Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024141 (systemic lupus erythematosus)
 44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The circulating levels of angiotensin I-converting enzyme (ACE) are linked with a 287-base pair insertion/deletion (I/D) polymorphism at intron 16 of the ACE gene. Thus, the homozygous deletion (D/D genotype) could cause chronic vasoconstriction, arterial hypertension and, possibly, coronary artery disease. Also, the increase in plasminogen activator inhibitor-1 level and impaired fibrinolysis were related with the D/D genotype. The D allele has been recently associated with venous thrombosis among African-American men as well as among patients that underwent elective total hip replacement. We assess the risk of venous thromboembolism (VTE) linked with each genotype of the I/D ACE gene polymorphism in a Caucasian population by means of a case-control study. We genotyped the ACE gene in a series of 148 patients aged 45.0 +/- 16.0 years (range, 11-80 years), objectively diagnosed in our centre of deep-vein thrombosis or pulmonary embolism, and in 240 thrombosis-free subjects (25-75 years) from the same geographic area. The observed difference in D allele frequencies between patients (0.56) and controls (0.62) was nonsignificant overall; however, statistical significance (P = 0.05) was found by considering the recessive hypothesis (D/D versus I/ D + I/I) [odds ratio (OR) = 0.64, 95% confidence interval (CI95) = 0.42-0.99]. The OR was 0.88 (CI95 = 0.51-1.53; P = 0.65) for the dominant hypothesis (D/D + I/D versus I/I genotypes). The relative risk for the D allele was close to 1 for the dominant hypothesis, both considering gender and recurrent tendency; however, it was protective in men regarding the recessive hypothesis (OR = 0.53, CI95 = 0.29-0.97, P = 0.04). The I/D ACE allele distribution was similar among the 46 thrombophilic patients (antithrombin, protein C or protein S deficiencies, factor V R506Q, factor II G20210A or lupus anticoagulant). In conclusion, among (Spanish) Caucasians, this study does not support the hypothesis that the deletion allele (D) of the ACE gene could be a significant risk factor for VTE, being protective in men.
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PMID:Risk of venous thromboembolism associated with the insertion/deletion polymorphism in the angiotensin-converting enzyme gene. 1093 9

Thrombosis is a major clinical feature of the antiphospholipid syndrome. Interactions between genetic and acquired factors could contribute to thrombosis development. In this study, we evaluated 40 patients with antiphospholipid syndrome and thrombosis, 31 primary and nine secondary to systemic lupus erythemathosus, to estimate the carrier rates of factor V Leiden, 20210A --> G prothrombin variant and 677C --> T in the MTHFR gene. Protein C, protein S and antithrombin were measured in 30 patients, with a median of 100.66 +/- 23.86, 93.57 +/- 36.44 and 98.8 +/- 5.67%, respectively. None of the patients were deficient on these natural anticoagulants. No significant variation was found between the patient group and the controls, regarding the prevalence of homozygotes for the mutated 677T allele (2.5 versus 5.4%), or heterozygotes for factor V Leiden (0 versus 0.7%). Despite the fact that these mutations are relatively common in Brazilian thrombophilic patients, its low prevalence in this cohort of patients suggest that these genetic alterations are not risk factors for thrombosis in antiphospholipid syndrome. The prevalence of the mutated allele 20210A of the prothrombin gene was higher in patients when compared with controls (5 versus 0.7%; P = 0.01), suggesting that prothrombin variant could increase the risk of thrombosis in patients with antiphospholipid syndrome.
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PMID:The impact of the search for thrombophilia risk factors among antiphospholipid syndrome patients with thrombosis. 1108 90

