Q.37 Which of the following cytokines are endogenous pyrogens?
P. Tumor necrosis factor-α
Q. Interleukin-1
R. Transforming growth factor-β
S. Interleukin-10
(A) P and Q only
(B) P and R only
(C) R and S only
(D) Q and S only
Endogenous pyrogens are cytokines produced by immune cells that trigger fever by acting on the hypothalamus to raise body temperature. Tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1) qualify as such, making option (A) P and Q only the correct choice.
Correct Answer
(A) P and Q only
Option Breakdown
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P. Tumor necrosis factor-α: Functions as an endogenous pyrogen by stimulating hypothalamic PGE2 synthesis and inducing fever directly or via IL-1 release.
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Q. Interleukin-1: Classic endogenous pyrogen that signals the hypothalamus to elevate body temperature during infection.
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R. Transforming growth factor-β: Anti-inflammatory cytokine that suppresses immune responses, not a pyrogen.
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S. Interleukin-10: Regulatory cytokine inhibiting pro-inflammatory signals like fever induction.
Why TNF-α and IL-1 Induce Fever
These cytokines activate the thermoregulatory center, leading to prostaglandin E2 production and elevated set-point temperature. Others like TGF-β and IL-10 counteract inflammation instead.
