LAUSR

OBJECTIVE To identify clinical and serological features that distinguish patients with systemic lupus erythematosus (SLE) who require single as opposed to repeated rituximab (RTX) cycles. METHODS All 175 SLE patients followed-up at University College hospital from 2000 onwards were retrospectively reviewed. They were divided into a one RTX cycle and multiple-cycle groups (2 or more). Patients included had a follow-up of at least 3 years after their first RTX cycle, unless they needed a second infusion sooner. RESULTS 131 patients were included; 44 (33.6%) received one cycle of RTX and 87 (66.4%) received two or more. The former were older at diagnosis (31.4 vs 21 years, p< 0.001) and at first RTX infusion (39.9 vs 29 years, p< 0.001). This group of patients had more organs/systems involved (p= 0.044), more leukopenia, lymphopenia and thrombocytopenia (p= 0.001, <0.0001 and 0.003 respectively) and lower C3 levels (p= 0.035). They also had fewer immunosuppressive (IS) drugs before RTX therapy compared with those who required multiple RTX cycles (p= 0.003). There was no statistical difference in the clinical and serological response after the first RTX cycle between both groups.Furthermore, patients who had received more IS treatments were more likely to require more than one cycle of RTX infusions (p= 0.007). CONCLUSIONS RTX is an effective option for SLE patients with severe flares. Patients who received more immunosuppressive drugs are more likely to receive more than one set of RTX infusions. This suggests that RTX is best used for SLE patients with no history of refractory disease.