Xpert® MTB/RIF in pleural fluid for the diagnosis of tuberculosis [Short communication]

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.

Evaluation of Xpert MTB/RIF assay performance in diagnosing extrapulmonary tuberculosis among adults in a tertiary care centre in India

“…Suboptimal performance of the assay was observed for various body fluids, with sensitivity ranging from 18% to 40%, which is consistent with several previous studies [7][8][9][10][11][12]. The present study also indicates exemplary performance of the assay in patients with cold abscesses and lymph nodes and these findings are similar to previously published literature [7][8][9]13].…”

“…In the present study, we excluded patients who were already on anti-TB treatment for .2 weeks. The overall performance of Xpert MTB/RIF in our study might vary from different studies across the globe because of the variation in proportion of sample types [7][8][9][10][11][12][13][14][15].…”

Xpert MTB/RIF assay for the diagnosis of extrapulmonary tuberculosis: a systematic review and meta-analysis

“…Seven studies included only one sample type (e.g. pleural fluid only) [17,18,21,25,26,30,39] (table 1). The remainder of the studies included different sample types in varying percentages.…”

“…1) [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] that included 4461 samples. TB prevalence (based on culture) ranged from 0% to 81%.…”

“…The majority of studies collected data prospectively (n514; 78%) (table 1) and only three studies used a case-control design [15,23,26]. All studies were performed either in tertiary care centres or reference laboratories.…”