Tuberculosis in Patients with Anthracosis of Lung Underlying Mechanism or Superimposed Disease

Background: Anthracosis is the black pigment discoloration of bronchi with an unknown cause which can cause bronchial destruction and deformity (anthracofibrosis). The objective of this study was to determine the frequency of tuberculosis in anthracosis and evaluate their association. Methods: One hundred and twenty subjects with bronchoscopy diagnosis of simple anthracosis, anthracofibrosis and non-anthracotic control groups entered this study. Demographic data and important clinical and radiological findings were recorded. Bronchial biopsy and bronchoalveolar lavage were performed for further cytopathological, acid-fast bacilli staining and culture in all cases. Results: Cough and dyspnea were significantly higher in anthracosis subjects. Radiological characteristic of tuberculosis such as upper lobe localization and cavity were not significantly higher in anthracosis subjects that suffer from tuberculosis. Laboratory test for tuberculosis showed positive acid fast bacilli in 17.5 and 25% and caseating granuloma in 20 and 17.5% of anthracosis and anthracofibrosis subjects. Adding the result of culture, the frequency of tuberculosis in both groups of anthracosis was 27.5% that was significantly more than non-anthracotic control group (Odd ratio=6.15, CL=1.29<OR<40.06). Conclusion: Anthracosis and tuberculosis showed a significant association. Anti-tuberculosis therapy promised better treatment of anthracosis in subjects proved to suffer from tuberculosis.