Occurrence of thyroid autoimmunity and dysfunction throughout a nine-monthfollow-up in patients undergoing interferon-beta therapy for multiple sclerosis

Thyroid autoimmunity and dysfunction are a well known side effect of IFN al pha therapy for viral hepatitis and tumors, while the IFN beta effects on t he thyroid gland in neurological patients have not been studied. The aim of this longitudinal study was to look for the appearance of thyroid autoimmu nity as well as for the occurrence of overt thyroid disease in the patients affected by multiple sclerosis (MS) treated with IFN beta 1b. Eight patien ts (4 males, 4 females) undergoing r-IFN beta 1b treatment (8 M.U. every ot her day for 9 months) for relapsing remitting multiple sclerosis entered th e study. We have analyzed thyroid function parameters and auto antibody lev ers before and after 1, 2, 3, 6 and 9 months of therapy. None of them refer red to familiar thyroid pathology or presented clinically overt thyroid dis ease except for one patient (case 4) who showed TPO-Ab pretreatment positiv ity and another (case 8) who was in therapy with Levothyroxine 100 mu g/die for multinodular goiter. The number of patients with appearance of thyroid antibodies has slowly increased, until the third month of therapy with 3 p atients out of 7 positive for TPO-Ab. The only case of overt thyroid dysfun ction reported by us appeared after nine months of therapy and consisted of a hypothyroidism. Our data suggest that short-term interferon beta treatme nt is able to induce thyroid autoimmunity (42.8%) and dysfunction (12.5%). (C) 1998, Editrice Kurtis.