Development of Rh-specific maternal autoantibodies following intensive plasmapheresis for Rh immunisation during pregnancy.

Two cases of autoantibody formation following large volume plasmapheresis for rhesus immunisation during pregnancy are described. In each case the autoantibody was directed against the Rh complex but showed a preference for G-positive cells. It is postulated that repeated plasmapheresis in the presence of persistent antigenic stimulation has removed a feedback inhibition of the immune response. The specificity of the alloantibody has broadened resulting in cross-reactivity against self-antigens. The possible implications of these cases in relation to autoimmunity are discussed.