Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The HELLP syndrome (HS) belongs to the list of obstetric complications believed to be associated with coagulation disorders. It was formerly thought that chronic intravascular clotting (DIC) in the placental vessels was the main cause. A hypercoagulable state has been reported in cases of severe HS associated with microvascular abnormalities that may involve cerebral, placental, hepatic and renal vessels. A case of acute pancreatitis and DVT of inferior cava in a pregnant woman, presenting with HS at 29 weeks, who was found to have a R506Q mutation, is reported. Preeclampsia-associated pancreatitis and DVT have rarely been reported. It is hypothesized that APC-R and Factor V Leiden mutation may prove to be new and more important markers capable of predicting a more significant maternal morbidity associated with HS. Thrombosis prophylaxis may be considered during pregnancy in order to reduce hazardous multiorgan failure (MOF) in women who are heterozygous for Factor V Leiden mutation.
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PMID:Acute pancreatitis and deep vein thrombosis associated with HELLP syndrome. 1023 Feb 42

Postoperative venous thromboembolic complications are commonly seen after total replacement of the hip or knee. Recently, an inherited defect with resistance to the anticoagulant activity of activated protein C (APC-resistance) has been detected. APC-resistance seems to be a common risk factor, especially in Sweden, and it increases the propensity for venous thrombosis. This study assesses the prevalence of APC-resistance in a general population and its clinical significance for patients undergoing surgery associated with a high risk of thromboembolic complications. In a prospective cohort study, we analysed for APC-resistance in 645 consecutive patients before elective replacement of the hip or knee at 3 hospitals in southern Sweden. Thromboprophylaxis with LMWH-heparin was given to all patients throughout the hospitalisation period. We recorded events of clinical thromboembolism for 3 months postoperatively. Venography, ultrasonography or pulmonary scintigraphy was requested by the clinicians according to the existing routines, i.e. only patients with symptoms of thromboembolism were examined. A thromboembolic complication was registered in 20 (3.1%) patients. Fifty per cent of the venous thrombi had a proximal location. Only 0.3% of the patients had verified pulmonary embolism. APC-resistance was found in 14.1% of the patients, of whom 9.9% had experienced postoperative thromboembolism compared with 2.0% of the patients without APC-resistance (p<0.0007). We conclude that APC-resistance is a frequent risk factor for symptomatic postoperative deep venous thrombosis with an estimated relative risk of 5.0 (95% confidence interval: from 1.9 to 12.9) in elective replacement of the hip or knee.
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PMID:APC-resistance is a risk factor for postoperative thromboembolism in elective replacement of the hip or knee--a prospective study. 1034 13

The European Concerted Action on Thrombosis (ECAT) DVT Study was a collaborative study of preoperative haemostatic tests in prediction of DVT (diagnosed by routine bilateral venography) after elective hip replacement. 480 patients were recruited in 11 centres across Europe. Clinical risk factors were assessed, and stored citrated plasma aliquots were centrally assayed for 29 haemostatic factors according to the ECAT methodology. 120 (32%) of 375 evaluable patients had DVT, and 41 (11%) had proximal DVT. Among clinical variables, DVT was significantly associated with increased age, obesity, and possibly non-use of stockings. Of the 29 haemostatic factors, mean preoperative levels were significantly higher in patients with subsequent DVT (on univariate analyses) for factor VIII activity, prothrombin fragment F1+2, thrombin-antithrombin complexes, and fibrin D-dimer; and significantly lower for APTT and APC sensitivity ratio. Factor V Leiden was also associated with DVT. Most of these variables were also associated with age, while D-dimer was higher in patients with varicose veins. On multivariate analyses including clinical variables, only a shorter APTT (locally but not centrally performed) and APC resistance showed a statistically significant association with DVT. We conclude that (a) DVT is common after elective hip replacement despite prophylaxis; (b) the study provides some evidence that DVT is associated with a preoperative hypercoaguable state; and (c) preoperative haemostatic tests do not add significantly to prediction of DVT from clinical variables, with the possible exception of APC resistance.
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PMID:Prediction of deep vein thrombosis after elective hip replacement surgery by preoperative clinical and haemostatic variables: the ECAT DVT Study. European Concerted Action on Thrombosis. 1040 61

The role of hereditary antithrombotic protein defects in juvenile deep vein thrombosis (DVT) was evaluated. Fifty six young patients (age <45 yr) with doppler-proven DVT were investigated for the presence of resistance to activated protein C (APC-R), lupus anticoagulant (LA), anticardiolipin antibodies and deficiencies of protein C, protein S, ATIII activities. Fifty nine normal healthy individuals served as controls. APC-R was observed to be the commonest defect underlying the Indian DVT as seen in 39.2% of patients followed by elevated ACA (5.3%), PAI (2.8%), presence of LA (2.8%) and reduced ATIII levels (2.8%). None of the subjects had protein C or S deficiency. APC-R was associated with ATIII deficiency in one case, and elevated ACA in two cases. In two subjects, APC-R was associated with elevated PAI levels. Patients with more than one prothrombotic factor had a higher prevalence of pulmonary thromboembolism, suggesting that the thrombogenic potential of APC-R is enhanced by the presence of coexisting hereditary or acquired prothrombotic defect.
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PMID:Pathogenetic factors underlying juvenile deep vein thrombosis (DVT) in Indians. 1041 51

