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Interpretation of laboratory data and need for reference laboratories.
No full textA single positive laboratory test among those exploring the presence of antiphospholipid antibodies is not associated with thromboembolic events and does not identify patients with antiphospholipid syndrome. On the other hand, more than one laboratory test positive, and in particular all three tests positive, is strongly associated to thromboembolic events and identifies high risk patients. Triple positivity is in fact related to the presence of a specific anti-β2-glycoprotein I (anti-Domain I) antibody, also able to prolong coagulation tests. Monoclonal antibodies against Domain I with Lupus Anticoagulant activity might be candidate material for standardization of antiphospholipid assays. Much work remains to be done in this field
Secondary prevention in thrombotic antiphospholipid syndrome.
No full textSecondary prevention of venous thromboembolism in antiphospholipid syndrome (APS) is usually made using vitamin K antagonists (VKAs) to maintain an international normalized ratio (INR) between 2.0 and 3.0. The optimal intensity of anticoagulation was determined in two prospective randomized controlled trials, both excluding the benefit of more intense anticoagulation. The same regimen is also recommended in patients with APS and arterial thromboembolism as aspirin does not appear to protect against recurrences. The duration of treatment is usually indefinite because of a substantial risk of recurrenc
Efficacy and safety of rivaroxaban vs warfarin in high-risk patients with antiphospholipid syndrome: Rationale and design of the Trial on Rivaroxaban in AntiPhospholipid Syndrome (TRAPS) trial
No full textCorrect laboratory approach to APS diagnosis and monitoring
No full textTriple positivity (positive Lupus Anticoagulant, anticardiolipin and anti β2-glycoptrotein I antibodies) identifies the pathogenic autoantibody (anti Domain I of β2-glycoptroteinI) that is present in patients with definite Antiphospholipid Syndrome (APS). This is supported by the fact that aβ2GPI antibodies obtained by affinity purification in these patients possess LA activity. Moreover, patients and carriers of this profile carry a much higher risk of thrombosis and pregnancy loss than APS patients with positivity for only one of the tests. Thus, very different risk categories exist among patients with APS as well as among carriers of aPL. Clinical studies and interventional trials should first take these high risk subjects into consideration.
Copyright © 2012 Elsevier B.V. All rights reserved
The Paradox of the Lupus Anticoagulant: History and Perspectives
No full textA unique coagulation inhibitor prolonging whole-blood clotting time was described
more than 50 years ago in two patients with systemic lupus erythematosus (SLE). The
immunoglobulin nature of the inhibitor and its interaction with antiphospholipid
antibodies was later demonstrated and the term “lupus anticoagulant (LA)” was
coined to describe this laboratory finding. It soon became apparent that LA was a
misnomer as it is often found in plasma from patients with clinical conditions other
than SLE and is associated with thromboembolic events that may occur in otherwise
healthy individuals. Individuals with LA have circulating autoantibodies that inhibits
blood coagulation. These are mostly of IgG or IgM class and mainly directed against a
phospholipid (PL)-binding plasma protein, β2-glycoprotein I (β2GPI). The presence of
β2GPI-dependent LA represents a well-recognized risk factor for venous and arterial
thromboembolism, as well as pregnancy loss and morbidity. β2GPI-dependent LA in
the presence of documented previous thromboembolism, or history of pregnancy
loss/morbidity, identifies definite anti-PL syndrome. Laboratory diagnosis of LA is thus
of particular importance, as it may assign patients with a common event (thrombosis)
to a group with a high risk for recurrence, which is a prerequisite for long-term oral antithrombotic treatment
Antiphospholipid syndrome: critical analysis of the diagnostic path
No full textAntiphospholipid syndrome (APS) is diagnosed in the presence of vascular thrombosis or pregnancy morbidity occurring in patients with circulating antiphospholipid antibodies (lupus anticoagulant [LA] and/or IgG/IgM anticardiolipin [aCL] and/or IgG/IgM anti-beta2glycoprotein I [abeta2GPI] antibodies). Each test may identify different autoantibodies; a single test makes the diagnosis possible when positive on two or more occasions at least 12 weeks apart. However, single test positivity may be unrelated to pathogenic antibodies, which are now considered to be a subclass of abeta2GPI antibodies directed against the domain I of this protein. Conversely, all three positive tests identify a single class of abeta2GPI antibodies, thus identifying high-risk patients with APS
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Laboratory Diagnostics of Antiphospholipid Syndrome
No full textDiagnosis of antiphospholipid syndrome (APS) lies in the recognition of antiphospholipid antibodies (aPL). As standardization of tests for the detection of aPL is far from being optimal and reference material is not available, inappropriate diagnoses of APS are not unusual. In the last few years, the concept of triple test positivity has emerged as a useful tool to identify patients with APS. Clinical studies on patients and carriers of triple positivity clearly show that these individuals are at high risk of thromboembolic events and pregnancy loss. Moreover, triple positivity arises from a single (probably pathogenic) antibody directed to domain 1 of β2-glycoprotein I, a protein whose function is still unknown. Studies on homogenous group of patients with single or double positivity are scant, and uncertainties arise on their association with clinical events. Promising but undetermined results come also from the determination of antibodies directed to phosphatidylserine/prothrombin complex. Interpretation of laboratory profile in APS is challenging, and the collaboration between clinical pathologists and clinicians is highly desirable
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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