Neutrophil-to-lymphocyte ratio (NLR) greater than 6.5 may reflect the progression of COVID-19 towards an unfavorable clinical outcome

  • Ali Pirsalehi Department of Internal Medicine, School of Medicine, Ayatollah Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  • Sina Salari Department of Medical Oncology, Hematology and Bone Marrow Transplantation, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  • Ahmadreza Baghestani Department of Biostatistics, Physiotherapy Research Center, Faculty of Paramedical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  • Mohammad Vahidi Department of Internal Medicine, School of Medicine, Shahid Beheshti University of Medical Science, Tehran, Iran
  • Laya Jalilian Khave Department of Internal Medicine, School of Medicine, Shahid Beheshti University of Medical Science, Tehran, Iran
  • Mohammad Esmaeil Akbari Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  • Davood Bashash Mail Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Keywords:
COVID-19;, SARS-CoV-2;, Prognosis;, Neutrophil-to-lymphocyte ratio;, Hematological parameters

Abstract

Background and Objectives: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was first described during a pneumonia outbreak in Wuhan, has attracted tremendous attention in a short period of time as the death toll and the number of confirmed cases is growing unceasingly. Although molecular testing is the gold standard method of SARS-CoV-2 detection, the existence of the false-negative results presents a major limitation to this method.
Materials and Methods: This retrospective Double-Centre study was conducted on 1320 COVID-19 patients recruited at Taleghani and Shohadae Tajrish Hospitals in Tehran, Iran. We analyzed the leukocyte, lymphocyte and neutrophil counts of hospitalized cases both on admission and at discharge. We also evaluated the alteration of these parameters within a seven-day follow-up.
Results: Of the whole, 1077 (81.6%) neither were admitted to intensive care unit (ICU) nor experienced death, and were defined as the mild-moderate group. Of 243 severe cases, while 59 (24.3%) were admitted to ICU and cured with the intensive care services, 184 (75.7%) patients died of the disease, either with or without ICU admission. Calculation of neutrophil-to-lymphocyte ratio (NLR) revealed that the mild-moderate cases had a lower ratio at discharge. On the other hand, the ratio was significantly higher in the death group as compared to the ICU group; highlighting the fact that patients with a higher degree of neutrophilia and a greater level of lymphopenia have a poor prognosis.
Conclusion: We suggest that NLR greater than 6.5 may reflect the progression of the disease towards an unfavorable clinical outcome, with this notion that the ratios higher than 9 may strongly result in death.

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Published
2020-10-31
How to Cite
1.
Pirsalehi A, Salari S, Baghestani A, Vahidi M, Jalilian Khave L, Akbari ME, Bashash D. Neutrophil-to-lymphocyte ratio (NLR) greater than 6.5 may reflect the progression of COVID-19 towards an unfavorable clinical outcome. Iran J Microbiol. 12(5):466-474.
Section
Original Article(s)