Protein C assays in uremia.
Protein C was determined in 42 patients with terminal uremia and 20 healthy controls in three different ways 1) anticoagulant activity 2) amidolytic activity 3) antigen level. Protein C anticoagulant activity was markedly decreased in uremia, but was partly normalized during hemodialysis treatment, whereas the amidolytic activity and antigen level of protein C were normal and without changes during dialysis. The activities and antigen levels of factor II and X were normal before and after hemodialysis. In anticoagulated patients we found a good correlation between prothrombin levels and protein C levels determined with three different assays. We did not find any evidence for a defect carboxylation of protein C as the cause for the defective protein C in uremia. The BaCl2 precipitation in the Protein C anticoagulant assay was incomplete both in uremia and in controls but without differences between the two groups. In vitro addition of urea and creatinine did not decrease protein C activity. The cause of the defective protein C in uremia is still not known but it might contribute to thromboembolic complications.
Department of Medicine, Nephrology C and Clinical Chemistry, Aalborg Hospital, Denmark.
P J
PJ
Sørensen
F
F
Knudsen
A H
AH
Nielsen
J
J
Dyerberg
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011486:Protein C / Q000032:analysis*; D012016:Reference Values; D006435:Renal Dialysis; D014511:Uremia / Q000097:blood* / Q000628:therapy
D011486:Protein C