Xuejiao Hu1, Mengqiao Shang1, Xuerong Chen2, Yi Xie1, Yuanxin Ye1, Juan Zhou1, Xingbo Song1, Xiaojun Lu1, Binwu Ying3, Lanlan Wang4. 1. Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, PR China. 2. Division of Pulmonary Disease, Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, PR China. 3. Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, PR China. Electronic address: docbwy@126.com. 4. Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, PR China. Electronic address: huaxiwangll@gmail.com.
Abstract
OBJECTIVES: To assess the capacity of rapid and accurate confirmation of the Mycobacterium tuberculosis complex (MTBC) in a Chinese clinical laboratory. DESIGN AND METHODS: This prospective study investigated three rapid assays, the Amplified Mycobacterium Tuberculosis Direct (MTD) test, real-time PCR, and acid-fast bacilli (AFB) smear, for direct detection of MTBC in a large consecutive series of different clinical specimens. Performance parameters were estimated and compared overall and for separate specimen categories using a combined reference gold standard. RESULTS: The overall sensitivities were similar for MTD and real-time PCR (62.26% vs. 58.49%), significantly higher than those of AFB smear (31.13%). Among three assays, MTD had a satisfactory sensitivity in respiratory specimen (73.33%) and a nearly perfect detection for smear-positive samples (96.97%). Real-time PCR showed a high positive rate (58.97%) in regard to nonrespiratory specimen. A combination of molecular assays with conventional methods reached marked additive diagnostic values (sensitivity up to 76.42%), higher than each method individually. All detection systems showed excellent specificities (>96.00%). CONCLUSIONS: The present study indicated that our lab had a moderate diagnostic performance for tuberculosis. Quality guarantee for specimen pretreatment, as well as combination analysis, will enable these assays to better incorporate into the routine laboratory workflow in China.
OBJECTIVES: To assess the capacity of rapid and accurate confirmation of the Mycobacterium tuberculosis complex (MTBC) in a Chinese clinical laboratory. DESIGN AND METHODS: This prospective study investigated three rapid assays, the Amplified Mycobacterium Tuberculosis Direct (MTD) test, real-time PCR, and acid-fast bacilli (AFB) smear, for direct detection of MTBC in a large consecutive series of different clinical specimens. Performance parameters were estimated and compared overall and for separate specimen categories using a combined reference gold standard. RESULTS: The overall sensitivities were similar for MTD and real-time PCR (62.26% vs. 58.49%), significantly higher than those of AFB smear (31.13%). Among three assays, MTD had a satisfactory sensitivity in respiratory specimen (73.33%) and a nearly perfect detection for smear-positive samples (96.97%). Real-time PCR showed a high positive rate (58.97%) in regard to nonrespiratory specimen. A combination of molecular assays with conventional methods reached marked additive diagnostic values (sensitivity up to 76.42%), higher than each method individually. All detection systems showed excellent specificities (>96.00%). CONCLUSIONS: The present study indicated that our lab had a moderate diagnostic performance for tuberculosis. Quality guarantee for specimen pretreatment, as well as combination analysis, will enable these assays to better incorporate into the routine laboratory workflow in China.