Abstract
Background: Although there are several severity predictors for COVID-19, none are specific. Serum levels of phenylalanine were recently associated with increased inflammation, higher SOFA scores, ICU admission, and mortality rates among non-COVID-19 patients. Here, we investigated the relationship between phenylalanine and inflammatory markers in adults with COVID-19.
Methods: We assessed adults with COVID-19 at hospital admission for clinical and laboratory data. Nuclear magnetic resonance spectroscopy measured serum levels of phenylalanine and other amino acids of its metabolomic pathway. Flow Cytometry measured serum levels of IL-2, IL-4, IL-6, Il-10, TNF-α, and IFN-γ. Linear regression models adjusted for potential confounders assessed the relationship between serum levels of phenylalanine and inflammatory cytokines.
Results: Phenylalanine and tyrosine were significantly lower in mild disease as compared to moderate and severe groups. Linear regression models showed that phenylalanine is independently and positively associated with disease severity regardless of the cytokine analyzed and after adjustment for potential confounders. In addition, mild cases showed consistently lower serum phenylalanine levels within the first ten days from disease onset to hospital admission.
Conclusions: Phenylalanine is a marker of disease severity. This association is independent of the time between the onset of symptoms and the magnitude of the inflammatory state.
Keywords: COVID-19; Cytokines; Phenylalanine; SARS-CoV-2; Tyrosine.
【저자키워드】 COVID-19, SARS-CoV-2, Cytokines, Phenylalanine, Tyrosine., 【초록키워드】 Inflammation, Cytokines, IL-6, severity, disease severity, inflammatory markers, cytokine, flow cytometry, serum, ICU admission, amino acids, pathway, Mild, Hospital admission, Inflammatory marker, Inflammatory cytokines, mortality rate, predictor, IL-10, nuclear magnetic resonance, mortality rates, disease, moderate, IFN-γ, Mild disease, TNF-α, IL-2, association, marker, Amino acid, Phenylalanine, IL-4, inflammatory state, disease onset, Flow, independent of, tyrosine, Non-COVID-19 patients, Serum level, serum levels, laboratory data, mild cases, confounders, significantly lower, Clinical and laboratory data, linear regression models, Linear regression model, metabolomic, confounder, independent, SOFA scores, analyzed, addition, investigated, onset of symptom, adjusted, magnitude, groups, mild case, with COVID-19, 【제목키워드】 Phenylalanine,