6-keto-PGF1 alpha levels and prostacyclin therapy in 2 adult patients with hemolytic-uremic syndrome.

Evidence supports the hypothesis that plasma prostacyclin activity is deficient in hemolytic-uremic syndrome (HUS). We studied 2 adult patients with HUS. Plasma levels of 6-keto-PGF1 alpha, the stable metabolite of prostacyclin, were measured by radioimmunoassay. Both patients were found to have elevated 6-keto-PGF1 alpha levels. These findings are in contradiction with the prostacyclin deficiency hypothesis and with earlier reports of low or undetectable plasma levels of this metabolite. The patients were treated with IV prostacyclin after a single plasma exchange. The first patient, admitted with advanced renal failure, obtained a rapid remission but renal function did not recover; the second patient, admitted with a less pronounced degree of renal failure, reacted slowly to therapy but renal function partially recovered. We believe that, if any benefit is to be expected from prostacyclin therapy in HUS, it should be started early in the course of the disease.