Thrombotic disease is less frequent in children than in adults, but may result in severe morbidity and mortality. The coagulation system is balanced to provide rapid activation to stop bleeding and appropriate inhibition to prevent unwanted clot extension. It is regulated by fibrinolysis and by three major anticoagulant pathways: the protein C, antithrombin, and tissue factor pathway inhibitor systems. Acquired or inherited abnormalities of coagulation proteins or hemostatic regulatory mechanisms, particularly when combined with dehydration or the presence of indwelling catheters, may pose a high risk for thrombosis. Thrombosis in a child warrants investigation of potential underlying prothrombotic conditions. These include acquired antiphospholipid antibodies or the lupus anticoagulant as well as abnormalities of the inherited anticoagulant factors including protein C, protein S, antithrombin, and Factor V Leiden. Other abnormalities may result in heightened levels of otherwise normal coagulation proteins such as hyperprothrombinemia due to the prothrombin 20210 mutation. A large survey of children with thrombosis indicated that Factor V Leiden, protein C deficiency, and increased lipoprotein(a) were found most commonly. The most severe predisposition occurs with homozygous protein S or protein C deficiency with resultant purpura fulminans in the newborn. The risk of thrombosis in children with heterozygous deficiencies of anticoagulant proteins is not well defined, although it is clear that combined heterozygotes or a combination of an inherited and an acquired defect heightens the risk for thrombosis. Treatment of thrombosis primarily involves a rapidly acting anticoagulant such as heparin or low-molecular-weight heparin to prevent extension, and long-term anticoagulation with warfarin may be instituted to prevent recurrence. Fibrinolytic therapy is infrequently used because of the risk of serious bleeding complications and is reserved for selected cases of arterial thrombosis to initiate rapid reperfusion of ischemic tissue or used in those patients with a large venous thrombosis and pulmonary emboli causing hemodynamic compromise.
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PMID:Anticoagulant proteins in childhood venous and arterial thrombosis: a review. 1111 87

The array of clinicopathologic factors associated with acquired immune deficiency syndrome (AIDS) patients continues to increase and surprise many physicians. The recent literature contains reports of thrombotic episodes occurring in patients with human immunodeficiency virus (HIV) infection. Various abnormalities predisposing to a hypercoagulable state have also been reported in AIDS patients including the presence of antiphospholipid antibodies and the lupus anticoagulant; deficiencies of protein C, protein S, heparin cofactor II, and antithrombin and increased levels of von Willebrand factor, and d-dimers. These abnormalities correlate with the severity of HIV-associated immunosuppression as measured by the CD4 cell counts and with the presence of concurrent infectious or neoplastic diseases. The authors reviewed the medical literature and describe various abnormalities predisposing to a hypercoagulable state in AIDS patients along with the management of such complications. This issue is important because deep venous thrombosis (DVT), pulmonary embolus (PE), or thrombosis at other sites can develop in patients with AIDS who are ambulatory and have no known risk factors for pathologic thrombus formation, providing another challenge in an already difficult clinical situation. This also provides a strong rationale for careful prospective studies focusing on the prevalence and risk factors involved in the development of thromboembolic complications in patients with AIDS.
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PMID:HIV and thrombosis: a review. 1117 84

Deep venous thrombosis of the upper extremity (DVTUE) is a rare thrombotic disorder that may occur spontaneously but is most often related to predisposing factors, such as an indwelling central venous catheter, malignancy, or exercise. The role of coagulation disorders, i.e., a hypercoagulable state in the pathogenesis of DVTUE is not well known. We have evaluated both genetic and acquired thrombophilia parameters in consecutive patients with DVTUE. A hypercoagulable state was found in 32% of the patients. The most frequent coagulation abnormality was the presence of lupus anticoagulant or anticardiolipin antibodies (27%). Factor V Leiden mutation was detected in two patients, antithrombin deficiency in one, and none of the patients had the prothrombin G20210A gene variant or protein C or S deficiency. The prevalence of coagulation abnormalities was not significantly different in a subgroup of patients with spontaneous DVTUE as compared to those with an obvious predisposing factor, such as an indwelling central venous catheter. We conclude that antiphospholipid antibodies are frequently found in patients with DVTUE. Factor V Leiden mutation, prothrombin 20210A gene variant, protein C deficiency, and protein S deficiency do not seem to play a major pathogenetic role in DVTUE.
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PMID:Hypercoagulability states in upper-extremity deep venous thrombosis. 1127 52

