Global landscape of autoimmune diseases across different lifespan: A three-decade perspective

Autoimmune diseases (ADs) are immune-mediated disorders characterized by a malfunction of the immune system, leading to inflammation, organ dysfunction, and a significant impact on patients' quality of life. This study aimed to comprehensively evaluate the dynamic trends in the prevalence of ADs across geographies, life cycles, and sex, and to project the prevalence up to 2050. We utilized data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2021 to estimate the age-standardized prevalence rate of ADs. We assessed the dynamic trends from 1990 to 2021 by calculating the average annual percentage change using linkage regression analysis and evaluated age-period-cohort effects. The prevalence of ADs up to 2050 was projected using a mixed-effects model. The global age-standardized prevalence rate of ADs nearly doubled from 1990 to 2021. We observed a notable increase in type 1 diabetes, downward trends in inflammatory bowel disease, multiple sclerosis, and psoriasis, and stable trends in alopecia areata, rheumatic heart disease, and rheumatoid arthritis. The disease burden was lower in childhood but higher in young and middle-aged adults, particularly among females. Age-period-cohort analysis revealed that the risk of ADs increased with age across all regions. Our model projected an upward trend in prevalence from 2022 to 2032, followed by a gradual decline until 2050. Our findings highlight the need for tailored health policies and resource allocation to address the distinct needs of patients with ADs across different life cycles and gender groups, which is crucial for mitigating the projected future challenges to healthcare system sustainability.