Abstract:

Objective To investigate the diagnostic efficacy of serum matrix metalloproteinase-9（MMP-9） combined with Xpert MTB/RIF assay in alveolar lavage fluid and interferon gamma（INF-γ） release test for pulmonary tuberculosis. Methods Totally,200 patients with suspected pulmonary tuberculosis in Hebei Chest Hospital from May 2019 to May 2020 were enrolled. According to the examination results,pulmonary tuberculosis group was subclassified into mycotic-positive pulmonary tuberculosis group（62 cases）,mycotic-negative pulmonary tuberculosis group（88 cases） and non-pulmonary tuberculosis group（50 cases）. The result differences of serum MMP-9,interleukin（IL）-15,tumor necrosis factor-alpha（TNF-α）,C-reactive protein（CRP）,erythrocyte sedimentation rate（ESR）,INF-γ release test,culture of sputum Mycobacterium tuberculosis（MTB）,Xpert MTB/RIF assay in alveolar lavage fluid were compared among the 3 groups on the day of admission. Logistic regression analysis was used to draw receiver operating characteristic（ROC） curve to evaluate the diagnostic efficacy of serum MMP-9,Xpert MTB/RIF assay in alveolar lavage fluid and INF-γ release test for pulmonary tuberculosis. Results There was statistical significance for MMP-9 and INF-γ among the 3 groups（P<0.05）,and there was no statistical significance for the other indicators（P>0.05）. The levels of MMP-9 and INF-γ in pulmonary tuberculosis group were higher than those in non-pulmonary tuberculosis group（P<0.05）. The positive rate of Xpert MTB/RIF in mycotic-positive pulmonary tuberculosis group was higher than that in mycotic-negative pulmonary tuberculosis group（P<0.05）. Between mycotic-positive and mycotic-negative pulmonary tuberculosis groups,there was no statistical significance for the positive rate of INF-γ release test and INF-γ level（P>0.05）. The positive rate of INF-γ had no statistical significance between mycotic-positive and mycotic-negative pulmonary tuberculosis groups（P>0.05）. Logistic regression analysis showed that MMP-9 [odds ratio（OR）=1.687,P=0.004],INF-γ（OR=2.511,P=0.005） and Xpert MTB/RIF（OR=1.340,P=0.005） were the risk factors of pulmonary tuberculosis. The sensitivity,specificity and accuracy of Xpert MTB/RIF assay in pulmonary tuberculosis diagnosis were 86.7%,96.0% and 89.0%,respectively. The sensitivity,specificity and accuracy of INF-γ release test in the diagnosis of pulmonary tuberculosis were 80.0%,62.0% and 75.5%,respectively. The sensitivity of MMP-9 in the diagnosis of pulmonary tuberculosis was 80.7%,the specificity was 60.0%,and the accuracy was 75.0%. The sensitivity,specificity and accuracy of the combined determination for the diagnosis of pulmonary tuberculosis were 90.7%,78.0% and 87.5%,respectively. Conclusions The high expressions of MMP-9 and INF-γ and the positivity of Xpert MTB/RIF are the risk factors of pulmonary tuberculosis. The sensitivity and specificity of the combined determination of the 3 indicators in the diagnosis of pulmonary tuberculosis are increased,which has certain clinical significance.

Key words: Matrix metalloproteinase-9, Alveolar lavage fluid, Xpert MTB/RIF assay, Interferon gamma release test, Pulmonary tuberculosis