肺部感染相关脓毒症患儿MBL2和HLA-DRB1基因表达及BALF中肺泡巨噬细胞表型分析

Relationship of MBL2 and HLA-DRB1 gene expression and alveolar macrophage phenotype of pulmonary infection-associated sepsis

目的探究甘露糖结合凝集素2(MBL2)、人类白细胞抗原(HLA)-DRB1基因在肺部感染相关脓毒症患儿中的表达水平,评估患儿支气管肺泡灌洗液(BALF)中肺泡巨噬细胞(AM)表型变化,并分析基因表达水平、AM表型与脓毒症患儿预后的关系。方法选取2019年6月-2021年6月十堰市太和医院儿童医疗中心收治的肺部感染患儿122例,根据是否并发脓毒症分为脓毒症组(n=57)和非脓毒症组(n=65)。根据28 d死亡情况将脓毒症组患儿分为死亡组(n=11)和存活组(n=46)。采用实时荧光定量聚合酶链反应法检测外周血MBL2、HLA-DRB1基因表达情况,采用流式细胞术检测BALF中AM表型。结果脓毒症组患儿外周血MBL2 mRNA相对表达量为(0.35±0.08),高于非脓毒症组(0.24±0.07)(t=4.440,P<0.001);HLA-DRB1 mRNA相对表达量为(0.25±0.08),低于非脓毒症组(0.59±0.13)(t=8.632,P<0.001),差异均有统计学意义。入院时,脓毒症组患儿M1型AM比例高于非脓毒症组,M2型AM比例低于非脓毒症组,差异均有统计学意义(t=3.161、7.748,P均<0.01)。存活组外周血MBL2 mRNA相对表达量低于死亡组,HLA-DRB1 mRNA相对表达量高于死亡组,差异均有统计学意义(t=3.950、3.327,P均<0.01)。确诊第1天,存活组M2型AM比例明显低于死亡组,差异有统计学意义(t=18.135,P<0.001),两组患儿M1型AM比例差异无统计学意义(t=0.935,P=0.354);确诊第7天,存活组M1型AM比例明显低于死亡组,M2型AM比例明显高于死亡组,差异均有统计学意义(t=6.014、4.999,P均<0.001)。逻辑回归分析结果显示,MBL2、HLA-DRB1基因表达和确诊第7天M1、M2型AM与患儿预后不良存在明显相关性(P=0.003、0.033、0.001、0.040)。结论MBL2、HLA-DRB1基因表达、肺泡巨噬细胞表型与肺部感染相关脓毒症及患儿预后相关,早期动态监测MBL2、HLA-DRB1基因表达和肺泡巨噬细胞表型变化,有助于肺部感染相关脓毒症的预测及患儿28 d预后情况的评估。

Objective To investigate the expression levels of mannose-binding lectin 2(MBL2)and human leukocyte antigen(HLA)-DRB1 genes in children with pulmonary infection-associated sepsis,evaluate the changes in alveolar macrophage(AM)phenotypes in alveolar lavage fluid(BALF),and analyze the relationship of gene expression levels and AM phenotypes with the prognosis of children with sepsis.Methods A total of 122 children with pulmonary infection-associated sepsis admitted to the Children's Medical Center,Shiyan Taihe Hospital,from June 2019 to June 2021 were selected,and divided into sepsis group(n=57)and non-sepsis group(n=65)according to the presence or absence of sepsis.Children in the sepsis group were divided into death group(n=11)and survival group(n=46)according to the 28-day prognosis.The expression of MBL2 and HLA-DRB1 genes in peripheral blood was detected by real-time fluorescent quantitative PCR method,and AM phenotypes in alveolar lavage fluid were detected by flow cytometry.Results The relative expression of MBL2 mRNA was(0.35±0.08),higher than that of the non-sepsis group(0.24±0.07)(t=4.440,P<0.001);the relative expression of HLA-DRB1 mRNA was(0.25±0.08),lower than that of the non-sepsis group(0.59±0.032)(t=8.632,P<0.001);the difference was statistically significant.The relative expression level of MBL2 mRNA in peripheral blood of the sepsis group was higher than that in the non-sepsis group(t=4.440,P<0.001),and the relative expression level of HLA-DRB1 mRNA was lower than that in the non-sepsis group(t=8.632,P<0.001).The proportion of M1 type AM was higher and the proportion of M2 type AM was lower in the sepsis group than in the non-sepsis group on admission(t=3.161,7.748;all P<0.05).The relative expression level of MBL2 mRNA in peripheral blood of the survival group was lower than that in the death group(t=3.950,P<0.001),and the relative expression level of HLA-DRB1 mRNA was higher than that in the death group(t=3.327,P=0.002).On the 1st day after confirmed diagnosis,the proportion of M2 type AM in the survival group was significantly lower than that in the death group(t=18.135,P<0.001),but there was no significant difference in the proportion of M1 type AM between the 2 groups(t=0.935,P=0.354).On the 7th day after confirmed diagnosis,the proportion of M1 type AM in the survival group was significantly lower than that in the death group(t=6.014,P<0.001),and the proportion of M2 type AM was significantly higher than that in the death group(t=4.999,P<0.001).Logistic regression analysis showed that MBL2 and HLA-DRB1 gene expression and the 7th day after confirmed diagnosis M1 and M2 type AM were significantly correlated with poor prognosis of the children(P=0.003,0.033,0.001,0.040).Conclusions MBL2 and HLA-DRB1 gene expression and AM phenotype were related to pulmonary infection-associated sepsis and the prognosis of children.Early dynamic monitoring of MBL2 and HLA-DRB1 gene expression and alveolar macrophage phenotype was helpful for predicting pulmonary infection-associated sepsis and 28-day prognosis.