Rivaroxaban Levels in Patients' Plasmas are Comparable by Using Two Different Anti Xa Assay/Coagulometer Systems Calibrated with Two Different Calibrators.

Background: Rivaroxaban oral anticoagulant does not need laboratory monitoring, but in some situations plasma level measurement is useful. The objective of this paper was to verify analytical performance and compare two rivaroxaban calibrated anti Xa assays/coagulometer systems with specific or other branch calibrators.

Methods: In 59 samples drawn at trough or peak from patients taking rivaroxaban, plasma levels were measured by HemosIL Liquid anti Xa in ACLTOP 300/500, and STA liquid Anti Xa in TCoag Destiny Plus.

Evaluation of phosphatidylserine-dependent antiprothrombin antibody testing for the diagnosis of antiphospholipid syndrome: results of an international multicentre study.

Objective A task force of scientists at the International Congress on Antiphospholipid Antibodies recognized that phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT) might contribute to a better identification of antiphospholipid syndrome (APS). Accordingly, initial and replication retrospective, cross-sectional multicentre studies were conducted to ascertain the value of aPS/PT for APS diagnosis. Methods In the initial study (eight centres, seven countries), clinical/laboratory data were retrospectively collected.

The emerging role of multiple antiphospholipid antibodies positivity in patients with antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by clinical symptoms of vascular thrombosis and/or pregnancy morbidity in the presence of autoimmune antiphospholipid antibodies (aPL). Current laboratory APS criteria include the presence of at least one of the three relevant aPL: lupus anticoagulant, anticardiolipin antibodies and anti-β2 glycoprotein I antibodies. Therefore, patients could have a single aPL pattern or combinations of aPL.

Patient-level analysis of five international cohorts further confirms the efficacy of aspirin for the primary prevention of thrombosis in patients with antiphospholipid antibodies.

We performed an individual patient meta-analysis to determine whether aspirin has a significant protective effect on the risk of first thrombosis among patients with antiphospholipid antibodies (aPL). Five international cohort studies with available individual patient-level data, reporting on primary prophylaxis with continuous treatment with low-dose aspirin in patients with aPL were included. The main outcome was the occurrence of a first thrombotic in patients with aPL treated with low-dose aspirin compared to those not treated with low-dose aspirin.

Multiple antiphospholipid antibodies positivity and antiphospholipid syndrome criteria re-evaluation.

The antiphospholipid syndrome (APS) is characterized by the presence of aPL and thrombosis and/or pregnancy morbidity. The last APS laboratory classification criteria include the presence of at least one of the antiphospholipid antibodies (aPL) [lupus anticoagulant (LA), anticardiolipin (aCL) and/or anti-β2 glycoprotein I antibodies (aβ2GPI)] and introduced the concept of subclassification of APS patients into two different categories of aPL assay positivity (combination or single aPL). Several studies have recently shown that the risk for thrombosis increases with each additional aPL detected.

14th International Congress on Antiphospholipid Antibodies Task Force. Report on antiphospholipid syndrome laboratory diagnostics and trends.

Current classification criteria for definite Antiphospholipid Syndrome (APS) require the use of three laboratory assays to detect antiphospholipid antibodies (aCL, anti-β2GPI and LA) in the presence of at least one of the two major clinical manifestations (i.e. thrombosis or pregnancy morbidity) of the syndrome.

Evaluation of different immunoassays for the detection of antiphospholipid antibodies: report of a wet workshop during the 13th International Congress on Antiphospholipid Antibodies.

Background: The performance and standardization of anticardiolipin (aCL) and anti-β₂ glycoprotein I antibodies (aβ₂GPI) tests for the confirmation of diagnosis of antiphospholipid syndrome (APS) remain a matter of debate and concern. We evaluated the performance of different ELISAs and other new immunoassays for the detection of aCL and aβ₂GPI in a wet workshop at the 13th International Congress on Antiphospholipid Antibodies in Galveston, TX (April 13th, 2010, APLA 2010).

Methods: Aliquots of 26 un-identified APS or persistently aPL positive serum samples and 21 controls (9 from healthy individuals and 5 from patients with infectious diseases and 7 with various autoimmune diseases) were distributed to all participants/groups.

Efficacy of aspirin for the primary prevention of thrombosis in patients with antiphospholipid antibodies: an international and collaborative meta-analysis.

We performed a meta-analysis to determine whether aspirin has a significant protective effect on risk of first thrombosis among patients with antiphospholipid antibodies (aPL+). Observational and interventional studies identified from the Medline, Embase and Cochrane databases were selected if they assessed the incidence of first thrombosis in aPL+ patients treated with aspirin versus those without. Pooled effect estimates were obtained using a random-effects model.

Bleeding in the antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is an autoimmune disease characterized clinically by the occurrence of venous or arterial thrombosis, and/or pregnancy morbidity. The detection of persistently elevated levels of antiphospholipid antibodies (aPL) is a requisite laboratory feature for the diagnosis of APS. The positivity for at least one aPL test: lupus anticoagulant and/or IgG/IgM anticardiolipin and/ or IgG/IgM anti-β2 glycoprotein I antibodies must be detected.

[Levels of antiplatelet factor 4-heparin antibodies and 4T score for heparin induced thrombocytopenia].

