Postpartum hemolytic uremic syndrome (HUS) is described in a woman with a history of spontaneous abortions and both circulating lupus anticoagulant and anticardiolipin antibody (ACA). After termination of her pregnancy because of severe preeclampsia, ACA blood levels increased simultaneously with the onset of a microangiopathic process associated with severe hypertension and renal failure. Plasma exchange resulted in a rapid decline in ACA levels and immediate improvement in her clinical condition. This case strongly suggests an important causal relationship between ACA and postpartum HUS. The possible mechanisms of ACA-related postpartum HUS and the potential role of plasmapheresis in its treatment are reviewed and discussed.

B-cell function was tested in siblings of insulin-dependent diabetics (IDD). From previous studies, it is now recognized that the risk of developing IDD is highest in those sharing both haplotypes (S2H) and lowest in those sharing neither haplotype (S0H) with the diabetic. Insulin secretion in response to intravenous arginine and glucose was evaluated in S2H, S0H, and matched controls. Intravenous arginine and glucose elicited an exaggerated acute phase of insulin secretion in S2H compared with controls when analyzed as incremental insulin area 0-10', peak level attained, and mean insulin levels postinjection. Insulin responses to arginine and glucose in S0H and matched controls were identical. We hypothesize that the increased beta-cell activity found in S2H predisposes their beta-cells to damage by environmental factors and may be part of the mechanism conferring the increased risk of IDD in S2H.