TNF and infectious meningitis: When a panel of cytokines (including GM-CSF, IFNγ, IL-1α, IL-1β, IL-1ra, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, and TNF-α) was measured in saliva from healthy pigs and in pigs with meningitis and S. suis infection, upregulation of several cytokines was observed in the diseased animals.