MP—DNA与IgM在儿童肺炎支原体感染病程中动态检测的意义

目的利用FQ—PCR技术和DIGFA试验对儿童呼吸道感染患者分别检测MP—DNA和MP—IgM，观察分析其在不同病程中的变化规律，探讨FQ—PCR检测MP—DNA和DIGFA检测MP—IgM用于儿童肺炎支原体感染中的诊断价值。方法入选患儿留取呼吸道分泌物和血清标本，采用FQ—PCR法检测呼吸道分泌物MP—DNA，用胶体金DIGFA法检测患儿血清MP—IgM。入院患儿被检出单一MP—DNA阳性或MP—IgM阳性或两者双阳性者均确诊为MP感染病例，对确诊的病例观察分析病程不同时期MP—DNA和MP—IgM阳性率消长的动态及其变化规律。结果根据患儿MP—DNA和MP—IgM检出情况，被确诊为肺炎支原体感染的患儿共56例。对这56例患儿进行病程追踪检查分析显示：在病程初期阶段，MP—DNA检出阳性率为82．14％（46／56），MP—IgM阳性率为35．7l％（20／56）；两种检测阳性率比较，MP—DNA阳性率显著高于MP—IgM阳性率，两者差异有显著性（P〈0．05）。在病程中期，MP—DNA检出阳性率下降为64．29％（36／56），MP—IgM阳性率上升为80．36％（45／56）；到恢复期，MP—DNA阳性检出率继续下降为1．79％（1／56），而MP—IgM阳性率在中期升高后又返降为23．21％（13／56）。结论在肺炎支原体感染患儿不同病程中，存在MP—DNA随病程延长逐渐降低而MP—IgM随病程延长逐渐增高至中期又返折下降的消长规律。FQ—PCR检测MP—DNA对MP感染患儿发病初期就诊者确诊价值较高，而DIGFA检测MP—IgM对发病时间已较长而又初次就诊者诊断意义较大。两种方法联合应用既可在诊断上优势互补，又可用于患儿病情转归预测评估。

Significance of dynamic detection of MP-DNA and IgM in the course of mycoplasma pneumoniae infection in children

Objective To explore the values of FQ-PCR for detecting MP-DNA and DIGFA for MP-IgM in the diagnosis of mycoplasma pneumoniae（ MP ） infection in children. Methods Respiratory secretions and serum samples were collected. MP-DNA in respiratory secretions was detected by FQ-PCR and serum MP-IgM by DIGFA. Children with positive MP-DNA or MP-IgM alone or both MP- DNA and MP-IgM were diagnosed as MP infection. The changes in the positive rates of MP-DNA and MP-IgM during different courses were observed and analyzed. Results 56 children were diagnosed as MP infection. In the early disease course, the positive rate of MP-DNA was 82.14% （ 46/56 ）, and that of MP-IgM was 35.71% （ 20/56 ）the former was significantly higher than the latter, with a significant difference （ P 〈 0.05 ）. In the middle disease course, the positive rate of MP-DNA dropped to 64.29% （ 36/56 ）, while that of MP-IgM increased to 80.36% （ 45/56 ） In the recovery course, the positive rate of MP-DNA continued to decline to 1.79% （ 1/56 ）, while that of MP-IgM decreased to 23.21% （ 13/56 ）. Conclusions In children with MP infection, MP-DNA is gradually decreased with the prolongation of the disease course, while MP-IgM is increased until to the middle course and then is declined. FQ-PCR for MP-DNA has a greater value in the diagnosis of MP infection at the early stage, while DIGFA for MP-IgM has a diagnostic significance for the children who has a longer disease course and makes a first visit. Combination of two methods is beneficial for the diagnosis and can be used for prediction of the disease outcome.