Evaluation of Transbronchial Needle Aspiration Samples from Sarcoidosis Patients for the Presence of Mycobacterium

Abstract

Background: Tuberculosis (TB) and sarcoidosis are two chronic, systemic, and granulomatous diseases that have similar pulmonary and extrapulmonary manifestations. Given the similarities between the two diseases, it is suggested that the Mycobacterium genome may play a role in sarcoidosis. Identification of Mycobacterium species isolated from sarcoidosis patients optimizes the treatment process of patients. The present study investigates biopsy tissue samples from patients with sarcoidosis for the presence of Mycobacterium in the tissues. Methods: This descriptive cross-sectional study was performed on all sarcoidosis patients referred to Masih Daneshvari Hospital during 2017–2018 (401 patients). All patients who were outpatients or hospitalized in the bronchoscopy ward of Masih Daneshvari Hospital underwent transbronchial needle aspiration (TBNA). The cause of the TBNA procedure in patients was the presence of bilateral hilar lymphadenopathy in patients. Out of 401 patients with sarcoidosis, five patients showed positive smear or culture for Mycobacterium and were excluded from the study. Finally, 396 patients were included in the study. Results: The majority of participants in the present study were female (56.1%) with a mean age of 48.2 years and a mean ACE index of 73.4. Hypertension was found in16.2% of patients with sarcoidosis. 16.4% of patients had hyperlipidemia and 4.3% of patients had a history of ischemic heart disease. Redness of the eyes was seen in 13.1% of patients and 12.4% of the patients had diabetes. Also, 43.4% of the patients had skin lesions. Out of a total of 396 patients with sarcoidosis in the present study, 3.5% of the lymph and lung tissues of sarcoidosis patients (who were not infected with Mycobacterium tuberculosis by clinical signs and culture) contained amplifiable MTB DNA. Conclusion: In the present study and many previous related studies, the Mycobacterium genome has been observed in lymph node samples of mediastinal nodes and lung tissue of sarcoidosis patients. One of the strengths of the present study, which can make the results very reliable, is the high sample size in this study. It is suggested that similar studies with the use of control groups in large samples, investigate the presence of the Mycobacterium genome and its type in sarcoidosis patients.