The Glomerular Deposition of PAS Positive Material Correlates with Renal Function in Human Kidney Diseases

General agreement exists on the correlation of renal insufficiency with the severity of tubulointerstitial abnormalities in the biopsy. This could not be shown for the severity of glomerular pathology by semiquantitative methods. The relation between renal function and glomerular pathology was therefore evaluated in patients with various kidney diseases using quantitative measurements. Fifty-five patients and ten controls were studied. Histomorphometric measurements of renal biopsies were obtained for both frozen and paraffin sections and were correlated with serum creatinine values. The frozen sections were stained with an indirect immunoperoxidase technique using antibodies against collagen types I, IV, V, VI, laminin, fibronectin, decorin and heparansulphate proteoglycan core protein. The contribution of each component to the composition of the mesangial extracellular matrix was scored with a semiquantitative technique. All glomerular histomorphometric indices correlated with the severity of renal insufficiency expressed as serum creatinine at the time of biopsy. However, quantitative estimates of the glomerular deposition of periodic acid-Schiff positive extracellular matrix seemed to be the most important structural correlate of renal function (r = 0.524, p = 0.0001). Semiquantitative estimates of interstitial extracellular matrix accumulation were less correlated with renal function (r = 0.370, p = 0.01). The composition of the mesangial extracellular matrix did not differ in patients and controls, with the exception of the extent of laminin staining, which was significantly higher in patients. The extent of fibronectin staining in patients correlated with the severity of glomerular structural abnormalities. This study demonstrates that the severity of renal insufficiency in a variety of renal diseases correlates with the severity of glomerular pathology, when quantitative scoring is applied.