{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,26]],"date-time":"2026-01-26T15:57:07Z","timestamp":1769443027165,"version":"3.49.0"},"reference-count":38,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,1,26]],"date-time":"2026-01-26T00:00:00Z","timestamp":1769385600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>The aim of the following study is to determine the association between lymphocyte subsets (total lymphocytes, CD3, CD4, CD8, B cells, NK cells) and clinical outcomes (need for non-invasive ventilatory support, ICU admission and in-hospital death) in patients hospitalized with SARS-CoV-2 infection.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We conducted a single-center, pre-vaccination, retrospective cohort study including adults hospitalized between March 2020 and April 2021. Peripheral blood samples were collected within the first 24 h of admission for immune phenotyping. Additional clinical data were obtained from electronic health records. Statistical analyses included chi-square tests and multivariable logistic regression, adjusted for clinical characteristics and inflammatory biomarkers. Optimal cutoff points for immune and inflammatory markers were determined using the Youden index.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Among 959 patients, 29.4% required ventilatory support, 11.3% required ICU admission, and 10.7% died. In multivariable analysis adjusted by clinical and laboratory confounders, CD3+ cells (cutoff point: 666 cells\/mm\n                      <jats:sup>3<\/jats:sup>\n                      ) were independently associated with ventilatory support (aOR: 2.3, 95%CI: 1.5\u20133.4,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.013) and in-hospital death (aOR: 2.4, 95%CI: 1.3\u20134.3,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.048); and CD4+ cells (cutoff point: 359 cells\/mm\n                      <jats:sup>3<\/jats:sup>\n                      ) were independently associated with in-hospital death (aOR: 2.8, 95%CI: 1.4\u20135.5,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.045).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Adaptive immunity, especially T CD3+ and T CD4+ cells, is relevant in the prognosis of COVID-19, and T-cell counts can help identify hospitalized COVID-19 patients at risk for severe outcomes: ventilatory support and in-hospital death.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmed.2026.1740358","type":"journal-article","created":{"date-parts":[[2026,1,26]],"date-time":"2026-01-26T05:40:37Z","timestamp":1769406037000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Low CD3+ and CD4+ T cell levels predict need for ventilatory support and in-hospital mortality in patients with COVID-19: a retrospective cohort study"],"prefix":"10.3389","volume":"13","author":[{"given":"Ester Lobato","family":"Mart\u00ednez","sequence":"first","affiliation":[{"name":"Department of Internal Medicine, Alicante Institute for Health and Biomedical Research (ISABIAL), Dr. Balmis General University Hospital","place":["Alicante, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"\u00d3scar","family":"Moreno-P\u00e9rez","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Nutrition, Alicante Institute for Health and Biomedical Research (ISABIAL), Dr. Balmis General University Hospital","place":["Alicante, Spain"]},{"name":"Department of Clinical Medicine, Miguel Hern\u00e1ndez University","place":["Alicante, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Silvia","family":"Otero-Rodr\u00edguez","sequence":"additional","affiliation":[{"name":"Infectious Diseases Unit, Alicante Institute for Health and Biomedical Research (ISABIAL), Dr. Balmis General University Hospital","place":["Alicante, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Raquel","family":"Garc\u00eda-Sevila","sequence":"additional","affiliation":[{"name":"Department of Clinical Medicine, Miguel Hern\u00e1ndez University","place":["Alicante, Spain"]},{"name":"Department of Pneumology, Alicante Institute for Health and Biomedical Research (ISABIAL), Dr. Balmis General University Hospital","place":["Alicante, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Francisco","family":"Marco-de-la-Calle","sequence":"additional","affiliation":[{"name":"Department of Immunology, Alicante Institute for Health and Biomedical Research (ISABIAL), Dr. Balmis General University Hospital","place":["Alicante, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rosario","family":"S\u00e1nchez-Mart\u00ednez","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Alicante Institute for Health and Biomedical Research (ISABIAL), Dr. Balmis General University Hospital","place":["Alicante, Spain"]},{"name":"Department of Clinical Medicine, Miguel Hern\u00e1ndez University","place":["Alicante, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Esperanza","family":"Merino-de-Lucas","sequence":"additional","affiliation":[{"name":"Department of Clinical Medicine, Miguel Hern\u00e1ndez University","place":["Alicante, Spain"]},{"name":"Infectious Diseases Unit, Alicante Institute for Health and Biomedical Research (ISABIAL), Dr. Balmis General University Hospital","place":["Alicante, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jos\u00e9-Manuel","family":"Ramos-Rinc\u00f3n","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Alicante Institute for Health and Biomedical Research (ISABIAL), Dr. Balmis General University Hospital","place":["Alicante, Spain"]},{"name":"Department of Clinical Medicine, Miguel Hern\u00e1ndez University","place":["Alicante, 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