Association of thrombotic thrombocytopenic purpura and human immunodeficiency virus infection.

A 35 year-old HIV-positive male intravenous drug abuser developed thrombotic thrombocytopenic purpura (TTP) during the course of recto-sigmoiditis secondary to Shigella flexneri. Complete remission was achieved by aggressive treatment of a combination of plasma exchange, fresh frozen plasma infusion, continuous prostacyclin perfusion, p.o. administered aspirin-dipyridamol and intravenous injections of vincristine. During acute microangiopathy, an acquired type II von Willebrand disease was diagnosed. TTP is a newly-recognized hematologic manifestation of HIV-1 infection; endothelial damage by endotoxin during course of infection or by high serum levels of circulating immune complexes may be a causative mechanism of microangiopathy causing hemolysis and platelet consumption.