Question

Which of the following statements regarding leprosy is false?

1) It is caused by the bacterium Mycobacterium leprae.
2) Disease progression is influenced depending on whether the immune response is polarized toward either a TH1 or TH₂ response.
3) The tuberculoid form of leprosy is associated with localized inflammation and granuloma formation.
4) In lepromatous leprosy, the patient makes a TH₂ response that clears the mycobacteria from the body.
5) The less severe form of leprosy presents with high levels of IL-2 and IFN-γ produced by responding T cells.

Answer 1

The false statement regarding leprosy is that in lepromatous leprosy, the patient makes a TH2 response that clears the mycobacteria from the body. In fact, the TH2 response is ineffective in clearing the mycobacteria, leading to a more severe form of the disease.

Step-by-step explanation:

Leprosy, also known as Hansen's disease, is a chronic infectious disease caused by the bacterium Mycobacterium leprae. It primarily affects the peripheral nervous system, leading to nerve damage and can cause skin lesions and deformities if not treated properly. There are two main types of responses to the infection: Tuberculoid leprosy is associated with a TH1 immune response and is characterized by localized skin lesions and granuloma formation.

The lepromatous leprosy, on the other hand, occurs when the patient's immune response is skewed towards a TH2 response, which is ineffective in clearing the mycobacteria, leading to widespread disease. The statement that lepromatous leprosy is associated with a TH2 response that clears the mycobacteria from the body is false. High levels of IL-2 and IFN-γ produced by responding T cells are indicative of a more effective immune response seen in the less severe form of leprosy, which is the tuberculoid form.