<prompt> A 9 year old girl receives an intradermal tuberculin injection and later develops an indurated, erythematous papule 12 mm in diameter. This reaction is an example of which of the following?Antibody-dependent cell-mediated cytotoxicityLocal anaphylaxisT-cell mediated cytotoxicityType IV hypersensitivity  <response>: The tuberculin reaction is an example of delayed-type hypersensitivity a form of Type IV hypersensitivity in which the bulk of the tissue damage is done by macrophages that are stimulated by a few previously sensitized CD4 memory T-cells recognizing antigens presented by the macrophages. In contrast, in T-cell mediated cytotoxicity another form of Type IV sensitivity the damage is done by CD8 cytotoxic T-cells that recognize foreign cell surface antigens and directly lyse targeted cells. Antibody-dependent cell-mediated cytotoxicity reactions a form of Type II hypersensitivity involves cells coated with a thin layer of antibody that triggers attack by cells monocytes, neutrophils, eosinophils, and natural killer cells that can bind to Fc receptors. Local anaphylaxis a form of Type I hypersensitivity is due to the release of vasoactive substances by mast cells and basophils stimulated by memory CD4 T-cells reacting to antigen. Ref: Ray C.G., Ryan K.J. 2010. Chapter 27. Mycobacteria. In C.G. Ray, K.J. Ryan Eds, Sherris Medical Microbiology, 5e. 