Beyond clinical criteria: emerging biomarkers and advanced imaging in the diagnosis, monitoring and treatment of vasculitides

Vasculitides are a group of immune-mediated diseases characterized by inflammation of blood vessel walls, leading to ischemic injury in multiple organs. Despite advances in classification according to 2022 ACR/EULAR criteria, clinical management of vasculitis remains challenging, particularly regarding accurate diagnosis, assessment of disease activity, and prediction of relapse. Traditional clinical markers such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) lack sufficient specificity. In recent years, a new generation of biomarkers has emerged, including serological proteins, urinary markers, cytokines, and endothelial activation molecules. Advanced imaging modalities such as PET/CT with fluorodeoxyglucose, vessel wall magnetic resonance imaging, and vascular ultrasound enable detailed visualization of vascular inflammation. This review synthesizes evidence on relevant biomarkers and imaging techniques in major forms of vasculitis including ANCA-associated vasculitis, giant cell arteritis, and Takayasu arteritis.