Recurrent focal glomerulosclerosis: natural course and treatment with plasma exchange

Background. Focal glomerulosclerosis (FGS) can recur after renal transplant ation and prognosis is poor in untreated patients. A circulating plasma fac tor has been implicated in the pathogenesis of a recurrent FGS and treatmen t with plasma exchange has proven effective in decreasing proteinuria in so me patients. Methods. We retrospectively studied the course of disease in patients with recurrent FGS, transplanted in our centre. Seven patients transplanted betw een 1991 and 1997, received treatment with plasma exchange, whereas 10 pati ents, transplanted between 1973 and 1991, were left untreated and served as historical controls. Results. The time of onset of proteinuria (> 3.5 g/day) was comparable in t he untreated and treated patients (9 and 10 days respectively), as was the average proteinuria at that time (5.5 and 5.8 g/day respectively). In the u ntreated patients, proteinuria persisted and eventually all grafts were los t, on average 43 months after the diagnosis of a recurrence. In five cases (50%) the recurrence was the single cause of graft loss. The clinical cours e was different in the seven patients who were treated with plasma exchange . In five of these patients, the recurrence occurred within 3 weeks after t ransplantation. Plasma exchange was started 1-14 days after onset of protei nuria in these patients. Two lost their grafts after 0.7 and 1.0 months bec ause of untreatable rejection. In the remaining three patients the plasma e xchange resulted in abrupt disappearance of the proteinuria, and the respon se has been lasting for 2-3.2 years. In these patients the only histologica l abnormality was foot effacement on electron-microscopy. In two patients t he recurrence became manifest at 9 weeks and 5.8 years after transplantatio n respectively. These two patients relapsed after the initial course of pla sma exchange, but responded to repeated session, and are currently being tr eated once a month. They have been followed for 1.7 and 1.4 years after the onset of proteinuria and their urinary protein levels are 0.23 and 1.2 g/1 0 mmol creatinine. Conclusions. The prognosis of untreated recurrent FGS is poor. Treatment wi th plasma exchange can lead to complete remission of proteinuria and relaps ing patients may respond to repeated sessions. Best results are obtained wh en plasma exchange is started early, when there an no visible lesions on li ght-microscopy.