Detection of Mycobacterium tuberculosis in Peripheral Blood Mononuclear Cells from Patients with Pulmonary Tuberculosis

Background: Pulmonary tuberculosis is currently diagnosed using traditional techniques, such as smear production from sputum samples, to detect acid-fast bacilli (AFB) and bacteriological culture. The detection of Mycobacterium tuberculosis DNA in peripheral blood samples could potentially aid in tuberculosis diagnosis. Objectives: This study aimed to compare the effectiveness of polymerase chain reaction (PCR) assay on peripheral blood mononuclear cells (PBMCs) with established diagnostic techniques for detecting M. tuberculosis. Methods: We collected peripheral blood and sputum samples from 45 patients with smear-positive pulmonary tuberculosis. Standard microscopy and culture techniques were performed on both sputum and PBMC samples. The PCR was conducted on PBMC and sputum specimens using primers specific for the M. tuberculosis complex insertion sequence IS6110. Results: Thirty-nine sputum samples and 2 PBMC samples were determined to contain M. tuberculosis based on bacterial culture and biochemical tests. PCR results were positive for 32 (82%) sputum samples and 29 (75%) PBMC samples. None of the PBMCs tested positive through AFB staining. Conclusions: The M. tuberculosis PCR assay on PBMCs using IS6110 primers demonstrated high sensitivity and specificity in detecting M. tuberculosis DNA. However, the implementation of real-time PCR with a specific probe may further enhance the detection of M. tuberculosis DNA in peripheral blood.