Defective Protein C in Uraemia

Abstract

Protein C activity and antigen levels were determined in 10 haemodialysis patients and 10 healthy controls matched for age and sex. Markedly decreased protein C activity was found whereas protein C antigen level was normal in uraemics. This finding, together with our recent observation that plasma protein C activity is partly normalised during haemodialysis, lead us to suggest the presence of one or more inhibitors of protein C activity in plasma from patients with uraemia.

Further Investigations of the Defective Protein C in Hemodialysis, Hemofiltration and Continuous Ambulatory Peritoneal Dialysis

“…Protein C activity measured before and after in vitro dialysis of uremic plasma against normal plasma and vice versa ity but normal antigen level in advanced ure mia [3]. The normal protein C antigen level in hemodialysis patients has been confirmed by other reports [12,13].…”

“…Earlier we reported decreased protein C activity but normal pro tein C antigen level in hemodialysis patients and suggested that this could contribute to the thromboembolic complications observed in uremia [3]. The reason for this defective protein C is not clear but it could be due to the presence of a hitherto unknown dialyzable inhibitor of protein C in uremic plasma or a defect in the dicarboxylation of protein C. In order to further elucidate this we have determined protein C activity in patients with terminal renal failure treated in three different ways: intermittent hemodialysis, intermittent hemofiltration and continuous ambulatory peritoneal dialysis (CAPD).…”

Calciphylaxis in a Chronic Hemodialysis Patient with Protein S Deficiency

“…Normal protein C antigen levels with decreased pro tein C activity have already been reported in patients on chronic hemodialysis [6] and with end-stage renal dis eases [4], Metha et al [5] found protein C functional levels within the normal range in patients undergoing hemodial ysis, whereas this level decreased in those with calciphy laxis. Our patient had functional protein C level within the normal range.…”

“…Skin necrosis, seen in patients with calciphylaxis, may have the same clinical presenta tion as dicoumarin-induced skin necrosis which is related to an acute decrease of protein C plasma levels [3], Low protein C plasma activity has been described in uremic patients [4] and hemodialysis patients with [5] or without calciphylaxis [6], Protein S deficiency-associated calci phylaxis has already been reported in 2 patients on con tinuous ambulatory peritoneal dialysis [7], We report the case of a chronic hemodialysis patient, on long-term nicoumalone therapy, who developed calci phylaxis in the context of hyperparathyroidism and func tional protein S deficiency. …”

Functional Impairment of Protein C Activity during Haemodialysis - A New Mechanism of Extracorporeal Thrombogenesis

“…Activated protein C exerts its activity by inactivation of factor V and VIII [9], and by stimulating fibrinolysis [10]. Congenital pro tein C deficiency causes thrombotic ten dency which points to a significant biological effect [11], Uraemic patients treated with haemodialysis have decreased activity of protein C in plasma, and it has been sug gested that this may contribute to the throm botic complications observed in uraemia [ 12].…”