肺炎支原体肺炎患儿肺泡灌洗液MP-DNA载量及免疫炎症指标变化的临床意义

Clinical significance of changes of MP-DNA load and immune inflammatory markers in bronchoalveolar lavage fluid of children with Mycoplasma pneumoniae pneumonia

目的探讨肺炎支原体肺炎(MPP)患儿肺泡灌洗液(BALF)MP-DNA载量,及其与免疫细胞的相关性。方法选取2015年10月-2016年4月在郴州第一人民医院儿童呼吸科确诊为MPP的患儿24例,作为MPP组,另选同期入院治疗的28例支气管异物患儿作为对照组;比较两组患儿相关炎症指标变化,被动凝集法检测血清MP抗体滴度,采用实时荧光定量PCR法检测其BALF MP-DNA载量,镜检并计算各类免疫细胞百分比。结果 MPP患儿组血清C-反应蛋白(CRP)和红细胞沉降率(ESR)水平分别为(18.30±14.29)mg/L、(32.18±19.85)mm/h,均高于对照组(10.28±12.20)mg/L、(12.67±6.31)mm/h(P<0.05),两组其他各项指标比较差异均无统计学意义;MPP患儿组血清MP抗体阳性率79.2%(19/24),高于对照组14.28%(4/28)(P<0.05);MPP组患儿BALF中性粒细胞比例高于对照组,巨噬细胞比例低于对照组,两组比较差异有统计学意义(P<0.05);MPP患儿BALF中性粒细胞比例与BALF MP-DNA含量呈正相关(r=0.477,P=0.018),巨噬细胞比例与BALF MP-DNA含量呈负相关(r=-0.457,P=0.024)。结论 MPP患儿BALF MP-DNA与中性粒细胞含量显著增加,提示MP可激活中性粒细胞,诱发机体细胞和体液免疫反应。

OBJECTIVE To explore the MP-DNA load in bronchoalveolar lavage fluid （BALF） of children with My- coplasma pneumoniae pneumonia （MPP） and analyze its relationship with immune cells.METHODS A total of 24 children who were diagnosed with MPP in the respiratory department of the First People＇s Hospital of Chenzhou from Oct 2015 to Apt 2016 were enrolled in the study and assigned as the MPP group, meanwhile, 28 children who had bronchial foreign bodies were chosen as the control group.The levels of related inflammatory indexes were compared between the two groups of children, the serum MP antibody titer was detected by using passive aggluti- nation method, the MP-DNA load in BALF was detected by means of real-time fluorescence quantification PCR, and the percentages of the immune cells were calculated by using microscope.RESULTS The levels of serum C-re- active protein （CRP） and erythrocyte sedimentation rate （ESR） of the MPP group were respectively （18.30 ± 14.29）mg/L and （32.18±85）mm/h, significantly higher than （10.28±12.20）mg/L and （12.67±6.31）mm/h of the control group（P〈0.05）,however, there were no significant differences in other indexes between the two groups.The positive rate of serum MP antibody of the MPP group was 79.2% （19/24）, significantly higher than14.28% （4/28） of the control group（P ~0.05）.The percentage of neutrophils in BALF was higher in the MPP group than in the control group, while the percentage of macrophages was significantly lower in the MPP group than in the control group（P〈0.05）.The percentage of neutrophils in BALF of the children with MPP was posi- tively correlated with the BALF MP-DNA load （r = 0.477,P = 0.018）, while the percentage of macrophages was negatively correlated with the BALF MP-DNA load （r = - 0.457, P = 0.024） .CONCLUSION The MP-DNA and neutrophils are remarkably increased in BALF of the children with MPP, indicating that the MP may activate the neutrophils and induce the immune cells and humoral immune response.