ABSTRACT
Objective@#To evaluate the effectiveness of different laboratory methods for the supplementary diagnosis of pulmonary tuberculosis（PTB）and provide reference data for the early diagnosis of PTB. @*Methods@#A total of 298 suspected PTB patients, who were diagnosed and treated in the outpatient department of Shanghai Tongren Hospital from January 2016 to December 2018, were divided into 3 groups: active PTB (138 cases)，inactive PTB (43 cases) and non-PTB (117 cases) group. Sputum acid-fast staining, MGIT liquid culture system and Xpert MTB/RIF test were performed to detect the sputum specimens. The sensitivity and specificity were compared by Chi-square test. @*Results@#The three methods showed certain significance for distinguishing active PTB, inactive PTB combined with non-PTB (χ 2 values were 89.08, 138.94 and 137.12 respectively, all P＜0.01). There was no significant difference for the positive rate of the three methods between inactive PTB and non-PTB. The sensitivities of acid-fast staining, MGIT liquid culture, Xpert MTB/RIF test and the combination of three methods in the diagnosis of active PTB were 45.7% (63/138), 63.8% (88/138), 65.4% (87/133) and 78.2% (104/133) respectively. The sensitivities of MGIT culture and Xpert MTB/RIF test were significantly higher than that of acid-fast staining (χ 2 was 35.79 and 11.26 respectively，all P＜0.01). There was no significant difference for the sensitivities between MGIT liquid culture and Xpert MTB/RIF test（χ 2 was 29.87, P＞0.05) . The sensitivity of combined detection was higher than that of single detection（χ 2 was 30.84, 64.62, 70.14, respectively, all P＜0.01）. The diagnostic specificities of the three methods and their combination were 99.1%（116/117), 98.3%（115/116）, 99.1%（113/114) and 97.3%（110/113）respectively. There was no significant difference for the specificities of the three methods. @*Conclusion@#High sensitivities of MGIT liquid culture and Xpert MTB/RIF test were shown in PTB diagnosis. Combined detection of the three methods may improve the sensitivity of detection.