To describe the prevalence, characteristics, and associations of VN with other disease manifestations in new-onset AAV in the DCVAS (diagnosis and classification of vasculitis) study and stratify for diagnostic certainty of VN.

From a prospective cross-sectional observational study (DCVAS) conducted at 135 centers worldwide, 1268 patients had an investigator-assigned diagnosis of AAV. 955 patients (mean age 57, range 18-91 years, 51% female), in whom the diagnosis was confirmed by an expert panel, were included in the final analysis. 572 had granulomatosis with polyangiitis (GPA), 218 microscopic polyangiitis (MPA)and 165 eosinophilic granulomatosis with polyangiitis (EGPA).

Presence of VN was categorized as definite (histology proven), probable (multiple mononeuropathy or nerve biopsy consistent with vasculitis) or possible (all others). Patients with possible VN and positive other-organ biopsy were sub-categorized as “possible+”. Associations with laboratory findings and other organ manifestations were compared in patients with and without VN.

269/955 (28%) AAV patients had VN. Prevalence was 65% EGPA, 23% MPA, and 19% GPA. Nerve biopsy was performed in 32/269 (12%) patients. Diagnostic certainty for VN was definite 6%, probable 38%, and possible 56%. 46% of possible cases were categorized possible+. VN was associated with skin (p<0.001), musculoskeletal (p<0.001) and cardiovascular (p=0.005) involvement. VN patients were less likely to have renal (p<0.001), eye (p<0.001) and gastrointestinal (p=0.023) involvement. VN was associated withMPO-ANCA-positivity (p=0.004).