Detection of Mycobacterium tuberculosis DNA by PCR in peripheral blood of patients with pulmonary tuberculosis

Background: Although pulmonary tuberculosis (TB) is a respiratory disease, the presence of Mycobacterium tuberculosis (Mtb) DNA or Mtb itself has been reported in the peripheral blood (PB) of several patients with pulmonary TB. Additionally, it was recently announced that active pulmonary TB patients donated PB, and that this blood was then transfused to other individuals in Korea. Methods: Sixty-nine patients with bacteriologically-confirmed pulmonary TB (35), non-tuberculous mycobacterial (NTM) lung disease (6), and other lung diseases (28) were enrolled in this study, which was conducted to determine if Mtb DNA could be detected in the PB by PCR. In addition, 10 pulmonary TB patients with high-burden bacilli were also enrolled in this study for the culture of Mtb in PB. Results: PCR detected the presence of Mtb in 22.8% (8/35) of the pulmonary TB patients, in 16.7% (1/6) of the patients with NTM lung disease, and in none of the patients with other diseases (0%). In addition, no Mtb was cultured from the PB of the 10 pulmonary TB patients. Conclusion: Although Mtb DNA was detected in the PB of some patients with pulmonary TB, viable Mtb was not isolated from the PB of those patients, which indicates that patients that viable Mth may not be transmitted via trasfusion of blood of pulmonary TB patients.