Thrombotic Thrombocytopenic Purpura and Hemolytic-Uremic Syndrome in HLA-Identical Siblings

Abstract

Thrombocytopenia, microangiopathic hemolytic anemia, and renal failure are features common to both hemolytic-uremic syndrome and thrombotic thrombocytopenic purpura, with neurologic disturbances being more frequently observed in the latter disorder. The causes of these syndromes are unknown. Neither the occurrence of hemolytic-uremic syndrome and thrombotic thrombocytopenic purpura in the same family nor tissue-typing using the HLA system in siblings with these disorders has been previously reported. The cases described below occurred 6½ years apart in HLA-identical brothers. Although features of these two cases appear sufficiently different to allow separation into thrombotic thrombocytopenic purpura and hemolytic-uremic syndrome, the unique occurrence in brothers