The goal of this article is to study the association of known markers of thrombophilia with venous thrombosis in young patients (< 45 years) from the Western part of India. A prospective study of 432 patients (252 males and 180 females, age 1-45 years) was conducted between 1994 and 2000 (6 years). The diagnosis was confirmed in all the patients by ultrasound with Doppler or by a computed tomograph (CT) scan of the brain with or without contrast depending on the case. Detailed clinical examination, and family history was taken to establish recurrent thrombosis and familial occurrence of thrombosis. The markers studied were protein C, protein S, antithrombin (AT) III, factor V Leiden mutation, prothrombin gene G20210A polymorphism, and the thermolabile MTHFR variant C677T polymorphism, using appropriate techniques. Lupus inhibitor was tested in the first 72 patients using Dilute Russel Viper Venom Time (DRVVT) test, and anticardiolipin antibodies were tested by enzyme-linked immunosorbent assay. Protein C, protein S, and AT III deficiency was detected in 9.5%, 6.5%, and 2.6%, respectively, among the patients. Anticardiolipin antibody was present in 9.9% of the patients, whereas lupus anticoagulant was present in 8.3% of patients; factor V Leiden mutation was detected in 3% of patients; thermolabile variant of MTHFR C677T polymorphism was present in 14.9% of patients with 1.2% homozygotes. Prothrombin G20210A polymorphism was not detected in any sample in this population. One hundred and four patients of 432 (24.9%) had recurrent attacks of thrombosis without any proximate precipitating cause, whereas 7.5 % of the patients had another close member of the family with a history of deep venous thrombosis. Eighty-six members from 28 families (out of 32 families giving family history of thrombosis) were investigated and found to have protein C and protein S deficiency in seven each; factor V Leiden was present in 6, and MTHFR C677T polymorphism was present in 5 cases. Hence, 25 of 86 members (28%) from the family of patients with familial history deep venous thrombosis had positive markers for thrombophilia. Thus, we could show that in young patients presenting with thrombosis, at least 34% of them had a demonstrable cause for thrombophilia. Prothrombin gene polymorphism G20210A seems to be nonexistent in our population and AT III deficiency also appears to be low compared to other markers of thrombophilia. There is a high prevalence of variant MTHFR C677T in our series, but the incidence of MTHFR C677T in our general population is also high. Hence, the significance of this finding in our cases of deep venous thrombosis remains to be seen, but we did not see any homozygotes when we tested 70 randomly selected asymptomatic persons, whereas in the present series, 1.8% of the patients had homozygosity for the MTHFR C677T polymorphism.
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PMID:Venous thromboembolism in young patients from western India: a study. 1129 95

We encountered 16 cases of venous thromboembolism (VTE) in women during pregnancy and/or puerperium over the past 15 years at our perinatal center, representing 0.14% of all patients who delivered babies. The present study was undertaken to analyze the risk factors, clinical course and outcomes in these 16 cases. The ages of the patients varied from 29 to 39 years. Four women had pulmonary embolism (PE), 3 of which after caesarean section (C/S) at 35 to 40 weeks, and one case after ovarian cystectomy at 13 weeks of gestation. Twelve cases had deep venous thrombosis (DVT), 4 of which during pregnancy, and the remaining 8 cases after C/S. Four patients who had DVT during a normal course of pregnancy had severe thrombophilia: antiphospholipid antibody syndrome, a history of thrombosis and antithrombin (AT) deficiency. They were treated with heparin with or without AT and had healthy babies via successful vaginal deliveries. The common risk factors in 3 cases of PE with C/S was prolonged bed rest due to threatened premature delivery with total placenta previa, uterine myoma and Ehlers-Danlos syndrome. Other risk factors were massive bleeding, and positive lupus anticoagulant. However, the case of the ovarian cystectomy had only one risk factor, which was obesity. This patient died but the remaining patients recovered with treatment. Because of the low incidence of thrombosis in the Japanese population, prophylactic anticoagulant therapy has not routinely been given to patients undergoing obstetrical operations. However, proper management including prophylactic anticoagulant therapy might be considered for risk patients, depending on the risk factors.
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PMID:Clinical study of venous thromboembolism during pregnancy and puerperium. 1137 69

