Noninfectious, Severe Cryoglobulinemic Vasculitis with Renal Involvement - Safety and Efficacy of Long-Term Treatment with Rituximab.

Background The management of nonviral cryoglobulinemic vasculitis (CV) has not been established yet. Randomized control trials are challenging to perform because of the rarity of the disease. The most promising biological therapy is rituximab (RTX), an anti-CD 20 monoclonal antibody. The aim of the study was to assess rituximab treatment's safety and effectiveness in patients with severe noninfectious cryoglobulinemic vasculitis. Materials and methods We retrospectively reviewed 8 courses of RTX treatment in three patients with severe noninfectious CV. In 2 patients, the indication for the start of RTX therapy was the relapse of the disease despite the maintenance treatment, for the third patient, it was the first-line therapy. Results Clinical, renal, and immunologic efficacy was observed in all evaluable RTX courses. We found a significant decrease of cryoglobulins in the 3-rd month from RTX treatment. However, 5 clinical relapses occurred and two patients experienced severe adverse events (SAEs) after RTX therapy. Patients with SAEs were relatively older and had a longer duration of disease. Lower levels of hemoglobin, C3 component of complement and eGFR as well as higher rheumatoid factor (RF) concentration were observed before RTX treatments complicated with SAEs. Conclusion Data from our observation show the efficacy of rituximab in the refractory, nonviral cryoglobulinemic vasculitis with a severe course of the disease. However, the therapy is associated with the risk of SAEs, especially in elderly patients with kidney failure and significant immunologic alterations.