支气管肺泡灌洗液荧光定量PCR对儿童肺炎支原体肺炎诊断研究

Value of fluorescence quantitative PCR assay of bronchoalveolar lavage fluid samples in the diagnosis of Mycoplasma pneumoniae pneumonia in children

摘要:

目的：探讨荧光实时定量 PCR（FQ-PCR）检测肺泡灌洗液（BALF）中 MP-DNA 基因在肺炎支原体肺炎（MPP）早期病原诊断中的价值。方法：采用FQ-PCR检测 61 例患儿BALF中 MP-DNA，并与目前常用血清 MP 抗体检测方法颗粒凝集法进行比较。结果：FQ-PCR 检测 MP-DNA 敏感度 94％，特异度 100％；病程早期及难治性病例中FQ-PCR 检测 BALF 中 MP-DNA 准确性优于单份血清 MP 抗体检测（P< 0.01）。难治性病例中 MP-DNA 拷贝数显著高于普通MPP组（P<0.05），且与 CRP 呈正相关 （r= 0.845, P< 0.01）。结论：FQ-PCR 检测 BALF 中 MP-DNA 是早期MPP特别是难治性MPP病原诊断的可靠方法，优于血清 MP 抗体检测。MP-DNA 的拷贝量可以作为评价难治性MPP的转归以及判断药物疗效的指标。

Abstract:

OBJECTIVE: To study the value of fluorescence quantitative polymerase chain reaction (FQ-PCR) for detecting Mycoplasma pneumoniae (MP)-DNA in bronchoalveolar lavage fluid (BALF) in the early diagnosis of Mycoplasma pneumoniae pneumonia (MPP). METHODS: FQ-PCR was used to detect MP-DNA in BALF obtained by fiberoptic bronchoscopy from 61 children with MPP, and the sensitivity and the specificity of FQ-PCR were compared with the traditional serological test. RESULTS: The sensitivity and the specificity of BALF FQ-PCR for detecting MP-DNA were 94% and 100% respectively. The accuracy of BALF FQ-PCR assay for detecting MP-DNA was higher than that of the serological test at the early stage of the disease (1-7 days) (P<0.01). In the children with refractory MPP, BALF FQ-PCR assay also showed higher accuracy for detecting MP-DNA than the serological test (P<0.01). The copies of MP-DNA in children with refractory MPP were significant higher than those in children with common MPP (P<0.05). The copies of MP-DNA were positively correlated with CRP values (r=0.845, P<0.01). CONCLUSIONS: FQ-PCR assay of BALF for detecting MP-DNA in BALF is superior to the serological test. It is a reliable method for the early diagnosis of MPP, especially refractory MPP. The copies of MP-DNA can be used as an index for evaluation of the treatment outcome of refractory MPP.