Ge Menglei, Song Qinwei, Guo Qi, Zhou Lin, Li Jing, Li Zhiyan, Ma Lijuan
Clin Lab. 2021 Jan 1;67(1). doi: 10.7754/Clin.Lab.2020.200321.
The study was aimed to compare ELISA results of Mycoplasma pneumoniae IgG (MP-IgG) and Mycoplasma pneumoniae IgM (MP-IgM) with the passive particle agglutination (PA) test, as well as to evaluate their application value in the diagnosis of Mycoplasma pneumoniae pneumonia (MPP) in children.
Serum MP antibodies were detected by ELISA for MP-IgM, MP-IgG, and PA for 292 patients in the MPP group and 89 patients in NMP group. The PA results were used as reference standards. These patients were treated in the respiratory department of Children's Hospital Capital Institute of Pediatrics, China, from July to December, 2019.
In the MPP group, the positive rate for MP-IgM was 75% higher than that of the PA titer (73.97%), Pearson's coefficient was 0.711, and the Kappa coefficient was 0.662, p < 0.01, suggesting that both the correlation and the consistency of the two methods were high. In the PA-negative group (< 1:160), 22.38% of patients were MP-IgM positive, indicating that the sensitivity to MP-IgM was higher compared to PA, when the disease duration was less than 7 days. The diagnostic value for MP-IgG was lower than that for MP-IgM, and the high positive rate of MP-IgG (48.31%) in the NMP group suggested a high background value of MP-IgG in children. Testing of paired serum obtained a more accurate diagnosis. At admission, 47.57% of patients with paired serum who were negative for MP-IgM, converted to a net positive after 4 - 6 days, except for one patient. In the paired serum, 57.8% of patients had a 4-fold increase of MP-IgG.
MP-IgM was a sensitive indicator of MP infection in children with a high consistency and correlation with the reference positive standard of PA titer ≥ 1:160. For a more accurate diagnosis, testing of paired serum is still necessary, and a 4-fold increase in MP-IgG could be the supplementary diagnosis method.
本研究旨在比较肺炎支原体IgG（MP-IgG）和肺炎支原体IgM（MP-IgM）的酶联免疫吸附测定（ELISA）结果与被动颗粒凝集试验（PA），并评估它们在儿童肺炎支原体肺炎（MPP）诊断中的应用价值。
对首都儿科研究所附属儿童医院呼吸科2019年7月至12月收治的292例MPP组患儿和89例非MPP组患儿，采用ELISA法检测血清MP-IgM、MP-IgG抗体及PA。以PA结果作为参考标准。
MPP组中，MP-IgM阳性率比PA滴度阳性率（73.97%）高75%，Pearson系数为0.711，Kappa系数为0.662，p<0.01，表明两种方法的相关性和一致性均较高。在PA阴性组（<1:160）中，22.38%的患者MP-IgM呈阳性，表明在病程小于7天时，MP-IgM相对于PA的敏感性更高。MP-IgG的诊断价值低于MP-IgM，非MPP组中MP-IgG的高阳性率（48.31%）表明儿童MP-IgG的背景值较高。检测配对血清可获得更准确的诊断。入院时，配对血清MP-IgM阴性的患者中，除1例患者外，47.57%的患者在4 - 6天后转为净阳性。在配对血清中，57.8%的患者MP-IgG升高4倍。
MP-IgM是儿童MP感染的敏感指标，与PA滴度≥1:160的参考阳性标准具有较高的一致性和相关性。为获得更准确的诊断，仍需检测配对血清，MP-IgG升高4倍可作为补充诊断方法。
