Determination of Protein C Antigen Levels in Hospitalized Patients with Blood Coagulative Defects

2021 ◽  
Vol 2 (1) ◽  
pp. 1-04
Author(s):  
George Zhu

Protein C, a vitamin K-dependent anticoagulant serine protease, is involved in blood coagulation. Activated protein C inactivates Va and VIIIa in purified protein systems and stimulates fibrinolysis by indirectly increasing the level of circulating plasminogen activator. In this process, protein S serve as an important factor for activated protein C. In recent years, excess protein S drives cancer cell proliferation and cell survival through oncogenic receptor Axl (Anexelekto). We determined changes of plasma protein C antigen by using rocket immunoassay both in 50 healthy individuals and 103 distinct hospitalized patients. In healthy individuals protein C antigen(PC:Ag) ranges o.6439- 1.4752 µ/ml. The results showed that plasma protein C antigen was considerably high in 22 diabetes mellitus. In contrast, the PC:Ag was significantly decreased in 19 liver cirrhosis(p< 0.001) and in closely line with serum albumin levels(p< 0.05). In 31 acute leukemias, on the average, there was slightly lower values in PC:Ag, and accompanied with the distribution of significant decrease of PC:Ag values in 5 FAB M5 subtype and in 9 hyperleukocytic leukemias. However, the 3 acute promyelocytic leukemia (APL) with overt laboratory criteria of disseminated intravascular coagulation (DIC) had protein C concentration no lower than the remaining 2 patients with infectious DIC, which suggested the coagulopathy in APL might be due to mechanisms different from other forms of DIC.

Author(s):  
George Zhu ◽  
AW Broekmans ◽  
RM Bertina

 Objective: Protein C, a vitamin K-dependent coagulation factor, is involved in blood coagulation. Activated protein C inactivates Va and VIIIa and stimulates fibrinolysis. In this process, protein S serve as an important factor for activated protein C. Furthermore, excess protein S drives cancer cell proliferation and cell survival through oncogenic receptor Axl(Anexelekto). We determined ranges of protein C both in healthy individuals and distinct hospitalized patients. Methods: A total of 100 patients with different diagnostic diseases and 50 healthy individuals were included in their plasma protein C determination. A rabbit antibody against human protein C was used for the quantitative estimation of plasma protein C antigen by using rocket immunoassay. Results: In healthy individuals protein C antigen (PC:Ag) ranges o.6439- 1.4752 µ/ml. The mean coefficient of variation (CV) of length of rocket was calculated to be 12.45%. PC:Ag within laboratory variation was 11.47%. Plasma protein C antigen was destroyed at 56℃ for 30 minutes, whereas no significant decrease of protein C was found at 4℃ refrigerator for one week. Conclusion:  The results showed that plasma protein C antigen was considerably high in 22 diabetes mellitus. On the other hand, the PC:Ag was significantly decreased in 19 liver cirrhosis(p< 0.001) and was positively correlation with serum albumin levels(p< 0.05). In 20 acute leukemias, on the average,there was slightly lower values in PC:Ag, and accompanied with significant decrease of PC:Ag in 5 M5 subtype and in 9 hyper- leukocytes acute leukemias. However, the 3 acute promyelocytic leukemia (APL) with overt laboratory picture of DIC(disseminated intravascular coagulation) had protein C concentration no lower than the remaining 2 patients with infectious DIC, which suggested the coagulopathy in APL might be due to mechanisms different from other forms of DIC.                     Peer Review History: Received 17 November  2020; Revised 12 Decembe; Accepted 1 January, Available online 15 January 2021 UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                           Comments of reviewer(s):         Average Peer review marks at initial stage: 5.5/10 Average Peer review marks at publication stage: 7.5/10 Reviewer(s) detail: Dr. Idoko Alexander, Caritas University, Enugu, Nigeria, [email protected] Dr. Rawaa Souhil Al-Kayali, Aleppo University, Syria, [email protected] Similar Articles: THE ASSOCIATION BETWEEN LEVELS OF HEPCIDIN, IRON STATUS AND MICRO-INFLAMMATION MARKERS AMONG HAEMODIALYSIS COUMARIN ANALOGUES AS A POTENTIAL INHIBITOR OF LEISHMANIASIS: A MULTI-TARGETING PROTEIN INHIBITION APPROACH BY MOLECULAR DOCKING VITAMIN A, RETINOIC ACID AND TAMIBAROTENE, A FRONT TOWARD ITS ADVANCES: A REVIEW


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1137-1137
Author(s):  
Mary J. Heeb ◽  
Erning Duan

