Application of rituximab to treat minimal change disease with refractory nephrotic syndrome in the remission maintenance phase with long-term follow-up

Background: Minimal change disease (MCD) has a high recurrence rate, with refractory MCD frequently requiring long-term corticosteroid therapy or combination regimens with other immunosuppressive agents. Rituximab has been confirmed to be an effective treatment for refractory MCD. However, in the remission maintenance phase, the effects of multiple factors remain unclear, including the dose or infusion interval of rituximab, the use of concomitant immunosuppressants, the relapse rate, the relationship between B-cell reconstruction and relapse, and relapse-related factors. Methods: We reviewed 14 refractory MCD patients receiving rituximab with a mean follow-up duration of 25.9±8.9 months. Three patients were in partial remission, and 11 patients achieved complete remission before RTX treatment. RTX was administered intravenously at a dose of 375 mg/m ² body surface area or 1000 mg initially. In the subsequent treatment, RTX was administered at 375 mg/m ² body surface area or 1000 mg every infusion. Result: Nine patients with a mean annual RTX dose of 1929±504 mg remained in remission. Five patients experience a relapse, and their mean annual RTX dose significantly decreased to 940±111 mg (P<0.05). Eleven patients stopped steroids or immunosuppressants, and 3 patients had a reduction in steroids or immunosuppressants. The relapse frequency significantly decreased from 1.87 (0.43, 2.69) to 0 (0, 1.33). B-cell reconstruction was not associated with relapse. The cumulative annual dose of RTX was significantly negatively correlated with relapse. Conclusion: RTX significantly reduced the relapse rate and facilitated earlier withdrawal of corticosteroids and immunosuppressants during the remission maintenance phase in refractory MCD patients. Serious side effects were not reported. During the remission phase, we can extend the infusion interval appropriately but cannot ignore the case of an accumulated annual dose of RTX.