The coronavirus disease 2019 (COVID-19) pandemic has affected the entire world, and has a variety of clinical presentations. The aim of this study is to determine the relationships of fecal cytokines and markers with the symptoms and prognosis of children with COVID-19 infection, and to identify noninvasive markers during follow-up. In a cohort of 40 COVID-19-positive children and 40 healthy controls, fecal cytokines and markers were examined in stool samples. A binary logistic model was used to assess the potential of cytokines as risk factors for hospitalization. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported. A P-value <0.05 was accepted as statistically significant. Levels of fecal lysozyme, myeloperoxidase, hemoglobin, and interleukin-5 (IL-5) (P < 0.05) were significantly higher among the patients than controls. In a logistic regression analysis, fecal IL-2 (OR = 3.83; 95% CI: 1.44-15.92), IL-4 (OR = 2.96; 95% CI: 1.09-12.93), IL-5 (OR = 4.56; 95% CI: 1.18-27.88), IL-10 (OR = 2.71 95% CI: 1.19-7.94), interferon-gamma (IFN-γ) (OR = 4.03; 95% CI: 1.44-15.73), IFN-α (OR = 3.02; 95% CI: 1.08-11.65), calcium-binding protein B S100 (S100 B) (OR = 4.78; 95% CI: 1.31-27.82), neutrophil elastase (NE) 2 (OR = 4.07; 95% CI: 1.17-19.69), and matrix metalloproteinase 1 (MMP-1) (OR = 3.67; 95% CI: 1.1-18.82) levels were significantly higher in hospitalized patients with COVID-19 infection than outpatients. We demonstrated that various fecal cytokines and markers were increased in patients who had COVID-19. Fecal IL-2, IL-4, IL-5, IL-10, IFN-γ, IFN-α, S100 B, NE, and MMP-1 levels were significantly elevated in hospitalized patients. We suggest that the fecal and serum levels of cytokines could be used to predict the prognosis of COVID-19 disease, although more studies are needed to confirm this.
Keywords: COVID-19 disease; children; fecal cytokines; fecal markers.