Xpert® MTB/RIF in pleural fluid for the diagnosis of tuberculosis

Abstract

An automated nucleic acid amplification assay that simultaneously identifies Mycobacterium tuberculosis and rifampicin resistance, the Xpert® MTB/RIF test, has undergone extensive evaluation in sputum samples. Our aim was to define its diagnostic accuracy when performed on pleural fluid specimens. In 67 patients with pleural effusions, of whom half had tuberculous pleuritis, Xpert yielded 15% sensitivity and 100% specificity in the detection of tuberculosis (TB). Positive Xpert results tended to be more common in patients with microbiologically confirmed TB. Due to its low sensitivity, Xpert testing of pleural fluids has a limited role in the work-up of pleural effusions.