CD8A and Alzheimer disease: Therefore, focus should be directed toward adaptive immunity, encompassing both humoral and cellular immunity.<h4>Methods</h4>Relevant publications and clinical trial data up to February 2026 were systematically reviewed to summarize the mechanisms, therapeutic targets, safety profiles, and translational applications of CD8+ T cells in AD.<h4>Results</h4>Clinical and animal studies have particularly suggested a potential involvement of T cells in AD pathogenesis.