CD4+, CD8+ T Cell Dynamics and Cytokine Profiles as Prognostic Biomarkers in Early COVID-19: Insights from a Prospective Single-Center Study

Background The aim of this study was to investigate CD4 + and CD8 + T cell dynamics and cytokine profiles as prognostic biomarkers in the early stage of COVID-19. Methods This cross-sectional study included patients whose diagnosis of COVID-19 was confirmed by quantitative RT-PCR. A total of 20 patients aged over 18 years were randomly selected. Laboratory findings obtained prior to the initiation of treatment and on the third day of treatment were compared. Patients with a history of convalescent plasma therapy, tocilizumab, or systemic corticosteroid treatment were excluded from the study. Results Of the patients included in the study, 55% were female, with a mean age of 56.10 ± 18.67 years. Hypertension was present in 15% of the patients, chronic obstructive pulmonary disease (COPD) in 10%, and diabetes mellitus in 20%. Regarding the clinical manifestations of COVID-19, 35% of patients had fever, 75% had cough, 20% had dyspnea, 5% had anosmia, and 5% had muscle/joint pain. Fatigue was observed in 65% of the patients. When laboratory values from day 1 and day 3 were compared, statistically significant differences were found in WBC, PLT, NLR, AST, and CK-MB levels (p < 0.05). In contrast, no significant changes were observed in CD4 + and CD8 + T cell dynamics, cytokine profiles, or other laboratory parameters (p > 0.05). Conclusion In this study, the demographic characteristics, clinical manifestations, and changes in laboratory parameters of patients with COVID-19 were examined in detail. Statistically significant changes were observed in parameters such as WBC, PLT, NLR, and AST, whereas no significant differences were found in CD4 + and CD8 + T cell dynamics or cytokine profiles, which were evaluated as prognostic biomarkers. These findings contribute valuable insights into the clinical and laboratory characteristics of COVID-19 patients; however, further studies with larger sample sizes and longer follow-up periods are warranted.