Utility of the neutrophil-to-lymphocyte ratio and C-reactive protein level for coronavirus disease 2019 (COVID-19)

To investigate the value of the combined detection of the neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein level (CRP) in the diagnosis of COVID-19. A total of 191 patients with COVID-19 were recruited at the Third Hospital of Wuhan from 21 January 2020 to 20 February 2020. Fifty healthy volunteers were randomly selected as the control group. Age, gender, white blood cell count (WBC), CRP, lymphocyte percentage, and NLR were extracted. Quantitative clinical characteristics and laboratory values were compared between groups. Risk factors and receiver operating characteristic (ROC) curves for COVID-19 were analyzed. We found that the NLR and CRP were higher, while the lymphocyte percentage was lower in patients with COVID-19 than in healthy controls. Among patients confirmed to have COVID-19, the NLR and CRP of the moderate group were lower than those of severely ill patients (severe, critical and death groups), and the lymphocyte percentage of the moderate group was higher than that of the critical and death group. There were no significant differences in WBC among all groups. Logistic regression analysis showed that the NLR, CRP, and lymphocyte percentage were independent risk factors for COVID-19. The AUC of the combined determination of NLR and CRP was 0.863, which was higher than that of NLR, CRP, WBC, and lymphocyte percentage (AUC: 0.835, 0.775, 0.416, and 0.749, respectively). Our results showed that the NLR and CRP were independent risk factors for COVID-19, and the combined detection of the NLR and CRP showed improved diagnostic performance for COVID-19.