Erythrocyte Autoantibody Associated with Alpha-Methyldopa: Heterogeneity of Structure and Specificity

Abstract

Abstract A case of Coombs-positive hemolytic anemia associated with alpha-methyldopa therapy was studied with particular attention to the structure and specificity of the erythrocyte autoantibodies. Eluted auotantibodies were found to be heterogeneous in both respects. Serologic evidence was obtained for the presence of at least four antibody specificities, all possibly related to the Rh complex: "anti-e," "anti-c," and at least two additional specificities for undefined antigens which may be a part of the hypothetic Rh "core" or precursor substance. The autoantibody population was found to contain γG globulins with both κ and λ light chains and three heavy-chain subclasses, in proportions approximating those found in normal human serum. These findings are judged to be most compatible with a response of basically normal lymphoid tissue to some antigenic alteration brought about by alpha-methyldopa or a derivative.