[Tumor necrosis factor alpha. Biological aspects].

Human Tumor Necrosis Factor-alpha (TNF-alpha) is a multifaceted cytokine mainly produced by activated monocytes or macrophages. Several recent studies have shown that TNF-alpha can exert a variety of in vitro and in vivo effects including: modulation of normal and malignant haemopoiesis, antineoplastic activity, activation of neutrophils, induction of IL-1 production, hyperpyrexia and induction of cachexia. Furthermore this cytokine is thought to play an important role in the pathogenesis of septic shock. The principal biochemical characteristics and biological activities of this cytokine will be here summarized.