Cytokine profile and disease severity in patients with COVID-19

Cytokine dysregulation is the proposed mechanism for Coronavirus disease 2019 (COVID-19). The aim of this study was to evaluate the serum levels of interferon (IFN)-gamma, interleukin (IL)-5, IL-8, Il-9, IL-17, TGF-beta and IFN-gamma in patients infected with SARS-CoV-2. The study was conducted between 63 adult patients with COVID-19 and compared with 33 age and gender-matched healthy subjects as controls. The age range in both groups was 50-70 years. The patients were classified into mild group (33 patients) and severe group (30 patients). Serum samples were collected from all participants and tested for the cytokine levels by ELISA (enzyme-linked immunosorbent assay) method. Statistical analysis was performed using the one-way ANOVA. The mean serum levels of IFN-gamma, TGF-beta, IL-17 and IL-8 in the COVID-19 patients were significantly higher than those observed in the control group. A comparison of between the mild and severe groups showed significant differences in TGF-beta levels. The mean concentration of serum IL-5 and IL-9 in patients with COVID-19 did not differ from those in the control group. Systemic IL-17 levels correlated positively and significantly with TGF-beta in patients with COVID-19. Th1 (IFN-gamma), Treg (TGF-beta), and Th17 (IL-17) cytokines concentration were increased in COVID-19 patients. Interferon-gamma and IL-17 are involved in inducing and mediating proinflammatory responses. Our data suggest that TGF-beta can be used as a predictive factor of disease severity in patients with COVID-19.