鼻咽抽吸物MP-DNA拷贝数与肺炎支原体肺炎临床表现的关系

Investigation of nasopharyngeal Mycoplasma pneumoniae-DNA copies and clinical characteristics in childhood Mycoplasma pneumoniae pneumonia

目的探讨鼻咽抽吸物肺炎支原体基因MP-DNA拷贝数与肺炎支原体肺炎(MPP)临床表现的关系。方法回顾分析294例MPP住院患儿的临床资料,根据其MP-DNA拷贝数分为低拷贝组(MP-DNA拷贝数≤10~3/mL)21例、中拷贝组(10~4～10~6/mL)156例、高拷贝组(> 10~6/mL)117例。对三组患儿的临床表现、实验室检查结果、胸部X线变化进行比较分析;并用ROC曲线分析鼻咽抽吸物MP-DNA拷贝数对难治性肺炎支原体肺炎(RMPP)的诊断价值。结果与低、中拷贝组相比,高拷贝组的热程延长,热峰、C反应蛋白、乳酸脱氢酶增高,大片肺实变或肺不张、胸腔积液、肺外多器官受累以及RMPP发生率也增高,差异均有统计学意义(P<0.05)。MP-DNA拷贝数判断RMPP的ROC曲线下面积(AUC)为0. 701;当临界值为4. 83×10~6时,灵敏度和特异度分别为80.8%和55.4%。结论鼻咽抽吸物MP-DNA拷贝数与MPP炎症反应及肺内外损害可能相关,高MP-DNA拷贝数对早期诊断RMPP有一定参考意义。

Objective To explore relationship between nasopharyngeal Mycoplasma pneumoniae(MP)-DNA copies and clinical characteristics in Mycoplasma pneumoniae pneumonia(MPP)children.Method A total of 294 hospitalized MPP children were enrolled retrospectively and grouped according to the levels of nasopharyngeal MP-DNA copies tested:low copy level group(≤10^3/mL,n=21),moderate copy level group(10^4-10^6/mL,n=156)and high copy level group(>10^6/mL,n=117).Clinical manifestations,laboratory results and image features of the three groups were compared.ROC curve was used to analyze the predictive value of MP-DNA copies in refractory Mycoplasma pneumoniae pneumonia(RMPP).Results Compared with low and moderate MP-DNA copies groups,high MP-DNA copies group had longer duration of fever,higher peak temperature and CRP level.The incidence of consolidation or atelectasis,pleural effusion,multiple extrapulmonary complications and RMPP were significantly higher in high MP-DNA copies group than those in low/moderate groups.ROC curve analysis showed AUC of the MP-DNA copies for the diagnosis of RMPP was 0.701.The best threshold value estimated was 4.83×10^6/mL,the diagnostic sensitivity and specificity was 80.8%and 55.4%,respectively.Conclusions There may be positive correlation between nasopharyngeal MP-DNA copies and inflammation,pulmonary and extrapulmonary damage in MPP children.High MP-DNA copies may serve as a clinical indicator for early diagnosis of RMPP.