Does levothyroxine induce Hashimoto's Thyroditis?

[nigel19]

The patient has an elevated TSH but no other symptoms.  The GP prescribes Levothyroxine and the result is the patient develops the full range of hypothyroid symptoms.

After a year with no solution patient gets a referral to an Endo and requests additional labs for Hashimoto's (thyroid antibodies).  The Endo refuses, stating that 90% of hypothyroid patients are positive for Hashimoto's.  Patient insists that GP order the thyroid antibodies labs.

The labs show that the patient has Hashimoto's (increased thyroid antibodies).  The question is: Did the levothyroxine treatment cause the immune response and in fact create an ongoing autoimmune response (allergy) to normal thyroid hormone production?

Questions:
Has anyone with sub-clinical hypothyroidism tested positive for Hashimoto's prior to receiving levothyroxine treatment?

Have the patients that had negative Hashimoto's prior to levothyroxine treatment been retested after the start of levothyroxine, and are the test results positive?

Are there any creditable studies that answer this question?

Do once daily doses of levothyroxine elevate the T4 hormone level to the point that a thyroid antibody response is triggered?

My conclusions:
Thyroid antibodies attack the thyroid and reduce the level of thyroid hormone available in the blood.  Everybody has some thyroid antibodies and the antibodies are the normal mechanism to control excessive thyroid hormone levels.  An elevated TSH indicates that the thyroid is not producing enough thyroid hormone.  Logic suggests that a elevated TSH would be contrary to a Hashimoto's response.  If the TSH is elevated the thyroid hormone level is low, there should be no increase of thyroid antibodies.

I am the patient mentioned above.

[gimel]

Not an opinion, just fact.  I know of no scientific studies on the subject because to the medical community it is not even a question.  There is plenty of anecdotal information on patients with subclinical hypothyroidism and antibodies without ever being treated with thyroid hormone.  Linked below, there is even one currently active on the Forum.  So thyroid med does not cause antibodies as a control mechanism to prevent excessive levels of thyroid hormone.

http://www.medhelp.org/posts/Thyroid-Disorders/Is-normal-really-normal/show/2957694

[gimel]

Pardon me.  The answers to your questions are well known, so I skipped to trying to understand your situation, in order to help.

No, thyroid med does not cause antibodies of Hashimoto's to develop.  That essentially answers all your questions.

Also, thyroid antibodies are not the mechanism to control excessive thyroid hormone levels.  There are a couple of ways that happens.  Under normal situations, the TSH, Free T4 and Free T3 are in equilibrium.  If thyroid med was added, the hypothalamus/pituitary system will reduce TSH levels, and the output of the thyroid gland also goes down.  Another control mechanism to maintain the right levels is conversion of more T4 to Reverse T3, instead of T3..  

[nigel19]

Please provide references to studies or articles that support your opinion.

[gimel]

What was your TSH level that prompted the doctor to prescribe Levo?  If tested at the time for Free T4 and Free T3 what were the results and reference ranges shown on the lab report?

[gimel]

What was your TSH level that prompted the doctor to prescribe Levo?  If tested at the time for Free T4 and Free T3 what were the results and reference ranges shown on the lab report?

[nigel19]

Thanks for the response.  Please concentrate on the questions asked and provide any constructive information that may help.  The impression I got from the Endo was that if you are being treated with levothyroxine, you will be positive for Hashimoto's.