PRIMARY FOCAL SEGMENTAL GLOMERULAR SCLEROSIS IN ADULTS - PROGNOSTIC VALUE OF HISTOLOGIC VARIANTS

Primary focal segmental glomerular sclerosis (FSGS) is a clinicopathol ogic syndrome in which variable amounts of proteinuria are associated with the renal biopsy finding of segmental glomerular scarring in some , but not all, of the glomeruli. Additional histologic features have b een described in FSGS, including the position of the scar relative to the vascular and tubular pole of the glomerulus, foam cells, hyalinosi s, mesangial deposits of immunoglobulin M, diffuse mesangial hypercell ularity, glomerular visceral epithelial cell hyperplasia and hypertrop hy, and the extent of associated interstitial fibrosis and tubular atr ophy. We performed a retrospective study on 81 patients with biopsy-pr oven, primary FSGS to determine whether any of the histologic features of FSGS correlated with renal function at the time of biopsy and the incidence of end-stage renal disease at follow-up. Sixty patients were nephrotic and 21 had nonnephrotic proteinuria. Only the degree of int erstitial fibrosis correlated with the initial serum creatinine (r = 0 .536) and none of the histologic features predicted the presence of ne phrotic-range proteinuria at the time of biopsy. Segmental scars invol ved 21% +/- 14% of the glomeruli per biopsy specimen, but their positi on within the glomerulus was uniform in only 13% of the cases. Diffuse mesangial hypercellularity was present in 17% of the biopsy specimens , and glomerular epithelial cell lesions were present in 57% of the bi opsy specimens. Multivariate analysis showed that only the degree of i nterstitial fibrosis predicted end-stage renal disease in all 81 patie nts and in the 60 patients with nephrotic-range proteinuria. The curre nt data do not support different therapeutic approaches in primary FSG S based on histologic subtypes. (C) 1995 by the National Kidney Founda tion, Inc.