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)

By virtue of a severely prolonged aPTT with a normal thromboplastin time (prothrombin time) and a normal thrombin time, severe FXII deficiency has been diagnosed in a woman without a bleeding diathesis or a history of thromboembolic complications. A deficiency of a factor of the contact activation system (FXII, prekallikrein, high molecular weight kininogen) is usually diagnosed during routine coagulation tests demonstrating a prolonged aPTT. The severe and partial deficiency of FXII, of prekallikrein or high molecular weight kininogen is not associated with a bleeding tendency. In contrast, severely factor XI deficient subjects may suffer from a mild hemorrhagic diathesis, whereas FVIII deficiency (hemophilia A, autoimmune "hemophilia", von Willebrand disease) and FIX deficiency (hemophilia B) are associated with a bleeding tendency of varying severity, depending on the clotting activity of FVIII or FIX, respectively. An isolated prolongation of the aPTT due to a lupus anticoagulant, however, is frequently associated with arterial and/or venous thrombosis. Therefore, in case of a prolongation of the aPTT, its cause has to be determined.
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PMID:[A patient with isolated prolongation of aPTT without hemorrhagic diathesis anamnesis: severe, hereditary factor XII deficiency]. 1051 21

Lupus anticoagulants (LA) are a family of autoantibodies that are associated with in vitro anticoagulant activity but a strong predisposition to in vivo thrombosis. They are directed against plasma phospholipid binding proteins, including prothrombin. We found that a murine monoclonal antiprothrombin antibody and 7 of 7 LA IgGs tested enhanced binding of prothrombin to 25:75 phosphatidyl serine:phosphatidyl choline vesicles in a concentration-dependent manner. We hypothesized that enhanced binding of prothrombin to phospholipid in the presence of LA IgG might result in increased thrombin production when reactions are performed in flow. Thrombin production by purified prothrombinase components was measured in a phospholipid-coated flow reactor. The flow reactor was incubated with prothrombin, calcium ions, and the IgGs and then perfused with prothrombin, calcium ions, the IgGs, factor Va, and factor Xa. A murine monoclonal antiprothrombin antibody and 4 of 6 LA IgGs from patients with a history of thrombosis increased thrombin production up to 100% over control in the first 15 minutes. In summary, LA IgGs concentrate prothrombin on a phospholipid surface that can augment thrombin production by prothrombinase in flow. These observations suggest that LA might propagate coagulation in flowing blood by facilitating prothrombin interaction with the damaged blood vessel wall.
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PMID:Lupus anticoagulants form immune complexes with prothrombin and phospholipid that can augment thrombin production in flow. 1055 52

Systemic lupus erythematosus (SLE) is a systemic autoimmune disorder with overwhelming thrombotic states. The precise pathogenetic mechanisms underlying the prethrombotic state in SLE is not fully understood, but interactions between the antiphospholipid antibodies and antigen targets on the coagulation components have been incriminated to play fundamental roles. To evaluate this issue, 34 women with antiphospholipid antibody negative SLE were investigated for molecular markers of blood coagulation and fibrinolytic activity: prothrombin fragment1+2 (PF1+2), thrombin-antithrombin complex (TAT), plasmin-alpha2-antiplasmin inhibitor complex (PAP), and tissue factor pathway inhibitor (TFPI). We also analysed plasma soluble thrombomodulin (sTM) levels. SLE disease activity was determined using the SLE Disease Activity Index (SLEDAI). Concentrations of TAT, PAP, PF1+2 and sTM were significantly elevated (P<0.0001, P=0.0002, P<0.0001, and P<0.0001, respectively), while TFPI antigen levels were found to be reduced (P<0.0001) in patients with SLE compared to the control group. In patients with active SLE, anti-ds DNA levels were correlated positively with plasma TAT (P<0.05), PF1+2 (P<0.05), and sTM (P<0.01) concentrations and negatively with plasma TFPI levels (P<0.05). SLEDAI scores were correlated positively with plasma TAT (P<0.01), PF1+2 (<0.01), and sTM (P<0.01) levels. This study illustrates that both a prethrombotic state and a compensatory fibrinolytic process secondary to subclinical intravascular coagulation might coexist in SLE with elevated sTM levels, indicating impaired endothelial functions.
Lupus 1999
PMID:Clinical significance of hemostatic markers and thrombomodulin in systemic lupus erythematosus: evidence for a prothrombotic state. 1060 46

