Clinical, Radiological and B Cell Count Follow Up of Egyptian Patients with Neuromyelitis Optica Spectrum Disorder on Rituximab Therapy

Abstract Background Neuromyelitis optica spectrum disorder is an uncommon chronic inflammatory disease of the central nervous system, manifesting clinically as optic neuritis, myelitis, and certain brain and brainstem syndromes. Rituximab targets the CD20 antigen on B-cells and leads to profound B-cell depletion, principally over an antibody-dependent cell cytotoxicity mechanism and decreases attack frequency and severity in patients with NMOSD. This study aimed to assess the correlation between clinical, radiological findings and the count of peripheral circulating B cells (CD 19) during rituximab treatment over 12 months. It included 15 Egyptian adult patients diagnosed with NMOSD. Results There was a predominance of women with female: male ratio 2:1. AQP4- IgG antibody was detected in 65% of the patients. The mean age was 36.47 years, mean duration of illness was 3.71 years. MRI of brain showed no abnormality in 82% of patients. Cord MRI showed single lesion in 59% and multiple lesions in 41%. Visual evoked potential showed that most of patients have optic nerve affection either unilateral or bilateral. Median CD19 B cell percentage depleted significantly from 7.3 to 0.2 after treatment. No serious adverse event was encountered in our patients; 35% developed either hypersensitivity or mild infections. Conclusion The effect of rituximab treatment on B cells has no correlation with clinical or radiological outcome of patients.