Focal segmental glomerulosclerosis in renal allografts with chronic nephropathy: implications for graft survival

De novo focal segmental glomerulosclerosis (FSGS) in renal allografts most often is diagnosed in association with chronic allograft nephropathy (CN). In this study, we assessed the clinical and pathological variables that correlate with the presence of de novo FSGS and the implications of FSGS for the survival of grafts with CN. The study population included 293 renal allograft recipients (52 living related donor, 241 cadaveric donor) diagnosed with CN by biopsy more than 6 months after transplantation. Patients with recurrent FSGS or FSGS associated with other glomerulopathies were excluded. FSGS was present in 87 patients with CN (30%). FSGS was diagnosed more commonly in the following groups of patients: young (P = 0.04), black (P = 0.02), and those with elevated serum cholesterol levels (P = 0.002) and/or high-grade proteinuria (P < 0. 0001, all univariate analysis). FSGS was diagnosed later after transplantation than CN without FSGS (P < 0.0001), and FSGS correlated with the presence of arteriolar hyalinosis in the biopsy specimen (P = 0.04). Compared with CN without FSGS, FSGS was associated with significantly worse death-censored graft survival (P = 0.008, univariate Cox). In addition, when we analyzed all patients with CN, graft survival correlated by multivariate analysis with the following parameters: serum creatinine level (P < 0.0001) and proteinuria (P = 0.004) at the time of diagnosis, presence of FSGS (P = 0.03), and degree of interstitial fibrosis and tubular atrophy (CN score; P < 0.0001, Cox). Of interest, the use of lipid-reducing agents was also associated with improved graft survival in patients with CN (P = 0.0002, univariate Cox), although total lipid levels were not significantly less in patients receiving these drugs. In conclusion, de novo FSGS presents late after transplantation and in association with arteriolar hyalinosis, suggesting these lesions may be related to chronic cyclosporine toxicity. In CN, the presence of FSGS and the severity of interstitial fibrosis are negative independent predictors of graft survival. The possible relationship between lipid-reducing agents and graft survival clearly needs to be examined carefully in future studies.