P86 Rituximab therapy in lupus nephritis resistant to conventional therapy – A single center experience (case series)

Objective Lupus nephritis (LN) is challenging, especially in treatment-resistant cases. This retrospective study evaluates rituximab's effectiveness in LN patients at our clinic. Methods We retrospectively analyzed LN patients who received rituximab at our clinic from 2010 to 2022. We measured key parameters before and after rituximab, including creatinine clearance, serum creatinine, 24-hour proteinuria, and SLE-DAI-2K. Our primary goals were reducing prednisolone to ≤ 5 mg and proteinuria to ≤ 500 mg, while also examining rituximab's side effects. Results In this study, 47 patients (34 females, 13 males) with active lupus nephritis received rituximab. Their average disease duration was 10.44 years ± 6, confirmed by renal biopsy. They underwent an average of 4.1 ± 3.68 rituximab courses. Initially, high-dose steroids were administered, along with prior treatments such as cyclophosphamide (n=35), mycophenolate mofetil (n=31), azathioprine (n=6), and cyclosporine (n=2). The pre-treatment proteinuria level significantly decreased from 3599.5 ± 2485.3 mg/day to a median of 747 (396, 1500) mg/day (p=0.00) after rituximab. Serum creatinine levels dropped from 0.94 ± 0.59 to 0.78 (0.6, 1.13) (p=0.031), and mean serum creatinine clearance increased from 102.01 ± 43.2 to 109.1 ± 51.3 (p=0.28). Mean SLE-DAI-2K scores reduced from 16.3 ± 6.2 to 7.2 ± 4.8 (p=0.00). The initial steroid dose decreased from 24.13 ± 18.47 mg/day to 7.5 ± 5.8 mg/day (p=0.0) at the last rituximab course. Three patients developed end-stage renal disease. For primary endpoints, 53.1% achieved a prednisolone dose of ≤ 5mg, and 36.1% achieved 24-hour proteinuria ≤ 500 mg. Both criteria were met by 25.5% of patients. Adverse events included serum reactions in two patients, pneumonia in three, and herpes zoster in three. Three patients developed hypogammaglobulinemia, successfully treated with intravenous immunoglobulin. Importantly, no patients succumbed to lupus nephritis. Conclusion For patients resistant to conventional treatments, rituximab appears to be a viable alternative in managing lupus nephritis. In our single-center analysis, class 3 lupus nephritis patients derived the most benefit from rituximab. Overall, the side effects were manageable, making rituximab a valuable option for reducing steroid dependence and achieving favorable clinical outcomes in these patients.