Clinical Delphi on aPLnegativization: report from the from the APS Study Group of the Italian Society for Rheumatology (SIR-APS)

The rate of antiphospholipid antibodies (aPL) negativization in antiphospholipid syndrome (APS) patients is uncertain, but it is estimated to be as high as 8%. Currently, a consensus definition of aPL negativization is lacking, as well as international recommendations on how to approach treatment in patients with a persistent aPL negative seroconversion. Evaluate the clinical approach and level of consensus among experts from the APS Study Group of the Italian Society for Rheumatology (SIR-APS) in different clinical scenario. Experts of SIR-APS were contacted using a survey methodology. A structured survey was circulated among 30 experts.Up to 90% of the interviewed experts agreed on defining aPL negativization as the presence of two negative determinations, one year apart (90%).Almost full consensus exist among experts in some clinical settings, including: a) the role of aPL negativization in the management of a thrombotic event determined by concomitant presence of cardiovascular risk factors, both modifiable and not modifiable (90%); b) approach to young patients with triple aPL positivity who experienced pulmonary arterial thrombotic event and tested negative for aPL detection after five year of vitamin K antagonist (VKA) treatment (90%); c)the use of "extra criteria" aPL antibodies testing before pondering VKA suspension (93%). A substantial agreement exists among expert on how to define aPL negativization. VKA suspension should be embraced with extreme caution, particularly in case of previous thrombotic events and/or triple aPL positivity. Nevertheless, VKA cessation might be considered when risk factors are carefully monitored/treated and the presence for "extra criteria" is ruled out.