TB infection enters its second stage after 7-21 days after initial infection, and it is generally asymptomatic. The TB bacilli start reproducing exponentially within the inactivated macrophages, this eventually result in a rapid expansion of the initial TB bacillus,until the macrophages cannot contain the spread anymore and it will bust and spreading necrotic residue and bacilli throughout the surrounding tissue. Other macrophages will also begin to extravasate from peripheral blood, but they are inactive because they phagocytose the Mycobacterium tuberculosis, therefore they cannot destroy the bacteria anymore.
Stage Three: At stage three, lymphocytes (specifically T cells) will begin to infiltrate and recognize TB antigens. This results in T-cell activation and then it release of cytokines including gamma interferon (IFN). The releasing of IFN triggers the activation of macrophages, which then release lytic enzymes and reactive intermediates that facilitates immune system. These activated macrophages are now capable of destroying MTB. This is the stage where the individual patient becomes tuberculin-positive, which is the result of developing a cell mediated …show more content…
The reactivated TB bacilli reproduce quickly and form a cavity in the tissue, where the body’s immune system cannot reach them. From this cavity, the TB bacilli quickly spread through the tissue. The center of the tubercle is liquefied and boasts pathologic tissue synonymous with cheesy-looking caseous necrosis, which is crucial for TB to grow extracellularly. The person will develops signs and symptoms of active TB such as coughing with blood, night sweats and fever. Now, the person is highly contagious because his or her sputum contains active TB bacteria. Reactivation is more likely to happen if patient’s immune system is weakened, such as with HIV infection or
Stage Three: At stage three, lymphocytes (specifically T cells) will begin to infiltrate and recognize TB antigens. This results in T-cell activation and then it release of cytokines including gamma interferon (IFN). The releasing of IFN triggers the activation of macrophages, which then release lytic enzymes and reactive intermediates that facilitates immune system. These activated macrophages are now capable of destroying MTB. This is the stage where the individual patient becomes tuberculin-positive, which is the result of developing a cell mediated …show more content…
The reactivated TB bacilli reproduce quickly and form a cavity in the tissue, where the body’s immune system cannot reach them. From this cavity, the TB bacilli quickly spread through the tissue. The center of the tubercle is liquefied and boasts pathologic tissue synonymous with cheesy-looking caseous necrosis, which is crucial for TB to grow extracellularly. The person will develops signs and symptoms of active TB such as coughing with blood, night sweats and fever. Now, the person is highly contagious because his or her sputum contains active TB bacteria. Reactivation is more likely to happen if patient’s immune system is weakened, such as with HIV infection or