The Impact of Peripheral Eosinophil Counts and Eosinophil to Lymphocyte Ratio (ELR) in the Clinical Course of COVID-19 Patients: A Retrospective Study

Background/aim: Eosinophils are blood cells responsible for response against parasites and allergens. Eosinophil to lymphocyte ratio (ELR) is a biomarker for inflammatory conditions. Our aim was to evaluate the role of eosinophils and ELR in COVID-19 patients.

Patients And Methods: The study included 96 patients hospitalized with COVID-19. They were classified into moderate to severe cases and critical cases. Eosinophils and ELR were determined in both groups, in patients that died or survived and were correlated to duration of hospitalization.

Results: There was a statistically significant decrease in eosinophils and ELR between patients that died and patients that survived (p<0.05), and in mean values of the two biomarkers (p<0.05 for eosinophils and p<0.05 for ELR) between patients hospitalized for more or less than 15 days among those with moderate to severe disease.

Conclusion: Lower eosinophil counts and ERL could probably predict worse outcome in COVID-19 patients.

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References

Barton L, Duval E, Stroberg E, Ghosh S, Mukhopadhyay S . COVID-19 Autopsies, Oklahoma, USA. Am J Clin Pathol. 2020; 153(6):725-733. PMC: 7184436. DOI: 10.1093/ajcp/aqaa062. View

Xu Z, Shi L, Wang Y, Zhang J, Huang L, Zhang C . Pathological findings of COVID-19 associated with acute respiratory distress syndrome. Lancet Respir Med. 2020; 8(4):420-422. PMC: 7164771. DOI: 10.1016/S2213-2600(20)30076-X. View

Samarasinghe A, Melo R, Duan S, LeMessurier K, Liedmann S, Surman S . Eosinophils Promote Antiviral Immunity in Mice Infected with Influenza A Virus. J Immunol. 2017; 198(8):3214-3226. PMC: 5384374. DOI: 10.4049/jimmunol.1600787. View

Chang M, Park Y, Kim B, Park D . Risk factors for disease progression in COVID-19 patients. BMC Infect Dis. 2020; 20(1):445. PMC: 7309210. DOI: 10.1186/s12879-020-05144-x. View

Zhao L, Zhang Y, Yang X, Liu X . Eosinopenia is associated with greater severity in patients with coronavirus disease 2019. Allergy. 2020; 76(2):562-564. PMC: 7323424. DOI: 10.1111/all.14455. View

Abdul-Cader M, Amarasinghe A, Abdul-Careem M . Activation of toll-like receptor signaling pathways leading to nitric oxide-mediated antiviral responses. Arch Virol. 2016; 161(8):2075-86. PMC: 7087267. DOI: 10.1007/s00705-016-2904-x. View

Flores-Torres A, Salinas-Carmona M, Salinas E, Rosas-Taraco A . Eosinophils and Respiratory Viruses. Viral Immunol. 2019; 32(5):198-207. DOI: 10.1089/vim.2018.0150. View

Cekici Y, Yilmaz M, Secen O . New inflammatory indicators: association of high eosinophil-to-lymphocyte ratio and low lymphocyte-to-monocyte ratio with smoking. J Int Med Res. 2019; 47(9):4292-4303. PMC: 6753567. DOI: 10.1177/0300060519862077. View

Liu J, Liu Y, Xiang P, Pu L, Xiong H, Li C . Neutrophil-to-lymphocyte ratio predicts critical illness patients with 2019 coronavirus disease in the early stage. J Transl Med. 2020; 18(1):206. PMC: 7237880. DOI: 10.1186/s12967-020-02374-0. View

10.

Tanni F, Akker E, Zaman M, Figueroa N, Tharian B, Hupart K . Eosinopenia and COVID-19. J Am Osteopath Assoc. 2020; . DOI: 10.7556/jaoa.2020.091. View

11.

Damaskos C, Garmpi A, Georgakopoulou V, Farmaki P, Diamantis E, Dimitroulis D . COVID-19: do it like Greece. Why Greece is coping with COVID-19 better than other countries?. Pan Afr Med J. 2020; 35(Suppl 2):109. PMC: 7687507. DOI: 10.11604/pamj.supp.2020.35.2.24946. View

12.

Lu G, Wang J . Dynamic changes in routine blood parameters of a severe COVID-19 case. Clin Chim Acta. 2020; 508:98-102. PMC: 7217800. DOI: 10.1016/j.cca.2020.04.034. View

13.

Tian S, Hu W, Niu L, Liu H, Xu H, Xiao S . Pulmonary Pathology of Early-Phase 2019 Novel Coronavirus (COVID-19) Pneumonia in Two Patients With Lung Cancer. J Thorac Oncol. 2020; 15(5):700-704. PMC: 7128866. DOI: 10.1016/j.jtho.2020.02.010. View

14.

Xie G, Ding F, Han L, Yin D, Lu H, Zhang M . The role of peripheral blood eosinophil counts in COVID-19 patients. Allergy. 2020; 76(2):471-482. PMC: 7323233. DOI: 10.1111/all.14465. View

15.

Phipps S, Lam C, Mahalingam S, Newhouse M, Ramirez R, Rosenberg H . Eosinophils contribute to innate antiviral immunity and promote clearance of respiratory syncytial virus. Blood. 2007; 110(5):1578-86. DOI: 10.1182/blood-2007-01-071340. View

16.

Wong C, Cheung P, Ip W, Lam C . Intracellular signaling mechanisms regulating toll-like receptor-mediated activation of eosinophils. Am J Respir Cell Mol Biol. 2007; 37(1):85-96. DOI: 10.1165/rcmb.2006-0457OC. View

17.

Butterfield J . Treatment of hypereosinophilic syndromes with prednisone, hydroxyurea, and interferon. Immunol Allergy Clin North Am. 2007; 27(3):493-518. DOI: 10.1016/j.iac.2007.06.003. View

18.

Branicka O, Rogala B, Gluck J . Eosinophil/Neutrophil/Platelet-to-Lymphocyte Ratios in Various Types of Immediate Hypersensitivity to NSAIDs: A Preliminary Study. Int Arch Allergy Immunol. 2020; 181(10):774-782. DOI: 10.1159/000509116. View

19.

Holub K, Biete A . New pre-treatment eosinophil-related ratios as prognostic biomarkers for survival outcomes in endometrial cancer. BMC Cancer. 2018; 18(1):1280. PMC: 6304088. DOI: 10.1186/s12885-018-5131-x. View

20.

Santotoribio J, Nunez-Jurado D, Lepe-Balsalobre E . Evaluation of Routine Blood Tests for Diagnosis of Suspected Coronavirus Disease 2019. Clin Lab. 2020; 66(9). DOI: 10.7754/Clin.Lab.2020.200522. View