Annals of Internal Medicine

Interleukin-1 is a hormone-like polypeptide produced in response to infection, injury, physiologic stress, or antigenic challenge. Originally named for its ability to act as an intercellular signal between leukocytes, inter-leukin-1 has pleiotropic effects on tissues and organs (1). Fever, elevation of acute-phase reactive proteins, and neutrophilia are some responses to systemic inter-leukin-1 that make it a key mediator of inflammation (2). As an inflammatory mediator, interleukin-1 may be both beneficial and harmful. Current studies focus on possible therapeutic uses of interleukin-1 itself, as well as its agonists and antagonists. Although the availability of large quantities of recombinant interleu-kin-1 has made in-vivo studies possible only for the past 3 years, it is already regarded as a potential thera