To determine incidence of patients with myelin oligodendrocyte glycoprotein antibody–associated disease (MOGAD).

We conducted a retrospective cohort study of people who met the 2023 MOGAD diagnostic criteria with symptom onset 1/1/2019-12/31/2024 from the 6,754,063 population-based membership of Kaiser Permanente Southern California (KPSC). Electronic health records were manually reviewed. Social Vulnerability Index (SVI) was obtained from the Centers for Disease Control and Prevention.  

Among 75 incident MOGAD patients, 31 (41.3%) were children (<18 years old) at symptom onset, 40 (53.3%) were female, 46 (61.3%) identified as Hispanic and 37 (49.3%) resided in the most vulnerable neighborhoods (4th SVI quartile). The most common presenting symptom was optic neuritis in both children (54.8%) and adults (79.6%). Para-infectious triggers were ubiquitous under 11 years-old (100%), but uncommon in adults (27.3%). The crude incidence (per million person-years) of MOGAD was: 5.3 in children; 1.5 in adults; 3.9 in people residing in the 4th SVI quartile; and 2.1 in total. The incidence risk ratio (IRR) was significantly higher in people residing in the 4th SVI quartile compared to those in SVI quartiles 1-3 (less vulnerable neighborhoods), even after adjusting for age, sex, and Hispanic ethnicity (IRR=2.47, 95%CI=1.54-3.97, p=0.0002). There were no significant differences in incidence by sex or in Black or Asian/Pacific Islander compared to White, non-Hispanic people. The higher IRR in Hispanic people was no longer significant after accounting for SVI.

Our findings indicate MOGAD risk is highest in people residing in the most vulnerable neighborhoods, particularly children. There were no significant differences in risk between racial and ethnic groups after accounting for neighborhood-level factors. These results reinforce the need for accessible, high-quality pediatric hospital care in areas with high socioeconomic vulnerability.