Tuberculosis (abbreviated as TB for tubercle bacillus or Tuberculosis) is a common and deadly infectious disease caused by mycobacteria, mainly Mycobacterium tuberculosis. Tuberculosis most commonly attacks the lungs (as pulmonary TB) but can also affect the central nervous system, the lymphatic system, the circulatory system, the genitourinary system, bones, joints and even the skin. Other mycobacteria can also cause tuberculosis, but these species do not usually infect healthy adults.
About 90% infected with Mycobacterium tuberculosis have asymptomatic, latent TB infection
There are a 10% chances that the latent infection will progress into TB disease
Death rate for untreated active TB cases is more than 50%
TB infection begins when the mycobacteria reaches the pulmonary alveoli
They invade and replicate within the alveolar macrophages
The bacteria are picked up by dendritic cells which do not allow replication
TB is spread further through the bloodstream to other more distant tissues and organs where secondary TB lesions can develop in lung apices, peripheral lymph nodes, kidneys, brains, and bone
Tuberculosis is classified as one of the granulomatous inflammatory conditions
Macrophages, T lymphocytes, B lymphocytes and fibroblasts aggregate to form a granuloma with lymphocytes surrounding the infected macrophages.
T lymphocytes (CD4+) secrete cytokines such as interferon gamma
Interferon gamma activates macrophages to destroy the bacteria which they are infected.
T lymphocytes (CD8+) can also directly kill the infected cells.
The bacteria can also remain dormant resulting in a latent infection
Granulomas of human tuberculosis also develop cell death know as necrosis in the center of tubercles
To the naked eyes this has the texture of soft white cheese as was termed ceseous necrosis
TB bacteria gain entry to the bloodstream from an area of damaged tissue spread through the body and set up many foci of infection which appear as tiny white tubercles in the tissue
Patients with this disseminated TB have a fatality rate of approximately 20%
During active disease, some of these cavities are joined to the air passage bronchi and this material can be coughed up
It contains living bacteria and can therefore pass on infection
You are listing the pathological condition of a TB patients. Not covering the virulent factor and the pathogenecity of TB.
Please reconfirm that gamma interferon actually involve in a typical TB infection? As I know that interferon usually generated during a viral infection.
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You are listing the pathological condition of a TB patients. Not covering the virulent factor and the pathogenecity of TB.
Please reconfirm that gamma interferon actually involve in a typical TB infection? As I know that interferon usually generated during a viral infection.
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