Int J Clin Exp Pathol 2017;10(4):4847-4851 www.ijcep.com /ISSN:1936-2625/IJCEP0045802 Original Article Evaluation of Xpert MTB/RIF in detection of pulmonary and extrapulmonary tuberculosis cases in China Hui Jing 1 , Zhiming Lu 2 , Yunfeng Deng 1 , Dachuan Gao 1 , Liang Li 3 , Edward A Graviss 4 , Xin Ma 1,4 1 Katharine Hsu International Research Center of Human Infectious Diseases, Shandong Provincial Hospital Affliated to Shandong University, Jinan, Shandong, China; 2 Department of Laboratory Medicine, Shandong Provincial Hospital Affliated to Shandong University, Jinan, Shandong, China; 3 Clinical Center on TB, Chinese Center for Disease Control and Prevention, Beijing, China; 4 The Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Hospital Research Institute, Houston, Texas, USA Received December 5, 2016; Accepted February 6, 2017; Epub April 1, 2017; Published April 15, 2017 Abstract: Background: To evaluate the performance of Xpert MTB/RIF assay for direct detection of Mycobacterium tuberculosis (Mtb) and rifampin resistance in pulmonary and extrapulmonary tuberculosis (TB) patients in China. Material/Methods: We prospectively enrolled 506 TB patients to evaluate sensitivity and specifcity of Xpert MTB/ RIF by comparing with Mtb culture, fuorescent staining smear microscopy and clinical diagnosis. Results: Overall, 402 of 506 (79.4%) included patients were clinically diagnosed with TB. Sensitivities of Xpert MTB/RIF, Mtb culture, and AFB microscopy, and combined three methods among clinically-diagnosed pulmonary TB patients were 67.7% (130/192), 65.1% (125/192), 61.5% (118/192), and 69.8% (134/192) respectively; and 19.0% (40/210), 23.8% (50/210), 5.2% (11/210), and 34.3% (72/210) respectively among clinically-diagnosed extrapulmonary TB pa- tients. Specifcities of Xpert MTB/RIF assay for pulmonary and extrapulmonary TB were 100%. Compared with MGIT drug susceptibility test, the sensitivity and specifcity of Xpert MTB/RIF for diagnosis of rifampin-resistant TB was 77.3% and 96.0% respectively. Conclusion: The Xpert MTB/RIF assay has a comparable sensitivity with Mtb culture for pulmonary TB, but less sensitive than Mtb culture for extrapulmonary TB. Combined three methods achieved a better sensitivity than any individual test. Keywords: Xpert MTB/RIF, pulmonary, extrapulmonary, tuberculosis, China Introduction Tuberculosis (TB), especially drug resistant TB, remains one of the major public health con- cerns worldwide with a mortality ranging from 1.6 to 2.2 million per year [1]. Rapid and accu- rate diagnosis of active TB disease can signif- cantly prevent TB transmission in populations. Laboratory assays currently in use for active TB diagnosis include the acid-fast bacilli (AFB) microscopy, mycobacterial culture, and the interferon gamma releasing assays (IGRAs), all of which still suffer from either low sensitivity, specifcity, long turnaround time, and/or high costs [2]. Xpert MTB/RIF assay, a method based on DNA amplifcation, was recently intro- duced to tackle TB diagnostic limitations, with increased sensitivity and specifcity for rapid TB diagnosis. The Xpert MTB/RIF assay was recommended by World Health Organization (WHO) in 2011 to facilitate the rapid detection of active TB and rifampin resistance with more than 95% sensitivity for smear-positive cases and 55% for smear-negative cases [3]. How- ever, data on the utility of Xpert MTB/RIF in extra-pulmonary specimens are still limited. China has the second highest incidence of TB and the highest drug-resistant TB in the world [4]. Performance of the Xpert MTB/RIF assay in the Chinese population is still under investiga- tion. The objectives of this study were to evalu- ate the performance of the Xpert MTB/RIF assay for the direct detection of M. tuberculosis (Mtb) and rifampin resistance in pulmonary and extrapulmonary TB patients in China. Materials and methods This study was conducted in Shandong Provincial Chest Hospital, which is the only pro-