High Plasma Levels of Protein C Activity and Antigen in the Nephrotic Syndrome

Abstract

SummaryLow plasma levels of antithrombin III due to excessive urinary loss are thought to be the cause of thrombotic complications in patients with the nephrotic syndrome. To see whether protein C (PC), another antithrombotic protein, is also reduced in plasma by the same mechanism, plasma and urinary protein C were determined in 24 patients with nephrotic syndrome and no thrombotic complication, and compared to plasma and urinary antithrombin III. Twenty patients (83%) had high plasma levels of protein C activity (mean ± SD 157 ± 41 U/dl) and antigen (158 ± 41). Even though measurable amounts of PC antigen were found in the urines of all but two patients the urinary loss of protein C relative to its plasma concentration was about 40 times lower than that of antithrombin III. High protein C might help to counteract hypercoagulability in nephrotic syndrome.

Coagulation Factors in Nephrotic Syndrome

“…Investigation of antithrom bin III (AT III) plasma level has led to somewhat discor dant results. Mean plasma AT III was found to be either low (less than 75-80% of normal value) [18,19] or nor mal [8,[20][21][22]; moreover, a variable proportion of ne phrotic patients, ranging from 7% [5] to 40% [22,23] or 60% [18] had low AT III. Plasma AT III, however, cor related positively with serum albumin level and nega tively with proteinuria in all studies [6,18,21,23], The relationship between AT III level and the intensity of NS protein disturbances might in part account for discre pant results of AT III measurements obtained at differ ent phases of NS in various studies.…”

“…Absolute plasma levels of both protein C and protein S antigens were found elevated in three stud ies [20,26,27], while in one study protein C antigen was found normal [19], However, because of both increased plasma concentration of C4b-binding protein, with which protein S forms a complex, and urinary losses, free (active) protein S may be reduced [26,27], Besides, specific activity of free protein S. i.e. the ratio of its anti coagulant activity to its antigen level, was decreased [26], while specific activity of protein C was either nor mal [22] or decreased [26].…”

Does the Choice of Renal Replacement Therapy Adversely Affect the Hypercoagulability Associated with Renal Disease?

“…Thus, extracorporeal circulation and exposure to heparin during hemodialysis have been implicated in contributing to hypercoagulability by recurrent platelet stimulation thereby enhancing their aggregation [21][22][23][24][25], contributing to reduced levels of the heparin cofactor II necessary for normal activity of antithrombin III [26], and being associated with elevated levels of coagulation factors due stimulation of acute phase reactants [27]. The abnormalities related to the extracorporeal circulation procedure itself are transient in nature and, as a rule, are restored to normalcy shortly after completion of the procedure.…”

Hypercoagulability risk factors associated with venous thromboembolic events in patients with idiopathic membranous nephropathy and nephrotic syndrome: a prospective observational study

“…Although there are various studies demonstrating the DDi value as the test with the highest specificity and sensitivity for DVT and pulmonary emboli in general population, there are few studies using DDi levels monitoring as a screening test for VTE in patients with NS (13)(14)(15). In our study population, 25% of patients with peak DDi >2 mcg/ ml had VTE and this cut-off value had an 86.5% specificity and a 90.9% sensitivity to predict VTE occurence.…”