Current Controversies in Lupus Anticoagulant Detection

Abstract

Antiphospholipid syndrome is an autoimmune, acquired thrombophilia diagnosed when vascular thrombosis or pregnancy morbidity are accompanied by persistent antiphospholipid antibodies. Lupus anticoagulants (LA) are one of the criteria antibodies but calibration plasmas are unavailable and they are detected by inference based on antibody behaviour in a medley of coagulation-based assays. Elevated screening tests suggest the presence of a LA, which is confirmed with mixing tests to evidence inhibition and confirmatory tests to demonstrate phospholipid-dependence. At least two screening tests of different principle must be used to account for antibody heterogeneity and controversy exists on whether assays, in addition to dilute Russell's viper venom time and activated partial thromboplastin time, should be employed. A variety of approaches to raw data manipulation and interpretation attract debate, as does inclusion or exclusion of mixing studies in circumstances where the presence of a LA is already evident from other results. Therapeutic anticoagulation compromises coagulation-based assays but careful data interpretation and use of alternative reagents can detect or exclude LA in specific circumstances, and this aspect of LA detection continues to evolve. This review focuses on the main areas of debate in LA detection.

Addendum to British Society for Haematology Guidelines on Investigation and Management of Antiphospholipid syndrome, 2012 (Br. J. Haematol. 2012; 157: 47–58): use of direct acting oral anticoagulants

“…Although low molecular weight heparins (LMWH) have little effect on APTT and DRVVT this may be dependent on LMWH type and APTT reagent (Liestol & Wisloff, ). Therefore, the possible effect of LMWH should be taken into account even if reagents with heparin neutralisers are used (Moore, ). Samples should be taken just before the next dose of LMWH to minimise the effect of LMWH.…”

Pitfalls in hemostasis exploration, a case report of a girl with Henoch-Schönlein type vasculitis

“…It can really be a "thorny issue" to answer this question. (4,7,15) In our case, the ELISA antigenic tests performed for anti F VIII and IX inhibitors remained negative, which undoubtedly pleaded for a rare type of transient LA syndrome, invalidating the diagnosis of AH-A, B and C.…”

“…(15)(16)(17)(18) The important heterogeneity of antibodies, the different types of thromboplastine and other reagents used, the variate modality of measurements (coagulometric or chromogenic), addition of phosphopolipids aso, impose a better standardised diagnostic strategy.…”

Interferencia del inhibidor lúpico en la prueba de protrombina: efecto de la variabilidad de los reactivos. informe de un caso

“…Tel: (506) 25-11 4492, Fax: ime, but not inactive the known coagulation factors" Currently, different international committees agree to define the lupus anticoagulant as a heterogeneous group of antibodies specific for lipoproteins or phospholipid components that frequently interfere with standard tion tests [59][60][61][62][63]. This definition is subject to many controversies due to the lack of standardization of the different techniques, a wide range of cefalines available commercially, antibodies heterogeneity and differing interpretation strategies [64].…”