A comparative analysis of demographic, clinical and imaging features of myelin oligodendrocyte glycoprotein antibody positive, aquaporin 4 antibody positive, and double seronegative demyelinating disorders - An Indian tertiary care center prospective study.

Objectives: The aim of the study was to study the demographical, clinical, radiological features, and outcome of anti-myelin oligodendrocyte glycoprotein (MOG) antibody spectrum disorder and compare these features with patients negative for anti-MOG antibody. MOG antibody-associated disease (MOGAD) and aquaporin-4 (AQP4) antibody-related diseases are immunologically distinct pathologies. Our aim was to compare the clinical and radiological features of MOG antibody-related diseases with AQP4 antibody-related diseases and seronegative demyelinating diseases (Non-multiple sclerosis).

Materials and methods: This was a prospective and cohort study conducted at an apex tertiary care institute in the northern part of India from Jan 2019 to May 2021. We compared clinical, laboratory, and radiological findings of patients with MOGAD, AQP4 antibody-related diseases, and seronegative demyelinating disease.

Results: There were a total of 103 patients - 41 patients of MOGAD, 37 patients of AQP4 antibody-related diseases and 25 seronegative demyelinating disease. Bilateral optic neuritis was the most frequent phenotype in patients with MOGAD (18/41) whereas myelitis was the most common phenotype in the AQP4 (30/37) and seronegative groups (13/25). Cortical, juxtacortical lesions, anterior segment optic neuritis, optic sheath enhancement, and conus involvement in myelitis were radiological findings that separated MOGAD from AQP4 related diseases. Nadir Expanded Disability Status Scale (EDSS) and visual acuity were similar across the groups. Last follow-up EDSS was significantly better in the MOG antibody group as compared to AQP4 antibody group (1 [0-8] vs. 3.5 [0-8]; P = 0.03). Encephalitis, myelitis, and seizures were more common in the younger population (<18 vs. >18 years) in MOGAD (9 vs. 2, P = 0.001; 9 vs. 7, P = 0.03; 6 vs. 0, P = 0.001).

Conclusion: We identified several clinical and radiological features that can help physicians to distinguish MOGAD from AQP4-immunoglobulin G+neuromyelitis optica spectrum disorder. Differentiation is vital as treatment response might vary among both groups.