[Proceedings: Familial hemolytic-uremic syndrome. Studies on pathogenesis in the survivors].

The findings are reported in 4 siblings in whom death was due to typical hemolytic-uremic syndrome. In one, successive treatment with heparin, dipyridamole and aspirin was unsuccessful. 125I-fibrinogen half-life was 2.1 days under aspirin and 1.9 days under combined aspirin/heparin therapy. The parents and 4 surviving sibs had normal renal function and normal platelet and fibrinogen survival. The mother and 3 sibs had an increased percentage of megathrombocytes. Two exhibited renal accumulation of 51Cr-platelet radioactivity which was suppressed by platelet inhibitors. In both, renal biopsy disclosed definite ultrastructural endothelial alterations. These changes are probably responsible for the local platelet sequestration and appear to be the primary defect in this family with hemolytic-uremic syndrome.