Methyldopa: Physicochemical Characterization of the Erythrocyte Autoantibody

A modification of the Polybrene techniquefor red blood cell antibody characterizationhas been employed to differentiate thepanhemagglutinins arising during methyldopa administration from those accompanying other disease states. Dissociationcharacteristics of methyldopa-associatedantigen-antibody complexes were determined by temperature gradient dissociation technique. Data obtained by this technique for cell-bound antibody were foundto distinguish this antibody from those accompanying systemic lupus erythematosus (SLE) and Pronestyl therapy.Graphic data derived from temperaturegradient dissociation curves at varyingantibody concentrations were obtained forthe methyldopa-induced serum antibodies.Results obtained with samples from all sixpatients were found to be relatively uniform in relation to each other, and differentfrom similarly derived results for red cellantibodies accompanying idiopathic autoimmune hemolytic anemia and Hodgkin’sdisease. By means of these procedures, aswell as standard blood banking techniques,distinguishing features are described thatpermit in vitro segregation of these distinctgroups of red cell autoantibodies.

Submitted on November 27, 1972 Revised on January 24, 1973 Accepted on February 9, 1973