Thrombotic thrombocytopenic purpura-like syndrome associated with infective endocarditis. A possible immune complex disorder.

A thrombotic thrombocytopenic purpura (TTP)-like syndrome was the chief presenting feature in two patients with infective endocarditis. Clinical and laboratory aberrations of the syndrome were rapidly reversed by specific antimicrobial therapy. Hypocomplementemia and high levels of circulating immune complexes were detected initially in both patients. Because these returned to normal as the TTP syndrome abated, an immunopathologic mechanism may have been operative.