Rapid and persistent reduction of proteinuria following plasma exchange in a case of steroid-resistant focal segmental glomerulosclerosis.

We report on the case of a 45 year old male with focal segmental glomerulosclerosis (FSGS) in whom steroid-resistant proteinuria was reduced rapidly by plasma exchange. In 1994, he was admitted to our hospital because of massive proteinuria of several years' duration. Renal biopsy confirmed the diagnosis of FSGS. Proteinuria was suppressed partially with the use of dipyridamole. Though oral prednisolone (PSL, 30 mg/day) was effective initially, relapse occurred during PSL tapering. Doses of PSL up to 30 mg/day or additional mizoribine were ineffective. The patient was readmitted for a trial of plasma exchange in April 2000. Four sessions of plasma exchange with albumin replacement over 2 weeks immediately reduced the proteinuria from 3.2 g/day to 0.6 g/day without any change in medication. After discharge, proteinuria remained suppressed for more than 6 months despite a reduction of PSL dose to 15 mg. The rapid and long lasting effect of plasma exchange in the present case argues for the role of a putative circulatory factor in the pathogenesis of proteinuria in FSGS.