Quality of Life in Japanese Patients with Primary Immunodeficiency Disease is Disrupted throughout the Year.

Patients with primary immunodeficiency disease (PID) have an increased susceptibility to infection and may experience negative impacts on health-related quality of life (HR-QOL) and activities of daily living. This prospective observational study of patients aged ≥ 12 years with PID assessed HR-QOL, work impairment, and disease-related daily burden over a full year, with a focus on seasonal variation. The study period was from October 2021 to November 2023. Data were collected using an online system. HR-QOL was assessed using EuroQol-5 Dimensions-5 Levels (EQ-5D-5L) and the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), work impairment with the Work Productivity and Activity Impairment (WPAI) questionnaire, and disease-related burden with a questionnaire designed for this study. In patients with PID (N = 56) and healthy volunteers (N = 43), no significant seasonal variation was observed in EQ-5D-5L, SF-36, or WPAI scores. With few exceptions, patients with PID had significantly lower EQ-5D-5L, SF-36, and WPAI scores than healthy volunteers in all seasons. In patients with PID, disease-related symptoms and limitations of daily living persisted throughout the year, regardless of season. In conclusion, patients with PID had lower quality of life and were more socially, physically, and mentally stressed in all seasons compared with healthy individuals.