Prognostic value of neutrophil to lymphocyte ratio and platelet to lymphocyte ratio for mortality in patients infected with SARS-CoV-2

Abstract

The COVID-19 pandemic, which originated in China and spread all over the world, continues to be a significant public health crisis. Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) are valuable parameters that can be evaluated in routine blood tests and provide information about the inflammation in many diseases.

This study aimed to evaluate the effect of NLR and PLR on mortality.

Methods. Our cross-sectional cohort study included patients who were hospitalized due to COVID-19 with positive polymerase chain reaction test results and patients whose test results were negative at the time of the first admission to the hospital, but whose computed tomography imaging was suspicious for COVID-19 and test results were found to be positive in repeated tests during their hospitalization. Prognosis of the hospitalization outcomes was investigated and discharge, hospital admission, intensive care unit (ICU) admission, and mortality data during the 30 days were recorded and the relationship between these parameters was evaluated.

Results. The mean age of the patients was 57.5 ± 16.7 years. Cough was the most common symptom and was present in over half of patients. Almost one-third of patients (27.1%) had at least three symptoms at presentation. Both increased levels of NLR and PLR were observed to significantly predict the mortality of patients with COVID-19 (p<0.001, p=0.001, respectively). Sensitivity and specificity were 65.2% and 80.4% for NLR (AUC: 0.767, cut-off>5.49) and 43.5% and 81.9% for PLR, respectively (AUC: 0.622, cut-off>228.13).

Conclusions. The present study has concluded that NLR and PLR are effective mortality predictors in patients infected with SARS-CoV-2.