Objectives: Rituximab (RTX) is a therapeutic option for patients with SLE or RA. We conducted a prospective, longitudinal, observational study to compare rates of RTX-related adverse events (AEs) in these two patient groups.
Methods: RTX was used in 23 patients with SLE that was refractory to conventional therapy and in 31 patients with RA that had been unsuccessfully treated with TNF-α inhibitors. Infusion-related and infectious AE rates were calculated for each group.
Results: Seven (22.5%) RA patients experienced an infusion-related reaction. These AEs involved 7/91 (7.7%) infusions administered in the RA group. None of the 102 infusions administered to SLE patients was associated with infusion-related AEs (P = 0.038 vs RA group). The mean daily glucocorticoid dose administered during the week preceding RTX treatment in the SLE group was higher than that for the RA group [0.25 (0.2) vs 0.18 (0.14) mg/kg, P = not significant] and significantly higher than that received by the subgroup of the seven RA patients who experienced infusion-related AEs [0.10 (0.02) mg/kg; P = 0.0017]. Infectious AE rates were also lower (but not significantly so) in the SLE group (8.7 vs 12.9% in RA).
Conclusions: Repeated cycles of RTX in combination with different immunosuppressants is a safe therapeutic option for SLE and RA patients. The lower incidence of infusion-related AEs in the SLE patients might reflect the higher dosage glucocorticoid therapy they received during the week before RTX infusion.