Monitoring of anticoagulation in thrombotic antiphospholipid syndrome

Anticoagulation is central to the management of thrombotic antiphospholipid syndrome (APS). The standard anticoagulant treatment for thrombotic APS is life-long warfarin or an alternative vitamin K antagonist. The role of direct oral anticoagulants for thrombotic APS is not established due to the lack of definitive evidence and has recently been addressed in international guidance. Other anticoagulant options include low-molecular-weight heparin, unfractionated heparin and fondaparinux. In APS patients, lupus anticoagulant can affect phospholipid-dependent coagulation monitoring tests, so that they may not reflect true anticoagulation intensity. Accurate assessment of anticoagulation intensity is essential, to optimise anticoagulant dosing and facilitate thrombus resolution; minimise the risk of recurrent thrombosis or bleeding; inform assessment of whether recurrent thrombosis is related to breakthrough thrombosis while on therapeutic anticoagulation, subtherapeutic anticoagulation, non-adherence or spurious results; and guide the management of bleeding. Knowledge of anticoagulant intensity also informs assessment and comparison of anticoagulation regimens in clinical studies. Considerations regarding anticoagulation dosing and/or monitoring of thrombotic APS patients underpin appropriate management in special situations, notably APS-related severe renal impairment, that may occur in APS or APS/systemic lupus erythematosus-related nephropathy or catastrophic APS; and APS-related thrombocytopenia. Anticoagulant dosing and monitoring in thrombotic APS patients also requires consideration in anticoagulant-refractory APS and pregnancy. In this review, we summarise the tests generally used in monitoring anticoagulant therapy, use of the main anticoagulants considered for thrombotic APS, lupus anticoagulant effects on anticoagulation monitoring tests, and strategies for appropriate anticoagulant monitoring in thrombotic APS

Clinical and laboratory practice for lupus anticoagulant testing: An International Society of Thrombosis and Haemostasis Scientific and Standardization Committee survey

Background: Current guidelines have contributed to more uniformity in the performance and interpretation of lupus anticoagulant (LA ) testing. However, points to reconsider include testing for LA in patients on anticoagulation, cut‐off values, and interpretation of results. Objectives: The aim of this International Society of Thrombosis and Haemostasis Scientific and Standardization committee (ISTH SSC ) questionnaire was to capture the spectrum of clinical and laboratory practice in LA detection, focusing on variability in practice, so that the responses could inform further ISTH SSC recommendations. Methods: Members of the ISTH SSC on Lupus Anticoagulant/Antiphospholipid Antibodies and participants of the Lupus Anticoagulant/Antiphospholipid Antibodies Programme of the External quality Control of diagnostic Assays and Tests Foundation were invited to complete a questionnaire on LA testing that was placed on the ISTH website using RedCap, with data tallied using simple descriptive statistics. Results: There was good agreement on several key recommendations in the ISTH and other guidelines on LA testing, such as sample processing, principles of testing, choice of tests, repeat testing to confirm persistent positivity and the use of interpretative reporting. However, the results highlight that there is less agreement on some other aspects, including the timing of testing in relation to thrombosis or pregnancy, testing in patients on anticoagulation, cut‐off values, and calculation and interpretation of results. Conclusions: Although some of the variability in practice in LA testing reflects the lack of substantive data to underpin evidence‐based recommendations, a more uniform approach, based on further guidance, should reduce the inter‐center variability of LA testing

Illustrated State-of-the-Art Capsules of the ISTH 2023 Congress

This year’s Congress of the International Society of Thrombosis and Haemostasis (ISTH) took place in person in Montréal, Canada, from June 24-28, 2023. The conference, held annually, highlighted cutting-edge advances in basic, translational, population and clinical sciences relevant to the Society. As for all ISTH congresses, we offered a special, congress-specific scientific theme; this year, the special theme was immunothrombosis. Certainly, over the last few years, COVID-19 infection and its related thrombotic and other complications have renewed interest in the concepts of thromboinflammation and immunothrombosis; namely, the relationship between inflammation, infection and clotting. Other main scientific themes of the Congress included Arterial Thromboembolism, Coagulation and Natural Anticoagulants, Diagnostics and Omics, Fibrinolysis and Proteolysis, Hemophilia and Rare Bleeding Disorders, Hemostatic System in Cancer, Inflammation and Immunity, Pediatrics, Platelet Disorders, von Willebrand Disease and Thrombotic Microangiopathies, Platelets and Megakaryocytes, Vascular Biology, Venous Thromboembolism and Women’s Health. Among other sessions, the program included 28 State-of-the-Art (SOA) sessions with a total of 84 talks given by internationally recognized leaders in the field. SOA speakers were invited to prepare brief illustrated reviews of their talks that were peer reviewed and are included in this article. These illustrated capsules highlight the major scientific advances with potential to impact clinical practice. Readers are invited to take advantage of the excellent educational resource provided by these illustrated capsules. They are also encouraged to use the image in social media to draw attention to the high quality and impact of the science presented at the Congress

Antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of antiphospholipid antibodies, such as lupus anticoagulant, anticardiolipin antibodies and anti-beta 2-glycoprotein 1 antibodies. APS can present with a variety of clinical phenotypes, including thrombosis in the veins, arteries and microvasculature as well as obstetrical complications. The pathophysiological hallmark is thrombosis, but other factors such as complement activation might be important. Prevention of thrombotic manifestations associated with APS includes lifestyle changes and, in individuals at high risk, low-dose aspirin. Prevention and treatment of thrombotic events are dependent mainly on the use of vitamin K antagonists. Immunosuppression and anticomplement therapy have been used anecdotally but have not been adequately tested. Pregnancy morbidity includes unexplained recurrent early miscarriage, fetal death and late obstetrical manifestation such as pre-eclampsia, premature birth or fetal growth restriction associated with placental insufficiency. Current treatment to prevent obstetrical morbidity is based on low-dose aspirin and/or low-molecular- weight heparin and has improved pregnancy outcomes to achieve successful live birth in > 70% of pregnancies. Although hydroxychloroquine and pravastatin might further improve pregnancy outcomes, prospective clinical trials are required to confirm these findings