Autoantibodies against prothrombin, including lupus anticoagulant antibodies (LAC), have been identified in patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). To identify the epitopes of LAC in patients with SLE and APS, we analyzed B cell epitopes of anti-prothrombin Abs. Prothrombin was purified from fresh plasma samples from healthy subjects, and fragmented by thrombin. Two fragments (prethrombin-1, 50 kDa, and fragment-1, 22 kDa) were separated and used for further experiments. The two fragments were coated on irradiated plate and the binding activities of sera from 13 patients with anti-prothrombin Abs (SLE, 7; APS, 4; SLE+APS, 2) were determined by using ELISA. The assay was conducted under the following conditions: use of irradiated plates, and TBS containing Tween-20. We detected two types of anti-prothrombin Abs. The first was anti-prethrombin-1 (n=5) while the other was Ab against fragment-1 (n=8). There were no patients with Abs that showed binding activities to both fragments. A higher proportion of patients with thrombosis were positive for anti-prethrombin-1 Abs (80%) than for anti-fragment-1 Abs (25%). Two patients with anti-prethrombin-1 Ab were positive for LAC and negative for anti-cardiolipin-beta2 glycoprotein I antibody (aCL-beta2GPI). Our results strongly support the notion that both prethrombin-1 and fragment-1 on prothrombin molecule are B cell epitopes.
Lupus 1999
PMID:Relationship between clinical features and binding domains of anti-prothrombin autoantibodies in patients with systemic lupus erythematosus and antiphospholipid syndrome. 1060 50

A 26-year-old female presented with an episode of severe mucus membrane bleeding. Investigations revealed prolonged prothrombin time (PT), and partial thromboplastin time (PTT), normal thrombin time (TT) and reptilase time, thrombocytopenia, a positive test for lupus anticoagulant (LA), as well as anti-cardiolipin antibodies (ACL). A toxicology screen for toxic drugs and coumadin was negative. Coagulation factor assays revealed low levels for factor II and XII. Low level inhibitor to factor II was demonstrated. Patient had a negative VDRL test and positive anti-nuclear antibodies (ANA). The diagnosis of acquired hypoprothrombinaemia secondary to circulating inhibitor induced by LA was made, and then the patient was started on prednisone, which led to cessation of the bleeding and normalization of PT and PTT, as well as an increase of factor II and factor XII levels. A few months later, the patient developed arthralgia and alopecia, and antibodies against double-stranded DNA were detected, and the diagnosis of systemic lupus erythematosis (SLE) was confirmed. The patient continued to have mild prolongation of PT and PTT while on a low dose of prednisone, but she had no bleeding symptoms. A computed tomography scan of the brain was carried out for unexplained central nervous system (CNS) symptoms, and it revealed mild hydrocephalus, which was thought to be part of the CNS manifestations of SLE. It was concluded that patients with SLE may present with haemostatic defects that are a result of either platelet-related causes (quantitative or qualitative) or coagulation factor deficiency secondary to circulating inhibitor, or both, in the absence of other features of SLE which may appear later.
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PMID:Systemic lupus erythematosus presenting with haemorrhagic manifestation. 1067 97

We reported an autopsy case of cerebral infarction with primary lung cancer. The patient was a 50-year-old man. Despite having been treated with warfarin potassium and ticlopidine hydrochloride, he relapsed cerebral infarction. His laboratory data on admission showed that lupus anticoagulant was positive, together with a high value of beta-thromboglobulin, thrombin-antithrombin III complex, markers of platelet and coagulation activation, CEA and CA 19-9. The autopsy finding revealed a primary papillary adenocarcinoma in the right lower lung, multiple cerebral infarction, renal infarction, pulmonary infarction and splenic infarction. The atherosclerotic changes were mild in the whole tissues and findings of vasculitis were not observed. Recurrence of cerebral infarction was effectively suppressed with the addition of steroid therapy to antithrombotic therapy. This case was considered as catastrophic antiphospholipid syndrome. It is necessary to differentiate antiphospholipid syndrome in case of the abnormal coagulation and fibrinolytic factors with recurrent cerebral infarction. Moreover, systemic examinations are important, because malignant tumor may exist on the background of the case.
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PMID:[An autopsy case of catastrophic antiphospholipid syndrome presenting with recurrent multiple cerebral infarction associated with lung cancer]. 1068 94

The clinically relevant antiphospholipid antibodies (APA) include anticardiolipin antibodies and lupus anticoagulant. Most autoimmune APA require the presence of a cofactor for phospholipid binding, and the growing list of candidate cofactors has prompted redefinition of APA to 'antiphospholipid protein antibodies'. Current evidence favours beta2-glycoprotein I (beta2GPI) and prothrombin as the primary antigens for anticardiolipin antibodies and lupus anticoagulant respectively. Patients with APA show a predisposition for venous and arterial thromboembolism, recurrent fetal loss, thrombocytopenia and a number of neurological syndromes and miscellaneous conditions. The association between APA and thrombosis has been well documented, but a definite mechanism remains to be clarified. Proposed mechanisms have included disruption of endothelial regulatory processes, impairment of fibrinolysis, augmented platelet activation and/or adhesion, inhibition of antithrombin activity and negation of the anticoagulant effects of beta2GPI and annexin V. In this review we describe recent insights into the role of beta2GPI as a natural anticoagulant, the procoagulant effects of APA on the Protein C system, the interactions between APA and prothrombin resulting in augmentation of thrombin generation, and cellular expression of Tissue Factor in patients with APA. Cellular immunity to beta2GPI is also discussed. Elucidation of these pathophysiological mechanisms may shed further light on the association between APA and thrombosis.
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PMID:Recent insights into antiphospholipid antibody-mediated thrombosis. 1085 78

