SIGNIFICANCE OF GLOMERULAR DEPOSITION OF PROTEIN-S IN VARIOUS GLOMERULOPATHIES

To elucidate the relationship between glomerular deposition of protein S (PS) and renal lesions or dysfunction, 30 patients with various glo merulopathies were examined. Glomerular PS deposition was found in 20 patients (group A), and other 10 patients showed no deposition (group B), PS was found mainly along the capillary loops and segmentally in t he mesangium. Group A showed significantly more severe proteinuria tha n group B (p < 0.05). Group A patients showed significant decreases in glomerular filtration rate (p < 0.01). Patients in group A had signif icantly lower plasma levels of plasmin-alpha(2)-plasmin inhibitor comp lexes (p < 0.05) and thrombin-antithrombin III complexes (p < 0.01) th an those in group B. Group A showed significant decreases in the mean values of plasma total PS (p < 0.01) and protein C (PC) antigens (p < 0.01) and C4b-binding protein (C4bp; p < 0.05) as compared with group B patients. There was a positive correlation between plasma PS and C4b p (p < 0.02). Histologically, group A showed a significantly higher in cidence of glomerular deposition of factor XIII (subunit a), alpha(2)- plasmin inhibitor, PC (p < 0.05), and C4bp (p < 0.01). The present stu dy demonstrates that glomerular PS deposition indicates the existence of PC and C4bp in the glomeruli and suggests that the glomerular PS de position may modify the activation of fibrinolytic and coagulation sys tems within the glomeruli in various glomerulopathies.