Evaluation of the Agreement Between the Tissue Sample and Bronchoalveolar Lavage (BAL) Fluid in the Diagnosis of Tuberculosis in Patients with Anthracosis

Background: Black dust deposited in the lungs is called anthracosis. By damaging bronchial mucosa, anthracosis can affect the mucociliary cleaning function. Initial reports indicate that there is a relationship between anthracosis and pulmonary tuberculosis. Due to obstructive effects of anthracosis on distal airways and disruption in a proper sampling of bronchoalveolar lavage (BAL), other diagnostic methods are necessary for estimating the tuberculosis prevalence in these patients. The aims of this study was to evaluate tissue samples adjacent to an anthracotic plaque for acid-fast bacilli smear and culture. Methods: This is a cross-sectional analysis study on 100 patients referred to Shahid Sadoughi Hospital who required bronchoscopy and anthracotic plaque based on bronchoscopy results. Bronchial fluid lavage, two biopsy samples for culture, and a smear of Mycobacterium tuberculosis from the surrounding of these plaques were prepared. Data analyses were carried out using SPSS (version 18). Results: One-hundred patients og the age range 46-91years were studied. The patients with tuberculosis diagnosis based on the smear of BAL and bronchial tissue samples and culture of BAL and bronchial tissue samples were 7%, 13%, 6% and 8% respectively. The presence of granuloma in histopathology was seen in 15 patients infected with tuberculosis. (Κ > 0.04, p-value <0.05). In patients with positive tuberculosis, culture of bronchoalveolar lavage was superior to other methods. Conclusion: Diagnostic value of BAL method and tissue biopsy in anthracosis patients with tuberculosis did not show a statistically significant difference. As compared with other methods, BAL culture was more positive. Therefore, tissue biopsy is not a good alternative to BAL.