Pseudohomozygosity for activated protein C resistance (APC-r) is a rare condition due to the association of heterozygous FV Leiden mutation and partial type I FV deficiency. To assess the risk of venous thromboembolism in these subjects, seven families including 11 pseudohomozygotes and 45 relatives were examined. Among the relatives, 16 were heterozygous FV Leiden carriers, nine showed partial FV deficiency and 20 no abnormalities. Deep vein thrombosis occurred in 4/11 (36.3%) pseudohomozygous patients versus 6/16 (37. 4%) FV Leiden carriers and 1/20 (5%) normal relatives. Pseudohomozygotes and FV Leiden carriers had a significantly increased risk of venous thrombosis in comparison to normal relatives (RR 8.8 and 5.7, respectively). There was no difference between the thrombotic risk of pseudohomozygous subjects and of FV Leiden carriers (RR 1.6, 95% CI 0.43-5.7). Furthermore, there was no difference in thrombosis-free survival between pseudohomozygotes and 45 consecutive FV Leiden heterozygous outpatients, suggesting that a referral bias may explain the apparent younger age of thrombosis in the pseudohomozygotes in comparison to relatives with FV Leiden heterozygosity (27 years v 54 years; P = 0.01). Pseudohomozygosity for APC resistance carries a significantly higher risk for venous thromboembolism in comparison to normal subjects, but probably not in comparison to heterozygous FV Leiden carriers.
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PMID:Pseudohomozygosity for activated protein C resistance is a risk factor for venous thrombosis. 1044 92

Activated protein C resistance (APC-R) is the most common inherited defect of the coagulation system known to date, affecting 3-5% of Americans. It is an autosomal dominant disorder associated with an increased risk of venous thrombosis and is reportedly found in 21% of individuals with deep venous thrombosis. Medical examiners are in a unique position to make the diagnosis since a fatal pulmonary embolism may be the first manifestation of the disorder. This study examines the prevalence of APC-R in individuals who die suddenly of pulmonary embolism to help medical examiners decide if routine testing is indicated. We examined 66 cases of sudden death due to pulmonary embolism seen at the Bexar County Forensic Science Center in San Antonio, Texas, from 1993-1997. The median age was 46 years with a range of 14 to 93 years. Fifty-three percent were Caucasian, 24% were African-American, and 23% were Hispanic. Twenty-seven percent had no known risk factors for pulmonary embolism. Whole blood was tested for the factor V codon 506Q mutation responsible for APC-R using polymerase chain reaction. The prevalence of APC-R was 4.5%, which is similar to the prevalence of APC-R in the general American population. These data imply that individuals with APC-R are not in increased risk for sudden death due to pulmonary embolism, or, conversely, that most fatal pulmonary emboli seen in the medical examiner setting are not induced by APC-R. Routine postmortem testing for the factor V 506Q mutation does not appear indicated at this time, given the low prevalence and high cost of testing.
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PMID:Activated protein C resistance is uncommon in sudden death due to pulmonary embolism. 1058 51

Protein C (PC) is the zymogen of an anticoagulant serine protease and is converted to its active form (activated protein C: APC) by thrombin in the presence of thrombomodulin. APC plays an important role in regulating blood coagulation and fibrinolysis by inhibiting not only blood coagulation factors Va and VIIIa but also type-1 plasminogen activator inhibitor (PAI-1). In this study, it was reported that the antithrombotic effect of a human APC product (designated as CTC-111) compared with that of heparin and human PC on the deep venous thrombosis (DVT) model induced in mice by stasis caused by inferior vena cava ligation and operative invasion. Drugs were injected into a tail vein at -2, 30, 60, and 120 min after the inferior vena cava ligation. One-fifth amount of the total dosage of a given drug was injected at each time point. The wet weight of thrombus formed was reduced by APC or heparin administration, however, PC, which was equal to APC in protein amount, did not show any antithrombotic effect. To confirm whether human PC could be activated by mouse thrombin, PC was treated with mouse or human thrombin to measure the amount of APC formed. Mouse thrombin could activate human PC at a similar activation rate as human thrombin. These results suggest that externally administrated PC cannot exhibit antithrombotic effect in this DVT model due to slow activation rate to APC and that APC is a better antithrombic agent than PC for treating thrombotic diseases.
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PMID:Effect of activated human protein C on experimental venous thrombosis induced by stasis with operative invasion in mice. 1099 52

