Thrombotic Thrombocytopenic Purpura

The etiology of thrombotic thrombocytopenic purpura (TTP) remains obscure. Rickettsial organisms have recently been described in the peripheral blood of one patient with TTP and of two patients with the hemolytic uremic syndrome. The concomitant occurrence of TTP in two siblings has been reported. The concurrence of this disease in husband and wife, reported herein, further suggests an etiology of environmental origin.