Investigate seasonal variations for onsets and attacks among AQP4 antibody-positive NMOSD patients  in Asia

The changing of seasons is often accompanied by variations in sunlight, temperature, and infection patterns, which are believed to fine-tune the self-immunity threshold; however, there is still a lack of systematic data in Asian countries on whether NMOSD onset has predictable seasonal preference.

This study collected hospitalization data from 379 patients: 157 hospitalizations from 136 patients in Guangdong Province located at Southen China (2019–2024); 145 onset events from 121 patients  in Jilin Province located in Northern China (2019–2024); and 130 cases from Chiang Mai  in Thailand (2013–2022). Using descriptive and inferential statistical techniques, demographic and clinical data for all patients were juxtaposed with monthly weather data for the period, while exploring differences in the number of monthly incidence cases across seasons. 

Among the N=379 patients studied, a total of 432 hospitalization cases were recorded. Significant seasonal variation was observed in the number of hospitalization cases.  In Guangdong, July had the highest number of hospitalization cases at 23 (14.64%), followed by May and August with 19 (12.10%) and 17 (10.83%) cases, respectively.  In Jilin, July had the highest number of hospitalized cases at 18 (12.41%), followed by August and November, each with 15 cases (10.34%).  Interestingly, the annual hospitalization counts increased from 42 to 104 between 2023 and 2024, compared to the period from 2019 to 2022, despite an average annual decrease of 120 hours of sunshine duration. In Chiang Mai, June had the highest number of hospitalizations at 19 cases (14.61%), followed by July with 16 cases (12.31%).  

1.  The onsets and attacks of AQP-4 positive NMOSD  cases in Asia exhibit seasonal patterns, warranting attention in future diagnosis and treatment. The potential influence of climate change on these seasonal anomalies at the onset merits further investigation.