Thrombotic microangiopathy associated with Streptococcus pneumoniae bacteremia: case report and review.

Thrombotic microangiopathy, a disease within the clinical spectrum of thrombotic thrombocytopenic purpura and hemolytic-uremic syndrome, was recognized in a previously healthy 50-year-old woman who presented with pneumococcal bacteremia complicated by thrombocytopenia, microangiopathic hemolytic anemia, renal failure, and disorientation. After treatment with plasma exchange and antibiotics, the patient's clinical condition improved. Discontinuation of plasma exchange resulted in a relapse of thrombocytopenia and microangiopathic hemolytic anemia that responded to reinitiation of this intervention. The production of the enzyme neuraminidase by Streptococcus pneumoniae is thought to contribute to the pathogenesis of the thrombotic process. Although pneumococcal infection has been associated with hemolytic-uremic syndrome in children, review of the literature on adults revealed only one such case (in a patient who had undergone splenectomy in the remote past). This report therefore documents an unusual complication of pneumococcal bacteremia in an immunocompetent adult.