Anti-phospholipid (aPL) antibodies (Abs) are well known to be associated with thromboembolic events in patients with systemic lupus erythematosus (SLE). However, the clinical relevance of a PL Abs in patients without SLE (non-SLE) who have venous thromboembolism remains unclear. We evaluated 143 non-SLE patients with a first episode of clinically suspected deep vein thrombosis (DVT) by using objective tests for diagnosing DVT and laboratory tests including the activated protein C resistance (APC-R) test, the factor V Leiden test, and various aPL Abs. The prevalence of acquired APC-R, in which case there was no factor V Leiden mutation, was significantly higher in patients with DVT (15/58 cases, 25.9%, p < 0.0001) than in those without DVT (3/80 cases, 3.7%), and confirmed that acquired APC-R was a strong risk factor for DVT (odds ratio [OR], 8.95; 95% confidence intervals [CI], 2.45-32.7; p < 0.001). Multivariate logistic analysis revealed that the presence of LA, aCL, anti-beta2-glycoprotein I, anti-prothrombin and anti-protein C Abs was not reliable as a risk factor for DVT in non-SLE patients, and that the presence of anti-protein S Abs was the most significant risk factor for DVT (OR, 5.88; 95% CI, 1.96-17.7; p < 0.002). Furthermore, the presence of anti-protein S Abs was strongly associated with acquired APC-R (OR, 57.8; 95% CI, 8.53-391; p < 0.0001). These results suggest that acquired APC-R may reflect functional interference by anti-protein S Abs of the protein C pathway, which action may represent an important mechanism for the development DVT in non-SLE patients.
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PMID:Acquired activated protein C resistance associated with anti-protein S antibody as a strong risk factor for DVT in non-SLE patients. 1242 83

Activated protein C resistance (APCR) is the most common hereditary condition of thrombosis in Western countries. And it is significantly linked to a single nucleotide polymorphisms (SNPs) in the coagulation factor V gene that results in the mutations at R506, R306 and HR2 alleles. To determine the prevalence of APCR and its association with the factor V gene SNPs in Chinese Han thrombotic patients, we investigated a total of 346 Chinese thrombotic patients and 140 normal controls for APCR using the APTT-based assays, according to manufacturer's instructions, APC ratio </=2 indicated APC resistance. Mutations of factor V at R506, R306, HR2 allele were detected by PCRMnl/I, Bst/NI, Rsa/I digestion as described before respectively. The results showed that the incidence of APC resistance were 12.0% (12 of 100 cases) in acute cerebral thrombosis (ACT) patients (P <0.05), 13.5% (13 of 96 cases) in acute myocardial infarction (AMI) patients (P <0.05), 16.7% (10 of 60 cases) in deep venous thrombosis (DVT) patients (P <0.05), 15.6% (14 of 90 cases) in systemic lupus erythematosus (SLE) patients (P <0.05) and 5.0% (7 of 140 cases) in normal controls. APCR is associated with thrombotic events. But no factor V R506Q mutation (FV Leiden) was found in all 5 groups. Only one AMI patient and one DVT patient revealed heterozygous R306G mutation, which was confirmed by direct sequencing PCR products. Additionally, two SLE patients showed to be heterozygous HR2 allele for the first time in the Chinese Han population. We concluded that APC resistance in the Chinese Han population might not be associated with mutations of factor V at R506, R306 and HR2 polymorphisms. Some other factors might contribute to APC resistance in the Chinese Han population.
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PMID:No association between thrombosis and factor V gene polymorphisms in Chinese Han population. 1262 26

The role played by a hypercoagulable state, either inherited or acquired, in the pathogenesis of upper-extremity deep vein thrombosis (UEDVT) remains a question of debate. We performed a case-control study including 79 patients with a first objectively confirmed episode of UEDVT, 31 secondary and 48 primary, and 165 healthy controls. Nine patients (11.4%) with UEDVT were carriers of the prothrombin G20210A mutation vs. six (3.7%) in controls; P = 0.025, OR: 3.39 (95% CI 1.16 to 9.88). No statistical difference was observed between cases and controls for the factor V Leiden mutation, AT, protein C or protein S deficiency and anticardiolipin antibodies (ACAs). Thirteen (35.1%) UEDVT patients were oral contraceptive (OC) users vs. 12 (16%) controls; P = 0.020, OR: 2.89 (95% CI 1.16-7.21). When secondary UEDVT patients were compared with controls, no differences were observed in any of the risk factors analysed. On the other hand, when primary UEDVT was considered, six (12.5%) patients were carriers of the prothrombin G20210A mutation vs. six (3.7%) controls; P = 0.031, OR: 3.76 (95% CI 1.15-12.26). Regarding ACAs, a borderline statistical significance was observed when primary UEDVT was compared with controls, P = 0.048; OR: 4.88 (95% CI 1.05-22.61). In primary UEDVT, 52% of the fertile women were OC users vs. 16% of controls; P = 0.001, OR: 5.78 (95% CI 2.13-15.67). When the interaction of both factors, i.e. prothrombin G20210A mutation and OC intake, were considered, the risk increased markedly, indicating a synergistic effect as observed with other thrombotic locations. In patients with primary UEDVT screening for antithrombin, protein C and protein S deficiency and APC resistance would not be justified, although it might be reasonable to determine the carrier status of the prothrombin G20210A mutation only in OC users.
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PMID:Prothrombin G20210A mutation and oral contraceptive use increase upper-extremity deep vein thrombotic risk. 1262 27


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