Rituximab associated vasculitis flare: incidence, predictors and outcome

International audienceTo report the incidence, predictor, and outcome of rituximab-associated autoimmune disease flare.METHODS: We conducted a retrospective study in a tertiary referral centre from 2005 to 2015. Disease flare was defined as the onset of a new organ involvement or worsening of autoimmune disease, within 4 weeks following rituximab.RESULTS: Among the 185 patients, we identified 7 (3.4%) disease flares. All were due to type II mixed cryoglobulinemia vasculitis. Vasculitis flare occurred after a median time of 8 [2; 16] days following rituximab infusion and included acute kidney insufficiency (n=7), purpura (n=7), gastrointestinal tract involvement (n=4), and myocarditis (n=1). Patients with rituximab-associated cryoglobulinemia vasculitis flare had more frequently renal involvement (p=0.008), B cell-lymphoproliferation (p=0.015), higher level of cryoglobulin (2.1 vs 0.4 g/l, p=0.004) and lower level of C4 level (0.02 vs 0.05, p=0.023) as compared to patients without flare after rituximab (n=43). Four patients (57%) died after a median time of 3.3 months. The 1-year survival rate was poorer in patients with vasculitis flare after rituximab as compared to their negative counterpart [43% (95% CI: 18-100) vs 97% (95% CI: 92-100), p