ABSTRACT
PURPOSE: It has been proposed that a decreased nephron number may be associated with the increased risk of glomerulosclerosis. In order to test the hypothesis that a reduced number and an increased volume of glomeruli may contribute to the pathogenesis of focal segmental glomerulosclerosis (FSGS), we compared the number and volume of glomeruli between 9 patients with FSGS and 8 with minimal change nephrotic syndrome (MCNS). METHODS: Mean glomerular volume was measured using the method of Weibel and Gomez. An estimate of glomerular number (index) was obtained by multiplying the cortical volume of a kidney by the fraction of renal cortex made up of glomeruli and dividing this by the mean glomerular volume for that kidney x 10(6). We determined kidney volume from ultrasonographic measurement. RESULTS: Patients with FSGS had significantly greater glomerular volume than patients with MCNS [2.02+/-0.36 (x10(6) micrometer3) vs. 1.57+/-0.27 (x10(6) micrometer3)] (p<0.025). However, there was no significant difference in the index of glomerular number (estimated glomerular number) between FSGS & MCNS patients (2.8+/-1.4 vs. 3.0+/-0.8). CONCLUSION: The glomerular volume was greater in FSGS patients than MCNS patients. But there was no significant difference in the index of glomerular number between patients with FSGS and MCNS.