2023 ACR/EULAR antiphospholipid syndrome classification criteria

Area of Science:

• Rheumatology
• Immunology
• Clinical Criteria Development

Background:

• Antiphospholipid syndrome (APS) requires precise classification criteria for research.
• Existing criteria may lack specificity for observational studies and clinical trials.

Purpose of the Study:

• To develop and validate new, highly specific classification criteria for antiphospholipid syndrome (APS).
• To support the American College of Rheumatology (ACR) and EULAR in establishing updated APS diagnostic standards.

Main Methods:

• A four-phase international multidisciplinary initiative: criteria generation, reduction, definition with real-world scenarios, and validation.
• Utilized surveys, literature review, modified Delphi, nominal group technique, multicriteria decision analysis, and independent adjudicator consensus.

Main Results:

• The 2023 ACR/EULAR APS criteria include entry and weighted additive criteria across clinical and laboratory domains.
• Achieved 99% specificity and 84% sensitivity in validation, outperforming 2006 Sapporo criteria (86% specificity, 99% sensitivity).
• APS diagnosis requires ≥3 points from both clinical and laboratory domains.

Conclusions:

• Rigorous methodology and international input produced new, highly specific ACR/EULAR APS classification criteria.
• The criteria are hierarchically clustered, weighted, and risk-stratified, reflecting current understanding of APS.
• These criteria provide a robust foundation for future APS research and clinical trials.