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)

To evaluate the usefulness of preoperative screening for coagulation disorders in children, we prospectively studied laboratory and bleeding histories in 1603 children undergoing tonsillectomy. All patients had preoperative laboratory screening with a complete blood count, prothrombin time, activated partial thromboplastin time, and bleeding time. Persistent abnormalities on repeat testing 1 week later were investigated further by a standardized schema. A subset of 129 patients, including all those who bled perioperatively or had laboratory abnormalities, completed a standard historical questionnaire. Thirteen patients had persistent laboratory abnormalities diagnostic of lupus inhibitor (5), non-lupus inhibitor (6), mild hemophilia A (1), and vonWillebrand disease (1). Two patients had persistently prolonged activated partial thromboplastin times of undefined cause. Fourteen patients (10.8%) interviewed reported positive bleeding histories. Of these, five, including the patient with vonWillebrand disease, had persistent laboratory abnormalities. History alone failed to detect the patient with hemophilia A. For patients with inhibitors or prolonged activated partial thromboplastin times of unknown cause, surgery was delayed until the coagulation abnormalities resolved, and there was no perioperative bleeding. The patient with vonWillebrand disease had severe postoperative bleeding despite treatment with cryoprecipitate. In predicting perioperative bleeding, history and laboratory screening had a high specificity but a very low positive predictive value due to poor sensitivity and a low prevalence of bleeding. Some children with bleeding disorders may be identified first during routine preoperative coagulation testing, and replacement therapy or delay or cancellation of surgery may reduce or prevent perioperative hemorrhage. However, the large number of false positive laboratory tests and bleeding histories, coupled with the relative rarity of inherited and acquired coagulopathies, raises doubts about the overall value of routine screening.
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PMID:Preoperative history and coagulation screening in children undergoing tonsillectomy. 851 74

Lupus anticoagulants (LAs) are immunoglobulins (IgG, IgM, or both) which interfere with in vitro phospholipid (PL) dependent tests of coagulation (e. g. APTT, dilute PT, dilute Russell Viper Venom Time). These antibodies may be identified in a wide variety of clinical settings. With the exception of heparinized patient samples, the presence of LAs is often the most common cause of an unexplained APTT in a routine clinical laboratory. The diagnosis of LAs is difficult due to variable screening reagent sensitivity and intrinsic heterogeneity of LAs. Recently, Rauch and colleagues have shown human monoclonal hybridoma LAs were inhibited by hexagonal (II) phase PLs. In contrast, lamellar phase PLs had no effect. We have evaluated a new assay system, Staclot LA, which utilizes a hexagonal (II) phase PL (egg phosphatidylethanolamine [EPE]) as a confirmatory test for LAs. Plasma samples from the following patient populations were studied: LA positive, heparinized, oral anticoagulated, hemophilia A and B, and specific factor inhibitors (factors V, VIII, IX). Unlike previous studies, the LA positive patients were a mixed population including: autoimmune diseases, drug-induced, and post-infection. Our findings confirm the specificity of hexagonal (II) phase PL neutralization of LAs.
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PMID:A hexagonal (II) phase phospholipid neutralization assay for lupus anticoagulant identification. 812 36

Lupus anticoagulants (LA) are immunoglobulins (IgG, IgM, IgA or a mixture) which interfere with in vitro phospholipid (PL) dependent tests of coagulation (e.g. APTT, KCT, dilute Russell Viper Venom Time). LA are heterogeneous; consequently, the laboratory diagnosis is difficult and relies on multiple tests. We have developed a sensitive and relatively specific confirmatory test system based on fractions of two snake venoms. Textarin, a protein fraction of Pseudonaja textilis venom (Australian Eastern brown snake), activates prothrombin in the presence of PL, factor V and calcium ions. Ecarin, a protein fraction of Echis carinatus venom, will activate prothrombin in the absence of any cofactors. The activation of prothrombin by Textarin yields thrombin while Ecarin yields meizothrombin. In the presence of LA, the Textarin time is prolonged and the Ecarin time is unaffected. The test results are reported as a ratio of Textarin/Ecarin times (abnormal greater than 1.3). We have evaluated this test system in the following patient populations: LA positive, therapeutically heparinized, stable oral anticoagulated, liver disease, routine preoperative, anticardiolipin antibody positive LA negative, hemophilia A, various other hereditary factor deficiencies or dysfunctional proteins, and specific inhibitors of factor V and factor VIII. The LA positive patients represented a mixed population of autoimmune disease, drug-induced and post-infectious states. Our findings indicate the sensitivity of the Textarin/Ecarin system in the confirmation of LA. In order to use the test system most effectively, it is recommended to incorporate polybrene with Textarin when evaluating heparinized samples. Factor V deficiency and specific inhibitors of factor V yielded, in some instances, false positive results.
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PMID:The Textarin/Ecarin ratio: a confirmatory test for lupus anticoagulants. 816 13

