Neutrophil/Lymphocyte Ratio (NLR) and Lymphocyte/Monocyte Ratio (LMR) – Risk of Death Inflammatory Biomarkers in Patients with COVID-19

Violetta Dymicka-Piekarska,1,* Justyna Dorf,1,* Anna Milewska,2 Mateusz Łukaszyk,3 Jakub Wiktor Kosidło,4 Joanna Kamińska,1 Blanka Wolszczak-Biedrzycka,5 Wojciech Naumnik3 1Department of Clinical Laboratory Diagnostics, Medical University of Bialystok, Białystok, Poland; 2Department of Biostatistics and Medical Informatics, Medical University of Bialystok, Białystok, Poland; 3Temporary Hospital No 2 of Clinical Hospital in Bialystok, 1st Department of Lung Diseases and Tuberculosis, Medical University of Bialystok, Białystok, Poland; 4Students Scientific Club at the Department of Clinical Laboratory Diagnostics, Medical University of Bialystok, Bialystok, Poland; 5Department of Psychology and Sociology of Health and Public Health, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland*These authors contributed equally to this workCorrespondence: Violetta Dymicka-Piekarska, Email piekarskav@yahoo.comAim: The aim of our retrospective study was search for new prognostic parameters, which can help quickly and cheaply identify patients with risk for severe course of SARS-CoV-2 infection.Materials and Methods: The following peripheral blood combination biomarkers were calculated: NLR (neutrophil/lymphocytes ratio), LMR (lymphocyte/monocyte ratio), PLR (platelet/lymphocyte ratio), dNLR (neutrophils/(white blood cells − neutrophils)), NLPR (neutrophil/(lymphocyte × platelet ratio)) in 374 patients who were admitted to the Temporary Hospital no 2 of Clinical Hospital in Bialystok (Poland) with COVID-19. The patients were divided into four groups depending on the severity of the course of COVID-19 using MEWS classification.Results: The NLR and dNLR were significantly increased with the severity of COVID-19, according to MEWS score. The AUC for the assessed parameters was higher in predicting death in patients with COVID-19: NLR (0.656, p=0.0018, cut-off=6.22), dNLR (0.615, p=0.02, cut-off=3.52) and LMR (0.609, p=0.03, cut-off=2.06). Multivariate COX regression analysis showed that NLR median above 5.56 (OR: 1.050, P=0.002), LMR median below 2.23 (OR: 1.021, P=0.011), and age > 75 years old (OR: 1.072, P=0.000) had a significant association with high risk of death during COVID-19.Conclusion: Our results indicate that NLR, dNLR, and LMR calculated on admission to the hospital can quickly and easy identify patients with risk of a more severe course of COVID-19. Increase NLR and decrease LMR have a significant predictive value in COVID-19 patient’s mortality and might be a potential biomarker for predicting death in COVID-19 patients.Keywords: COVID-19, biomarker, mortality, NLR, dNLR, LMR, PLR