Anti-phospholipid syndrome: Current opinion on mechanisms involved, laboratory characterization and diagnostic aspects

摘要: Anti-phospholipid syndrome is a complex and severe clinical situation, associated with symptoms such as recurrent thrombosis, arterial or venous, at any site, pregnancy loss, other related syndromes. These burdens, are highly variable from patient to patient, biological abnormalities, the presence of Lupus Anticoagulant phospholipid dependent antibodies, confirmed on two occasions least 12 weeks apart. From diagnosis standpoint, both, functional (clotting) immunological assays, difficult standardize optimize, due absence reference material, characteristic group, international preparations. Large cohort studies necessary for defining usefulness each assay, in terms specificity, sensitivity, accuracy following-up disease evolution. Clotting assays based Activated Partial Thromboplastin Time (APTT) diluted Russell Viper Venom (dRVVT), performed low high concentration, 1:1 mixtures tested sample normal plasma pool. They allow evaluation paradoxal effects LAs, which pro-thrombotic vivo, anticoagulant vivo. Use synthetic phospholipids improves assay specificities sensitivities, especially patients treated anticoagulants. Immunoassays can also be used testing first identified measured anti-cardiolipin but now characterized targeted cofactor proteins: mainly β2GP1 (which exposes cryptic epitopes upon binding phospholipids), some cases prothrombin, more rarely Protein S, Factor XIII, Z Annexin V. optimized designed well-characterized anionic phospholipids, then complexed purified protein (mainly β2GP1), offers better link between reactivity associations, than former were empirically cardiolipin. Standardization remains complicated standards harmonized quantitation units. Validation large cohorts negative positive key approach performance usefulness. Laboratory practice all these methods greatly facilitated thanks use automated instruments dedicated software. Along criteria, laboratory great identification confirmation anti-phospholipid they follow-up when appropriate management place.