The purpose of this study is to assess lung immune responses in patients with active pulmonary tuberculosis (TB) and in healthy control persons who are exposed to Mycobacterium tuberculosis in households of patients with TB or who are unexposed.

BACKGROUND:

M. tuberculosis infects a third of the world's population, and TB is the leading cause of morbidity and mortality due to a single infectious agent. However, only 5% to 10% of M. tuberculosis-infected subjects without an underlying immunodeficiency develop disease during their lifetimes. Therefore protective immunity is induced in the majority of subjects. Understanding correlates of protection against M. tuberculosis in humans is needed to better direct efforts in the development of antituberculosis vaccines.

DESIGN NARRATIVE:

Patients are treated according to good clinical practice; however, no study medications are given as part of the research study. This study involves a one-time bronchoalveolar lavage and venipuncture to obtain immune cells for laboratory studies of immune responses.

Inclusion Criteria:

• TB patients who are 18 to 65 years old
• Clinical and radiographic signs and symptoms consistent with pulmonary TB
• Start date of antituberculous chemotherapy less than 10 days prior to procedures
• Sputum smear positive for acid fast bacilli
• Drug-sensitive, culture-confirmed growth of M. tuberculosis from sputum
• Willing to provide informed consent for participation in bronchoalveolar lavage and venipuncture studies

Exclusion Criteria:

• TB patients who have HIV-1 coinfection
• History of any chronic medical condition requiring daily medication (including diabetes mellitus, hypertension, chronic infections, renal or cardiac failure, and peptic ulcer disease)
• History of asthma or upper or lower respiratory tract infection within 2 months of the study
• Hemoglobin level less than 10g/dl

Patients with tuberculosis and household contacts of patients with tuberculosis.