EFFICACY AND SAFETY OF SINGLE DOSE RITUXIMAB IN STEROID-DEPENDENT OR FREQUENTLY RELAPSING MINIMAL CHANGE DISEASE IN A CHINESE MEDICAL CENTER

Abstract Background and Aims The purpose of our study was to evaluate efficacy and safety of single dose rituximab in steroid-dependent or frequently relapsing minimal change disease during one-year follow-up. Method Twenty patients with corticosteroid-dependent (n=12) or frequently relapsing (n=8) idiopathic minimal-change diseases were hospitalized between August 2018 and July 2019 in the tertiary hospital. They received a single-dose rituximab (1g) concomitantly with their corticosteroid and immunosuppressors. The side effects of RTX were also recorded. Results We included 20 patients (15 males and 5 females). The mean age of onset renal disease was 21±9 years old. The included patients were steroid dependent, of whom 8 patients were frequently relapse. All patients had been received steroid in the past. 14 patients had been treated with calcineurin inhibitors (n=13, 65%) or mycophenolate mofetil (n=1, 5%). The baseline serum albumin was 33±10g/L, and serum creatinine was 76±38μmol/L, and 24-hour urine protein was 0.22 (0.06, 6.07) g/d. B-cell depletion (CD19+B cell<5/μL) was achieved after RTX infusion within one week. The average frequency of administered RTX was 1.47 times per person per year. We observed B cell reconstitution (CD19+B cell>20/μL) in 8 cases (35%) after the first dose of RTX. During follow-up (15.5±7.0 months), 19 patients achieved complete remission, while one patient was resistant to treatment. However, five relapse episodes were recorded during tapering steroids or after stopping steroids. Compared with the year before rituximab treatment, the per-patient average number of relapses decreased from 1.4±0.6 to 0.4±0.7 during 1 year of follow-up. After rituximab, the per-patient prednisone maintenance median dose decreased from 0.28 mg/kg (0.17, 0.46) to 0mg/kg (0, 0.07) (P<0.001). Furthermore, the mean estimated GFR was stable (from 117±26 to 120±17 ml/min per 1.73m2, P>0.05). There were three cases of mild infusion reaction (manifested as skin itching and rash) and two cases of infection (one case each of pneumocystis pneumonia and skin infection caused by actinomycetes). Conclusion Single-dose of RTX effectively prevented relapse and reduced the need for steroid in steroid-dependent or frequently relapsing minimal change disease.