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

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.