目的:探讨呼吸道合胞病毒（RSV）肺炎患儿血清嗜酸性粒细胞阳离子蛋白（ECP）表达水平及临床意义。方法:选取2017年1月至2019年10月南京医科大学附属苏州科技城医院收治的106例RSV肺炎患儿（RSV肺炎组）和70例体检健康儿童（对照组）。RSV肺炎患儿中，低危68例，中危25例，高危13例。采用酶联免疫吸附法检测两组血清ECP水平，并检测肺功能，包括第1秒用力呼气容积占预计值百分比（FEVn 1%）、第1秒用力呼气容积（FEVn 1）/用力肺活量（FVC）和呼出气一氧化氮（FeNO）。多因素Logistic回归分析影响RSV肺炎患儿病情严重程度的危险因素，相关性采用Pearson相关分析。绘制受试者工作特征（ROC）曲线，利用曲线下面积（AUC）评价血清ECP对RSV肺炎的诊断效能。n 结果:RSV肺炎组FEVn 1%和FEVn 1/FVC明显低于对照组[（81.47 ± 14.08）%比（96.80 ± 17.10）%和（72.17 ± 21.63）%比（93.46 ± 26.57）%]，FeNO和ECP明显高于对照组[（17.88 ± 2.55）ppb比（9.79 ± 2.35）ppb和（64.00 ± 20.05）μg/L比（41.59 ± 16.99）μg/L]，差异有统计学意义（n P<0.01）。中危和高危RSV肺炎患儿血清ECP明显高于低危患儿[（70.82 ± 20.84）、（90.71 ± 19.75）μg/L比（58.05 ± 14.72）μg/L]，高危患儿明显高于中危患儿，差异均有统计学意义（n P<0.05）。多因素Logistic回归分析结果显示，FEVn 1%、FEVn 1/FVC、FeNO、ECP是影响RSV肺炎患儿病情严重程度的独立危险因素（n OR=12.913、17.845、0.002和0.126，95% n CI 2.641~63.139、2.972~107.139、0.000~0.017和0.028~0.566，n P<0.01）。ROC曲线分析结果显示，血清ECP诊断RSV肺炎的最佳临界值为51.84 μg/L，AUC为0.809，敏感度和特异度分别为78.57%和75.47%；血清ECP诊断早期RSV肺炎的最佳临界值为43.17 μg/L，AUC为0.714，敏感度和特异度分别为58.57%和82.35%。Pearson相关分析结果显示，血清ECP与FEVn 1%和FEVn 1/FVC呈负相关（n r=- 0.632和- 0.604，n P<0.01），与FeNO呈正相关（n r= 0.707，n P<0.01）。n 结论:RSV肺炎患儿血清ECP水平明显升高，与FEVn 1%、FEVn 1/FVC呈负相关，与FeNO呈正相关；血清ECP可作为RSV肺炎患儿诊断和病情严重程度评估的参考指标之一。n “,”Objective:To investigate the expression of serum eosinophil cationic protein (ECP) in children with respiratory syncytial viruses (RSV) pneumonia and its clinical significance.Method:One hundred and six children with RSV pneumonia (RSV pneumonia group) and 70 healthy children (control group) from January 2017 to October 2019 in the Affiliated Suzhou Science & Technology Town Hospital of Nanjing Medical University were selected. Among children with RSV pneumonia, low risk was in 68 cases, intermediate risk was in 25 cases and high risk was in 13 cases. The serum ECP level was measured by enzyme-linked immunosorbent assay. The lung function indexes were measured, including the forced expiratory volume in one second as a percentage of predicted value (FEV n 1%), forced expiratory volume in one second (FEVn 1)/forced vital capacity (FVC) and fractional exhaled nitric oxide (FeNO). Risk factors of severity in children with RSV pneumonia were analyzed by multivariate Logistic regression analysis. The area under the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of serum ECP for RSV pneumonia.n Results:The FEVn 1% and FEVn 1/FVC in RSV pneumonia group were significantly lower than those in control group: (81.47 ± 14.08)% vs. (96.80 ± 17.10)% vs. (72.17 ± 21.63)% and (93.46 ± 26.57)%, the FeNO and ECP were significantly higher than those in control group: (17.88 ± 2.55) ppb vs. (9.79 ± 2.35) ppb and (64.00 ± 20.05) μg/L vs. (41.59 ± 16.99) μg/L, and there were statistical differences ( n P<0.01). The serum ECP in RSV pneumonia children with intermediate risk and high risk were significantly higher than that in RSV pneumonia children with low risk: (70.82 ± 20.84), (90.71 ± 19.75) μg/L vs. (58.05 ± 14.72) μg/L, the serum ECP in high risk children was significantly higher than that in intermediate risk children, and there were statistical differences (n P<0.05). Multivariate Logistic regression analysis result showed that FEVn 1%, FEVn 1/FVC, FeNO and ECP were independent risk factors of severity in children with RSV pneumonia (n OR=12.913, 17.845, 0.002 and 0.126; 95% n CI 2.641 to 63.139, 2.972 to 107.139, 0.000 to 0.017 and 0.028 to 0.566; n P<0.01). ROC curve analysis result showed that the optimal cut-off value of serum ECP for the diagnosis of RSV pneumonia was 51.84 μg/L, AUC was 0.809, and the sensitivity and specificity were 78.57% and 75.47%; the optimal cut-off value of serum ECP for early diagnosis of RSV pneumonia was 43.17 μg/L, AUC was 0.714, and the sensitivity and specificity were 58.57% and 82.35%. Pearson correlation analysis result showed that serum ECP was negatively correlated with FEVn 1% and FEVn 1/FVC (n r=-0.632 and-0.604, n P<0.01), and it was positively correlated with FeNO (n r=0.707, n P<0.01).n Conclusions:Serum ECP level in children with RSV pneumonia is significantly increased, which is negatively correlated with FEVn 1% and FEVn 1/FVC, and positively correlated with FeNO. Serum ECP can be used as one of the reference indicators for the diagnosis and severity assessment of children with RSV pneumonia.n