Xpert MTB/RIF Ultra enhances tuberculous pleurisy diagnosis for patients with unexplained exudative pleural effusion who underwent a pleural biopsy via thoracoscopy: a prospective cohort study.

Abstract Introduction To evaluate the performance of Xpert MTB/RIF Ultra (Xpert-Ultra) in testing pleural tissue and fluid collected by medical thoracoscopy among patients with unexplained exudative pleural effusion. Methods Patients with an undiagnosed exudative pleural effusion were recruited prospectively and consecutively. Pleural tissue and fluid was collected by medical thoracoscopy and subjected to culture, Xpert MTB/RIF (Xpert) and Xpert-Ultra assays. Histopathological examination was also performed with the tissue and used as the major reference. Results Sixty one patients including 27 tuberculosis (TB) pleurisy, 15 malignancy and 19 other chronic infection cases were enrolled. The sensitivity, specificity, positive predict value and negative predict value of Xpert-Ultra for TB diagnosis were 85.19% (23/27), 97.06% (33/34), 95.83% (23/24) and 89.19% (33/37), respectively. Xpert-Ultra testing with the biopsy tissue alone had an equivalent diagnostic capacity to that of pathological examination for the diagnosis of confirmed TB cases. By combining pathological examination with Xpert-Ultra for biopsy, the percentage of confirmed TB cases increased greatly i.e. 92.59% (25/27). “Trace” positive outcome of Xpert-Ultra was highly supportive of TB diagnosis for both biopsy tissue and pleural fluid examinations. Conclusion With the specimens collected by medical thoracoscopy, Xpert-Ultra assay presented high value in identifying tuberculous among pleurisy patients who had difficulties in etiological diagnosis.