Development of a disease activity index (VEXAS-DAI) to quantify active inflammation across organ systems in patients with VEXAS syndrome, using modified Delphi methodology with a multinational expert advisory committee.
Consensus (≥75% concurrence) was reached after 4 Delphi rounds. The VEXAS-DAI covers 12 domains (inflammatory rash, chondritis, periorbital, ophthalmologic, joint, pulmonary, cardiovascular, genitourinary, neurological, oral/GI, renal, and constitutional symptoms) with a total score of 0–40; item grading was adapted from CTCAE criteria and scoring was developed using 158 test cases.
The VEXAS-DAI has not yet been prospectively validated; consensus-based development relies on expert opinion rather than empirical patient data; the index was built for an emerging disease with limited longitudinal outcome evidence.
The VEXAS-DAI provides the first structured tool to track inflammatory disease activity over time in VEXAS syndrome, which can support enrollment and outcome assessment in future clinical trials. Clinicians should await prospective validation before using it as a primary endpoint in research or routine care.