Abstract Abstract 1137 Background: Platelets contain in their alpha granules ∼2.5% of the protein S in blood. It has been suggested that this protein S supports the anticoagulant activity of exogenous activated protein C (APC), but it is not known whether protein S that is released from stimulated platelets can exert anticoagulant activity that is independent of APC and TFPI. We recently showed that at least some of the anticoagulant activity of plasma protein S is independent of APC and TFPI, although data suggested that plasma protein S may also have TFPI-dependent activity. Objective and methods: To determine if platelet protein S has anticoagulant activity that is independent of APC and TFPI, prothrombinase and extrinsic FXase reactions were initiated on the surface of fresh stimulated or unstimulated washed platelets in the presence and absence of blocking antibodies against APC, TFPI, and/or protein S, or in the presence and absence of purified plasma-derived protein S. Platelets were adjusted to a concentration of 0.7 to 2 × 10e8/ml, which contained 2.3–6.5 nM total platelet protein S. The last platelet wash contained negligible amounts of plasma protein S. Results: Neutralizing anti-protein S antibodies allowed up to 5.7-fold (mean: 2.1 ± 1.5 –fold, n=13) more thrombin generation on calcium ionophore-stimulated platelets following supplementation with 50–500 pM FXa and 600 nM prothrombin, and allowed up to 2.5-fold (mean: 1.7 ± 0.7 –fold, n=11) more thrombin generation on platelets that were not ionophore-stimulated but were gradually stimulated following FXa and prothrombin supplementation. Anti-protein S antibodies had no effect on thrombin generation on platelets that were treated with prostaglandin E1 (PGE1) to suppress platelet activation and then supplemented with procoagulants. This implies that platelet protein S is released from stimulated platelets and downregulates thrombin generation on platelets, and that neutralizing anti-protein S antibodies block this activity of protein S. Anti-protein S antibodies allowed up to 1.8-fold (mean 1.5 ± 0.2 –fold, n=8) more FXa generation on the surface of stimulated platelets supplemented with 5 pM TF, 100 pM FVIIa, and 160 nM FX, but anti-protein S antibodies had no effect on FXa generation on platelets treated with PGE1. Most of these experiments were performed in the presence of neutralizing antibodies against TFPI and APC, but thrombin and FXa generation on platelets under the varying conditions described were unaffected by the presence of these neutralizing antibodies. Purified plasma-derived zinc-containing protein S downregulated thrombin and FXa generation on platelets (IC50 = 6–18 nM PS) and in plasma >10-fold more potently than zinc-deficient protein S. We could not demonstrate a synergistic anticoagulant effect when TFPI was combined with zinc-deficient protein S in the presence of stimulated platelets and procoagulant proteins. Conclusion: Protein S that is released from stimulated platelets exerts anticoagulant activity that is independent of TFPI and APC. Disclosures: No relevant conflicts of interest to declare.


