Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0409974 (lupus)
 22,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antiphospholipid antibodies are a diverse group of immunoglobulins initially thought to have specificity to phospholipid epitopes. It is apparent that autoimmune anticardiolipin antibodies require a serum cofactor beta-2-glycoprotein I (beta 2GPI) for their binding to phospholipids. Lupus anticoagulant also may bind to phospholipids by beta 2GPI or by prothrombin. The description of binding to protein-phospholipid epitopes may explain several perplexing features of these antibodies both in vitro and in vivo. Antiphospholipid antibodies have a well-established association with clinical disease--in particular thrombosis, thrombocytopenia and recurrent fetal loss. The mechanism of the predisposition to thrombosis seen with these antibodies is poorly understood. It has been suggested that they may cause endothelial dysfunction by causing increased tissue factor expression, by inhibiting prostacyclin secretion or by inhibiting fibrinolysis. Various platelet-activating activities have also been described. The evidence that antiphospholipid antibodies promote thrombosis by effects on endothelium or platelets is inconclusive. Inhibition of protein C activation, or of activated protein C action, has been demonstrated in vitro. A poor correlation between thrombosis in vivo and these inhibitory effects has been found. Beta-2-glycoprotein I has been identified as a cofactor for binding to phospholipid by thrombogenic anticardiolipin antibodies. That beta 2GPI may be a natural anticoagulant of importance remains to be proved. Inhibition by antiphospholipid antibodies of this anticoagulant function could explain the propensity to thrombosis seen in association with these antibodies.
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PMID:Antiphospholipid antibodies and thrombosis. 784

Resistance to activated protein C (RAPC) has been described recently as a cause of trombophilia; this may justify up to 50% of thromboembolic disease without predisposing cause in patients under 45 years. A 29 years-old male with a previous deep venous thrombosis (DVT) in the lower left limb three years earlier, developed a DVT in the right lower limb after a trauma of the knee that required immobilization, was associated to pulmonary thromboembolism diagnosed by gammagraphic methods. The phlebographic study showed femoro-iliaco-caval venous thrombosis. The proband's father and a younger brother had a previous history of thrombotic episodes. The following tests, were performed in the proband and relatives: prothrombin time, aPTT, thrombin time, fibrinogen, (Von Clauss), antithrombin III (chromogenic), protein C and protein S (coagulometry and ELISA), plasminogen (chromogenic) and lupus anticoagulant (ITT, dRVVT, aCL). RAPC was evaluated in two different samples. The proband study was performed under oral anticoagulation treatment (OAT). Control groups were: 21 blood donors and 12 OAT patients. The results showed a decreased response to APC in the proband (ratio 1.5) and relatives: father (1.4), brothers (1.5 and 1.5), while the mother was within the normal range (> or = 2). In normal controls and OAT patients the ratio was over 2. No other abnormalities were detected in the assays performed. It is concluded that RAPC is the cause of this familial trombophilia. RAPC should be included in the evaluation study of trombophilia.
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PMID:[Familial thrombophilia due to resistance to activated protein C]. 798 58

The authors define pro-thrombotic states as conditions associated with a high frequency of thrombosis; this association is based on pathogenetic or simply clinical and epidemiological relationships. Thrombophilic states have well-defined, specific causes: antithrombin III, protein C and S and similar deficiencies for inherited thrombophilias, and lupus anticoagulant, antiphospholipid antibodies for the acquired forms. Another identifiable group is made up of several conditions predisposing to thrombosis (CPT) characterized by less specific and multiple mechanisms (e.g. malignancy, inflammatory bowel disease, nephrotic syndrome, diabetes, obesity, etc.). These conditions may induce thrombosis by themselves or contribute to its clinical onset in patients with true thrombophilic states. This is especially the case for patients who are taking contraceptive drugs, are pregnant, have undergone surgery or trauma. The term hypercoagulability states is by no means equivalent to either thrombophilia or CPT. In fact, hypercoagulability may be defined as "activation of blood coagulation" in the presence of specific markers such as fibrinopeptide A and prothrombin fragment F1 + 2. Hypercoagulability is therefore a laboratory rather than a clinical condition and can be a transient feature appearing during certain phases of thrombophilia or CPT. Lastly, conditions involving the presence of hemostatic risk factors for atherothrombosis are simply terms used to describe a statistical-epidemiological relationship between certain hemostatic variables (fibrinogen, factor VII, PAI, etc.) involving the risk of cardiovascular morbidity and mortality but not necessarily indicating a hypercoagulability state.
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PMID:Pro-thrombotic states and their diagnosis. 800 87

