scholarly journals Activation and complexation of protein C and cleavage and decrease of protein S in plasma of patients with intravascular coagulation

Blood ◽  
1989 ◽  
Vol 73 (2) ◽  
pp. 455-461
Author(s):  
MJ Heeb ◽  
D Mosher ◽  
JH Griffin
Keyword(s):  
Disseminated Intravascular Coagulation ◽  
Protein C ◽  
Activated Protein C ◽  
Protein S ◽  
Coagulation Test ◽  
Major Band ◽  
Intravascular Coagulation ◽  
Protein C Inhibitor ◽  
Dependent Protein

Activated protein C (APC) is inhibited by two major plasma inhibitors (PCIs). To find evidence for in vivo complexation of APC, immunoblotting studies were performed on plasmas of 85 patients with suspected disseminated intravascular coagulation (DIC). Samples from 62 of these patients contained 5% to 35% of protein C antigen in APC:inhibitor complexes, indicating that protein C activation and inhibition had occurred. In 24 normal plasmas, no detectable APC:PCI complexes were observed (less than 5%). Patients with higher levels of complexes had more abnormal coagulation test data for DIC. The major band of APC complexes detected by anti-protein C antibodies did not react with antibodies to the heparin-dependent protein C inhibitor (PCI- 1) previously described. Rather, APC was complexed with another recently described plasma protein C inhibitor, PCI-2. Immunoblotting studies for protein S, the cofactor for APC, revealed that the majority of the DIC patient plasmas contained a higher than normal proportion of protein S in cleaved form, suggesting that protein S may have been proteolytically inactivated. Protein S total antigen levels were also found to be low in DIC patients, excluding those with malignancy. These studies support the hypothesis that the protein C pathway is activated during DIC.

scholarly journals Activation and complexation of protein C and cleavage and decrease of protein S in plasma of patients with intravascular coagulation

Blood ◽  
1989 ◽  
Vol 73 (2) ◽  
pp. 455-461 ◽  
Author(s):  
MJ Heeb ◽  
D Mosher ◽  
JH Griffin
Keyword(s):  
Disseminated Intravascular Coagulation ◽  
Protein C ◽  
Activated Protein C ◽  
Protein S ◽  
Coagulation Test ◽  
Major Band ◽  
Intravascular Coagulation ◽  
Protein C Inhibitor ◽  
Dependent Protein

Abstract Activated protein C (APC) is inhibited by two major plasma inhibitors (PCIs). To find evidence for in vivo complexation of APC, immunoblotting studies were performed on plasmas of 85 patients with suspected disseminated intravascular coagulation (DIC). Samples from 62 of these patients contained 5% to 35% of protein C antigen in APC:inhibitor complexes, indicating that protein C activation and inhibition had occurred. In 24 normal plasmas, no detectable APC:PCI complexes were observed (less than 5%). Patients with higher levels of complexes had more abnormal coagulation test data for DIC. The major band of APC complexes detected by anti-protein C antibodies did not react with antibodies to the heparin-dependent protein C inhibitor (PCI- 1) previously described. Rather, APC was complexed with another recently described plasma protein C inhibitor, PCI-2. Immunoblotting studies for protein S, the cofactor for APC, revealed that the majority of the DIC patient plasmas contained a higher than normal proportion of protein S in cleaved form, suggesting that protein S may have been proteolytically inactivated. Protein S total antigen levels were also found to be low in DIC patients, excluding those with malignancy. These studies support the hypothesis that the protein C pathway is activated during DIC.

Platelet-mediated proteolytic down regulation of the anticoagulant activity of protein S in individuals with haematological malignancies

2012 ◽  
Vol 107 (03) ◽  
pp. 468-476 ◽  
Author(s):  
Ilze Dienava-Verdoold ◽  
Marina R. Marchetti ◽  
Liane C. J. te Boome ◽  
Laura Russo ◽  
Anna Falanga ◽  
...  
Keyword(s):  
Protein C ◽  
Normal Values ◽  
Anticoagulant Activity ◽  
Activated Protein C ◽  
Protein S ◽  
Intact Protein ◽  
The Impact ◽  
Independent Protein

