No abstract

Risk factors for the development of severe COVID 19 include several comorbidities, but age was the most striking one since elderly people were disproportionately affected by SARS Cov 2 Major drivers that can explain this markedly unfavourable response in the elderly are inflammaging and immunosenescence Recent reports have shown that the relationship between immunosenescence and COVID 19 can be bidirectional, since hospitalized patients with severe COVID 19 have an accumulation of senescent T cells suggesting that immunosenescence can be also exacerbated by SARSC oV 2 infection Therefore, the present work was designed to examine the emergence of immunosenescence in a longitudinal study in two distinct cohorts of COVID 19 patients, and to determine whether the senescence alterations were restricted to severe cases of the disease Our data, with patients from Portugal and Brazil, identified their distinctive inflammatory profile and provided evidence of increased frequencies of senescent and exhausted T cells within a seven day period in patients with mild to severe COVID 19 These results support the view that SARS CoV 2 infection can accelerate immunosenescence in both CD4 and CD8 T cell compartments in a short period of time Key words COVID 19, immunosenescence, T cell exhaustion, T cell senescence, inflammatory cytokines, inflammaging