肺炎支原体肺炎和哮喘患儿肺炎支原体特异性IgE检测的分析

Analysis on the Determination of Specific IgE Antibody in Children with Mycoplasma Pneumoniae Infection and Asthma

通过免疫手段 (SDS PAGE及Westernblot)分析MP引起变态反应的抗原成分 ,比较有哮喘史及无特应症的MP感染者特异性IgE阳性率 ,并探讨与MP特异性IgE产生的有关因素。MP IgM阳性的支气管肺炎患儿 35例 (平均年龄 6 0± 3 4岁 )及支气管哮喘患儿 32例 (平均年龄 6 7± 3 3岁 ) ,MP IgM、IgA均为阴性的正常健康者 2 7例 (平均年龄 7 0± 3 6岁 )作为对照组 ;采用免疫印迹技术观察上述各组待测血清针对所分离MPFH株菌体粉碎后蛋白成分的杂交条带 ,并对其出现频度进行统计分析 ;同时应用ELISA方法检测血清总IgE。结果SDS PAGE显示MP蛋白成分有十几条。与IgE反应的抗原多肽的相对分子质量为 2 16 0 0 0、 2 0 5 0 0 0、 170 0 0 0、 6 80 0 0、 5 6 0 0 0 ,其中前三者抗原性最强 ,不同组别、病程及年龄出现率明显高于后两者 (P <0 0 5 )。MP IgE阳性率 :MP感染组 71 4 %、哮喘组 78 13%、对照组 19 2 3% ,前两组间无明显差异 ,均显著高于对照组 (P <0 0 0 5 )。MP IgE阳性率在感染 8d后上升 ,2 8d后逐渐下降。与MP IgM滴度、血清T IgE无明显直接关系。结论 :(1)MP菌体粉碎后蛋白成分复杂 ,与IgE反应的抗原相对分子质量为 2 16 0 0 0、 2 0 5 0 0 0、 170 0 0 0、 6 80 0 0、 5 6 0 0 0 。

The aims of this study include analysis of the antigenic components of Mycoplasma pneumoniae (MP) by which the allergic responses are produced,comparison of frequencies of specific IgE antibodies produced by both non-atopic asthmatic children with MP infection and investigation for the related factors regarding to the production of MP-IgE. 35 children with MP-IgM positive broncho-pneumonia (average age 6.0±3.4 years),32 asthmatic children (average age 6.7±3.3 years),27 normal controls with negative MP-IgM and MP-IgA (average age 7.0±3.6 years) were selected for study. Western blotting was used to analyze MP-IgE and the total serum IgE was determined by ELISA. Position and frequency of the bands by which their polypeptides could respond to IgE antibodies were carefully recorded and analyzed. The results revealed that the protein components of MP were over 10 as shown on SDS-PAGE,in which those responding to IgE were 216,205,170,68 and 56 kD,the former three showing the strongest antigenicity in different trial groups and different stages of infection. The positive rates of MP-IgE were similar both in patients with non-atopic pneumonia and in asthmatics (71.43% or 78.13%),but were significantly elevated than in control individuals (71.43% or 78.13% vs 19.23%),and they elevated up 8 days after infection and gradually dropped down 28 days later.There was no significant correlation between positive rate of MP-IgE and serum level of total IgE as well as the titre of MP-IgM. It concludes that the positive rate of MP-IgE appears to be high during late stage of illness and coincides with persistent occurrence of respiratory symptoms,such as cough,but shows no any relation to titre of MP-IgM and serum total IgE.