SummaryThe natural anticoagulant protein S contains a so-called thrombin-sensitive region (TSR), which is susceptible to proteolytic cleavage. We have previously shown that a platelet-associated protease is able to cleave protein S under physiological plasma conditions in vitro. The aim of the present study was to investigate the relation between platelet-associated protein S cleaving activity and in vivo protein S cleavage, and to evaluate the impact of in vivo protein S cleavage on its anticoagulant activity. Protein S cleavage in healthy subjects and in thrombocytopenic and thrombocythaemic patients was evaluated by immunological techniques. Concentration of cleaved and intact protein S was correlated to levels of activated protein C (APC)-dependent and APC-independent protein S anticoagulant activity. In plasma from healthy volunteers 25% of protein S is cleaved in the TSR. While in plasma there was a clear positive correlation between levels of intact protein S and both APC-dependent and APC-independent protein S anticoagulant activities, these correlations were absent for cleaved protein S. Protein S cleavage was significantly increased in patients with essential thrombocythaemia (ET) and significantly reduced in patients with chemotherapy-induced thrombocytopenia. In ET patients on cytoreductive therapy, both platelet count and protein S cleavage returned to normal values. Accordingly, platelet transfusion restored cleavage of protein S to normal values in patients with chemotherapy-induced thrombocytopenia. In conclusion, proteases from platelets seem to contribute to the presence of cleaved protein S in the circulation and may enhance the coagulation response in vivo by down regulating the anticoagulant activity of protein S.

scholarly journals Turnover of *I-protein C inhibitor and *I-alpha 1-antitrypsin and their complexes with activated protein C

Blood ◽  
1990 ◽  
Vol 76 (11) ◽  
pp. 2290-2295 ◽  
Author(s):  
M Laurell ◽  
J Stenflo ◽  
TH Carlson
Keyword(s):  
Complex Formation ◽  
Protein C ◽  
Activated Protein C ◽  
Human Protein ◽  
Relative Contribution ◽  
Protein C Inhibitor ◽  
The Difference ◽  
Alpha 1 Antitrypsin

Abstract The rates of clearance and catabolism of human protein C inhibitor (PCI) and human alpha 1-antitrypsin (alpha 1-AT) and their complexes with human activated protein C (APC) were studied in the rabbit. The radioiodinated-free inhibitors had biologic half-lives of 23.4 and 62.1 hours, respectively, while the corresponding *I-labeled activated- protein C complexes were cleared with half-lives of 19.6 +/- 3.1 and 72.2 +/- 6.1 minutes. Complex clearances were linked to their catabolism as shown by a correlation between clearance and the appearance of free radioiodine in the plasma. Thus, the difference in the rates of catabolism would result in a fivefold greater amount of alpha 1-AT-APC complex than PCI-APC complex 1 hour after the formation of equal amounts of these in vivo. These results lead to the conclusion that the relative contribution of PCI and alpha 1-AT to the physiologic inhibition of APC cannot be determined only from the rates of the formation of these complexes in vitro, or from measurement of their levels in plasma. The APC-PCI complex is unstable as compared with the APC-alpha 1-AT complex, compounding the problem of estimating rates of complex formation from their levels in plasma.

scholarly journals Protein C, an antithrombotic protein, is reduced in hospitalized patients with intravascular coagulation

Blood ◽  
1982 ◽  
Vol 60 (1) ◽  
pp. 261-264 ◽  
Author(s):  
JH Griffin ◽  
DF Mosher ◽  
TS Zimmerman ◽  
AJ Kleiss
Keyword(s):  
Liver Disease ◽  
Serine Protease ◽  
Vitamin K ◽  
Protein C ◽  
Activated Protein C ◽  
Coagulation System ◽  
Antigen Concentration ◽  
Intravascular Coagulation ◽  
The Mean

Abstract Activated protein C is a potent anticoagulant and profibrinolytic enzyme that can be derived from the vitamin-K-dependent serine protease zymogen, protein C, by the action of thrombin. Protein C antigen concentration was determined in plasmas from normals (n = 40) and from 38 patients with intravascular coagulation as evidenced by positive FDP (greater than micrograms/ml). Plasma protein C was 4 micrograms/ml in normals and was significantly depressed (less than 2 SD below the mean of normals) in 19 of the 38 patients. Of 15 patients with suspected intravascular coagulation but normal FDP, protein C was decreased in 5 individuals; 3 of these 5 patients had liver disease. Based on these results, we suggest that extensive activation of the coagulation system in vivo causes a significant consumption of protein C, presumably due to its activation by thrombin and subsequent clearance.

