结核杆菌分泌抗原ESAT-6在肺结核组织中的表达特点

Expression characteristics of ESAT-6 secreted by Mycobacterium tuberculosis in pulmonary tuberculosis tissue

目的检测肺结核患者肺部结核病灶组织中结核杆菌(Mycobacterium tuberculosis,MTB)分泌抗原ESAT-6的表达特点,为肺结核病理诊断提供依据。方法使用川北医学院附属医院病理科所储存的手术切除的肺结核组织标本作为病例标本,阴性对照为正常肺组织标本。将肺组织蜡块连续切片后,采用免疫组化(immunohistochemistry,IHC)法检测肺结核患者结核病灶组织中ESAT-6表达,并与此标本连续切片的HE染色及抗酸染色结果进行比较分析。结果ESAT-6阳性信号主要分布在结核病灶坏死区及其周围,与抗酸染色结果相比,ESAT-6抗原阳性范围与抗酸杆菌分布有关,但分布更广泛。相关分析显示,抗酸染色与IHC平均光密度(average optical density,AOD)值呈显著正相关(r=0.87,P<0.05)。结论采用IHC可以检测到肺结核病变组织中ESAT-6的表达,有可能为肺结核诊断提供依据。

Objective To detect the expression characteristics of ESAT-6 secreted by Mycobacterium tuberculosis(MTB)in pulmonary tuberculosis focus tissue of patients with pulmonary tuberculosis,and provide basis for pathological diagnosis of pulmonary tuberculosis.Methods Surgically resected pulmonary tuberculosis tissue specimens stored in the Department of Pathology of the Affiliated Hospital of North Sichuan Medical College were used as case specimens,and the negative control was normal lung tissue specimens.Immunohistochemistry(IHC)method was used to detect the ESAT-6 expression in tuberculosis foci of patients with pulmonary tuberculosis after serial sectioning of lung tissues,and compared with the results of HE staining and antacid staining of serial sections of this specimen.Results ESAT-6 positive signals were mainly distributed in and around the necrotic areas of tuberculosis foci.Compared with the results of antacid staining,the range of ESAT-6 antigen positivity was related to the distribution of antacid bacilli,but the distribution was more extensive.Correlation analysis showed that there was a statistically significant positive correlation between the results of antacid staining and IHC average optical density(AOD)value(r=0.87,P<0.05).Conclusion The expression of ESAT-6 in the pathological tissues of pulmonary tuberculosis can be detected by IHC,which may potentially providing a basis for tuberculosis diagnosis.