Comparative Evaluation of Interleukin 2 and Tumor Necrosis Factor-Alpha Gene Expression Levels in Lymphocytes of COVID-19 Patients: Correlation with Severity and Recovery

Introduction: COVID-19 is caused by SARS-CoV-2 and triggers a significant immune dysregulation known as cytokine storm. This phenomenon is characterized by a systemic inflammatory response, leading to elevated levels of pro-inflammatory cytokines, particularly tumor necrosis factor-alpha (TNF-α) and interleukin 2 (IL-2). TNF-α is crucial for host defense, while IL-2 serves as a growth factor for immune cells, and both are linked to the severity of COVID-19. Symptoms associated with cytokine storm include fever, fatigue, and respiratory distress, correlating with the increased expression of these cytokines. This study evaluated the expression levels of IL-2 and TNF-α genes in intubated patients with severe SARS-CoV-2 compared to control individuals. Methods: Quantitative real-time polymerase chain reaction was used to compare the expression levels of IL-2 and TNF-α in lymphocytes from COVID-19 patients with severe and mild symptoms. A total of 20 samples of each of the severe and mild COVID-19 cases were investigated in this research. Results: A significantly higher expression level of IL-2 and TNF-α in the severe group demonstrated the positive correlation of these two molecular markers of cytokine storm with the severity of the disease. Conclusion: Our data emphasize the crucial role of cytokine balance in regulating viral infections and mitigating immune-mediated complications, supporting the pursuit of cytokine-targeted therapies to enhance clinical outcomes in COVID-19 patients.