Recurrence of nephrotic syndrome after transplantation in a mixed population of children and adults: course of glomerular lesions and value of the Columbia classification of histological variants of focal and segmental glomerulosclerosis (FSGS).

UNLABELLED Introduction. Recurrence of nephrotic-range proteinuria in patients with idiopathic nephrotic syndrome (INS) and focal and segmental glomerulosclerosis (FSGS) on native kidneys is associated with poor graft survival. Identification of risk factors for recurrence is therefore an important issue. In 2004, Columbia University introduced a histological classification of FSGS that identifies five mutually exclusive variants. In non-transplant patients, the Columbia classification appears to predict the outcome and response to treatment better than clinical characteristics alone. However, the predictive value of this classification to assess the risk of recurrence after transplantation has not been addressed. METHODS We retrospectively studied 77 patients with INS and FSGS on native kidneys who underwent renal transplantation. Of these, 42 recipients experienced recurrence of nephrotic range proteinuria. RESULTS At time of recurrence, minimal-change disease (MCD) was the main histological feature. On serial biopsies, the incidence of MCD decreased over time, while the incidence of FSGS variants increased. The variant type observed in the native kidneys was not predictive of either recurrence or type of FSGS seen on the allograft. Patients with complete and sustained remission did not developed FSGS. CONCLUSION In conclusion, the Columbia classification is of no help in predicting recurrence after renal transplantation or histological lesions in the case of recurrence of proteinuria.