RT Journal A1 Spencer CD, Crane FM, Kumar JR, Alving BM T1 POstpartum hemolytic uremic syndrome-reply JF JAMA JO JAMA YR 1982 FD November 19 VO 248 IS 19 SP 2450 OP 2450 DO 10.1001/jama.1982.03330190019014 UL http://dx.doi.org/10.1001/jama.1982.03330190019014 AB In Reply.—  Thrombotic thrombocytopenic purpura, HUS, and preeclampsia are a spectrum of diseases associated by evidence of a common underlying pathophysiology.1 Endothelial cell damage and platelet activation may be involved in the pathogenesis of thrombotic microangiopathy—the histological hallmark of these disorders. Varying degrees of renal dysfunction, thrombocytopenia, and hemolysis may be seen in each syndrome. When renal failure in addition to microangiopathic hemolysis and thrombocytopenia is present, HUS is diagnosed.2 The nomenclature, however, is confused by the presence of overlapping clinical features. Also, the severity of clinical expression may vary. Clear-cut cases of histologically verified HUS are recorded in both obstetric1 and nonobstetric3 patients, where renal failure, hemolysis, or thrombocytopenia was absent.Dr Weinstein reported that 57% of patients with HELLP syndrome had elevated levels of serum urea nitrogen and creatinine, although details as to severity were omitted. Those with frank renal failure and those with potentially