We developed a simple ELISA for FIX inhibitors (FIXinh). The relationship between absorbance and various dilutions of plasma containing known FIXinh (28 Bethesda units/ml) was linear, ranging from 200 to 25,600-fold dilution on semi-log paper. Converted into the value of Bethesda Inhibitor Assay, ELISA can detect as low as 0.219 Bethesda units/ml. Absorbance for 30 normal individuals was 0.213 +/- 0.008, which corresponds to < 0.44 Bethesda units/ml. With ELISA, only the value for hemophilia B with FIXinh, which was revealed as positive by Bethesda Inhibitor Assay, was significantly higher than that of normal controls, hemophilia B without FIXinh, hemophilia A with FVIIIinh and systematic lupus erythematosus (SLE) with lupus anticoagulant (LA). The value in the patient with SLE, who had a high level of FVIIIinh (1000 Bethesda units/ml), was 3 Bethesda units/ml of FIXinh with Bethesda Inhibitor Assay, which was not significantly higher than that of normal subjects with ELISA. FIXinh in hemophilia B patients by ELISA for FIXinh was not affected by the presence of other anticoagulants.
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PMID:A simple method for detection of human factor IX inhibitor using ELISA. 945 90

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

Activated partial thromboplastin time may be prolonged as the result of either of two different autoimmune complications of chronic lymphocytic leukemia: the development of antiphospholipid antibodies, such as lupus anticoagulant or anticardiolipin antibodies, or anti-factor VIII inhibitors, such as acquired hemophilia A. In the rare simultaneous occurrence of both inhibitors, differential diagnosis of a prolonged activated partial thromboplastin time poses a number of problems during laboratory work-up, due to mutual interference of the commonly performed tests. Only careful clinical follow-up can disclose the significance of the laboratory findings. We report the case of concurrent antiphospholipid antibodies (lupus anticoagulant positivity, anticardiolipin antibodies; IgM 3880 MPL/mL and IgG 265 GPL/mL) and anti-factor VIII antibodies (46.8 Bethesda Units) in a patient with chronic B-cell lymphocytic leukemia who had prolonged activated partial thromboplastin time (78.8 s). The relationship between lymphoproliferative and antiphospholipid syndrome, laboratory work-up in the case of the association of antiphospholipid and anti-factor VIII antibodies, and related problems that occur during clinical management of the patient are also discussed.
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PMID:[The antiphospholipid syndrome during chronic lymphatic leukemia. An association with anti-factor VIII antibodies]. 1052 24

Lupus anticoagulants (LA) are associated with an increased risk of thrombosis and laboratory detection is of major importance. Multiple tests are available for screening and confirmation, but they differ in sensitivity and specificity, frequently lacking the ability to discriminate between the presence of LA, heparin, and oral anticoagulants. Based on the test-principle of the Lupus Ratio-test, an automated, sensitive APTT-based assay, using mixtures of a lupussensitive and a lupusinsensitive APTT-reagent with normal plasma for detection of lupus anticoagulants was developed. Ninety-nine healthy volunteers, ten patients treated with unfractionated heparin intravenously, 19 patients taking stable oral anticoagulation, five patients with hemophilia A, and 15 patients with antiphospholipid-antibody-syndrome (APS) were investigated. In all patients, two APTTs were performed, one with each reagent, on 1:1 mixtures of test plasma and normal plasma (MIXCON-LA assay). The ratio between the two clotting times was divided by the corresponding ratio for the normal plasma. This final lupus ratio (LR) was used for evaluation. The within-series imprecision and the between-series imprecision were excellent with coefficients of variation between 1.5% and 1.9%. The mean +/- 2 SD of the LR of the 99 healthy volunteers was used as reference range (LR: 0.95-1.07). All patients treated either with heparin or oral anticoagulants remained negative in the MLXCON-LA assay (specificity, 100%), while one of five patients with hemophilia A, in whom a factor VIII-inhibitor developed, showed a false-positive result. In 13 of 15 patients with APS, an increased ratio was observed (sensitivity, 87%). This assay system allows precise, specific, and sensitive detection of lupus anticoagulants.
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PMID:MIXCON-LA: a precise, sensitive and specific aPTT-based assay for detection of lupus anticoagulant. 1212 Oct 58

