Simultaneous screening for antibodies to myelin oligodendrocyte glycoprotein and aquaporin-4 in patients with optic neuritis using cell-based assay

Background: This study was aimed to test simultaneous detection of antibodies to myelin oligodendrocyte glycoprotein (MOG)/aquaporin4 (AQP4) in serum samples of patients with clinically-diagnosed optic neuritis (ON), by fixed cell-based immunofluorescence assay (CBIFA). Methods: The study involved 237 serum samples of patients with ON which were tested for MOG and AQP4 antibodies using fixed CBIFA kit which utilizes AQP4 or MOG protein transfected cells as a substrate. Results: Of 237 serum samples, 22 (9%) were positive for AQP4, 66 (28%) were positive for MOG, and 138 (58%) were negative for both AQP4 and MOG antibodies. 11 (5%) patients with clinically-diagnosed multiple sclerosis (MS) were negative for both antibodies. None of the samples were positive for both AQP4 and MOG. Among 237, 132 women [18 (13.6%) and 37 (28%)] and 105 men [4 (3.8%) and 29 (27.6%)] were positive for AQP4/MOG antibodies and remaining percentage belonged to double negative and MS. Seropositivity rate was higher in women than men. Antibodies to MOG were significantly higher than AQP4 antibodies and evenly found in all age groups. There was no ambiguous result encountered in the study. Conclusion: In this study, the seropositivity for antibodies to MOG is more than AQP4 antibody in patients with ON. Fixed CBIFA is a useful tool for laboratory diagnosis of ON in the clinical setting of neuro-ophthalmology to plan the next line of treatment management effectively.