title: [Clinical significance of MP-DNA from endotracheal aspirates in diagnosis of Mycoplasma pneumoniae pneumonia in children].
abstract: OBJECTIVE
  To compare the detection rates of Mycoplasma pneumoniae (MP) from nasopharyngeal aspirates (NPA) and bronchoalveolar lavage fluid (BALF) in children with pneumonia.
  
  
  METHODS
  A total of 164 hospitalized children with pneumonia were enrolled. NPA and BALF of these children were collected within 24 hours of admission, and MP-DNA was detected by fluorescence quantitative PCR. Venous blood samples of all these children were collected within 24 hours of admission and on days 7-10 of treatment, and serum MP-IgM was detected using ELISA.
  
  
  RESULTS
  The positive rate of MP-DNA in NAP of the 164 cases was 51.8% , which was lower than 63.4% as the detection rate of MP-IgM in serum (P=0.044), and the two detection rates were moderately consistent with each other (Kappa=0.618, P<0.01). The positive rate of MP in BALF was 71.3%, which was not significantly different with that of MP-IgM in serum (P>0.05), and the detection rates were well consistent (Kappa=0.793, P<0.01). The detection rate of MP in NPA was lower than that in BALF (P<0.01), with moderate consistency between two of them (Kappa=0.529, P<0.01). The median MP copy number in BALF was significantly higher than that in NPA (P<0.01). The MP detection rates in NPA and BALF were significantly different among different courses of disease (P<0.05). As the course of disease extended, the MP detection rates in both NPA and BALF showed a declining trend; children with MP pneumonia of 1-2 weeks' duration and 2-4 weeks' duration had a higher MP-DNA detection rate in BALF than in NPA (P<0.05).
  
  
  CONCLUSIONS
  MP-DNA in BALF has a high sensitivity, with a great significance for early diagnosis of MP pneumonia, while NPA MP-DNA tests may lead to a missed diagnosis.
authors.affiliation: Department of Respiratory Disease, Childrenγs Hospital Affiliated to Soochow University, Suzhou, Jiangsu 215003, China. szdxjiwei@163.com.
authors.forename: Wen-Jing
authors.initials: WJ
authors.lastname: Gu
authors.forename: Xin-Xing
authors.initials: XX
authors.lastname: Zhang
authors.forename: Zheng-Rong
authors.initials: ZR
authors.lastname: Chen
authors.forename: Yong-Dong
authors.initials: YD
authors.lastname: Yan
authors.forename: Can-Hong
authors.initials: CH
authors.lastname: Zhu
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.forename: Mei-Juan
authors.initials: MJ
authors.lastname: Wang
authors.forename: Xue-Jun
authors.initials: XJ
authors.lastname: Shao
authors.forename: Wei
authors.initials: W
authors.lastname: Ji
mesh_terms: D000293:Adolescent; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000032:analysis*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009305:Nasopharynx / Q000382:microbiology*; D011019:Pneumonia, Mycoplasma / Q000175:diagnosis*
chemical_list: D004269:DNA, Bacterial