Age-Related Thymic Involution

The age-related thymic involution has intrigued scientists since its first observations. This phenomenon is well-conserved across different species, but the reason why it exists is not clear since the thymus is a key organ in the immune system responsible for the maturation of immunocompetent T lymphocytes. As thymic function declines with age, it significantly affects the health of older individuals, leading to reduced responses to new pathogens, tumor cells, and vaccines. This impact was notably evident during the COVID-19 pandemic, where a substantial number of elderly individuals succumbed to the disease. This chapter explores the characteristics of age-related thymic involution, including new findings using recently developed technologies. We also highlight emerging research trends aimed at rejuvenating thymus function.