Role of Bronchoalveolar Lavage (BAL) Gene Xpert in Diagnosis of PTB in Sputum Smear Negative Patients

Abstract

The aim of this study was to assess the diagnostic efficacy of Xpert MTB/RIF assay in bronchoalveolar lavage (BAL) in the diagnosis of pulmonary tuberculosis in sputum-smear negative patients. This observational case series study was conducted in a tertiary base institute of Bangladesh from July 2017 to June 2019. All patients with suspected pulmonary tuberculosis who were sputum-smear negative, irrespective of age and gender were included in this study. BAL fluid thus obtained and examined the smear for acid fast bacilli (AFB) and Xpert MTB/RIF assay. The sensitivity, specificity and accuracy values were calculated for smear AFB and Xpert MTB/RIF assay. Xpert MTB/RIF was identified 33 (36.7%) of 90 patients on bronchoalveolar lavage fluid in the final analysis. AFB Fluid culture was positive in 28 (31.2%) cases. The sensitivity and specificity of Xpert MTB/RIF assay was 85.7%, and 85.5% respectively. The positive likelihood ratio was 5.90, and the negative likelihood ratio was 0.167. The accuracy was 85.56%. Xpert MTB/RIF on BAL fluid can be recommended as a fruitful diagnostic tool for mycobacterium pulmonary tuberculosis especially in sputum smear negative, and culture negative patients.

CBMJ 2023 January: Vol. 12 No. 01 P: 60-66