The Leiden Mutation and Activated Protein C Resistance as Risk Factors for Disseminated Intravascular Coagulation in Acutely Poisoned Patients

2006 ◽  
Vol 44 (1) ◽  
pp. 53-57
Author(s):  
Mirosław Prazanowski ◽  
Barbara Kur ◽  
Małgorzata Barańska ◽  
Waldemar Lutz ◽  
Bożena Piłacik ◽  
...  
Keyword(s):  
Risk Factors ◽  
Disseminated Intravascular Coagulation ◽  
Protein C ◽  
Activated Protein C ◽  
Activated Protein C Resistance ◽  
Intravascular Coagulation

Aggravation of endotoxin-induced disseminated intravascular coagulation and cytokine activation in heterozygous protein-C–deficient mice

Blood ◽  
2003 ◽  
Vol 101 (12) ◽  
pp. 4823-4827 ◽  
Author(s):  
Marcel Levi ◽  
Janine Dörffler-Melly ◽  
Pieter Reitsma ◽  
Harry Büller ◽  
Sandrine Florquin ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Disseminated Intravascular Coagulation ◽  
Protein C ◽  
Activated Protein C ◽  
Intravascular Coagulation ◽  
Cytokine Activation ◽  
Tnf Α ◽  
Single Allele ◽  
Factor Α ◽  
Heterozygous Deficiency

Abstract In the pathogenesis of sepsis and disseminated intravascular coagulation (DIC), dysfunctional anticoagulant pathways are important. The function of the protein C system in DIC is impaired because of low levels of protein C and down-regulation of thrombomodulin. The administration of (activated) protein C results in an improved outcome in experimental and clinical studies of DIC. It is unknown whether congenital deficiencies in the protein C system are associated with more severe DIC. The aim of the present study was to investigate the effect of a heterozygous deficiency of protein C on experimental DIC in mice. Mice with single-allele targeted disruption of the protein C gene (PC+/–) mice and wild-type littermates (PC+/+) were injected with Escherichia coli endotoxin (50 mg/kg) intraperitoneally. PC+/–mice had more severe DIC, as evidenced by a greater decrease in fibrinogen level and a larger drop in platelet count. Histologic examination showed more fibrin deposition in lungs, kidneys, and liver in mice with a heterozygous deficiency of protein C. Interestingly, PC+/– mice had significantly higher levels of proinflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β, indicating an interaction between the protein C system and the inflammatory response. Survival was lower at 12 and 24 hours after endotoxin in the PC+/– mice. These results confirm the important role of the protein C system in the coagulative-inflammatory response on endotoxemia and may suggest that congenital deficiencies in the protein C system are associated with more severe DIC and adverse outcome in sepsis.

scholarly journals The role of hypercoagulability in the development of osteonecrosis of the femoral head

2012 ◽  
Vol 4 (2) ◽  
pp. 17 ◽  
Author(s):  
Marios G. Lykissas ◽  
Ioannis P. Kostas-Agnantis ◽  
Ioannis D. Gelalis ◽  
Georgios Vozonelos ◽  
Anastasios V. Korompilias
Keyword(s):  
Plasminogen Activator ◽  
Lupus Erythematosus ◽  
Protein C ◽  
Activated Protein C ◽  
Plasminogen Activator Inhibitor ◽  
Protein S ◽  
Intravascular Coagulation ◽  
S Deficiency ◽  
Increased Risk ◽  
Von Willebrand

Despite the large number of the outstanding researches, pathogenesis of osteonecrosis remains unknown. During the last decades the hypothesis that increased intravascular coagulation may be the pathogenetic mechanism which leads to osteonecrosis is gaining constantly support. Both primary factors of hypercoagulability, such as resistance to activated protein C, protein C and protein S deficiency, low levels of tissue plasminogen activator, high levels of plasminogen activator inhibitor, von Willebrand factor, lipoprotein (a), and secondary factors of hypercoagulability with factors potentially activating intravascular coagulation, such as pregnancy, antiphospholipid antibodies, systemic lupus erythematosus, hemoglobinopathies and sickle cell disease, and hemato-oncologic diseases are discussed in this article. Although coagulation abnormalities in patients with hip osteonecrosis might represent increased risk factors for the development of bone necrosis by predisposing the patient to thromboembolic phenomena, further investigation is needed to indicate the definite correlation between factors leading to increased intravascular coagulation and pathogenesis of osteonecrosis.

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