1987 ◽  
Author(s):  
P C Comp ◽  
C T Esmon

Activated protein C functions as an anticoagulant by enzymatically degrading factors Va and Villa in the clotting cascade. Protein C may be converted to its enzymatically active form bythrombin. The rate at which thrombin cleavage of the zymogen occurs is greatly enhanced when thrombin is bound to an endothelial cell receptor protein, thrombomodulin. Activated proteinC has a relatively long half-life in vivo and the formation of activated protein C in response to low level thrombin infusion suggests that the protein C system may provide a feedback mechanism to limit blood clotting. Clinical support for such a physiologic role for activated protein C includes an increased incidence of thrombophlebitis and pulmonary emboli in heterozygous deficient individuals, and severe, often fatal, cutaneous thrombosis in homozygous deficient newborns. A third thrombotic condition associated with protein C deficiency is coumarin induced skin (tissue) necrosis. This localized skin necrosis occurs shortly after the initiation of coumarin therapy and is hypothesized to bedue to the rapid disappearance of protein C activity in the plasma beforean adequate intensity of anticoagulation is achieved. Recent estimates of heterozygous protein C deficiency range as high as 1 in 300 individuals in the general population. Since coumarin compounds are in routine clinical use throughout the world and skin necrosis remains a relatively rare clinical finding, this suggests that factors other than protein C deficiency alone may be involved in the pathogenesis of the skin necrosis.The anticoagulant properties of activated protein C are greatly enhanced by another vitamin K-dependent plasma protein, protein S. Protein S functions by increasing the affinity of activated protein C for cell surfaces.Protein S is found in two forms in plasma: free and in complex with C4b-binding protein, "an inhibitor of the complement system. Free protein S is functionally active and the complexed protein S is not active. Individuals congenitally deficient in protein S ae subject to recurrent thromboembolicevents. At least two classes of protin S deficiency occur.Some patienshavedecreased levels of protein S antigen and reduced protein S functional activity. A second group of deficient individuals have normal levels of protein S antigen but most or all their protein S is complexed to C4b-binding protein and they have little or no functional protein S activity. Such a protein S distribution could result from abnormal forms of protein S or C4b-binding protein or some other abnormal plasma or cellular component. Patients with functionally inactive forms of protein S have yet to be identified. Identification of protein S deficient individuals is complicated by thepossible effect of sex hormones on plasma protein S levels. Total protein S antigen is reduced during pregnancyand during oral contraceptive administration. This finding is of practicalclinical importance since the decrease in protein S which occurs during pregnancy may be an added risk factor for congenitally protein S deficient women and may explain why some proteinS deficient women experience their first episode of thrombosis during pregnancy.In addition to having anticoagulant properties, activated protein C enhances fibrinolysis, at least in part,by inhibiting the inhibitor of tissueplasminogen activator. This profibrinolytic effect is enhanced by protein S and cell surfaces. This protection of plasminogen activator activity suggests that the combination of tissue plasminogen activator and activated protein C may be useful in the treatment of coronary artery thrombi. Tissueplasminogen activator would promote clot lysis while activated protein C protected the plasminogen activatorfrom inhibition and also prevented further clot deposition. There is no evidence at present that fibrinolytic activity is reduced in protein C deficient individuals. The possible clinical relevance of this aspect of protein Cfunction in the predisposition of protein C deficient individuals to thrombosis remains to be defined.


2006 ◽  
Vol 95 (02) ◽  
pp. 236-242 ◽  
Author(s):  
Jeroen Brugge ◽  
Guido Tans ◽  
Jan Rosing ◽  
Elisabetta Castoldi

SummaryElevated plasma prothrombin levels, due to the prothrombin 20210 G/A mutation or to acquired causes, area risk factor for venous thrombosis,partly because of prothrombin-mediated inhibition of the protein C anticoagulant pathway and consequent activated proteinC (APC) resistance. We determined the effect of plasma prothrombin concentration on the APC resistance phenotype and evaluated the role of protein S levels asa modulating variable. The effect of prothrombin and protein S levels on APC resistance was investigated in reconstituted plasma systems and in a population of healthy individuals using both the aPTT-based and the thrombin generation-based APC resistance tests. In reconstituted plasma, APC resistance increased at increasing prothrombin concentration in both assays. Enhanced APC resistance was caused by the effect of prothrombin on the clotting time in the absence of APC in the aPTT-based test, and on thrombin formation in the presence of APC in the thrombin generation-based test. In plasma from healthy individuals prothrombin levels were highly correlated to protein S levels. Since prothrombin and proteinS had opposite effects on the APC resistance phenotype, the prothrombin/protein S ratio was a better predictor of APC resistance than the levels of either protein alone. Prothrombin titrations in plasmas containing different amounts of proteinS confirmed that proteinS levels modulate the ability of prothrombin to induce APC resistance. These findings suggest that carriers of the prothrombin 20210 G/A mutation, who have a high prothrombin/protein S ratio, may experience a higher thrombosis risk than non-carriers with comparable prothrombin levels.


Blood ◽  
1984 ◽  
Vol 64 (6) ◽  
pp. 1297-1300 ◽  
Author(s):  
HP Schwarz ◽  
M Fischer ◽  
P Hopmeier ◽  
MA Batard ◽  
JH Griffin

Abstract A family with a history of severe recurrent venous thromboembolic disease was studied to determine if a plasma protein deficiency could account for observed disease. Protein S levels in plasma were determined immunologically using the Laurell rocket technique. The propositus, his mother, his aunt, and his cousin who were clinically affected had 17% to 65% of the control levels of protein S antigen (normal range, 71% to 147%). Since three of these patients were receiving oral anticoagulant therapy, the ratios of protein S to prothrombin, factor X, and protein C in these patients were compared with values for a group of orally anticoagulated controls. These results suggested that protein S is half-normal in all family members with thrombotic disease. Other proteins known to be associated with familial thrombotic disease, including antithrombin III, plasminogen, fibrinogen, and protein C, were normal. Because plasma protein S serves as a cofactor for the anticoagulant activity of activated protein C and because protein C deficiency is associated with recurrent thrombotic disease, it is suggested that recurrent thrombotic disease in this family is the result of an inherited deficiency of protein S.


