PT - JOURNAL ARTICLE AU - Anne Claire Desbois AU - Lucie Biard AU - Damien Sène AU - Isabelle Brocheriou AU - Philippe Rouvier AU - Bertrand Lioger AU - Lucile Musset AU - Sophie Candon AU - Thierry Zenone AU - Matthieu Resche-Rigon AU - Jean-Charles Piette AU - Neila Benameur AU - Patrice Cacoub AU - David Saadoun TI - Rituximab-associated Vasculitis Flare: Incidence, Predictors, and Outcome AID - 10.3899/jrheum.190076 DP - 2020 Jun 01 TA - The Journal of Rheumatology PG - 896--902 VI - 47 IP - 6 4099 - http://www.jrheum.org/content/47/6/896.short 4100 - http://www.jrheum.org/content/47/6/896.full SO - J Rheumatol2020 Jun 01; 47 AB - Objective. To report the incidence, predictors, and outcome of rituximab (RTX)-associated autoimmune disease flare.Methods. We conducted a retrospective study in a tertiary referral center 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 RTX.Results. Among the 185 patients, we identified 7 disease flares (3.4%). All were due to type II mixed cryoglobulinemia vasculitis. Vasculitis flare occurred after a median time of 8 days (range 2–16) following RTX infusion and included acute kidney insufficiency (n = 7), purpura with cutaneous (n = 7), gastrointestinal (GI) tract involvement (n = 4), and myocarditis (n = 1). Patients with RTX-associated cryoglobulinemia vasculitis flare had these conditions more frequently: renal involvement (p = 0.0008), B cell lymphoproliferation (p = 0.015), higher level of cryoglobulin (2.1 vs 0.4 g/l, p = 0.0004), and lower level of C4 (0.02 vs 0.05, p = 0.023) compared to patients without flare after RTX (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 RTX compared to their negative counterpart [43% (95% CI 18–100) vs 97% (95% CI 92–100), p < 0.001]. Immunofluorescence analysis of kidney biopsy in patients with worsening RTX-associated vasculitis highlighted the presence of RTX-, IgM-, and IgG1-positive staining of endomembranous deposits and thrombi within kidney lesions.Conclusion. RTX-associated cryoglobulinemia vasculitis flare is associated with high mortality rate. We provided evidence that kidney lesions are due to immune complex deposition and to glomerular obstruction by cryoglobulinemia and RTX.