Acquired hemophilia A is a life-threatening immune-mediated hemorrhagic disorder that is most often found in individuals older than 50 who present with an unexplained activated partial thromboplastin time (aPTT) prolongation and clinically significant bleeding. The prolonged aPTT associated with acquired hemophilia A reflects factor VIII activity deficiency due to neutralizing or clearing autoantibodies. Deep venous thrombosis, in contrast, is a veno-occlusive disorder associated with several distinct hypercoagulable states that can result in significant morbidity and mortality due to pulmonary embolism, thrombus extension, and the post-thrombotic syndrome. A prolonged aPTT in the setting of thrombosis may reflect the presence of a lupus anticoagulant. In the absence of accurate diagnosis and the immediate institution of specific therapy, both disorders can be fatal. Three cases of acquired factor VIII inhibitors that included a prolonged aPTT, bleeding, and duplex ultrasound evidence of deep venous thrombosis are presented. The diagnostic and therapeutic challenges posed by these cases as well as a proposed mechanism by which pathologic thrombosis can develop in a patient with a life-threatening bleeding disorder are discussed.
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PMID:Simultaneous deep venous thrombosis and acquired factor VIII inhibitor. 1251 88

We report the results of external quality assessment exercises in which 60 to 120 centers performed factor VIII (FVIII) inhibitor testing on a series of samples over a 13-year period. Samples from seven different subjects were distributed for analysis comprising the following: four different subjects with severe hemophilia A with antibodies following replacement therapy, one subject with acquired hemophilia A and antibodies to FVIII, one subject with normal FVIII and an easily detected lupus anticoagulant, and one subject with mild hemophilia A and a difficult-to-detect lupus anticoagulant but without antibodies to FVIII. In all of the surveys the results obtained in different centers analyzing the same sample varied to an extent that would influence patient management decisions. In the UK National External Quality Assessment Scheme surveys reported here, there was considerable interlaboratory variation in the results of FVIII inhibitor testing that did not improve over the survey period. The coefficient of variation of results in different centers was between 33% and 106% in samples from patients with severe congenital hemophilia A. In some cases, results were affected by assay components. For one plasma, the mean FVIII inhibitor results in centers using one source of normal plasma was 3.9 Bethesda unit (BU)/mL compared with a mean of 5.7 BU/mL in centers using a different normal plasma source ( P = 0.04). Our data indicate that the detection of FVIII inhibitors is not the same in different centers, and the degree of variability noted makes it likely that assay variability has contributed to the lack of international consensus in relation to the real incidence of FVIII inhibitors in different clinical settings. Improvements in assay standardization are urgently needed.
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PMID:Interlaboratory variation in factor VIII:C inhibitor assay results is sufficient to influence patient management: data from the UK national quality external assessment scheme for blood coagulation. 2016 14

Blood dose not normally coagulate in the blood vessels covered with endothelial cells, because these cells contain some substances responsible for antithrombotic action such as thrombomodulin, heparin-like substance, prostacyclin, nitric oxide and tissue plasminogen activator. Most important role of blood coagulation is hemostasis. Blood can coagulate in two ways: intrinsic coagulation pathway and extrinsic coagulation pathway that is activated by negatively charged substances and FVIIa-tissue-factor (TF) complex, respectively. Prothrombin time(PT) can represent extrinsic pathway, while activated partial thromboplastin time (APTT) can represent intrinsic pathway. PT is prolonged in such diseases as vitamin K deficiency, hepatic failure and warfarin intake, while APTT is prolonged such diseases as hemophilia A & B, von Willebrand disease and lupus anticoagulant. Cross mixing test is very useful to assess prolonged clotting time. FDP means fibrin/fibrinogen degradation products and D-dimer is the smallest products of fibrin degradation. These markers are often used to diagnose disseminated intravascular coagulation (DIC) and deep vein thrombosis (DVT). Thrombin-antithrombin complex (TAT) and plasmin-alpha2 plasmin inhibitor (PIC) can be used to evaluate the extent of coagulation and fibrinolysis activation, respectively. These two markers is essential for classify the pathophysiology of DIC: DIC with suppressed fibrinolysis, enhanced fibrinolysis or balanced fibrinolysis. In conclusion, exact interpretation of hemostatic and fibrinolytic markers is one of the most important abilities in clinical situation.
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PMID:[Interpretation of hemostatic and fibrinolytic markers]. 2218 80


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