MOGAD treatment outcomes and relapse characteristics: Real world experience from a Low-Middle income country.

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD) is a distinct immune-mediated neurological disorder requiring specific therapies. The study aims to evaluate relapse patterns, predictors, and compare relapse rates and disability outcomes of common immunotherapies in Indian MOGAD patients.

METHODOLOGY: We conducted an observational cohort study of 155 pediatric and adult MOGAD patients, classifying phenotypes into optic neuritis (ON), myelitis (MYE), acute disseminated encephalomyelitis (ADEM), opticomyelitis (OM), brainstem (BS) and others. Annualized relapse rates (ARR) and Expanded Disability Status Scale (EDSS) scores were calculated pre- and on-treatment for azathioprine (Imuran), mycophenolate mofetil (CellCept) and rituximab. Kaplan-Meier survival analysis and Cox proportional hazards regression identified predictors of relapse.

RESULTS

ON (39.4 %) was the most common phenotype though pediatric patients had significantly more ADEM cases (p < 0.001). Over half experienced relapses, more in pediatric (p = 0.011), and ADEM patients (p < 0.001). More frequent relapses correlated with higher EDSS scores at last follow-up (rho=0.442, p < 0.001). MYE patients had the longest relapse-free survival (median 132 months, p < 0.001). Mean(SD) ARR reduced from 1.12(2.00) to 0.26(0.49) with azathioprine (Imuran), from 1.08(2.43) to 0.11(0.54) with MMF (p = 0.006) and from 1.23(2.30) to 0.71(2.01) with rituximab (p = 0.007). EDSS scores significantly improved with all therapies (p < 0.001-0.007). Higher baseline ARR predicted relapse after treatment initiation (HR 1.23[95 % CI,1.05-1.43], p = 0.009), while myelitis at onset was protective (HR 0.22[95 % CI,0.05-0.95], p = 0.042).

CONCLUSION

Over half of MOGAD patients relapse, and increased relapses correlate with greater long-term disability. Myelitis at onset is associated with lower relapse risk. Conventional first-line immunotherapies are effective across medications, phenotypes and age groups.