Selection of optimal antibody titer and clinical value of passive agglutination for the diagnosis of Mycoplasma pneumoniae infection
Objective To investigate the optimal serum antibody titer in acute stage for the diagnosis of Mycoplasma pneumoniae(MP)infection by passive agglutination,and to evaluate the clinical diagnostic value of different antibody titers.Methods A cross-sectional study.Eighty-eight pairs of clinical serum samples were collected from children with MP infection treated at the Department of Pediatrics in Shengjing Hospital of China Medical University from December 2016 to February 2017 and Children's Hospital of Baotou in November 2019.The four-fold change of the double serum specific antibody titer was used as the gold standard,and the receiver operating characteristic(ROC)curve was plotted.When detecting the single serum in acute stage,different antibody titers were used as positive criteria to evaluate their clinical application value in the diagnosis of MP infection and find the most appropriate serum antibody titer as the diagnostic cut-off value.Results(1)When the serum specific antibody titer ≥1∶40 was used as the positive criterion,the sensitivity was 72.9％,the area under the ROC curve was 0.817,and the specificity was 87.5％,which might cause overdiagnosis.When the serum specific antibody titer ≥1∶160 was used as the positive criterion,the specificity was 97.5％,thearea under the ROC curve was 0.775,and the sensitivity was 52.1％,which might cause missed diagnosis.When the serum specific antibody titer ≥1∶80 was used as the positive criterion,the sensitivity was 60.4％,the specificity was 97.5％,and the area under the ROC curve was 0.823,overall performing better compared with the said two criteria.(2)After the disease lasted at least 5 days,blood samples were collected.About 72.5％of the children had antibodies,and 60.0％of the children had antibody titers ≥ 1∶80.Conclusions(1)When the passive agglutination method is used to detect MP infection,antibody titer ≥ 1∶80 is recommended as the diagnostic standard.However,in clinical practice,the diagnosis of MP infection depends on clinical and other laboratory test results.(2)It is appropriate to collect blood samples on 5-7 days of illness.If MP infection is clinically suspected,and an antibody titer of 1∶40 is also suggestive,it can perform cooperative diagnosis based on molecular biology lab results or retest at a shorter interval.
Mycoplasma pneumoniaePassive agglutination methodCut-off for optimal diagnosis
NETL
NSTL
万方数据
