Severe infections in patients with anti-neutrophil cytoplasmic antibody-associated vasculitides receiving rituximab: A meta-analysis.

Introduction: The efficacy of rituximab (RTX) for remission induction and maintenance in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) is now established, but the safety, particularly concerning severe infection risk, is not well known.

Objective: The purpose of this meta-analysis is to assess the prevalence and incidence of severe infections and the factors explaining heterogeneity in AAV patients treated with RTX.

Methods: PubMed and Embase were searched up to December 2017. Prevalence and incidence was pooled using a random-effects model in case of significant heterogeneity (I > 50%). Severe infection was defined as severe when it led to hospitalization, intravenous antibiotics therapy, and/or death. The heterogeneity was explored by subgroup analyses and meta-regression.

Results: The included studies encompassed 1434 patients with a median age of 51.9 years. The overall prevalence and incidence of severe infections was 15.4% (95% CI [8.9; 23.3], I = 90%, 33 studies) and 6.5 per 100 person-years (PY) (95% CI [2.9; 11.4], I = 76%, 18 studies), respectively. The most common infections were bacterial (9.4%, 95% CI [5.1; 14.8]). The prevalence of opportunistic infection was 1.5% (95% CI [0.5; 3.1], I = 58%) including pneumocytis jirovecii infections (0.2%, 95% CI [0.0; 0.6], I = 0), irrespective of prophylaxis administration. Mortality related to infection was estimated at 0.7% (95% CI [0.2; 1.2], I = 27%). The RTX cumulative dose was positively associated with prevalence of infections (13 studies, prevalence increase of 4% per 100 mg, p < .0001). The incidence of infection was negatively associated with duration of follow-up (8 studies, incidence decrease of 9% per year, p = .03).

Conclusion: Prevalence and incidence of severe infections, mainly bacterial ones, were high in AAV patients treated with RTX. This meta-analysis highlights the need for prospective studies to stratify infectious risk and validate cumulative RTX dose and duration of follow-up as modifying factors.