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

Abstract

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.

Quantification of Antiphospholipid Antibodies: The Importance of Using an Appropriate Methodology for Each Clinical Profile

“…Overall, we would like to highlight that the results from the most discrepant samples were near the cut-off value range, with a significant number of samples whose results were within that range. The low positive discrepancies between techniques may be clinically relevant for clinicians since the presence of the antibodies is considered for longterm treatment decisions [33]. This suggests that the definition of grey zones (equivocal ranges) by manufacturers is important and may contribute to harmonization efforts.…”