肺炎支原体抗体滴度和RNA检测在儿童肺炎支原体肺炎诊疗中的应用价值

Application value of Mycoplasma pneumoniae antibody titer and RNA detection in diagnosis and treatment of Mycoplasma pneumoniae pneumonia in children

目的:评价肺炎支原体抗体滴度和RNA病原检测在儿童肺炎支原体(Mp)肺炎诊断和治疗过程中的应用价值。方法:采用观察性研究,收集2019年6至11月首都儿科研究所附属儿童医院呼吸内科因社区获得性肺炎住院的患者433例,采用颗粒凝集法检测肺炎支原体抗体滴度,采用RNA实时荧光恒温扩增技术(SAT)测定Mp-RNA,明确支原体肺炎(Mpp)感染和诊疗情况。两种方法阳性率的比较及3种因素(年龄、病程天数、大环内酯类用药)对方法阳性率的影响分析,采用χ^2检验。结果:433例肺炎患者中Mpp组303例,非Mpp组128例,Mpp组抗体滴度阳性率(≥1∶160)79.5%(241/303),Mp-RNA阳性率77.2%(234/303),两种方法诊断价值一致。SAT方法检测Mp-RNA敏感度、特异度、阳性预测值、阴性预测值分别为77.2%(234/303),96.1%(123/128),97.9%(234/239),64.1%(123/192)。抗体滴度阳性率(≥1∶160)在长病程组显著高于短病程组(χ^2=93.227,P<0.01),滴度1∶160的天数为(5.89±1.72)d。Mp-RNA阳性率在短病程组显著高于长病程组(χ^2=20.103,P<0.01)。SAT方法检测Mp-RNA可用于治疗效果监测,Mp-RNA阳性患者出院转阴率34.2%(26/76),拷贝数下降率82.9%(63/76)。结论:两种检测方法各有优劣,抗体滴度检测需要正确把握时间窗并做动态监测,SAT检测Mp-RNA应在病程早期、未使用抗菌药物时进行。两种检测方法的联合应用可取长补短、加强优势,为Mpp临床确诊、正规治疗提供有价值的实验室依据。

Objective To evaluate the application value of Mycoplasma pneumonia(Mp)antibody titer and RNA detection in the diagnosis and treatment of Mycoplasma pneumoniae(Mp)pneumonia in children.Methods An observational study was used to collect 433 hospitalized patients with community-acquired pneumonia in the Department of Respiratory Medicine,Children′s Hospital Capital Institute of Pediatrics from June to November 2019.Particle agglutination method was used to detect Mycoplasma pneumoniae antibody titer,and Mp-RNA was detected by RNA real-time fluorescence constant temperature amplification(SAT).They both have certain value in Mycoplasma pneumonia(Mpp)infection,diagnosis and treatment.The comparison of the positive rate of the two methods and the analysis of the influence of three factors(age,number of days of disease course,and macrolides)on the positive rate of the method were performed using theχ^2test.Results Among 433 cases with pneumonia,303 cases were in the Mpp group and 128 case were in the non-Mpp group.The positive rates of antibody titer(≥1∶160)was 79.5%(241/303)and Mp-RNA was 77.2%(234/303).The diagnostic value of the two methods was consistent.The sensitivity,specificity,positive predictive value and negative predictive value of the Mp-RNA detected by SAT methods were 77.2%(234/303),96.1%(123/128),97.9%(234/239),64.1%(123/192),respectively.The positive rate of antibody titer(≥1∶160)in the long course group was significantly higher than that in the short course group(χ^2=93.227,P<0.01).The average days fortiter 1∶160 were(5.89±1.72)days.The positive rate of Mp-RNA in the short course group was significantly higher than that in the long course group(χ^2=20.103,P<0.01).The Mp-RNA detected by SAT method could be used to monitor the therapeutic effect.The negative conversion rate of Mp-RNA positive patients was 34.2%(26/76),and the copy number reduction rate was 82.9%(63/76).The combination of the two methods had a high diagnostic rate in any course of disease.Conclusions Both of the two methods had their own advantages and disadvantages.Antibody titer detection needs to correctly grasp the time window and perform dynamic monitoring.The Mp-RNA detected by SAT method should be performed in the early stage of the disease and before the antibiotics were used.The combined application of the two detection methods could complement each other and strengthen the advantages,providing valuable laboratory evidence for the clinical diagnosis and regular treatment of Mpp.