Clinical application of blood cell subtype ratio and inflammatory indicators in COVID-19

ABSTRACT

Objective: To explore the application value of blood cell subtype ratio [neutrophil/lymphocyte ratio (NLR) platelet/lymphocyte ratio (PLR)], platelet/neutrophil ratio (PNR) and inflammatory indicators in clinical treatment and prognosis of coronavirus disease 2019 (COVID - 19) patients. Methods The blood routine and inflammatory data were collected from 47 hospitalized COVID- 19 patients and 30 healthy subjects and analyzed retrospectively, and the ratios of NLR, PLR and PNR were calculated. The differences of each index were compared between the two groups, and the variation trend of NLR, PLR and PNR were dynamically monitored during the course of disease. ROC curve was used to evaluate the diagnostic value of blood cell subtype ratio and inflammatory indicators. Results Compared with the control group, white blood cell (WBC) and lymphocyte (LYMPH) were decreased (Z =-3.578, -5.558, all P <0.05), and NLR, PLR, C-reactive protein(CRP), serum amyloid A(SAA) and SAA/CRP were increased in COVID-19 patients group (Z =-4.210, -5.087, -2.434, -5.263, -3.091, all /1/40.05). Trend analysis of NLR, PLR and PNR showed that NLR and PLR increased first and reached the peak, and gradually decreased with the improvement of patients' condition (x2=27.441, 38.699, all PC 0.05). ROC curve analysis results showed that the area under curve (AUC) of SAA, PLR, NLR and CRP were 0.855, 0.845, 0.786 and 0.662, respectively. Conclusions The combination of NLR, PLR, SAA and CRP could reflect systemic inflammatory status of patients, and had good clinical diagnostic value for disease monitoring and prognosis.