The clinical manifestations of the antiphospholipid syndrome(APS) include arterial and venous thrombosis and a fetal loss, but the pathogenic mechanisms remain unclear. To clarify the mechanism of thrombogenic state in APS, we investigated the markers for thrombosis including thrombin-antithrombin complex(TAT) in patients with antiphospholipid antibodies(aPL). Prothrombin fragment 1 + 2(F1 + 2) in patients with APS and in autoimmune disease patients with aPL increased significantly compared with those obtained in autoimmune disease patients without aPL or in control subjects. However, there was not a significant difference in the TAT level of each group, suggesting that the formation of TAT was impeded in APS. To investigate which aPL is responsible for the disturbance of the TAT formation, the ratio of F1 + 2/TAT was calculated. The ratio increased in patients with lupus anticoagulant, especially with prolonged kaolin clotting time, and furthermore the ratio strongly increased in patients with IgG type-anticardiolipin antibodies(aCL). Our results suggest that IgG-aCL is associated with thrombogenic state in APS because free thrombin is present in patients' blood by impeding the formation of TAT by mainly IgG-aCL.
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PMID:[Evaluation of F1 + 2/TAT ratios in Japanese patients with antiphospholipid syndrome]. 1089 73

The diagnosis of inhibitors of blood coagulation is often the most challenging problem in the clinical laboratory. Immediate attention must be given to the following patient groups whose principal laboratory abnormality is the prolonged activated partial thromboplastin time (aPTT): the patient with (1) hemophilia who previously responded to an adequate dose of clotting factor product and now fails to show effective clinical response to the same replacement concentrate; (2) previously benign clinical history who now presents with soft tissue bleeding or emergent internal hemorrhaging; (3) sudden onset of generalized ecchymoses who was previously well; (4) postpartum state; (5) malignancy, lymphoma, rheumatoid arthritis, or other autoimmune disorders; and (6) drug reactions. Immediate attention must be given to the prolonged prothrombin time (PT), aPTT, and thrombin time (TT) in order to respond to urgent queries from a perplexed internist, hematologist, intensivist, or surgeon caring for a patient with unexpected bleeding. Sometimes the problem of a prolonged "clotting time" arises preoperatively, causing unanticipated delay in operative procedures. For this reason, the laboratory support, usually in the coagulation section of a clinical laboratory or reference laboratory, must be quick, unequivocal and precise. The most common finding is an isolated mild, moderate, or severe prolongation of the aPTT with a normal PT, TT, and platelet count. The aPTT mixing study (The Mix), usually modified for time and temperature, along with appropriate controls, is the seminal test. This is the basis for all further testing. It may be supported by direct factor assays, and, therefore, the laboratory must know the reagent responsiveness and sensitivity for each clotting factor. By definition, complete correction of the aPTT in a 1:1 mix of patient and reference plasma is a factor deficiency. In this article, incomplete or minimal correction of The Mix will be characterized with particular attention to the various inhibitor assays, in other words, Oxford, Bethesda, and Nijmegen assays and the enzyme-linked immunosorbent assay (ELISA). An investigative approach to final characterization of the intensity (quantification) of the inhibitor and the exclusion of a lupus anticoagulant (LA) will be discussed.
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PMID:Factor VIII inhibitors. Laboratory diagnosis of inhibitors. 1091 13

Fibrinogen Matsumoto V (M-V) is a dysfibrinogen identified in a 52-year-old woman with systemic lupus erythematous. The triplet AGG encoding the amino acid residue Aalpha19 was replaced by GGG, resulting in the substitution of Arg-->Gly. Residue Aalpha19 has been shown to be one of the most important amino acids in the so-called 'A' site or alpha-chain knob. The thrombin-catalyzed release of fibrinopeptide A from M-V fibrinogen was only slightly delayed yet release of fibrinopeptide B was significantly delayed. Both thrombin-catalyzed fibrin polymerization and fibrin monomer polymerization were markedly impaired compared to normal fibrinogen. In addition, reptilase-catalyzed fibrin polymerization of M-V was much more impaired than thrombin-catalyzed fibrin polymerization. These results indicate 'B' and/or 'b' site of M-V fibrinogen play a more important role in thrombin-catalyzed fibrin polymerization than that of normal control fibrinogen.
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PMID:Fibrinogen Matsumoto V: a variant with Aalpha19 Arg-->Gly (AGG-->GGG). Comparison between fibrin polymerization stimulated by thrombin or reptilase and fibrin monomer polymerization. 1120 60


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