Xpert MTB/RIF Assay for the Diagnosis of Pulmonary Tuberculosis Based on Bronchoalveolar Lavage Fluid: A Systematic Review and Meta-analysis

Abstract

Currently, tuberculosis (TB) is the second most lethal disease in the world caused by a single infectious pathogen. Rapid diagnosis of TB is of great importance for its treatment and management. Xpert MTB/RIF is a novel rapid diagnostic assay for the diagnosis of pulmonary TB (PTB). Use of the Xpert assay based on bronchoalveolar lavage fluid (BALF) samples is indicated when TB is suspected and sputum smears or cultures are negative. The aim of this meta-analysis was to systematically evaluate the diagnostic performance of the Xpert assay based on BALF samples for the diagnosis of PTB. A systematic review of previously published articles was performed, and relevant data were extracted. Meta-DiSc 1.4 and Stata 12.0 were used to analyze the data. When Mycobacterium tuberculosis cultures were used as the criterion standard, the combined sensitivity of BALF-based Xpert was 0.89 (95% CI, 0.87–0.91), the specificity was 0.87 (95% CI, 0.85-0.88), the positive likelihood ratio was 8.28 (95% CI, 5.39–12.71), the negative likelihood ratio was 0.14 (95% CI, 0.10–0.19) and the diagnostic ratio was 84.08 (95% CI, 42.00–168.31). When composite reference standard was used as the criterion standard, the above observations were 0.69 (95% CI, 0.67–0.72), 0.98 (95% CI, 0.97–0.98), 41.40 (95% CI, 14.56–117.71), 0.28 (95% CI, 0.21–0.37) and 190.47 (95% CI, 50.56–717.54), respectively. The area under the summary receiver operating characteristic curve was close to 1 for both. Overall, the Xpert MTB/RIF assay based on BALF samples showed high sensitivity and specificity for the diagnosis of PTB and seems to be a reliable rapid detection method.