Comparison of the Diagnostic Accuracy of Xpert MTB/RIF and CapitalBio Mycobacterium RT-PCR Detection Assay for Tuberculous Pericarditis

Purpose: We evaluated CapitalBio Mycobacterium RT-PCR assay diagnosing tuberculous pericarditis (TBP), performed a head-to-head comparison with Xpert MTB/RIF, and assessed the impact of a parallel test (positive result for either of these two tests). Methods: We reviewed suspected TBP patients with Xpert MTB/RIF, CapitalBio Mycobacterium RT-PCR assay, and Mycobacterium tuberculosis (MTB) culture. We analyzed sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC). Results: Seventy-four patients were included. Overall sensitivity, specificity, PPV, NPV, and AUC of CapitalBio Mycobacterium RT-PCR assay compared with culture were 50%, 91.1%, 64.3%, 85%, and 0.71, respectively. Overall sensitivity, specificity, PPV, NPV, and AUC of Xpert MTB/RIF for TBP were 61.1%, 91.1%, 68.8%, 87.9%, and 0.76. Parallel test values were 72.2%, 91.1%, 72.2%, 91.1%, and 0.82. The diagnostic accuracy of Xpert MTB/RIF was higher than CapitalBio Mycobacterium RT-PCR assay but was not significant ( P > 0.05). The parallel test could improve diagnostic accuracy, but it was not significant compared to single tests ( P > 0.05). Conclusion: CapitalBio Mycobacterium RT-PCR assay had a moderate diagnostic accuracy, similar to Xpert MTB/RIF. The parallel test maximized diagnostic efficacy, but differences were not significant. CapitalBio Mycobacterium RT-PCR assay and Xpert MTB/RIF for TBP could be an initial option for early diagnosis. Keywords: tuberculosis pericarditis, polymerase chain reaction, Xpert MTB/RIF, CapitalBio, accuracy