Heparin induced thrombocytopenia (HIT) is an immune-mediated disorder due to antibodies anti platelet factor 4-heparin (HPIA). Thrombocytopenia is often moderate but certain patients can develop morbid thrombotic complications. HPIA detection by ELISA has high sensitivity but low specificity, and low titers (without clinical significance) are frequent.

New guidelines for lupus anticoagulant: sensitivity and specificity of cut-off values calculated with plasmas from healthy controls in mixing and confirmatory tests.

Introduction: The updated guidelines for lupus anticoagulant (LA) diagnosis indicate locally calculate the cut-off values of the index of circulating anticoagulant (ICA) and the clotting time in seconds (s) for mixing studies and % of correction (%C) for confirmatory tests. We assess sensitivity (SEN) and specificity (SPC) of the cut-off values obtained as the 99th percentile from 60 plasmas of healthy individuals.

Methods: We analysed 647 plasmas from patients studied in the last 3 years, and results were revaluated according to the new criteria and cut-off values.

'Non-criteria' aPL tests: report of a task force and preconference workshop at the 13th International Congress on Antiphospholipid Antibodies, Galveston, TX, USA, April 2010.

Abstract: Current classification criteria for definite APS recommend the use of one or more of three positive standardized laboratory assays, including anticardiolipin antibodies (aCL), lupus anticoagulant (LA), and antibodies directed to β(2)glycoprotein I (anti-β(2)GPI) to detect antiphospholipid antibodies (aPL) in the presence of at least one of the two major clinical manifestations (i.e., thrombosis or pregnancy morbidity) of the syndrome.

An international multicentre-laboratory evaluation of a new assay to detect specifically lupus anticoagulants dependent on the presence of anti-beta2-glycoprotein autoantibodies.

Background: Antiphospholipid syndrome (APS) is diagnosed by the simultaneous presence of vascular thrombosis and/or pregnancy morbidity and detection of antiphospholipid antibodies in plasma.

Objectives: We have shown that prolongation of clotting time by anti-beta2-glycoprotein I (beta2GPI) antibodies correlates better with thrombosis than a positive classic lupus anticoagulant (LAC) assay in a single center study. To confirm or falsify this finding we have conducted a multicenter study.

Current management of antiphospholipid syndrome-related thrombosis.

Antiphospholipid syndrome (APS) is an acquired autoimmune disorder characterized by venous or arterial thrombosis, and recurrent pregnancy morbidity in the presence of antiphospholipid antibodies. Many physicians recommend a daily low dose of aspirin for primary thrombosis prevention in asymptomatic individuals with persistent antiphospholipid antibodies. However, recent data question the effectiveness of aspirin.

Prothrombotic mechanisms based on the impairment of fibrinolysis in the antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is a clinical autoimmune disorder characterised by thrombosis, venous or arterial, and recurrent pregnancy morbidity in association with the persistence of antiphospholipid antibodies (aPL). The clinical variety of aPL ranges from asymptomatic individuals to those with multiple organ thromboses and failure developing over a short period, also known as catastrophic APS. An increasing number of phospholipid-binding proteins with crucial functions in the regulation of blood coagulation and fibrinolysis are targeted by APS-related autoantibodies.

Thrombophilia in human immunodeficiency virus-infected patients with osteonecrosis: Is there a real connection? The first case-control study.

Several reports have described an increased incidence of osteonecrosis in human immunodeficiency virus-infected patients (HIV+), but the cause has not been established. The association between thrombophilia and osteonecrosis in HIV+ was studied. A case-control study in HIV+, 19 cases and 38 controls, was designed.

[Chronic thromboembolic pulmonary hypertension with and without antiphospholipid syndrome].

Unlabelled: Chronic thromboembolic pulmonary hypertension (CTE-PH) is defined as the chronic obstruction by organized thrombi in pulmonary artery and their branches causing pulmonary hypertension. The objective is to evaluate features and outcome of CTE-PH in patients with and without coexisting antiphospholipid syndrome (APS). All patients studied at our Institution with CTE-PH between June 1993 and June 2005 were analyzed retrospectively.

An insight into the pathophysiology of thrombosis in antiphospholipid syndrome.

The antiphospholipid syndrome (APS) is a disorder which is characterized by the presence of autoimmune antiphospholipid antibodies (APL) and increased risk of thrombosis and fetal loss. APL are associated with recurrent abortions in APS patients and participate in the pathogenesis of venous or arterial thrombosis, although the underlying mechanisms are poorly understood. Antigens that are targeted by APL include beta 2 glycoprotein I and prothrombin.

Prevalence of antiphospholipid antibodies in Chilean patients with rheumatoid arthritis.

Antiphospholipid (aPL) antibodies found in patients with autoimmune diseases are also detected in those with inflammatory diseases. The purpose of this study was to examine the prevalence of these antibodies in patients with rheumatoid arthritis (RA), and to evaluate the association of these antibodies with thrombosis and/or other clinical characteristics of this inflammatory disorder. Eighty-four patients with RA and 82 normal controls were studied.

Catastrophic antiphospholipid syndrome and Kikuchi-Fujimoto disease: the first case reported.

The case of a man with diagnosis of Kikuchi-Fujimoto disease (KFD) and catastrophic antiphospholipid syndrome (CAPS) is reported. He presented prolonged fever, lymphadenopathies, arthralgia, weight loss, hepatosplenomegaly and positive IgM for cytomegalovirus. While he was empirically treated with tuberculostatic drugs, he suddenly developed systemic inflammatory response syndrome, multiple organ failure and distal necrosis.