Occurrence of thyroid autoimmunity in relapsing remitting multiple sclerosis patients undergoing interferon-β treatment

We analyzed the titer of antithyroid autoantibodies Abs) and thyroid function in 17 multiple sclerosis (MS) patients undergoing interferon-β (IFN-β) treatment and in 40 MS control patients. Basal evaluation revealed normal thyroid function in all patients. Abs were detected in 5 IFN-β-treated patients (29%) and in 4 MS control patients (10%). Our results indicate that IFN-β treatment may lead to thyroid autoimmunity. We therefore recommend periodic evaluations of antithyroid Abs and thyroid functionality in IFN-β-treated MS patients.