The aquaporin4-IgG status and how it affects the clinical features and treatment response in NMOSD patients in Egypt.

Background: In Egypt, the characterization of Neuromyelitis Optica Spectrum Disorder (NMOSD) is lacking.
Objectives: To determine the demographics, clinical features, aquaporin4 antibodies (AQP4-IgG) status, and neuroimaging of Egyptian NMOSD patients.
Methods: Retrospective analysis of 70 NMOSD patients' records from the MS clinic, Kasr Alainy hospital, between January 2013 and June 2018.
Results: Patients' mean age was 34.9 ± 9.2 years, and the mean at disease onset was 28.9 ± 10.5 years. Fifty-nine patients had an initial monosymptomatic presentation. AQP4-IgG was measured using either enzyme-linked immunosorbent assay (ELISA) (22 patients) or cell-based assay (CBA) (34 patients). Six and 29 patients had positive results, respectively (p < 0.001). 84% had typical NMOSD brain lesions. Longitudinally extensive myelitis was detected in 49 patients, and 9 had either short segments or normal cords. Treatment failure was higher in seropositive patients. Rituximab significantly reduced the annualized relapse rate (ARR) compared to Azathioprine with a percentage reduction of (76.47 ± 13.28) and (10.21 ± 96.07), respectively (p = 0.04). Age at disease onset was the only independent predictor for disability (p < 0.01).
Conclusion: Treatment failure was higher in seropositive patients. However, there was no difference in clinical or radiological parameters between seropositive and seronegative patients. Patients, who are polysymptomatic or with older age of onset, are predicted to have higher future disability regardless of the AQP4-IgG status.