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

Abstract

BackgroundTuberculous 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.MethodsA 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.ResultsWe 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.ConclusionsOur 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.Electronic supplementary materialThe online version of this article (10.1186/s12879-018-3196-4) contains supplementary material, which is available to authorized users.

A retrospective study on Xpert MTB/RIF for detection of tuberculosis in a teaching hospital in China

“…Consistent with the literature (68-94%) [17], this research found that Xpert also showed high sensitivity (76.5%) in the diagnosis of EPTB. When pleural fluid was used to diagnose TP, the high specificity (100%) of Xpert suggested its high value in confirming TP diagnosis; however, the low sensitivity (15.0%), which was similar to previous studies (14-34%) [17,19,20], indicated that Xpert is of limited value for TP screening. Low sensitivity may be attributed to the presence of PCR inhibitors in pleural fluid [20], or the loading of MTB is too low that the detection limit cannot be reached even by centrifugation.…”

“…When pleural fluid was used to diagnose TP, the high specificity (100%) of Xpert suggested its high value in confirming TP diagnosis; however, the low sensitivity (15.0%), which was similar to previous studies (14-34%) [17,19,20], indicated that Xpert is of limited value for TP screening. Low sensitivity may be attributed to the presence of PCR inhibitors in pleural fluid [20], or the loading of MTB is too low that the detection limit cannot be reached even by centrifugation. Thus, this study together with previous literature, did not recommend the use of pleural fluid as a specimen of Xpert for the diagnosis of TP, until pleural fluid was optimized for improved sensitivity.…”

Performance of Xpert® MTB/RIF in diagnosing tuberculous pleuritis using thoracoscopic pleural biopsies

“…and 51% [10][11][12]. Other studies showed that pleural biopsies taken by medical thoracoscopy were the best specimens for diagnosing TPE [9,13,[20][21][22].…”

“…In 2013, WHO expanded its application for the diagnosis of extrapulmonary tuberculosis in adults and children, although the samples were only restricted to cerebrospinal fluid, lymph node fluid, and tissue specimens [9]. The pooled sensitivity of Xpert in the diagnosis of tuberculous pleural effusion (TPE) was between 30% and 51% [10][11][12]. Studies have shown that pleural biopsies taken under medical thoracoscopy are better specimens for diagnosing tuberculous pleuritis compared to pleural fluid [9,13,14].…”

Comparison of a Rapid Molecular Method with Conventional Methods for Identification of Mycobacterium tuberculosis complex and Detection of Rifampicin Resistance

“…(23) tarafından 23 çalışma dâhil edilerek plevral sıvı örneklerinde GX testinin uygunluğunun değerlendirildiği bir meta-analizde; testin duyarlılığı %30 olarak çalışmamıza benzer şekilde düşük bulunmuştur. Aynı meta-analizde; GX testinin plevral sıvı örneklerinde düşük duyarlılığının PCR inhibisyonu ve uygunsuz veya yetersiz örnekleme yöntemlerinden kaynaklanabileceği belirtilmiş, testin TB tanısını dışlamada değerinin düşük olduğundan sözsedilmiştir (23) . Mazzola ve ark.…”