巨噬细胞移动抑制因子在急性呼吸窘迫综合征发病中的作用

目的 探讨巨噬细胞移动抑制因子（MIF）在急性呼吸窘迫综合征（ARDS）中的表达和作用。方法 ARDS组12例，对照组20例，用ELISA法测定患者血清MIF水平，采用流式细胞仪检测外周血单个核细胞（PBMC）MIF的表达，用免疫组织化学双重染色和原位杂交技术观察肺组织中MIF mRNA和蛋白表达水平。结果 ARDS患者外周血清MIF水平和PBMC MIF表达率明显高于正常人（P＜0.01)。原位杂交和免疫组化染色结果显示，正常肺组织中未见MIF mRNA和蛋白表达，而在ARDS肺组织中MIF表达水平明显增高，肺间质、肺泡腔内可见巨噬细胞浸润并见有MIF表达，病理损伤较严重处MIF表达更强且与巨噬细胞浸润数量明显相关。结论 ARDS患者血清MIF水平和外周血单个核细胞表达MIF增多，肺组织存在MIF表达增多及巨噬细胞浸润情况，提示MIF在ARDS发病中起重要作用。

The pathogenic role of macrophage migration inhibitory factor in acute respiratory distress syndrome

Objective To investigate the expression and pathogenic role of macrophage migration inhibitory factor( MIF) in human acute respiratory distress syndrome(ARDS) Methods The serum level of MIF in ARDS patients and normal persons were measured by ELISA method Peripheral blood mononuclear cell (PBMC) MIF expression was determined by flow cytometry The expression of MIF mRNA and protein in the lung tissues were detected by using double immuno histochemistry labeling and in situ hybridization Results The serum level of MIF increased significantly in ARDS patients as compared with normal persons ( P <0 01); The percentage of PBMC MIF expression was higher in ARDS patients than in normal controls ( P <0 01) In situ hybridization and immunohistochemistry showed undetectable or weak MIF mRNA and protein expression in normal lungs In contrast, there was marked upregulation of MIF mRNA and protein expression in the ARDS lungs In ARDS,macrophages infiltrated the alveolar space and interstitium, most of which also expressed MIF Infiltrating macrophages were almost restricted to the areas of severe tissue damage The MIF expression level showed a strong correlation with the number of infiltrating macrophages Conclusions The serum level of MIF and PBMC MIF expression increased in ARDS patients with enhanced pulmonary MIF expression and macrophage infiltration, which suggests that MIF plays a pivotal role in the pathogenesis of ARDS