20 Questions
What does the large amount of interferon-γ production after stimulation with TB antigens indicate?
The patient has circulating effector memory Th1 cells specific for TB antigens
What is the purpose of incubating the patient's blood in tubes with the TB antigens CFP10 and ESAT-6 for 16 hours?
To stimulate the production of Interferon-γ in the blood sample
What is the significance of the IFN production in the negative control and PHA wells?
It confirms that the test is technically valid
Why is the supernatant removed from the tube after incubating the blood with TB antigens?
To isolate the cells at the bottom of the tube for further analysis
Why is it important to understand that the antigens used in the QFT Gold test are not contained in the BCG vaccine?
To differentiate between vaccine-induced and exposure-induced immunity
What is the purpose of analyzing the supernatant for IFN-γ using ELISA?
To detect the presence and quantity of Interferon-γ in the blood sample
Why is the QFT Gold test not a good test for active TB?
It doesn't measure interferon-γ production after stimulation with TB antigens
Based on the given information, what might be offered to a patient with a positive Interferon-γ release assay?
Treatment for active tuberculosis infection
What treatment may be warranted for a patient who has produced large amounts of interferon-γ after stimulation with TB antigens?
Chemoprophylaxis to reduce the risk of progression to active TB
What would be an appropriate interpretation of a positive result in an Interferon-γ release assay?
The patient has active tuberculosis infection requiring immediate treatment
What is the main purpose of the acidic environment, activation of digestive enzymes, and oxidative burst in the context of TB infection?
To destroy the TB organism
Why are some MTB organisms difficult to eliminate within macrophage phagolysosomes?
They inhibit phagosome maturation and phagosome/lysosome fusion
How are CD4 T helper cells activated during TB infection?
By MTB antigens inducing the macrophage to secrete IL-12, leading to a strong Th1 response
What immunological process results in the formation of a Ghon focus in TB infection?
Containment of primary MTB infection by the immune system
What role does lFN-γ play in the context of TB infection?
Promoting phagosome maturation and phagosome/lysosome fusion to eliminate MTB organisms
What is the primary function of Interferon-γ release assay (IGRA)?
To detect latent TB infection
In the context of TB infection, what type of immune response does Interferon-γ release assay (IGRA) measure?
Cell-mediated immune response
Which cells are involved in producing Interferon-γ in response to Mycobacterium tuberculosis antigens?
Helper T lymphocytes
How does Interferon-γ contribute to the immune response against Mycobacterium tuberculosis?
By enhancing the killing ability of macrophages
Which immunological technique is based on the principle of detecting Interferon-γ release from T cells exposed to Mycobacterium tuberculosis antigens?
ELISPOT assay
Explore the immune responses to infection, focusing on Mycobacterium tuberculosis as an example to understand T cell immunology and diagnostic immunology. This tutorial is designed to be completed in about 30 minutes, followed by a discussion of the answers.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
