Relapses shortly after rituximab treatment in neuromyelitis optica spectrum disorder

Objective Rituximab (RTX), an anti-CD20 monoclonal antibody, has been demonstrated to be a useful maintenance therapy for neuromyelitis optica spectrum disorder (NMOSD). However, few patients may suffer from relapses shortly after RTX. In order to investigate the clinical features of RTX-related relapses and guide therapeutic strategy, 3 patients in our department were reported and literatures were reviewed. Methods We reported three NMOSD patients suffered from relapses shortly after rituximab treatment in our hospital and reviewed 13 patients reported in literatures. Their demographic characteristics, clinical features and therapeutic strategy were retrospectively analyzed. Results Sixteen patients, including three cases reported in this study, experienced 21 attacks within 1 month after RTX infusion. All of them were women with an age at onset of 34.0 ± 15.0 years. Fourteen patients were seropositive for aquaporin-4 antibody, and one was seropositive for myelin oligodendrocyte glycoprotein antibody. 57.1% (12/21) of RTX-related relapses occurred after the first use of RTX. Their clinical manifestations included optic neuritis (8/21), myelitis (11/21), and the other two relapses without detailed descriptions. Also, 62.5% (10/16) of patients had a history of prior relapses within 3 months before RTX infusions, and the location of nine relapses overlapped with previous relapses. RTX was given again after the first RTX-related relapse in eight patients, three of them with low-dosage RTX stayed stable for years, and five patients with full-dosage RTX experienced another RTX-related relapse. Conclusions Relapses may occur shortly after RTX treatment in NMOSD. RTX-related relapse did not necessarily mean that RTX was ineffective in low-dosage regimen. Timely and sufficient treatment of RTX is crucial to prevent a relapse. It may be more reasonable to monitor B cell repopulation so as to determine a re-treatment regimen. RTX-related relapse following full-dosage RTX may be a predictor for a second time RTX-related relapse and it may be reasonable to switch to other immunosuppressants in early stage.