Tumour necrosis factor/cachectin: biology and relevance to disease.

Tumour necrosis factor/cachectin (TNF) is considered a primary mediator in the pathogenesis of injury, infection and inflammation and seems to be essential for host defense and tissue homeostasis. On the other hand, TNF can also cause septic shock, tissue injury and cachexia. There is a close interaction between TNF and other cytokines such as interferon, interleukin-1 and interleukin-2, and prostaglandins. TNF is responsible for the deleterious effects of endotoxaemia, and passive immunization against it substantially mitigates the lethal effect of endotoxin. It is also a potent pyrogen, causes bone resorption, activates neutrophil adherence and degranulation and phagocytosis, and ultimately participates in inflammatory diseases of the skin, gastrointestinal tract, joints, muscle and central nervous system and in neoplastic diseases.