Prognostic significance of the number of renal glomeruli in reflux nephropathy

Abstract

To monitor the decrease in the number of glomeruli in reflux nephropathy (RN) and to investigate its association with glomerular hypertrophy or clinical data, as some cases of RN progress to end-stage renal failure, although the mechanism of progression remains unknown and is generally thought to depend on remnant normal renal tissue mass, i.e. the number of remnant renal glomeruli (functional nephrons). From 1987 onward, a renal biopsy was taken in 71 patients (mean age 8.08 years) in two institutions to estimate the prognosis of patients with RN. The number of glomeruli per unit area and glomerular size in grossly normal renal tissue specimens were determined to explore the potential association between these variables and the total renal scars, renal function (glomerular filtration rate, GFR), or daily urinary protein excretion. The number of glomeruli was closely correlated with the actual size of glomeruli (y = 14.783 - 0.052x, R = 0.782). To a lesser extent, the number of glomeruli was also closely correlated with the size of glomeruli expressed in sds (y = 6.264 - 0.832x, R = 0.630). There was a good correlation between the number of glomeruli and the extent of renal scarring, renal function, or daily urinary protein excretion, although its association with renal function (GFR) was least evident. There was an association between the decrease in the number of glomeruli and glomerular hypertrophy, decreased renal function, or increased proteinuria. A renal biopsy taken from radiographically and macroscopically normal regions can be useful for assessing RN, and the size and number of glomeruli in the specimens might provide an important measure for estimating the prognosis of RN.