Françès, Camille

Objective To develop new antiphospholipid syndrome (APS) classification criteria with high specificity for use in observational studies and trials, jointly supported by the American College of Rheumatology (ACR) and EULAR. Methods This international multidisciplinary initiative included 4 phases: 1) Phase I, criteria generation by surveys and literature review; 2) Phase II, criteria reduction by modified Delphi and nominal group technique exercises; 3) Phase III, criteria definition, further reduction with the guidance of real‐world patient scenarios, and weighting via consensus‐based multicriteria decision analysis, and threshold identification; and 4) Phase IV, validation using independent adjudicators’ consensus as the gold standard. Results The 2023 ACR/EULAR APS classification criteria include an entry criterion of at least one positive antiphospholipid antibody (aPL) test within 3 years of identification of an aPL‐associated clinical criterion, followed by additive weighted criteria (score range 1–7 points each) clustered into 6 clinical domains (macrovascular venous thromboembolism, macrovascular arterial thrombosis, microvascular, obstetric, cardiac valve, and hematologic) and 2 laboratory domains (lupus anticoagulant functional coagulation assays, and solid‐phase enzyme‐linked immunosorbent assays for IgG/IgM anticardiolipin and/or IgG/IgM anti–β 2 ‐glycoprotein I antibodies). Patients accumulating at least 3 points each from the clinical and laboratory domains are classified as having APS. In the validation cohort, the new APS criteria versus the 2006 revised Sapporo classification criteria had a specificity of 99% versu s 86%, and a sensitivity of 84% versus 99%. Conclusion These new ACR/EULAR APS classification criteria were developed using rigorous methodology with multidisciplinary international input. Hierarchically clustered, weighted, and risk‐stratified criteria reflect the current thinking about APS, providing high specificity and a strong foundation for future APS research.

Objective To prepare a dermatologic addendum to the 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides ( CHCC 2012) to address vasculitides affecting the skin (D‐ CHCC ). The goal was to standardize the names and definitions for cutaneous vasculitis. Methods A nominal group technique with a facilitator was used to reach consensus on the D‐ CHCC nomenclature, using multiple face‐to‐face meetings, e‐mail discussions, and teleconferences. Results Standardized names, definitions, and descriptions were adopted for cutaneous components of systemic vasculitides (e.g., cutaneous IgA vasculitis as a component of systemic IgA vasculitis), skin‐limited variants of systemic vasculitides (e.g., skin‐limited IgA vasculitis, drug‐induced skin‐limited antineutrophil cytoplasmic antibody–associated vasculitis), and cutaneous single‐organ vasculitides that have no systemic counterparts (e.g., nodular vasculitis). Cutaneous vasculitides that were not included in the CHCC 2012 nomenclature were introduced. Conclusion Standardized names and definitions are a prerequisite for developing validated classification and diagnostic criteria for cutaneous vasculitis. Accurate identification of specifically defined variants of systemic and skin‐limited vasculitides requires knowledgeable integration of data from clinical, laboratory, and pathologic studies. This proposed nomenclature of vasculitides affecting the skin, the D‐ CHCC , provides a standard framework both for clinicians and for investigators.