抗体滴度检测在诊断儿童肺炎支原体急性期感染中的意义

Application of Detecting Mycoplasma Pneumonia Antibody Titer in Acute Infection in Children

目的 探讨抗体滴度在诊断儿童肺炎支原体（mycoplasma pneumonia,MP）急性期感染中的意义.方法 明胶颗粒凝集法检测2012年6月～2013年6月103例住院患儿血清MP抗体滴度,比较2周后抗体滴度变化≥4倍和＜4倍的例数差异;并通过与MP-DNA荧光定量PCR法做比较,分析MP抗体滴度在诊断儿童MP急性期感染的符合程度.结果 MP抗体滴度≥1：80与抗体滴度≥1：160间隔2周后抗体滴度变化≥4倍例数比较,差异有统计学意义（χ2=6.610,P=0.01）;抗体滴度≥1：160与抗体滴度≥1：320间隔2周后抗体滴度变化≥4倍例数比较,差异无统计学意义（χ2=0.046,P=0.830）;MP抗体滴度（滴度≥1：160）用于检测患儿急性期感染的灵敏度为94.5%,特异度为93.8%,Youden指数为88.3,阳性预测值和阴性预测值分别为0.945和0.938;MP抗体（滴度≥1：160）与MP-DNA荧光定量PCR两种方法检测结果差异无统计学意义（P=0.388）,一致率为88.3%,κ值为0.765.结论 MP抗体滴度≥1：160提示患儿急性期感染的可能性较大.

Objective To explore the application of Mycoplasma pneumonia （MP） antibody titer in detection of acute infection in children. Methods Using gelatin particles agglutination test for serum antibody titer detection of 103 cases from June 2012 to June 2013 ,compared the number of cases which the titer of paired serum antibody with the interval of two weeks has a 4 times increase or decrease at least. By comparing with the results of HCMV-DNA PCR,the coincidence degree of the re-sults in detection of acute infection in children was analyzed. Results There was significant difference in the number of cases which Mycoplasma pneumonia antibody titer≥80 and ≥1：160 with the interval of two weeks has a 4 times increase or de- crease at least （X^2=6. 610,P=0.01）. There was no significant difference in the number of cases which≥1 ： 160 and ≥1 ： 320 antibody titer with the interval of two weeks has a 4 times increase or decrease at least （X^2 = 0. 046, P= 0. 830）. The sensitivity of Mycoplasma pneumonia antibody titer in detection of acute infection in children was 94.5% ,the specificity was 93.8% ,Youden index was 88. 3,PVP and PVN were 0. 945 and 0. 938 respectively. There was no significant difference in detection of acute infection in children between Mycoplasma pneumonia antibody titer test and MP-DNA PCR（P=0. 388）. The consistent rate of Mycoplasma pneumonia antibody titer （≥1 ： 160） and MP-DNA PCR was 88. 3% and the value of Kappa was 0. 765. Conclusion The antibody titers higher than 1 ： 160 indicate acute infections with a high possibility.