GeneXpert MTB/RIF assay with transbronchial lung cryobiopsy for Mycobacterium tuberculosis diagnosis.

BACKGROUND

Early tuberculosis (TB) diagnostic is one of the critical steps to TB control. GeneXpert MTB/RIF has been widely proven for a prompt TB diagnosis. The use of GeneXpert MTB/RIF assay with transbronchial lung cryobiopsy samples may increase diagnostic accuracy. We aim to assess the diagnostic of TB with GeneXpert MTB/RIF assay with transbronchial lung cryobiopsy.

METHODS

Patients with suspected diagnosis of TB and negative smear microscopies, with TB culture and GeneXpert MTB/RIF assay with transbronchial lung cryobiopsy were included in this cross-sectional study. Participants were enrolled from 2016 to 2018 at National Institute of Respiratory Diseases, Mexico.

RESULTS

We included 54 patients (77.8% males) aged 30 to 65 years. The sensitivity of the GeneXpert MTB/RIF assay with transbronchial lung cryobiopsy was 81.3% (95% CI, 62.1-100%), with a specificity of 100% (95% CI, 100-100%) and a negative predictive value of 92.7% (95% CI, 84.7-100%). Twenty-two patients of the total population have HIV, the sensitivity of the test in these patients was 87.5% (95% CI, 64.6-100%). Also, 28 patients with a peripheral localized lesion which had a solid pattern were identified (51.9%). The sensitivity in patients with peripheral localized lesions was 88.9% (68.4-100%).

CONCLUSIONS

The GeneXpert MTB/RIF assay with transbronchial lung cryobiopsy test is as efficient as broncho alveolar lavage for TB diagnosis. Transbronchial lung cryobiopsy increases a major diagnostic opportunity when the nature of illness is malignant. Transbronchial lung cryobiopsy is efficient in HIV patients, especially in patients with peripheral localized lesion.