Is Xpert MTB/RIF appropriate for diagnosing tuberculous pleurisy with pleural fluid samples? A systematic review

Tuberculous pleurisy (TP) presents a diagnostic problem due to the limitations of traditional diagnostic methods. Different studies with the Xpert MTB/RIF assay have drawn variable conclusions about its values in TP diagnosis. We conducted a meta-analysis to assess whether the Xpert MTB/RIF assay is appropriate for the diagnosis of TP using pleural fluid samples.

A systematic search of four literature databases in English and Chinese language was performed to identify studies involving the use of Xpert MTB/RIF in patients with TP confirmed by plural biopsy and/or mycobacterial culture. Pooled sensitivity, specificity and accordance proportion were calculated, and the forest plots were generated to assess the accuracy of Xpert MTB/RIF for TP diagnosis.

We identified 23 studies meeting our inclusion criteria. The pooled sensitivity and specificity of Xpert MTB/RIF were 30% (95% CI: 21-42%, I² = 87.93%) and 99% (95% CI: 97-100%, I² = 96.20%), respectively, and the area under the SROC curve (AUC) of Xpert MTB/RIF was 0.86 (95% CI: 0.83-0.89). Compared with drug susceptibility testing (DST), the pooled accordance rate of Xpert MTB/RIF in detecting rifampicin-susceptible cases and rifampicin-resistant cases was 99% (95% CI: 95-104%, I² = 8.7%) and 94% (95% CI: 86-102%), respectively.

Our analysis suggests that the Xpert MTB/RIF assay is of limited value as a screening test for TP but has a high potential for confirming TP diagnosis and differentiating TP from non-TB diseases using pleural fluid samples.