In 70% to 80% of patients with venous thromboembolism, a thrombophilic defect can be identified. The most important defects are: antibodies to phospholipids or lupus anticoagulants, mutation of factor V Leiden, prothrombin mutation, mild hyperhomocysteinaemia, and increased factor VIII levels. Deficiencies of antithrombin, protein C or protein S are rare. Whether or not screening for thrombophilia in patients with idiopathic venous thromboembolism is justified, depends on the potential benefits for the patients, or their relatives. At present, patients with a thrombophilic defect do not appear to have a much higher risk for recurrent venous thromboembolism, than patients with thrombosis but without a defect. The absolute risks of venous thromboembolism in asymptomatic relatives with a thrombophilic defect are too low to justify initiating a general policy of family screening. In conclusion, a conservative approach towards thrombophilia screening in idiopathic venous thromboembolism is warranted.
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PMID:[No indication for thrombophilia screening in patients with idiopathic venous thromboembolism and their relatives]. 1141 64

A subgroup of children with arterial ischemic stroke in the pre- or perinatal period present with delayed diagnosis. We identified 22 children who met the following criteria: (1) normal neonatal neurological history, (2) hemiparesis and/or seizures first recognized after two months of age, and (3) computed tomography or magnetic resonance imaging showing remote cerebral infarct. Laboratory evaluations included protein C, protein S, antithrombin, activated protein C resistance screen (APCR), Factor V Leiden (FVL), prothrombin gene defect, methylene tetrahydrofolate reductase variant (MTHFR), anticardiolipin antibody (ACLA), and lupus anticoagulant. Not all children received all tests. Age at last visit ranged from 8 months to 16.5 years (median 4 years). Twelve were boys. Fourteen had left hemisphere infarcts. Median age at presentation was 6 months. Eighteen had gestational complications. Fourteen children had at least transient coagulation abnormalities (ACLA = 11, ACLA + APCR = 1, APCR = 2 with FVL + MTHFR = 1); six of these children had family histories suggestive of thrombosis. Cardiac echocardiogram was unremarkable in the 15 tested. Outcomes included persistent hemiparesis in 22; speech, behavior, or learning problems in 12; and persistent seizures in five, with no evidence of further stroke in any patient. The persistence and importance of coagulation abnormalities in this group need further study.
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PMID:Presumed pre- or perinatal arterial ischemic stroke: risk factors and outcomes. 1150 98

Until recently, laboratory diagnosis of thrombophilia was based on investigation of the plasmatic anticoagulant pathways to detect antithrombin, protein C, and protein S deficiencies and on the search for dysfibrinogenemia and anti-phospholipid antibodies/lupus anticoagulants. More recently, laboratory investigations have been expanded to include activated protein C (APC) resistance, attributable or not to the presence of the factor V Leiden mutation; hyperprothrombinemia attributable to the presence of the prothrombin gene mutation G20210A; and hyperhomocysteinemia attributable to impairment of the relevant metabolic pathway because of enzymatic and/or vitamin deficiencies. All of the above are established congenital or acquired conditions associated with an increased risk of venous and, more rarely, arterial thrombosis. Testing is recommended for patients who have a history of venous thrombosis and should be extended to their first-degree family members. Because most of the tests are not reliable during anticoagulation, it is preferable to postpone laboratory testing until after discontinuation of treatment. Whenever possible, testing should be performed by means of functional assays. DNA analysis is required for the prothrombin gene mutation G20210A. Laboratory diagnosis for anti-phospholipid antibodies/lupus anticoagulant should be performed by a combination of tests, including phospholipid-dependent clotting assays and solid-phase anti-cardiolipin antibodies. Hyperhomocysteinemia can be diagnosed by HPLC methods or by fluorescence polarization immunoassays.
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PMID:Laboratory investigation of thrombophilia. 1151 92


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