Clinical Delphi on aPL Negativization: Report from the APS Study Group of the Italian Society for Rheumatology (SIR-APS).

Background:  The rate of antiphospholipid antibody (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.

Aim:  The aim of the Delphi survey was to 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 scenarios.

Methods:  Experts of SIR-APS were contacted using a survey methodology.

Results:  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, 1 year apart (90%). Almost full consensus exists among experts in some clinical settings, including: (1) 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%); (2) approach to young patients with triple aPL positivity who experienced pulmonary arterial thrombotic events and tested negative for aPL detection after 5 years of vitamin K antagonist (VKA) treatment (90%); (3) the use of "" aPL antibody testing before pondering VKA suspension (93%).

Conclusion:  A substantial agreement exists among experts 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 of "" aPL is ruled out.