Efficacy of low dose of rituximab to treat systemic lupus erythematosus.

OBJECTIVE

This study aimed to compare the efficacy and safety of low-dose rituximab (RTX, 100 mg/month) versus belimumab (BEL, 10 mg/kg), as a control, in the treatment of systemic lupus erythematosus (SLE).

METHODS

A retrospective analysis was conducted on 117 SLE patients who received low-dose RTX (n=51) or BEL (n=66) at Fujian Medical University Union Hospital between January 2020 and June 2023. Data on baseline characteristics, laboratory parameters (platelet count, creatinine, proteinuria, complement C3/C4, erythrocyte sedimentation rate (ESR)), disease activity (SLEDAI-2K), glucocorticoid dosage, concomitant immunosuppressant use, efficacy assessments, and adverse events were collected. Paired t-tests or Wilcoxon tests were used for within-group comparisons, and independent-sample t-tests or Mann-Whitney U tests for between-group comparisons.

RESULTS

No significant differences were observed between the two groups at baseline for SLEDAI-2K, glucocorticoid levels, or anti-dsDNA (p > 0.05). After treatment, both groups showed significant improvements in SLEDAI-2K, dsDNA levels, and glucocorticoid dosage (all p < 0.05), with a greater reduction in glucocorticoid dosage in the BEL group (p = 0.02). Both treatments increased complement C3/C4 and decreased immunoglobulins (p < 0.05), with no significant between-group differences. Low-dose RTX achieved a overall efficacy of 39.2% versus 57.6% for BEL. Both agents increased platelet count, improved hypoalbuminemia and hypercoagulability, and decreased ESR; BEL was superior in reducing D-dimer (p = 0.03). In renal outcomes, both reduced proteinuria equivalently; BEL improved creatinine while RTX caused a small but clinically acceptable rise in creatinine. Adverse events occurred in 12.12% (BEL) and 7.8% (RTX) of patients, respectively (p > 0.05), with no unexpected safety signals. Concomitant immunosuppressant use also varied between groups, with mycophenolate mofetil (MMF) more common in BEL and Cyclosporine A (CsA) in RTX.

CONCLUSION

Low-dose RTX (100 mg/month) can be regarded as a treatment option for SLE, based on its comparable efficacy to BEL in improving disease activity, increasing platelet count, and ameliorating proteinuria. Although BEL shows greater advantages in reducing glucocorticoid dosage and improving hypercoagulability, the overall evidence supports low-dose RTX as an effective and safe alternative for SLE, with a favourable safety profile.