found in 10-13% of elderly women (mean age 80 years)and 3% of elderly men, but titers >1:6400 are present in only 1% of normal individuals.

Detection of TPOAb is strong evidence against a goiter being due to non-autoimmune causes of hypothyroidism. The risk for the development of hypothyroidism is 3% to 4% per year if TPOAb are present and TSH is elevated.

By the way, do you have a goiter? You should get your TPOAb levels checked, to be sure.
Best wishes!

| Check a doctor's response to similar questions

Are you a Doctor, Pharmacist, PA or a Nurse?

Join the Doctors Lounge online medical community

  • Editorial activities: Publish, peer review, edit online articles.

  • Ask a Doctor Teams: Respond to patient questions and discuss challenging presentations with other members.

Doctors Lounge Membership Application

Tools & Services: Follow DoctorsLounge on Twitter Follow us on Twitter | RSS News | Newsletter | Contact us