Fifteen renal biopsy specimens obtained from adult patients with idiopathic focal segmental glomerulosclerosis (FSGS) for whom both light and electron microscopy as well as immunofluorescence microscopy and full clinical data were available were examined quantitatively. Six biopsy and nine autopsy specimens of the normal kidneys were used as a control. Morphometric investigations were performed by means of a computer image analysis system to determine the significance of glomerular enlargement and mesangial alterations in adult FSGS as well as to study whether serum creatinine and interstitial fibrosis could correlate with the changes in quantitatively analyzed glomeruli. The morphometric comparisons of the glomeruli and renal interstitial tissue in patients with FSGS and controls revealed that the mean values of total glomerular area, total glomerular cells per total glomerular area, total glomerular cells per unit of glomerular area, mesangium (% of total glomerular area) and relative interstitial volume were in FSGS increased, most of them significantly. There were significant positive correlations between interstitial volume and serum creatinine (r&eguals;0.64, P < 0.01), between interstitial volume and glomerular mesangium (r=0.75, P < 0.002) and between total glomerular area and serum creatinine (r=0.54, P < 0.05). Correlation between interstitial volume and total glomerular cells per unit of glomerular area was weak and not significant (r=0.49, P - NS). Our morphometric data confirm that glomerular hypertrophy and the extent of interstitial fibrosis may be a valuable predictor of unfavorable evolution of FSGS. Although our findings suggest the role of glomerular mesangium in the mechanisms of interstitial fibrosis, this possible association needs further investigations.

Keywords: Glomerulosclerosis, morphometry