Protein C inhibitor and other components of the protein C pathway in patients with acute deep vein thrombosis during heparin treatment.
The protein C inhibitor (PCI) concentration and other parameters of the protein C pathway were studied in 19 patients with symptomatic acute deep vein thrombosis before and during the first 5 days of heparin treatment. The mean levels of PCI antigen and activity decreased rapidly and significantly during the first day of heparin therapy from 83 and 84% to 60 and 59% of the pooled normal human plasma (p less than 0.01), respectively, and to 56 and 54% after 5 days of treatment (p less than 0.01). In contrast, antithrombin III decreased progressively 25% during 5 days of heparin treatment. Protein C antigen and activity and total protein S remained unchanged during heparin treatment. Free protein S was decreased before heparin treatment (83%, p less than 0.05) and increased to normal values after 5 days of treatment. C4b-binding protein was significantly increased before and during heparin treatment (p less than 0.01). Activated protein C (APC) complexed to its two major plasma inhibitors, PCI and alpha 1-antitrypsin (alpha 1AT) were measured by specific ELISA's. Before treatment, 18 of the 19 patients studied had increased levels of APC:alpha 1AT complexes with a mean value of 27 +/- 22 ng/ml (range, 6-86 ng/ml) compared to normal values (8 +/- 2 ng/ml) and 12 of the patients also had detectable APC:PCI complex levels with a mean value of 11 +/- 17 ng/ml (range, 5-68 ng/ml). Both APC:inhibitor complexes decreased significantly during heparin treatment.
Tabernero
D
D
Department of Hematology, Hospital General, Salamanca, Spain.
España
F
F
Vicente
V
V
Estellés
A
A
Gilabert
J
J
Aznar
J
J
D000208:Acute Disease; D001798:Blood Proteins / Q000378:metabolism*; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D011486:Protein C / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018046:Protein C Inhibitor; D013924:Thrombophlebitis / Q000097:blood* / Q000188:drug therapy
D001798:Blood Proteins; D011486:Protein C; D018046:Protein C Inhibitor; D006493:Heparin