Plasma exchanges in frequently recurrent hemolytic-uremic syndrome in a child.

22 plasma exchanges (PE) were carried out on a 9 year old boy with frequently recurrent hemolytic-uremic syndrome (HUS) and persistently low plasma factor which normally stimulates vascular prostacyclin (PGI2) release. The factor was partially restored after PE but declined within 2-4 weeks. No major recurrence of HUS occurred, but "minor" attacks recurred despite PE. It is likely that a genetic predisposition is responsible for the recurrences of HUS, but the ultimate relationship between recurrent HUS and persistent plasma deficiency for PGI2-release remains to be defined.