Pathogenic mechanisms involved in tuberculosis

Pathogenic mechanisms involved in tuberculosis can be primarily attributed to which of the following? 

A. Toxin production by the mycobacteria 
B. Specific cell adhesion sites 
C. Cell-mediated hypersensitivity 
D. Humoral Immunity

Answer. C. Cell-mediated hypersensitivity

• Most cases of tuberculosis are caused when patients inhale droplet nuclei containing infectious organisms.

• While the bacilli are deposited on the alveolar spaces, they do not clog up the alveoli but are engulfed by macrophages.

• Tissue injury is not a result of toxin secretion but by cell-mediated hypersensitivity - immunologic injury