肺结核患者痰和血浆IFN-γ含量检测的临床意义探讨

Detection and clinical significance of IFN-γ level in sputum and plasma of pulmonary tuberculosis patients

目的探讨肺结核患者痰和血浆中γ-干扰素(interferon-gamma,IFN-γ)水平在结核病诊断、鉴别诊断中的意义。方法用酶联免疫吸附剂测定法(ELISA)分别检测44例活动性肺结核患者(PTB)、36例正常对照者、18例肺癌患者痰和血浆中IFN-γ含量。结果结核分枝杆菌潜伏感染者(LTBI)痰和血浆IFN-γ含量与健康人相接近(P>0.05);肺结核患者血浆IFN-γ含量显著高于正常对照及肺癌患者(P值均<0.05),肺结核患者痰中IFN-γ含量显著低于正常对照及肺癌患者(P值均<0.01);肺结核患者痰IFN-γ含量低于血浆IFN-γ含量;痰及血浆中IFN-γ的ROC曲线下面积(AUC)分别为0.90和0.91,当痰中IFN-γ诊断临界值为21.40 pg/ml时,敏感度85.71%、特异性82.35%;当血浆IFN-γ诊断临界值为27.91 pg/ml时,敏感度71.43%、特异性94.12%。结论痰和/或血浆中IFN-γ可以作为肺结核诊断(尤其是菌阴肺结核)、鉴别诊断的重要辅助指标之一。

Objective To estimate the clinical significance of the diagnosis and the differential diagnosis in patients with pulmonary tuberculosis（PTB） by investigating levels of IFN-γ in the sputum and plasma of the patients.Methods Levels of IFN-γ in sputum and plasma was detected in 44 cases of PTB,36 cases of controls and 18 cases of pulmonary cancer by using enzyme linked immunosorbent assay（ELISA）.Results The sputum and plasma IFN-γ levels were quite close in the Latent Mycobacterium tuberculosis infection（LTBI） and healthy controls（P〉0.05）.The plasma levels of IFN-γ were significantly higher in PTB patients when compared with the control and lung cancer groups,respectively（P〈0.05）.Levels of IFN-γ in sputum of patients with PTB was significantly lower than in controls and lung cancer patients,respectively（P〈0.01）.Sputum levels of IFN-γ in patients with PTB were lower than those in plasma.The receiver operator characteristic（ROC） curve for sputum and plasma IFN-gamma showed an area under the curve（AUC） value of 0.90 and 0.91,respectively,accompanied the best cutoff value 27.91 pg/ml and 21.40 pg/ml respectively.Using the cutoff value for IFN-γ levels in sputum and plasma for the diagnosis of PTB,the sensitivity and specificity were found to be 85.71%,82.35% and 71.43%,94.12%,respectively.Conclusions Levels of IFN-γ in sputum or/and plasma can be used as one of the important supplementary target for diagnosis and differential diagnosis of PTB（especially in smear and culture negative pulmonary tuberculosis）.