Abstract: Objective　To investigate the clinical value of routine blood indicators and their ratio changes in the diagnosis and differential diagnosis of COVID-19 and influenza. Methods　Blood routine data of 25 patients with COVID-19, 207 patients with influenza A virus infection, and 240 patients with influenza B virus infection were selected, including 237 males and 235 females, aged 14-77 years. The neutrophil count (NC), lymphocyte count (LC), white blood cell count (WBC), and monocyte count (MC) of the three groups were analyzed retrospectively, and the lymphocyte/monocyte ratio (LMR), platelet/lymphocyte ratio (PLR), and neutrophil/lymphocyte ratio (NLR) were calculated to investigate the diagnostic values of the above parameters for COVID-19 and influenza. Analysis of variance, LSD test, and Tamhane test were used. Results　The NC, MC, WBC, and NLR in the COVID-19 group were (3.52±1.33) ×10⁹/L, (0.46±0.16) ×10⁹/L, (5.50±1.46) ×10⁹/L, and (3.05±2.04), which were significantly lower than those in the influenza A group [(5.52±2.32) ×10⁹/L, (0.62±0.25) ×10⁹/L, (7.47±2.55) ×10⁹/L, and (5.51±3.82)], and the LMR was (3.37±1.72), which was slightly higher than (2.24±1.34) in the influenza A group, with statistically significant differences (all P<0.05). The MC and NLR of the COVID-19 group were significantly lower than those of the influenza B group, and the LMR was slightly higher than that of the influenza B group (all P<0.05). The NC, PLT, WBC, and NLR of the influenza A group were significantly higher than those of the influenza B group, with statistically significant differences (all P<0.05). The receiver operating characteristic curve (ROC) analysis showed that NLR had the highest diagnostic specificity and sensitivity for influenza A and influenza B, with 88.2% and 81.2% for influenza A and 91.2% and 65.0% for influenza B. Conclusion　Routine blood indicators and ratio changes can better assist in the diagnosis and differential diagnosis of COVID-19 and influenza, among which NLR has the highest diagnostic specificity and sensitivity for influenza, LC, NLR, LMR, and PLR have important clinical significance for the diagnosis of COVID-19, and MC, NLR, and LMR are important indicators for the differential diagnosis of COVID-19 and influenza.

Key words: Influenza, COVID-19, Neutrophil/lymphocyte ratio, Lymphocyte/monocyte ratio, Platelet/lymphocyte ratio

摘要： 目的　探究血常规指标及其比值变化在新型冠状病毒肺炎（COVID-19）和流感患者的诊断及鉴别诊断中的临床应用价值。方法　选取2020年1月至2022年1月，在四川绵阳地区确诊的25例COVID-19患者、207例甲型流感病毒感染者（甲流）和240例乙型流感病毒感染者（乙流）血常规数据，其中男237例、女235例，年龄14～77岁，回顾性分析3组的中性粒细胞计数（NC）、淋巴细胞计数（LC）、白细胞计数（WBC）和单核细胞计数（MC），并计算淋巴细胞/单核细胞比值（LMR）、血小板/淋巴细胞比值（PLR）和中性粒细胞/淋巴细胞比值（NLR），探讨上述参数对COVID-19和流感的诊断价值。采用方差分析、LSD检验、Tamhane检验。结果　COVID-19组NC、MC、WBC和NLR指标分别为（3.52±1.33）×10⁹/L、（0.46±0.16）×10⁹/L、（5.50±1.46）×10⁹/L、（3.05±2.04），均明显低于甲流组的（5.52±2.32）×10⁹/L、（0.62±0.25）×10⁹/L、（7.47±2.55）×10⁹/L、（5.51±3.82），LMR指标为（3.37±1.72），略高于甲流组的（2.24±1.34），差异均有统计学意义（均P<0.05）；COVID-19组MC和NLR明显低于乙流组，LMR略高于乙流组（均P<0.05）；甲流组NC、PLT、WBC和NLR明显高于乙流组，差异均有统计学意义（均P<0.05）。绘制受试者工作特征曲线（ROC）分析显示，NLR对甲型、乙型流感的诊断特异度和灵敏度均最高，其诊断甲型流感的特异度为88.2%、灵敏度为81.2%，诊断乙型流感的特异度为91.2%、灵敏度为65.0%。结论　血常规指标及比值变化能较好辅助诊断、鉴别诊断COVID-19和流感患者，其中NLR对流感诊断特异度和灵敏度最高，LC、NLR、LMR和PLR对COVID-19的诊断有重要临床意义，MC、NLR、LMR是鉴别诊断COVID-19和流感的重要指标。

关键词: 流感, COVID-19, 中性粒细胞/淋巴细胞比值, 淋巴细胞/单核细胞比值, 血小板/淋巴细胞比值