USMLE Forum - Largest USMLE Community

The tuberculin test is used to determinate if the patient has ever been exposed to M.tuberculosis.If the patient has been exposed,the side where M.tuberculosis protein were injected will triger a type IV hypersens.response that causes the site to become red and swolen because of:

a/unbound antibodies binding protein and the immune complex,then depositing protein in the tissue,which trigers a cell-mediates response

b/antibodies binding the protein and triggering Ne to release inflamatory cytokines that increase blood vessels permebility to other immune effector cells and fluid

c/cytotoxin CD8+-T cells recognizing the processed protein and releasing inflamatory cytokines as well as causing the antigen presenting cells to undegro apoptosis

d/proteins binding to antibodies on mast cells and trigering mast cell degranulation

e/specific T cells recognitizing the processed antigen and releasing inflamatory cytokines that increase blood vassels permeability to other immune effector cells and fluid

E.

Type IV,or delayed ,hypersensitivity reactions involve reactive lymphocytes recognizing an antigen and directing the immune response by the release of cytokines.---->anwer /E

Antibodies are not involved in this type of immune response,.
Ne and mast cells are part of nonspecific immune response, so they would not be a major mediators of the specific response to the tuberculin test.
Cytotoxin CD8+ T cells recognize antigen presentet only by MHC I,which would not present proteins that the cell obtained from its environment but only proteins made within the cell.
Therefore, these cells would not be part of the type IV response
==================

thanks mama.