Nationwide prevalence and incidence of MOG antibody-associated disease (MOGAD) in Denmark

To estimate the nationwide population-based incidence and prevalence of MOGAD in the Danish adult population (age ≥18 years) based on the 2023 International MOGAD Panel proposed criteria.

In this population-based historically prospective study, data were sourced from laboratories providing MOG-IgG test, the Danish Multiple Sclerosis Registry, and departments of neurology in Denmark. We computed the crude-, sex-, age-, race- specific incidence and prevalence.

We confirmed MOGAD in 71 cases between 2016 and 2020. The incidence of MOGAD in the Danish adult population was 0.205 per 100,000 person-years (95% CI: 0.145-0.281), and the prevalence was 1.51 per 100,000 persons (95% CI: 1.18-1.91). The incidence in the female adult population was 0.192 and in the male population 0.218 per 100,000 person-years (95% CI: 0.114-0.303 and 0.133-0.337). The prevalence among female was 1.43 while in male 1.6 per 100,000 persons, respectively (95% CI: 0.99-2.00 and 1.13-2.20). The incidence and prevalence peaked in the age group 18-39 years, however MOGAD occurred in all age groups inclusive in elderly (age 65≤). No difference in the race-specific data was found.

We report estimates of incidence and prevalence of MOGAD in a national population-based design according to the 2023 criteria. Considering recent national population-based data in neuromyelitis optica spectrum disorder (NMOSD) obtained with similar approaches in the Danish adult population, the incidence and prevalence of MOGAD are 3 times and 1.4 times higher, respectively.