The intraglomerular presence of thrombomodulin (TM) was examined in 19 patients with lupus glomerulonephritis (GN). TM is a cell surface glycoprotein found on endothelial cells and plays a key role in the protein C anticoagulant pathway. Renal biopsy specimens of patients with lupus GN and several kinds of renal disease other than lupus GN, i.e., membranous GN, IgA GN, minimal change nephrotic syndrome (MCNS) and hemolytic uremic syndrome (HUS) were examined by indirect immunofluorescence, using three kinds of monoclonal antibodies against human TM: KA-2, KA-3 and KA-4. It has been reported that KA-3 and KA-4 bind to enzyme-digested TM as well as intact TM, while KA-2 recognizes intact TM only. In the glomeruli from both normal subjects and patients with MCNS, only very weak staining of TM was found. Patients with HUS showed negative TM staining in the glomeruli. In contrast, positive to strongly positive staining of KA-2 as well as of KA-3 and KA-4 was observed mainly along the capillary wall of glomeruli from patients with lupus GN. Some patients with non-lupus GN showed positive staining of these monoclonal antibodies, but the staining was far more intense in most patients with lupus GN than in the patients with non-lupus GN. Staining of albumin and transferrin by the indirect method was negative in all cases of lupus GN that showed positive staining of TM. There was no relationship between the intensity of TM staining and the degree of proteinuria, creatinine clearance or histologic types of lupus GN.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Enhanced presence of thrombomodulin in the glomeruli of lupus glomerulonephritis. 802 12

Hypercoagulable states are found in up to 10 per cent of patients with a history of unexplained venous thrombosis. To investigate the prevalence in arterial thrombosis, thrombophilia screening was performed on 124 patients who had previously undergone lower-limb revascularization, 45 claudicants and 27 controls. Of the patients who had undergone revascularization 40 per cent had a hypercoagulation abnormality (low levels of protein C, protein S and antithrombin III or presence of the lupus anticoagulant) in comparison with 27 per cent of claudicants and 11 per cent of controls (P < 0.01). Furthermore, patients who had suffered reocclusion after revascularization were significantly more likely to have a hypercoagulation abnormality than those who had not (P < 0.05), even if the occlusion had occurred more than 6 months previously. Lupus anticoagulant was the abnormality most frequently detected and, like low protein C levels, was found only in patients with peripheral vascular disease. It appears that hypercoagulable states are common in patients with arterial disease and may predispose to failure of revascularization.
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PMID:Hypercoagulable states in patients with leg ischaemia. 804 89

Venous thromboembolism is rare in Chinese. To determine the incidence and disease profile of thrombophilia in Chinese patients with thrombosis, 52 unselected Chinese patients with documented venous thrombosis were studied for the presence of thrombophilia. Levels of antithrombin III (AT III), protein C (PC) and protein S (PS) as well as the presence of acquired lupus anticoagulant (LA) and anticardiolipin antibody (ACA) were investigated. Thirty patients were found to be abnormal. These consisted of 5 AT III deficiencies, 9 PC deficiencies, 10 PS deficiencies, 1 combined PC & PS deficiency (all in the heterozygous range), and 5 patients with LA and/or ACA. When the patients with LA and/or ACA are excluded, the incidence of hereditary thrombophilia is 25/47 i.e. 53.2% which is much higher than those reported in studies of Caucasian patients selected under strict criteria. Family studies performed in 16 cases of hereditary thrombophilia revealed involvement in 11 cases (68.7%); a total of 36 heterozygous family members were affected, most of which remain asymptomatic. Although 35 events predisposing to thrombosis (27 pregnancies, 1 oral contraceptive consumption and 7 surgical operations) were identified among these index patients, and the heterozygous family members, thrombosis was observed on only 6 occasions (17.1%). The data suggest that pregnancy and surgery do not carry the same degree of thrombotic risk in Chinese as in the Caucasian population with heterozygous AT III, PC and PS deficiency.
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PMID:High incidence of thrombophilia detected in Chinese patients with venous thrombosis. 805 55

