16th International congress on antiphospholipid antibodies task force report on antiphospholipid syndrome laboratory diagnostics and trends

Classification criteria for antiphospholipid syndrome (APS) require IgG or IgM isotypes of the anticardiolipin (aCL) antibodies, anti-beta 2 glycoprotein I (anti-beta 2GPI) antibodies, and/or the lupus anticoagulant (LA) to satisfy the laboratory disease definition. Over the past 20 years, non-criteria antiphospholipid antibodies (aPL) directed to other proteins of the coagulation cascade (i.e. prothrombin and/or phosphatidylserine-prothrombin complex) or to some domains of beta 2GPI have been proposed. This task force concentrated and reviewed the literature on data including aPS/PT, antibodies to domain 4/5 of beta 2GPI and the newly described antibodies to protein/HLA-DR complex. In addition, we discussed testing of LA in the 'new' oral anticoagulants' era and the value of triple positivity in the risk assessment of aPL. The conclusions were presented at a special session during the 16(th) International Congress on aPL, Manchester, UK, September 2019.

Automated summary

Classification criteria for antiphospholipid syndrome (APS) require specific antibodies to satisfy the laboratory disease definition, but there have been additional antibodies proposed in recent years. This article evaluates these new antibodies through the study and discussion of relevant data, and also discusses the testing of LA and the value of triple positivity.