GLOMERULAR ANTIGENS IN SEVERE HEREDITARY NEPHROSIS

In search of the basic defect and cell type responsible for the massiv e treatment-resistant proteinuria of congenital nephrotic syndrome of the Finnish type (CNF), we examined tissue samples of CNF kidneys usin g established antibody and lectin markers of various glomerular cell t ypes. Markers of vascular endothelium (antibodies to factor VIII and a human homologue of podocalyxin (anti-PHM5) and UEA I lectin) showed n o qualitative changes in the endothelial cells of glomeruli or peritub ular areas in CNF as compared with controls. Markers of glomerular mes angial cells (antibodies to desmin, smooth muscle actin, RCA I lectin) revealed a secondary increase in mesangial reactivity reflecting the sclerosis and expansion of the mesangial areas in CNE Markers of visce ral epithelial cells (antibodies to a human homologue of podocalyxin, C3b receptor, vimentin, common lymphocytic leukemia antigen, gp44, and the WGA, LFA and, after neuraminidase treatment, PNA lectin) failed t o show appreciable qualitative changes in CNF kidney samples. Interest ingly, the alpha 2 beta 1 integrins appeared greatly reduced in all CN F samples studied, possibly explaining the mechanisms of CNF-associate d proteinuria.