Serum Immunogllobulin G Levels in Graves’ disease Patients at Various Stages of Antithyroid Therapy

Thirty six patients with Graves’ disease (GD), diagnosed on the basis of clinical examination and appropriate laboratory tests were classified into three groups (A-C): Group A: twelve newly diagnosed Graves’ disease patients; Group B: twelve hyperthyroid Graves’ disease patients on Antithyroid drug therapy and Group C: twelve Graves’ disease patients who had been rendered cuthyroid with Antithyroid drug (ATD) therapy, Serum lgG was determined  by radial immunodiffusion method using commercially available kits (The Binding Site UK). The mean lgG in newly diagnosed patients with GD (Group A) was 18.78±1.81. It was 22.75 ± 1.89 in hyperthyroid GD patients on drug therapy (Group B), 14.3±0.8 in GD patients who were rendered euthyroid with drug therapy (Group C) and 11.85±0.72 in normal controls. The lgG level of group A patients were not significantly different from those of Group B. However, the levels of lgG and lgA were significantly low in group C Graves’ disease patients as compared to group A patients. A significant reduction in lgG LEVEL IN Graves’ disease patients who were rendered cuthyroid after Antithyroid drug therapy as compared to newly diagnosed Graves’ disease patients indicate the immunosuppressive effect of Antithyroid drug therapy.