Background Epidemiological data on vasculitic neuropathy (VN) in ANCA associated vasculitides (AAV) are scarce and controversial. The Diagnostic and Classification Criteria for Primary Systemic Vasculitis (DCVAS) study is a large multinational, observational case control study collecting detailed data from patients with primary vasculitides at inclusion.
Objectives To describe the prevalence, associations with other disease characteristics and patterns of VN in patients with AAV at initial presentation.
Methods Patients included in the DCVAS study and having completed 6 months follow-up until December 2016 were screened. All patients with a diagnosis of AAV confirmed by an independent expert team were included. VN was diagnosed by clinical features, neurophysiology and/or nerve biopsy. AAV organ manifestations were identified by described symptoms or by the items from the vasculitis damage index. Laboratory parameters and histology were retrieved from the database. Data were analysed descriptively.
Results By Dec 2016, 1268 patients with a physician submitted diagnosis of AAV had their case summaries reviewed by an expert panel and the diagnosis of AAV confirmed in 839. 484 (58%) had GPA, 195 (24%) MPA, 150 (18%) EGPA and 10 (1.2%) an unclassified AAV. Of these patients, 247 (29.4%) had findings compatible with VN. Mean age in patients with and without VN was 58.7 (SD 15) and 55.4 (SD 17) years, respectively. 133 (53.9%) of patients with VN and 289 (48.8%) without VN were female. VN was diagnosed by biopsy in 5.7%, by the presence of mononeuritis multiplex in 10.1% and by the description of new onset peripheral neuropathy in the context of AAV in 84.2%. Frequency of VN was 19.4% in GPA, 24.1% in MPA and 68.0% in EGPA. 5.6% of patients had motor, 27.9% sensory, 36.4% had sensorimotor neuropathy, and 7.4% had neuropathy exclusively documented on VDI. VN was associated with older age (p=0.008), the presence of MPO-ANCA (p=0.005), skin (p≤0.001), musculoskeletal (p≤0.001), cardiac (p=0.001) and multiorgan (>5 organs) involvement (p=0.05) and with the absence of renal (p=0.002), gastrointestinal (p=0.03) and eye involvement (p≤0.001).
Conclusions VN has a high prevalence in patients with AAV. In EGPA, more than half of the patients suffered from peripheral nerve involvement. A typical clinical scenario (e.g. older age, MPO positivity, skin and joint/muscle involvement) may help to identify patients at risk of neuropathy. DCVAS was not primarily designed to assess VN, therefore these data should be interpreted with caution.
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Disclosure of Interest None declared