Popis: |
Interleukin (IL)-6 is a member of the cytokine network that can not be simply classified as a pro- or an anti-inflammatory cytokine. It was originally described under many different names, including interferon (IFN)-β2, 26K factor, B-cell stimulatory factor, and hybridoma/plasmacytoma growth factor. In 1987, these seemingly unrelated factors turned out to be one and the same protein. In 1989 it was recommended that the provisional names be replaced by the term ‘IL-6’ [1]. It has been recognized for many years that the circulating levels of IL-6 increase in a variety of infectious, and non-infectious, conditions. IL-6 can be detected in the circulation of the vast majority of patients with sepsis, and the extent of IL-6 release during sepsis carries a strong predictive value for a bad prognosis (see below). Nonetheless, the scientific community has long considered IL-6 as ‘an innocent bystander’ rather than a mediator directly involved in pathogenetic mechanisms operative during sepsis. In this chapter we will discuss new evidence that IL-6 should not merely be considered a marker of disease severity, and that this cytokine may play a significant role in the pathogenesis of bacterial infections. |