Role Of Sputum And Bronchoalveolar Lavage CBNAAT In The Diagnosis Of PTB In Smear Negative Patients

Abstract

AIM. To study the use of sputum and broncho alveolar lavage (BAL) for CBNAAT, as an adjunct in the diagnosis of pulmonary tuberculosis, in sputum AFB smear negative patients. OBJECTIVE. To calculate and compare the yield of sputum Cartridge Based Nucleic Acid Amplification Test (CBNAAT) and BAL CBNAAT in sputum AFB smear negative patients. MATERIALS and METHODS. 50 Patients with respiratory symptoms which are suspected of pulmonary tuberculosis with Chest X-ray showing changes consistent with active pulmonary TB and Sputum negative for AFB on two samples were subsequently subjected to sputum CBNAAT, in which 23 out of 50, came out to be positive (46% yield). The remaining 27 patients were subjected to bronchoscopy and the BAL was sent for CBNAAT, in which 23 patients came out as positive (Yield 85%). CONCLUSION. Sputum CBNAAT and BAL CBNAAT prove to be useful adjuncts in the diagnosis of presumptive PTB patients who are sputum AFB smear negative. BAL CBNAAT has higher yield than sputum CBNAAT.