The prognostic value of neutrophil–to-lymphocyte ratio and platelet–to-lymphocyte ratio in the severe COVID-19 cases

Abstract

Aim: COVID-19 is a cause of high-mortality pandemic with the RNA virus in its etiology and has an effect all over the world. In the present study, the relationship between in-hospital prognosis and mortality was investigated by comparing neutrophil-to-lymphocyte ratio (NLR), platelet –to-lymphocyte ratio (PLR) values ​​with C-reactive protein (CRP) and with a detailed analysis of complete blood count and biochemical parameters in mild and severe COVID-19 cases.

Method: A total of 271 patients who were diagnosed with pneumonia because of COVID-19 and 278 healthy control groups were included in the study.  In our study, COVID-19 cases were divided into 2 groups as mild and severe, and the data were compared with healthy people without COVID-19. Lung tomography results of the cases that were diagnosed with COVID-19 were examined. Those with positive RT-PCR (Real-Time Polymerized Chain Reaction) test results were recorded from the system. Biochemical tests and complete blood count parameters of the patients, NLR/ lymphocyte- to- monocyte ratio (LMR)/PLR N/L, and CRP levels were compared with the control group. The results were evaluated and analyzed in statistical terms.

Results: When all the data were analyzed, NLR/PLR and CRP levels were found to be higher at statistically significant levels in the severe patient group than in the control group, and LMR was lower (p<0.01). In ROC analysis, NLR/PLR and CRP had a high AUC (area under the curve) (0.844/0.719/0.501) and LMR had a low AUC (0.225).

Conclusion: NLR and PLR might be useful in demonstrating the prognosis in severe COVID-19 cases.