Autoimmunity is due to an abnormal immune response in which the immune system fails to properly distinguish between self and non-self and attacks its own body. Our body produces antibodies (autoantibodies) and cytotoxic T cells that destroy our own tissues. If disease-state results, it is referred to as auto-immune disease.
Thus, autoimmunity is a misdirected immune response. Eg., Rheumatoid arthritis and multiple sclerosis

(i) A simple blood test is available that can determine whether the person has been infected with HIV.
(ii) The ELISA test (Enzyme Linked Immuno Sorbent Assay) detects the presence of HIV antibodies.
(iii) It is a preliminary test. Western blot test is more reliable and a confirmatory test.
(iv) It detects the viral core proteins. If both tests detect the presence of the antibodies, the person is considered to be HIV positive.

(i) An infection or tissue injury usually causes redness (rubber), swelling (tumor), pain (dolor). and production of heat (color) that may result in fever
(ii) Such localised expression is called inflammatory response, which occur due to release of certain chemical alarm signals such as histamine and prostaglandins.

Interferons: These are the proteins made and released by host cells in response to the presence of pathogens such as viruses, bacteria, parasites etc
RoIe: They inhibit viral infections and stimulate the entire immune system to fight disease. They also regulate many kinds of cell functions