Renal histomorphometry and resistance index in children with renal disease.

Abstract

The aim of this study was to examine the relationships between the renal resistance index (RI) and histomorphometric variables measured in children with glomerular or nonglomerular renal disease. Patients and Methods The medical records, sonography reports, and biopsy specimens of 30 children with glomerular or nonglomerular renal disease (mean age, 11.0 +/- 4.7 years; range, 2. 5-17 years) who underwent sonographic evaluation and biopsy of the right kidney were retrospectively studied. Biopsy specimens were evaluated for glomerular surface density, number of glomeruli in the stroma, capillary surface density, number of capillaries within the glomeruli, and the diameters of the afferent arterioles. The RI was negatively correlated with age in patients 2.5-4.0 years old (rho = -1.0, p < 0.001). The RI was positively correlated with serum creatinine levels (rho = 0.63, p < 0.001), and the RI differed significantly between patients with abnormally high and age-appropriate serum creatinine levels (0.8 +/- 0.1 and 0.6 +/- 0.1, respectively; p = 0.002). No differences in age, histomorphometric variables, RI, or arteriolar diameter were found between patients who had interstitial fibrosis and those who did not, and the RI was not correlated with histomorphometric variables in either group. However, the mean RI was significantly higher in patients with severe fibrosis than in those with mild fibrosis. In those with severe fibrosis, the RI was negatively correlated with number of glomeruli in the stroma (rho = -0.975, p < 0.01), glomerular surface density (rho = -0.931, p < 0.05), number of capillaries within the glomeruli (rho = -0.989, p < 0.01), and arteriolar diameter (rho = -1.00, p < 0.01). The RI was correlated with histomorphometric variables in patients with severe interstitial fibrosis and could be useful in the follow-up of these patients.