Exploring the clinical application value of peripheral blood T lymphocyte subset in patients with asymptomatic omicron infection

Objective To investigate the clinical significance and value of peripheral blood T lymphocyte subset in patients with asymptomatic novel coronavirus variant strains infection (OMICRON). Methods A retrospective analysis of 281 patients with asymptomatic OMICRON infection who were admitted and isolated to the Fuyang Second People's Hospital from March to April 2022 was conducted. With 32 normal people as the control group, T lymphocytes of the two groups (CD3 + T, CD3 + CD4 + T, CD3 + CD8 + T) were analyzed and the differences between the two groups were analyzed. CD4 + T lymphocytes between patients with asymptomatic OMICRON infection and patients with mild COVID-19 infection in 2020 were analyzed and compared. Based on CD3 CD4 + T lymphocyte changes, lymphocyte reference range: CD3 CD4 + T lymphocyte count 404–1612/μL. Lower than 404 × 106/μL was defined as lymphocytopenia, patients were divided into the reduced group (138) and the normal group (143). The CT value of novel coronavirus nucleic acid (ORF1ab gene, N gene) and the time of viral shedding were compared between the two groups. Results Differences in number of CD3 + T cells, CD3 + CD4 + T cells, and CD3 + CD8 + T cells were significant between both groups ( P < 0.05), which were significantly higher in the normal population than in the patients with asymptomatic OMICRON infection. There was no significant difference in CD4 + T lymphocytes between patients with asymptomatic OMICRON infection and patients with mild COVID-19 infection in 2020 ( P < 0.05). The novel coronavirus nucleic CT value was significantly lower in the CD3CD4 + T lymphocyte-reduced group than in the CD3CD4 + T lymphocyte-normal group ( P < 0.05). Moreover, the time of viral shedding was significantly longer in the reduced group compared with the normal group ( P < 0.05). Conclusion The changing characteristics of the peripheral blood T lymphocyte subset count in patients with asymptomatic OMICRON infections can provide an important basis for the diagnosis and outcome of the asymptomatic OMICRON infection.