GeneXpert analysis of bronchoalveolar lavage (BAL) samples: promising diagnostic modality in patients with smear-negative pulmonary tuberculosis

Abstract

Abstract Purpose The aim of the study is to assess the diagnostic utility of bronchoalveolar lavage (BAL) samples with GeneXpert test in diagnosis of TB in smear-negative patients. Method One-hundred sixty-nine cases were included in this study, as they had a radiological finding suggested to have pulmonary tuberculosis, while the sputum direct smear examination for acid-fast bacilli was negative. All cases prepared to do fiber-optic bronchoscope with bronchoalveolar lavage collection after their consent and post bronchoscope sputum collection for further molecular and microbiological examination. Results The combined diagnostic yield of all bronchoscopy procedures was 15.97% (27 cases of 169) and the final diagnosis of TB cases was established in 16 cases of 169 (9.4%) using BAL culture and in 20 cases of 169 (11.83%) by GeneXpert methods. Post bronchoscope direct sputum examination, culture, and GeneXpert evaluation gave diagnostic yield about 1.1%, 5.5%, and 7.1%, respectively. The specificity of GeneXpert examination of BAL and post bronchoscope sputum was 95.42% and 97.38%, respectively. Conclusion Early detection of pulmonary tuberculosis using fiber-optic bronchoscope BAL examination and post bronchoscope sputum with GeneXpert method promotes the accurate decision to start antituberculous therapy in patients with smear negative.

Keywords

• Smear-negative TB
• Bronchoscope
• Bronchoalveolar lavage
• Post bronchoscope sputum evaluation