Formation of the cavities in the patient\'s lungs is mainly mediated by:

A 45-year-old Caucasian male presents with a fever, recent weight loss, and a cough productive of bloody sputum. A chest X-ray and CT scan were performed, revealing cavities near the apex of his lungs. The patient is started on rifampin, isoniazid, ethambutol and pyrazinamide. Formation of the cavities in the patient’s lungs is mainly mediated by:

1.TH1 cells
2.Toxin secretion by the bacterium
3.B-cells
4.NK cells
5.Apoptosis

exp:

The immune response against M. tuberculosis primarily is marked by granuloma formation and is mediated by TH1 cells. Granulomas eventually contain caseous necrosis at their center and can cavitate.

The formation of a granuloma helps to wall-off and contain the M. tuberculosis infection, preventing it from spreading. The mycobacteria at the center of the granuloma can remain latent for decades and reactivation of the infection can lead to secondary tuberculosis. The constant battle between the bacteria and the immune response leads to progressive tissue damage manifested by caseating necrosis and cavities.

Illustration A shows a cavitation in the lung apex of a patient with tuberculosis.