AB0458 B cells depletion for the treatment of systemic autoimmune diseases

Background Systemic autoimmune diseases (SAD) have traditionally been treated with steroids and immunosuppressants, but not all patients respond to these measures. Rituximab (RTX) has been used in several SAD with favorable results, but there are only a few reports of isolated clinical experiences, with a very small number of patients. Data about use of this drug under conditions of daily clinical practice may be relevant. Objectives To describe the characteristics of patients with SAD who are candidates for treatment with RTX. To evaluate the response to this drug in the different SAD. Methods Demographic data and disease, treatment and response variables were included. We use the EULAR definitions of partial response (improvement of at least 50% of the main manifestations of the disease) and complete response (disappearance of the manifestations of the disease), because of the heterogeneity of the SAD and their multiple manifestations. Results We included 53 patients, 90.6% were women. The mean age at diagnosis was 31.42±14.33 years; and the median duration of disease at the onset of RTX 1.99 (0–7.5) years. Patients received a median of 2 cycles (1–3 min -1, max 12); and the median interval between cycles was 14.81 months (6–15.75, min 6, max 120). The EAS included SLE with 23 (43.4%) cases, systemic sclerosis with 7 (13.2%) cases, Sjogren9s syndrome with 6 (11.3%) cases, vasculitis with 5 (9.4%) cases, Still disease with 3 (5.7%) cases, autoinmune cytopenias with 3 (5.7%) cases, dermatomyositis with 2 (3.8%) cases, Behcet9s disease with 2 (3.8%) cases, IgG4 disease with 1 (1.9%) case and sarcoidosis with 1 case (1.9%). A partial response was observed in 27 patients (50.9%) and complete in 20 patients (37.7%). There was no response in 6 of the 53 patients (11.3%). The response by disease groups is detailed in Table 1. Conclusions In our study, patients treated with RTX achieved response in 88.7%; similar than some experiences of RTX off-label use. Remision of the disease occurs in 50% of the patients. The best results are observed in SLE, especially in lupus nephritis, and Sjogren disease. The results in SS are promising due to the limited therapeutic resources for this disease. References Ramos-Casals M, Garcia-Hernandez FJ, de Ramόn E, Callejas JL, Martinez-Berriotxoa A, Pallares L, et al. Off-label use of rituximab in 196 patients with severe, refractory systemic autoimmune diseases. Clinical and experimental rheumatology 2010; 28 (4): 468–76. Disclosure of Interest None declared