Association of CD4+/CD8+ T Cell Subsets and Cytokine Profiles with Clinical Outcomes in COVID-19

Abstract

Objective: This study aimed to evaluate the prognostic significance of CD4+ and CD8+ T cell dynamics and cytokine profiles during the early stage of COVID-19.

Methodology: This cross-sectional study included adult patients (≥18 years) with COVID-19 confirmed by quantitative reverse transcription polymerase chain reaction (RT-PCR). The study was conducted at Sakarya Training and Research Hospital between June to August 2020. A total of 20 patients were randomly selected. Laboratory parameters obtained before treatment initiation (day one) and on the third day of treatment (day three) were retrospectively compared. Patients with prior convalescent plasma therapy, tocilizumab use, or systemic corticosteroid treatment were excluded to minimize confounding effects on immune parameters.

Results: The study population comprised 55% female patients, with a mean age of 56.10 ± 18.67 years. Common comorbidities included diabetes mellitus (20%), hypertension (15%), and chronic obstructive pulmonary disease (10%). The most frequent clinical manifestations were cough (75%), fatigue (65%), fever (35%), and dyspnea (20%). Comparative analysis between day one and day three demonstrated statistically significant changes in white blood cell count, platelet count, neutrophil-to-lymphocyte ratio, aspartate aminotransferase, and creatine kinase-MB levels (p < 0.05). No significant differences were observed in CD4+ and CD8+ T cell counts, cytokine profiles, or other evaluated laboratory parameters (p > 0.05).

Conclusion: Although significant short-term changes in several inflammatory and biochemical markers, CD4+ and CD8+ T cell dynamics and cytokine profiles showed no prognostic value in early COVID-19. These findings highlight important immunological characteristics of COVID-19; however, larger studies with longer follow-up are warranted to clarify the prognostic role of immune biomarkers.