PROTEIN C AND OTHER CLOTTING STUDIES IN MEMBRANOUS AND NON-MEMBRANOUS GLOMERULONEPHRITIS

The occurrence of thrombosis in the nephrotic syn drome has long been known. Thrombotic complications are predominantly associated with membranous glomerulonephritis (MG). The aim of the present work was to study whether the tendency of nephrotic patients with MG to thrombotic episodes could be attributed to a hypercoagulable state. Thirty consecutive patients with the nephrotic syndrome were studied. Of these 17 suffered from MG and 13 had other forms of glomerulonephritis. The control group consisted of 10 healthy volunteers. In addition to standard coagulation assays, we studied: soluble fibrin monomer complexes (FM test, Boehringer), fibrin monomer polymerization, factor VIII:C, factor VIII:vWF, anti thrombin III (AT III) and alpha₂ antiplasmin (alpha₂AP) using chromogenie substrates; the levels of AT III and alpha₂ AP were measured immunologically; beta thromboglobulin (BTG), platelet factor 4 and fibrinopeptide A (FPA) using radioimmunoassay kits; protein C was studied functionally and immunologically. There was a significant shortening of the prothrombin time and activated partial thromboplastin time, increase in alpha9 AP, factor V111:vWF, FPA and BTG in nephrotic patients associated with in or eases in both functional and imminclogical protein C levels and impairment of fibrin polymerization. FM test was negative in all but one of the patients. None of the coagulation tests showed a significant difference in the two nephrotic groups. High protein C and impaired polymerization may be considered as mechanisms counteracting disclosed hypercoagulability in the nephrotic syndrome.