Neutrophil to lymphocyte ratio and C-reactive protein level as prognostic markers in mild versus severe COVID-19 patients

This research aimed to investigate neutrophil to lymphocyte ratio (NLR) with C-reactive protein to identify potential clinical predictors and analyze differences among severe and non-severe COVID-19 patients.

NLR and CRP are established markers that reflect systemic inflammatory, and these parameters alter in patients with novel coronavirus (SARS-CoV-2) pneumonia (COVID-19).

A population of patients with COVID-19 referred to Loghman Hospital in Tehran was analyzed. The baseline data of laboratory examinations, including NLR and CRP levels, was collected. Pearson analysis was used to assess the independent relationship between the NLR with disease severity and CRP levels.

COVID-19 cases comprised 14 (20%) patients with severe disease and 56 (80%) with non-severe infection. The mean values of WBC, NEU, LYM, and NLR of the severe patients were significantly higher than those of the non-severe patients. Forty-six patients (65.7%) had NLR >1, and the remaining patients had NLR <1. Plasma CRP levels were higher in severe cases than in nonsevere cases, and this difference was significant. The results showed that NLR was positively correlated with CRP levels (R=0.23) and negatively correlated with WBC (R=-0.38). CRP (AUC = 0.97, 95% CI: 0.95-0.99) and NLR (AUC = 0.87, 95% CI: 0.81-0.93) had very good accuracy in predicting the severity of COVID-19 disease.

The findings of this study indicated that the integration of NLR and CRP may lead to improved predictions and is recommended as a valuable early marker to assess prognosis and evaluate the severity of clinical symptoms in COVID-19 patients.