2013 ◽  
Vol 109 (02) ◽  
pp. 229-237 ◽  
Author(s):  
Fabian Stavenuiter ◽  
Nicole Davis ◽  
Erning Duan ◽  
Andrew Gale ◽  
Mary Heeb

SummaryAnticoagulant plasma protein S (PS) is essential for maintaining haemostatic balance. About 2.5% of PS is stored in platelets and released upon platelet stimulation. So far, little is known about the functionality and importance of platelet (plt)PS. A platelet-associated protease cleaves plasma-derived (pd)PS and pltPS in the “thrombin-sensitive region”, abolishing activated protein C (APC) cofactor activity. However, we showed that cleaved PS retains APC-independent anticoagulant activities (“PS-direct”). To investigate whether pltPS or pdPS exert PS-direct on platelets or platelet-shed microparticles, thrombin and factor (F)Xa generation on unstimulated or stimulated washed platelets and microparticles were measured. Western blotting revealed that pltPS and pdPS bound to washed, stimulated platelets and microparticles, and that pltPS had slower electrophoretic mobility than pdPS. Platelet stimulation in the presence of inhibitory anti-PS antibodies resulted in 2.6 ± 1.6-fold (p<0.0004, n=20) more thrombin generation upon addition of FXa and prothrombin. PltPS exerted PSdirect that was similar to or greater than that of Zn2+-containing pdPS and much greater than that of Zn2+-deficient pdPS. Findings were confirmed using purified pltPS. Platelet-bound pltPS and microparticlebound pltPS had similar PS-direct. Finally, platelet stimulation in the presence of inhibitory anti-PS antibodies resulted in 1.5 ± 0.2-fold (p<0.0001, n=11) more FXa generation upon addition of TF/FVIIa and FX. Thus, pltPS inhibits both prothrombinase and extrinsic FXase activities. Neutralising antibodies against APC and TFPI had no effect on the PS-direct of pltPS or pdPS on platelets. This study indicates that pltPS may be an essential pool of PS that counterbalances procoagulant activities on platelets.


1999 ◽  
Vol 103 (2) ◽  
pp. 219-227 ◽  
Author(s):  
John H. Griffin ◽  
Kazuhisa Kojima ◽  
Carole L. Banka ◽  
Linda K. Curtiss ◽  
José A. Fernández

1985 ◽  
Vol 53 (02) ◽  
pp. 268-272 ◽  
Author(s):  
R M Bertina ◽  
A van Wijngaarden ◽  
J Reinalda-Poot ◽  
S R Poort ◽  
V J J Bom

SummaryProtein S, an important cofactor of activated protein C, and C4b-binding protein were purified from human plasma. Specific antibodies against the purified proteins were raised in rabbits and used for the development of immunologic assays for these proteins in plasma: an immunoradiometric assay for protein S (which measures both free protein S and protein S complexed with C4b-binding protein) and an electroimmunoassay for C4b- binding protein. Ranges for the concentrations of these proteins were established in healthy volunteers and patients using oral anticoagulant therapy. A slight decrease in protein S antigen was observed in patients with liver disease (0.78 ± 0.25 U/ml); no significant decrease in protein S was observed in patients with DIC (0.95 ± 0.25 U/ml).Criteria were developed for the laboratory diagnosis of an isolated protein S deficiency


Blood ◽  
1984 ◽  
Vol 64 (6) ◽  
pp. 1297-1300 ◽  
Author(s):  
HP Schwarz ◽  
M Fischer ◽  
P Hopmeier ◽  
MA Batard ◽  
JH Griffin

A family with a history of severe recurrent venous thromboembolic disease was studied to determine if a plasma protein deficiency could account for observed disease. Protein S levels in plasma were determined immunologically using the Laurell rocket technique. The propositus, his mother, his aunt, and his cousin who were clinically affected had 17% to 65% of the control levels of protein S antigen (normal range, 71% to 147%). Since three of these patients were receiving oral anticoagulant therapy, the ratios of protein S to prothrombin, factor X, and protein C in these patients were compared with values for a group of orally anticoagulated controls. These results suggested that protein S is half-normal in all family members with thrombotic disease. Other proteins known to be associated with familial thrombotic disease, including antithrombin III, plasminogen, fibrinogen, and protein C, were normal. Because plasma protein S serves as a cofactor for the anticoagulant activity of activated protein C and because protein C deficiency is associated with recurrent thrombotic disease, it is suggested that recurrent thrombotic disease in this family is the result of an inherited deficiency of protein S.


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