Synergistic immunosuppressive action of antithymocyte antisera and thymectomy in the human.

The immunologic effects of antithymocyte antisera therapy were evaluated in ten patients with myasthenia gravis. Equal numbers (5) of prior thymectomized and non-thymectomized subjects were studied. Seven patients did not have additional immunosuppressive therapy; three received minimal doses of corticosteroids or azathioprine. Increases in the production of γG and the C-3 component of complement, elevated erythrocyte sedimentation rates, complement binding to the erythrocyte surface and variable degrees of depression of primary humoral and cellular immune reactions were seen. Pre-existing thymectomy potentiated the action of antithymocyte antiserum inhibition of DNCB sensitization and skin graft rejection and intensified the degree of induced lymphopenia.