Fatal thrombotic thrombocytopenic purpura in a patient with systemic lupus erythematosus. Relationship to circulating immune complexes.

An immunologic mechanism, possibly immune complex mediated, has been suggested as the basis for the pathogenesis of thrombotic thrombocytopenic purpura (TTP). The evidence supporting this concept has been the association of TTP with systemic lupus erythematosus and the successful therapy of TTP by plasmapheresis. However, most investigators have failed to demonstrate elevated circulating immune complexes during the course of TTP. This report describes a young woman with systemic lupus who developed TTP as a terminal event. Elevated levels of immune complexes were associated with periods of active lupus but were not detectable at the time she developed TTP.