Cytokines and fever.
Level 5 - mechanism / opinion, no new human data
Narrative review and mechanistic animal model data.
PubMed 9629288 · doi:10.1111/j.1749-6632.1998.tb09600.x
What was done
The author reviewed mechanisms of cytokine signaling in fever and synthesized findings from guinea pig models evaluating intravenous lipopolysaccharide (LPS) administration. Interventions evaluated in the reviewed experiments included subdiaphragmatic vagotomy, decomplementation, Kupffer cell blockade, and measurements of norepinephrine (NE) and prostaglandin E2 (PGE2) in the preoptic-anterior hypothalamus (POA).
What was found
No numerical figures were reported in the abstract. Intravenous LPS induced large increases in plasma IL-6 but only small increases in IL-1 and TNF-alpha, with cytokine elevations lagging behind fever onset. Subdiaphragmatic vagotomy, decomplementation, and Kupffer cell blockade suppressed the febrile response to IV LPS in guinea pigs. In addition, IV LPS rapidly stimulated NE and subsequent PGE2 release in the POA, leading to a proposed neural-immune signaling cascade.
Why it matters
This framework challenges the traditional model that fever relies solely on circulating cytokines directly crossing or acting on the blood-brain barrier, proposing a rapid neural route via vagal afferents.
Limits
The abstract describes a narrative review and mechanistic hypothesis based on animal models without human data. No sample sizes, quantitative estimates, variance, or statistical tests are reported in the abstract.
Cited by
- supports Immune cells secrete cytokines into the bloodstream that act as distributed chemical signals capable of inducing systemic responses like fever.