The Role of Apoptosis Associated Markers in Pathogenesis of Pulmonary Tuberculosis

Background: Tuberculosis (TB) remains the most important infectious disease worldwide. For controlling TB, the important strategy includes not only adequate anti-tuberculous treatment but also well control of latent TB infection (LTBI). Latent TB infection (LTBI) has 10% of reactivation or more in patients with immuno-compromised disorder. Although LTBI can be detected by interferon-gamma release assay (IGRA) or tuberculin skin test, how to predict who will become active TB from LTBI is still unclear but important. In overall prophylactic treatment for LTBI, the lengthy duration and possible serious side effect too scared to general application especially 90% of population who may not get illness. Therefore, to recognize who develop active TB from LTBI is important for targeted prophylactic therapy. The good marker is not discovered at present. When TB bacilli arrive our lung, macrohage is the first line defense and necrosis rather than apoptosis is the dominant form of cell death, which affords a protective milieu for M. tuberculosis. Though the apoptosis is suppressed in TB, the apoptosis-associated markers have rarely been investigated in human LTBI vs. active TB. We set up a cohort study to detect active TB developing from LTBI and first-step conduct a case control study to compare apoptosis markers between LTBI and active TB for evaluating the apoptosis markers in discriminating TB infection status. The significant markers should be verified in further cohort study of LTBI patients.