Late Breaking Abstract - Characterization of the immunological profile of COVID-19 patients and correlation of CD4+ and CD8+ T lymphocytes with disease severity during hospitalization

Abstract

Purpose: The aim of the study was to investigate the immunological profile of patients diagnosed with COVID-19 and its correlation with the clinical course of patients and disease severity.

Patients and methods: The study included 51 Covid-19 patients (mean age 68.7 ± 12.5 years), who were hospitalized in the Clinics of General Hospital "George Papanikolaou" during the period of November 2020 to March 2021. During their hospitalization, peripheral blood samples were taken at 4 time-points. Patients were categorized into those with moderate, severe and critical condition. Clinical features were recorded and samples were analyzed by flow cytometry.

Results: Eighteen patients were characterized as moderate, 14 as severe and 19 as critical. Among the 51 patients, 63% were men and 86% had comorbidities. Patients with moderate condition were found with significantly higher rates of CD4+ T lymphocytes (p<0.05), while patients with critical condition were found with a higher percentage of CD8+ T lymphocytes. It is noteworthy, that the CD4+/CD8+ ratio during admission of patients who developed a more severe clinical course was found to be lower and these levels remained low throughout their hospital stay. In addition, in patients with moderate condition on the first day of hospitalization, the percentage of NK cells were found higher in patients with comorbidities (p<0.05).

Conclusions: The above results highlight the usefulness of assessing CD4+ and CD8+ rates at admission, which may be associated with a relatively more serious Covid-19 disease with a potentially worse prognosis for patients.