Activated protein C (APC)-protein C inhibitor (PCI) complex and APC-alpha 1antitrypsin (alpha 1AT) complex levels were measured in 29 patients positive for lupus anticoagulant (LA). LA was considered positive if two of the following three criteria were fulfilled: (1) prolongation of the activated partial thromboplastin time, (2) prolongation of the kaolin clotting time (KCT) and KCT mixing test, and (3) prolongation of the dilute Russell's viper venom time (DRVVT) and DRVVT/DRVVT with high lipid concentration. Plasma thrombin-antithrombin III (AT-III) complex and plasmin-alpha 2-antiplasmin inhibitor complex levels in patients positive for LA were increased slightly, but not significantly, and FDP-D-dimer and t-PA levels were not markedly increased. Plasma PAI-1 level in the LA-positive patients was significantly increased compared with normal volunteers. AT-III activity, protein C antigen, PCI antigen, and protein S antigen levels in the LA-positive patients were virtually normal, while protein C activity was slightly, but not significantly, decreased. APC-PCI complex level was increased in all LA-positive patients, and was not detectable in patients with systemic lupus erythematosus and normal volunteers. APC-alpha 1AT complex was increased slightly, in only two LA-positive patients; it was not detectable in the other patients or in the normal volunteers. These findings suggest that patients positive for LA are in a hypercoagulable state and that protein C activity in such patients is decreased, due to the activation of this protein.
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PMID:Increased activated protein C-protein C inhibitor complex level in patients positive for lupus anticoagulant. 805 49

This review has stressed the common hereditary and acquired blood protein defects associated with thrombosis. The most common of the hereditary defects appear to be antithrombin, protein C, and protein S deficiency and the most common acquired defects are anticardiolipin antibodies and the lupus anticoagulant. Therefore these are the defects that should first be looked for in an individual with unexplained thrombosis. If these more common defects are not found, then the rarer defects, including heparin cofactor II, plasminogen or tissue plasminogen activator deficiency, dysfibrinogenemia, or elevated PAI-1 should next be sought. The importance of finding these defects has significant implications for therapy of the individual patient and for institution of family studies to identify, inform, and possibly treat others at risk. It is expected that as knowledge of hemostasis expands, more hereditary and acquired defects, such as elevated lipoprotein(a) or defects of extrinsic (tissue factor) pathway inhibitor may be associated with enhanced risks of thrombosis.
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PMID:Syndromes of hypercoagulability and thrombosis: a review. 805 29

Snake venoms contain a rich variety of factors affecting the haemostatic mechanism which can be broadly classified as possessing coagulatant, anticoagulant and haemorrhagic activity. Coagulant enzymes include activators of blood coagulation factors II (prothrombin), V and X; anticoagulants include protein C activators, inhibitors of prothrombin complex formation and fibrinogenases which can be further classified according to their specificity for the alpha-, beta- and gamma-chains of fibrinogen. Intermediate between true coagulants and true anticoagulants are the thrombin-like enzymes which bring about clotting in vitro but defibrination (anticoagulation) in vivo. Snake venoms also affect platelets either by inducing or inhibiting platelet aggregation and cause haemorrhage via an action on platelets or via proteolysis of the blood vessel wall. Haemorrhagins also include inter alia, the alpha-fibrinogenases. This rich diversity of snake venom components affecting haemostasis has enabled a range of practical applications to be established including therapeutic anticogulation with thrombin-like enzymes (Ancrod and Defibrase) and laboratory tests for individual haemostatic factors (protein C, prothrombin, factor X and lupus anticoagulant). This broad spectrum of materials in snake venoms suggests some evolutionary advantage to the venom producer, not only for dispatching prey but as agents which 'spread' the venom toxins throughout the body and initiate digestion.
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PMID:Snake venoms affecting the haemostatic mechanism--a consideration of their mechanisms, practical applications and biological significance. 807 11

This article has stressed the common hereditary and acquired blood protein defects associated with thrombosis. The commonest hereditary defects appear to be antithrombin, protein C, and protein S deficiency, and the commonest acquired defects are anticardiolipin antibodies and the lupus anticoagulant. Therefore these are the defects that should first be looked for in an individual with unexplained thrombosis. If these commoner defects are not found, the rarer defects, including HC-II, plasminogen or t-PA deficiency, dysfibrinogenemia, or elevated PAI-1, should next be sought. The incidence of activated protein C cofactor deficiency is not yet clear but may also represent a common defect. Likewise, PAI-1 defects may, with time, be shown to be quite common. The importance of finding these defects has significant implications for therapy of the individual patient and for institution of family studies to identify, inform, and possibly treat others at risk. It is expected that as knowledge of hemostasis expands, more hereditary and acquired defects, such as elevated lipoprotein (a) or defects of extrinsic (tissue factor) pathway inhibitor may be associated with enhanced risks of thrombosis.
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PMID:Hypercoagulability and thrombosis. 817 Feb 63


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