Prognosis of essential mixed cryoglobulinemia and connective tissue disease-related cryoglobulinemia after rituximab-induced remission

Objectives Rituximab (RTX) and glucocorticoids are the first line treatment for essential (EM) and connective tissue disease (CTD)-related mixed cryoglobulinemia vasculitis (CryoVas). Data on long term outcomes of these CryoVas are lacking. We aimed to describe the prognosis of patients with EM and CTD-related CryoVas. Methods We conducted a retrospective study on patients with EM or CTD-related CryoVas in remission after RTX-based therapy. Results We included 63 patients with a median follow-up of 58 months (IQR, 33–88 months). Relapse rates were 23% at 1 year, 42% at 2 years and 71% at 5 years after the initial flare. In univariate analysis, factors associated with relapse were purpura (HR, 2.2; 95% confidence interval (CI), 1.1–4.4; p = 0.02) and a previous flare of CryoVas (HR, 1.9; 95% CI, 1.0–3.7; p = 0.04). Maintenance therapy was associated with a lower risk of early relapse (HR, 0.3; 95% CI, 0.1–0.9; p = 0.03), but not of late relapse (HR, 2.0; 95% CI, 0.7–5.7; p = 0.21). In multivariable analysis, patients without purpura or previous flare remained at lower risk of relapse than those with at least one of the two (HR, 3.6; 95%CI, 1.6–8.2; p= 0.002). Maintenance regimen was associated with a lower risk of early relapse (HR, 0.3; 95% CI, 0.1–0.9; p = 0.03). Conclusion In patients with EM and CTD-related CryoVas who received RTX as induction therapy, relapses were frequent and associated with purpura and a previous flare, but were reduced with maintenance therapy.