Focal segmental glomerulosclerosis in renal transplants.

This is a study of the incidence and clinicopathological significance of focal segmental glomerulosclerosis (FSG) in 154 renal allografts (22 biopsies, 128 nephrectomies and four necropsies) from 137 cadaveric and 17 living-related donors. FSG was identified in 18 grafts (11.7%) from 16 patients: six as recurrent FSG in four patients (two developed FSG in two consecutive transplants) and 12 as de novo FSG. The incidence of recurrent FSG in patients who had FSG as their original kidney disease was 30.8% whereas that of de novo FSG in patients who had renal diseases other than FSG was 8.7%. Histologically, recurrent FSG was characterized by mild degrees of obliterative arteriopathy of rejection and preferential involvement of the juxtamedullary glomeruli. Whereas, in de novo FSG, the occlusive vascular changes of rejection were severe and the glomeruli in the outer cortical region were mostly involved. Clinically, however, the differences between them were less clear, although nephrotic syndrome tends to occur more often and earlier in patients with recurrent FSG. Obliterative arteriopathy of chronic rejection and consequent glomerular ischemia appeared to be of major importance in the pathogenesis of de novo FSG in renal allografts.