Prevalence of Thyroid Disease in a Multiple Sclerosis Clinic Cohort

Background: Multiple Sclerosis (MS) has been associated with thyroid disease, but there are conflicting reports. Thyroid disease has been reported as a consequence of Interferon Beta and Alemtuzumab therapies during the treatment of MS.

Objectives: to report the prevalence of thyroid disease in an American MS clinic cohort, most on approved MS therapies.

Methods: A retrospective study of 382 patient charts from 2010-2011 identified the incidence and prevalence of auto-immune illnesses associated with MS. Patients had a confirmed MS diagnosis based on 2010 McDonald criteria. Findings regarding thyroid disease are reported.

Results: Forty-seven patients (12.3%) had thyroid disease. Forty-six had hypothyroidism and 4 of these patients also had thyroiditis; 2 had thyroid surgery; 1 had benign thyroid nodules. One patient had thyroiditis alone. forty-two of these patients are female, 5 male. All 5 patients with thyroiditis are female. Eighteen patients were on Interferon Beta, 10 on Glatiramer Acetate, and 7 on Interferon Beta and Glatiramer Acetate at some time in their therapy. Eleven of the remaining patients had exposure to multiple medications including Beta Interferon (8), Glatiramer Acetate (7), Natalizumab (3), Fingolimod (2), monthly IV Methylprednisolone (2) and several other medications. One patient with Primary Progressive MS was on no therapy. Confounding factors include tongue cancer surgery, chemotherapy and radiation (1), Hodgkin’s lymphoma with radiation therapy and splenectomy (1), and radiation of thymus (1).

Conclusions: These data indicate thyroid disease is commonly observed in a MS Clinic Cohort. While Interferon Beta is the most commonly associated therapeutic exposure in these MS patients with thyroid disease, Glatiramer Acetate is also well represented suggesting that the underlying disease process itself is a major factor in the occurrence of thyroid disease for these patients. These data provide some further perspective regarding the occurrence of thyroid disease in the MS population, an important issue in the new era of MS therapeutics, as induction of autoimmune disease is a concern.