PATHOLOGY

Detailed explanation-1: -These innate immune cells release prostaglandin E2 (PGE2) as well as pyrogenic cytokines (namely, interleukin-1 (IL-1) IL-6, and tumour necrosis factor (TNF)) that act systemically to induce fever.

Detailed explanation-2: -IL-18 and IL-12 are Th1 cytokines that induce the expression of IFN- from NK and T cells, cells critically involved in innate and adaptive immune responses, respectively. IFN- is a pivotal Th1 cytokine with multiple effects on T cell recruitment and phagocyte-mediated clearance of pathogens.

Detailed explanation-3: -There are two types of cytokines responsible for the generation of fever. Endogenous pyrogens are cytokines that induce fever and include interleukin (IL)-1, IL-6, IL-8, macrophage-inflammatory protein-1 (MIP-1), and interferon-.

Detailed explanation-4: -These cytokines stimulate the anterior hypothalamus of the brain, the part of the brain that regulates body temperature, to produce prostaglandin E2, which leads to an increase bodily heat production and increased vasoconstriction.

Detailed explanation-5: -Fever is part of a systemic response to infection known as the acute phase response (Box 1). Fever itself is the controlled elevation of body temperature due to the upward resetting of the hypothalamic thermostat.