CD8A and rheumatoid arthritis: Notably, this CD8+ T cell subset shows a senescent/terminally differentiated immunoprofile, DDR activation, telomere shortening, and dysfunction and retains cytotoxic and proinflammatory functions (Figures 2, 3, 4, 5) and is also detectable with lower frequency in patients with RA and elderly HD participants (mean ± SD age: 51 ± 15).