Expression of IFN-γ, TNF-α and Interleukins in the Nasopharyngeal Cells and Mononuclear Cells of Mexican Patients with Influenza or SARS-CoV-2

Respiratory viral infections such as influenza and SARS-CoV-2 induce complex immune responses characterized by dysregulated cytokine production, which may influence disease severity and lead to post-infection immunometabolic alterations. However, comparative data on local epithelial and systemic immune responses during acute infection and recovery remain limited. Objective: To evaluate the expression of IFN-γ, TNF-α, and interleukins IL-2, IL-4, IL-6, and IL-10 in nasopharyngeal epithelial cells from patients with influenza and SARS-CoV-2 infection, as well as in peripheral blood mononuclear cells (PBMCs) from individuals who recovered from COVID-19. Methods: A total of 120 participants were distributed into four groups (control, influenza, asymptomatic SARS-CoV-2 infection, and symptomatic COVID-19; n = 30 per group), in addition to 90 individuals who had recovered from COVID-19. COVID-19 and influenza diagnoses were established by the treating physician based on clinical presentation and confirmed by RT–qPCR. Cytokine gene expression was quantified by real-time PCR, and hematological and biochemical parameters were measured using automated analyzers. Results: The asymptomatic SARS-CoV-2 group showed significantly increased expression of IFN-γ (p = 0.0001), TNF-α (p = 0.0007), and IL-4 (p = 0.01). Individuals who recovered from COVID-19 exhibited elevated erythrocyte and leukocyte counts, along with increased glucose, glycated hemoglobin, triglycerides, and very-low-density lipoprotein levels, while no significant alterations in liver function markers were observed. Conclusions:Influenza and SARS-CoV-2 infections are associated with distinct epithelial cytokine expression profiles during acute infection, and COVID-19 recovery is characterized by persistent immunometabolic alterations, suggesting prolonged systemic effects beyond viral clearance.