[Bone resorption and cytokines: the role of IL-1 beta, TNF and lymphotoxin].

Tumor necrosis factor (TNF) and interleukin-1 (IL-1) are soluble factors that play a pivotal role in acute and chronic inflammation. TNF is a 17 Kda protein mainly released by monocytes and macrophages and is a common mediator of toxic shock, cachexia and tumor necrosis. IL-1 was first described as a lymphocyte activating factor and it was then discovered that IL-1 has a number of other biological activities and that there are at least two major types of IL-1 (alpha and beta) which bind to the same receptor. Recently it has been shown that TNF and IL-1 beta have an important role in bone resorption.