The Role of TNF in the Pathogenesis of Inflammatory Bowel Disease

Tumor necrosis factor (TNF) is a pleotropic cytokine involved in a wide range of pathological processes, including inflammatory bowel disease (IBD). In the past, TNF was recognized as a pro-inflammatory cytokine with deleterious effects. This has led to the development of anti-TNF drugs, which revolutionized the treatment of inflammatory disorders such as Crohn’s disease. However, in the past 20 years, clinical studies have shown that anti-TNF drugs are not always effective. Moreover, in some rare cases, anti-TNF drugs can even cause an aggravation of the disease. Nowadays, there is increasing evidence that TNF is not only detrimental but can also play an important role in health and the maintenance of homeostasis. The aim of this chapter is to briefly summarize the literature demonstrating the complex dichotomous role of TNF in IBD and discuss the role of anti-TNF drugs in the treatment of IBD.