Introduction and Context
Antiphospholipid syndrome (APS) is a systemic, acquired thrombophilia characterized by arterial and venous thrombosis, pregnancy morbidity, and a range of microvascular and non-thrombotic manifestations associated with persistent antiphospholipid antibodies (aPL). For decades clinicians and researchers have lacked a standardized, validated measure of disease activity in APS. This has limited consistent monitoring of patients, hindered comparative effectiveness research, and made it difficult to design and interpret clinical trials of therapies aimed at reducing disease activity rather than simply preventing events.
In November 2025, Tektonidou and colleagues published the Development and validation of a EULAR disease activity score in antiphospholipid syndrome (EAPSDAS) (Ann Rheum Dis. 2025 Nov 19; S0003-4967(25)04437-1). EAPSDAS is the product of a multi-stage, data-driven consensus process involving EULAR task force members, international APS experts, patients, and healthcare professionals. It represents the first formal disease activity instrument for APS endorsed through EULAR methodologies and validated using real-world clinical vignettes.
