Nephron Numbers in Patients with Minimal Change Nephrotic Syndrome (MCNS) and Focal Segmental Glomerulosclerosis (FSGS)

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×106. We determined kidney volume from ultrasonographic measurement. Results : Patients with FSGS had significantly greater glomerular volume than patients with MCNS [2.02±0.36 (×106 m3) vs. 1.57±0.27 (×106 m3)] (p