Combination of Percutaneous Lung Biopsy and Xpert MTB/RIF Ultra Enhances the Differential Diagnosis of Tuberculosis: A Prospective Cohort Study

INTRODUCTION To evaluate the value of the combination of computed tomography (CT)-guided percutaneous lung biopsy and Xpert MTB/RIF Ultra (Xpert-Ultra) in enhancing the differential diagnosis of tuberculosis. METHODS Patients with lesions in the lungs for whom the differential diagnosis was difficult were prospectively and consecutively enrolled. Specimens collected by percutaneous lung biopsy were subject to Xpert-Ultra and histopathologic examination, respectively. RESULTS Biopsy was successfully performed for 147 patients who were eligible for analysis, including 65 TB, 55 lung cancer and 27 other chronic infection cases. The sensitivity, specificity, positive predictive value and negative predictive value of Xpert-Ultra for TB diagnosis were 75.38% (49/65) and 95.12% (78/82), 92.45% (49/53) and 82.98% (78/94), respectively. Among patients with strong evidence for TB diagnosis (categorized as confirmed or probable TB cases), the overall positive rate of the Xpert-Ultra assay was 83.63% (46/55), which was much higher than for any reported sample type with negative smear test outcomes to date. Five rifampicin (RIF)-resistant cases were identified using the biopsy tissues. However, "trace" positive did not seem reliable for TB diagnosis with lung biopsy specimens; a 25.61% (21/82) "trace"-positive rate was acquired in the non-TB group. CONCLUSION Percutaneous lung biopsy combined with Xpert-Ultra produced high sensitivity for culture-negative pulmonary TB patient diagnosis. "Trace" outcome might not be a reliable positive category for lung biopsy specimens. TRIAL REGISTRATION ClinicalTrials.gov identifier, ChiCTR1900026412. Retrospectively registered on Oct 8th, 2019).