Antiphospholipid Syndrome: To Classify or Not to Classify?

Antiphospholipid Syndrome (APS) is a systemic autoimmune disorder resulting in thrombosis, microvascular disease, pregnancy morbidity, and/or non-thrombotic manifestations. The recently introduced 2023 American College of Rheumatology (ACR) and European Alliance of Associations for Rheumatology (EULAR) APS classification criteria, with a significantly higher specificity compared to the revised Sapporo criteria, now reflect the current thinking about APS, and provide a new foundation for future APS research. The purpose of this short commentary is to discuss the appropriate circumstances that 2023 ACR/EULAR classification criteria could be used, and to demonstrate how the new criteria can be applied to simple case scenarios.