immuno 1 - mohammed92120

[ArchivalUser]

A 45-year-old homeless man has a chronic cough, a cavitary lesion of the lung, and is sputum positive for acid-fast bacilli.

Which of the following is the principle form of defense by which the patient's body fights this infection?


A. Antibody-mediated phagocytosis
B. Cell-mediated immunity
C. IgA-mediated hypersensitivity
D. IgE-mediated hypersensitivity
E. Neutrophil ingestion of bacteria

[ArchivalUser]

B. Cell-mediated immunity
tb??

[ArchivalUser]

yep Good job... The correct answer is B.

The principle host defense in mycobacterial infections (such as this patient's tuberculosis) is cell-mediated immunity, which causes formation of granulomas. Unfortunately, in tuberculosis and in many other infectious diseases characterized by granuloma formation, the organisms may persist intracellularly for years in the granulomas, only to be a source of activation of the infection up to decades later.

While antibody-mediated phagocytosis (choice A) is a major host defense against many bacteria, it is not the principle defense against Mycobacteria.

IgA-mediated hypersensitivity (choice C) is not involved in the body's defense against Mycobacteria.
IgE-mediated hypersensitivity (choice D) is not involved in the body's defense against Mycobacteria. It is important in allergic reactions.

Neutrophil ingestion of bacteria (choice E) is a major host defense against bacteria, but is not the principle defense against Mycobacteria.

[ArchivalUser]

Thanks Bro for posting immuno q and answer wit expl., haven't touch for a while