Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Mar;36(3):e24257.
doi: 10.1002/jcla.24257. Epub 2022 Jan 29.

Kynurenine pathway in Coronavirus disease (COVID-19): Potential role in prognosis

Murat Cihan  1 , Özlem Doğan  2 , Ceyhan Ceran Serdar  3 , Arzu Altunçekiç Yıldırım  4 , Celali Kurt  4 , Muhittin A Serdar  5
Affiliations

Kynurenine pathway in Coronavirus disease (COVID-19): Potential role in prognosis

Murat Cihan et al. J Clin Lab Anal. 2022 Mar.

Abstract

Background: It is known that inflammatory responses play an important role in the pathophysiology of COVID-19.

Aims: In this study, we aimed to examine the role of kynurenine (KYN) metabolism on the severity of COVID-19 disease AQ5.

Materials & methods: Seventy COVID-19 patients of varying severity and 30 controls were included in the study. In addition to the classical laboratory parameters, KYN, tryptophan (TRP), kynurenic acid (KYNA), 3 hydroxykynurenine (3OHKYN), quinolinic acid (QA), and picolinic acid (PA) were measured with mass spectrometry.

Results: TRP, KYN, KYN:TRP ratio, KYNA, 3OHKYN, PA, and QA results were found to be significantly different in COVID-19 patients (p < 0.001 for all). The KYN:TRP ratio and PA of severe COVID-19 patients was statistically higher than that of mild-moderate COVID-19 patients (p < 0.001 for all). When results were examined, statistically significant correlations with KYN:TRP ratio, IL-6, ferritin, and procalcitonin were only found in COVID-19 patients. ROC analysis indicated that highest AUC values were obtained by KYN:TRP ratio and PA (0.751 vs 0.742). In determining the severity of COVID-19 disease, the odd ratios (and confidence intervals) of KYN:TRP ratio and PA levels that were adjusted according to age, gender, and comorbidity were determined to be 1.44 (1.1-1.87, p = 0.008) and 1.06 (1.02-1.11, p = 0.006), respectively.

Discussion & conclusion: According to the results of this study, KYN metabolites play a role in the pathophysiology of COVID-19, especially KYN:TRP ratio and PA could be markers for identification of severe COVID-19 cases.

Keywords: coronavirus-19 disease (COVID-19); kynurenine pathway; prognosis.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

FIGURE 1
FIGURE 1
Metabolites in the KYN pathway and its possible relationship with COVID‐19
FIGURE 2
FIGURE 2
Comparison of COVID‐19 patient groups with different severity levels and healthy control groups with respect
FIGURE 3
FIGURE 3
ROC analysis results of the comparison of COVID‐19 patients with the control group and mild‐moderate COVID‐19 patients with severe COVID‐19‐ICU patients with respect to inflammatory markers and KYN metabolites
See this image and copyright information in PMC

References

    1. Gustine JN, Jones D. Immunopathology of hyperinflammation in COVID‐19. Am J Pathol. 2021;191:4‐17. - PMC - PubMed
    1. Tay MZ, Poh CM, Rénia L, MacAry PA, Ng LFP. The trinity of COVID‐19: immunity, inflammation and intervention. Nat Rev Immunol. 2020;20:363‐374. - PMC - PubMed
    1. Qin C, Zhou L, Hu Z, et al. Dysregulation of immune response in patients with coronavirus 2019 (COVID‐19) in Wuhan, China. Clin Infect Dis. 2020;71:762‐768. - PMC - PubMed
    1. Wong CK, Lam CWK, Wu AKL, et al. Plasma inflammatory cytokines and chemokines in severe acute respiratory syndrome. Clin Exp Immunol. 2004;136:95‐103. - PMC - PubMed
    1. Zhou F, Yu T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID‐19 in Wuhan, China: a retrospective cohort study. Lancet. 2020;395:1054‐1062. - PMC - PubMed