胶体金免疫层析法诊断肺炎支原体感染的临床价值评估

Clinical evaluation of colloidal gold immunochromatography in Mycoplasma pneumonia infection

目的评估胶体金免疫层析法诊断肺炎支原体感染(Mycoplasma pneumonia,MP)的临床价值。方法采用回顾性研究方法,采集2016年12月至2017年1月就诊于中国医科大学附属盛京医院及2019年10月至12月就诊于包头市儿童医院,临床诊断为MP感染患儿的双份血清样本115对,采用胶体金免疫层析法(简称胶体金法)检测急性期单份血清,以被动凝集法(PA)检测双份血清,特异性抗体滴度4倍升高或下降为标准,绘制受试者工作特征(ROC)曲线,评估胶体金法检测MP感染临床应用价值。结果胶体金法与参考标准比较,诊断MP感染敏感度为86.4%,特异度为98.2%。ROC曲线下面积0.90,准确度0.91。病程5~7 d,胶体金法检测敏感度82.6%、特异度100%,ROC曲线下面积0.91,被动凝集法以1∶40为判定标准,敏感度73.9%,特异度85%,误诊率15%,以1∶160为判定标准,敏感度39.1%,特异度100%,漏诊率60.9%。病程>7 d,胶体金法敏感度93.1%,特异度94.7%。PA法分别以1∶40与1∶160为阳性判定标准,敏感度均为82.6%,特异度分别为89.4%,100%。结论胶体金法,敏感、快速,特异度高,诊断准确性高,操作简单,更经济,适于病程早期、门诊、基层医院MP快速检测。可作为临床诊断MP感染的参考指标。若采血时间在病程5~7 d,胶体金法检测阳性,应考虑MP感染,临床可进行抗MP感染治疗。若采用PA法,以1∶40为阳性判定标准,有15%误诊率,诊断需结合临床表现及核酸检测结果等具体分析。若以1∶160为标准,敏感度仅39.1%,漏诊率高。若采血时间为病程7 d以后,胶体金法与被动凝集法均有较高敏感度。若采血时间较早,抗体检测阴性,临床又高度怀疑MP感染患儿,建议病程1周后复查抗体或同时进行核酸检测。

Objective To evaluate the clinical value of colloidal gold immunochromatography in the diagnosis of Mycoplasma pneumoniae infection.Methods A retrospective study was used in this study.Totally 115 paired sera of children with MP infection were collected from December 2016 to January 2017 in Shengjing Hospital Affiliated to China Medical University,and from October to December 2019 in Baotou Children's Hospital.The colloidal gold immunochrom-atography was used to detect acute serum.Passive agglutination(PA)was used to detect the paired serum.Taking the 4-fold increase or decrease of the specific antibody titer of the double serum as the gold standard,the receiver operating characteristic curve(ROC curve)was drawn to compare and evaluate the colloidal gold method in MP infection.Results 1.The sensitivity and specificity of colloidal gold method were 86.4%and 98.2%.The area under the ROC curve was 0.90 and the accuracy was 0.91,indicatingits high accuracy of method.2.The course of disease was 5~7 days,the sensitivity and specificity of colloidal gold assay were 82.6%and 100%,and the area under the ROC curve was 0.91.Taking 1∶40 as judgment standard,the sensitivity,specificity and misdiagnosis rate of the passive agglutination method were 73.9%,85%and 15%respectively,whereas by 1∶160,the sensitivity was 39.1%,the specificity was 100%,and the missed diagnosis rate was 60.9%.3.When the disease course was more than 7 days,the sensitivity and specificity of colloidal gold assay were 93.1%,94.7%.The sensitivity of the PA assay for 1∶40 and 1∶160 positive criteria were both 82.6%,and specificity were 89.4%,100%.Conclusion 1.The advantages of being simple,economical,sensitive,fast and highly specific make the colloidal gold immunochromatography suitable for rapid diagnosis of mycoplasma pneumoniae in outpatient and grass-root hospitals.It can be used as a reference index for M.pneumoniae infection.2.When the course of disease is in 5~7days and colloidal gold assay is positive,MP infection should be considered,and anti-MP infection treatment can be used clinically.,When PA method is used,with 1:40 as the positive judgment standard,there is a 15%misdiagnosis rate,and the diagnosis should be made by combination with clinical manifestations and other laboratory test results.If the sensitivity of 1∶160 is only 39.1%,the rate of missed diagnosis is high.When the blood collection time is 7 after days of disease,both colloidal gold method and passive agglutination method have high sensitivity.3.If the blood sample is collected early,the antibody test is positive,and MP infection is highly possible in clinic.it is suggested that antibody be rechecked at one week after the disease or nucleic acid test be performed.