EULAR, the European Alliance of Associations for Rheumatology, has introduced a novel disease activity score, EAPSDAS, designed to quantify disease activity in individuals with antiphospholipid syndrome (APS). While awaiting prospective validation, EAPSDAS is expected to be instrumental in differentiating disease activity from severity, facilitating its use in both clinical trials and routine practice.
APS is a systemic autoimmune disorder marked by antiphospholipid antibodies and diverse clinical manifestations, including obstetric, thrombotic, microvascular, and non-thrombotic symptoms. The disorder’s complexity arises from its varying severity and potential involvement across multiple sites. Emerging evidence suggests that APS may result from the interplay of thrombotic and inflammatory mechanisms.
In collaboration with the American College of Rheumatology, EULAR developed classification criteria for APS in 2023, focusing on five key domains. The introduction of a disease activity score, such as EAPSDAS, is critical for evaluating patient responses to treatment in clinical trials and monitoring disease progression in observational studies and clinical settings.
EAPSDAS distinguishes between disease activity and severity, which includes current activity and accumulated damage impacting health, function, quality of life, and prognosis. Disease activity relates to new events, like venous thromboembolism, or improvements post-treatment, such as thrombocytopenia.
The EAPSDAS development involved healthcare professionals and patient research partners. Initially generating 170 items, the task force refined these to 30 consensus items, with 24 in the TMN scale and 6 in the obstetric scale. Separate scores for these domains prevent bias against non-pregnant individuals. The tool is a scale, not an index, accommodating both episodic and continuous APS manifestations.
EAPSDAS calculates the TMN scale by dividing observation time into monthly intervals, defining the highest score in any interval as the maximum score. The average TMN score is the mean of these monthly scores, indicating persistence, while the maximum score shows peak activity levels. The obstetric scale focuses on single events.
Professor Maria Tektonidou, lead author and Head of the Rheumatology Unit at the National and Kapodistrian University of Athens, emphasises that EAPSDAS will support clinical trials for new APS treatments. By using EAPSDAS as a primary outcome, trials can better evaluate disease activity and treatment response for various APS manifestations.
Developed using data-driven and consensus methods, EAPSDAS has undergone initial validation, with further studies needed. EULAR anticipates EAPSDAS will play a crucial role in assessing APS activity in future treatment trials.
