Clinical Characteristics of an Internet-Based Cohort of Patient-Reported Diagnosis of Granulomatosis With Polyangiitis and Microscopic Polyangiitis: Observational Study.

In this large, internet-based cohort of patients with a self-reported diagnosis of granulomatosis with polyangiitis or microscopic polyangiitis, disease manifestations were consistent with expectations for each type of vasculitis. Given the rarity of these and other vasculitides, conducting some types of research through internet-based registries may provide an efficient alternative to inperson, center-of-excellence clinical trials.