TNF and bacterial infectious disease: Although the production of procalcitonin in viral infections isinhibited by interferon (INF-y), procalcitonin is elevated in severe patients.This could reflect the presence of an over-aggregated bacterial infection, whichwould cause increase in the concentrations of interleukin 1 beta (IL1-b), tumornecrosis factor alpha (TNF-a), and IL-6.61