OBJECTIVETo explore the role of natural killer T (NK T) cells in the pathogenesis of Graves' disease.

METHODSNK T cell deficient mice and wild BALB/c mice were immunized with cells expressing TSH receptor once every two weeks 6 times. Two weeks after the final immunization, the mice were killed and serum thyroxine levels, anti-TSH receptor antibodies and thyroid pathological changes were examined.

RESULTSThe mean levels of TT(4) and TRAb in the immunized NK T cell deficient group were slightly elevated but significantly different from those of the non-immunized control group, while comparable to those in the immunized wild group. There were no significant changes of the activity levels of TSAb or TSBAb in the immunized NK T cell deficient mice compared to those in immunized wild control mice. Thyroids from immunized NK T cell deficient mice showed mild hypertrophy of some follicles as compared with non-immunized control mice. This change was comparable to immunized wild control mice.

CONCLUSIONNK T cells may not be involved in the pathogenesis of Graves' disease.