ANCA-associated vasculitis in patients with rheumatoid arthritis: A single-center cohort study

Abstract

Aim

To evaluate characteristics of antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) in patients with rheumatoid arthritis (RA) and positive ANCA, and, to compare patients with RA+ANCA and RA+AAV.

Methods

This retrospective study included patients with RA and +ANCA. Patients with AAV were identified and data abstracted. RA+AAV were compared to RA+ANCA to evaluate factors associated with AAV.

Results

The study included 77 patients with RA+ANCA, mean (±SD) age 62.1 (17.2) years, 79 % female, 65 % seropositive. p-ANCA positivity was noted in 45 % and myeloperoxidase-positivity in 42 %. AAV was diagnosed in 29 %; granulomatosis with polyangiitis (GPA) (45 %), microscopic polyangiitis (36 %), eosinophilic granulomatosis with polyangiitis (5 %), unclassifiable (14 %). Renal (41 %) and upper airway involvement (36 %) were most frequently observed. Diagnosis of RA preceded AAV in 59 %. Positive rheumatoid factor (RhF), myeloperoxidase (MPO)-ANCA, rheumatoid nodules and inflammatory eye disease were more frequent in RA+AAV than RA+ANCA while positive ANCA via immunofluorescence alone and positive dsDNA were more frequent in RA+AAV (p < 0.05). Treatment exposure for RA did not differ between the two groups.

Conclusions

RA often preceded the diagnosis of AAV and GPA was the most frequently observed AAV. The interplay of +RhF and +MPO antibodies and AAV in patients with RA+ANCA warrants further investigation.