Lymph and blood cytokines in fever of different severity.

Experiments on rats showed that pyrogenal-induced fever is associated with elevation of IL-1β, IL-6, and IL-10 content in the thoracic duct lymph and blood plasma, whereas lowgrade fever induced by administration of Freund’s complete adjuvant is associated with elevation of only IL-6 concentration. The increase in IL-1β concentration during fever and IL-6 concentration in both processes was more pronounced in the central lymph than in blood plasma. Unchanged concentrations of IL-1β and IL-10 in low-grade fever apparently refl ect differences in the mechanisms of these pathological processes.