MO225: A Past Medical History of Autoimmune Disease Predicts a Future With Fewer Relapses in Patients With ANCA Vasculitis

Abstract BACKGROUND AND AIMS To explore the frequency and impact of an autoimmune disease past-medical history (PMH) in the clinical picture and outcomes of patients with ANCA-associated vasculitis (AAV). METHOD This is a retrospective study of patients with biopsy-proven AAV, >16 years old, with detailed information about their PMH. Outcomes of interest included remission, treatment resistance, relapse, end-stage kidney disease (ESKD), and death. RESULTS 215 patients with biopsy-proven AAV and available information regarding their PMH were studied. A total of 65 (30.2%) of them had a history of autoimmune disease prior to PIV diagnosis. The mean age overall was 53.9 years. One hundred and five patients (48.8%) were positive for PR3-ANCA, 101(47.2%) for MPO-ANCA, and 9(4.2%) were negative ANCA. Granulomatosis with polyangiitis was diagnosed in 79 (36.7%), microscopic polyangiitis in 101(47.0%) and renal-limited vasculitis in 35 (16.3%) individuals. Remission rate was similar among patients with and without a PMH of autoimmune disease. Time-to-event analysis indicated that the relapse-free survival was significantly longer in patients with PMH of autoimmune disease (148.2 versus 52.8 months, P-value < .001). After adjusting for covariates, autoimmune disease history was associated with significantly lower risk of relapse {HR 0.31, [95% confidence interval (CI) 0.14–0.69]}, which remained significant in males, patients ≥ 60 years old and those with C/PR3-ANCA, kidney and lung involvement. CONCLUSION Patients with a PMH of autoimmune disease, prior to AAV diagnosis, experienced significantly fewer relapses after achievement of remission, compared with patients without such a history, underlining the importance of individualization of maintenance immunosuppressive therapy, given the different etiopathogenetic settings the disease was developed.