Safety of anti-tumor necrosis factor therapy in inflammatory bowel disease

Inflammatory bowel disease (IBD), in particular Crohn's disease refractory to conventional therapy, fistulizing Crohn's disease and chronic active ulcerative colitis, generally respond well to anti-tumor necrosis factor (TNF) therapy. However, serious side effects do occur, necessitating careful monitoring of therapy. Potential side effects of anti-TNF therapy include opportunistic infections, which show a higher incidence when concomitant immunosuppression is used. Furthermore, antibody formation against anti-TNF is associated with decreased efficacy and an increased frequency of infusion reactions. The hypothesis of a slightly increased risk of lymphomas in IBD patients treated with anti TNF-therapy is debatable, since most studies lack the specific design to properly address this issue. Alarmingly, the occurrence of hepatosplenic T-cell lymphomas coincides with combined immunosuppressive therapy. Despite the potential serious side effects, anti- TNF therapy is an effective and relatively safe treatment option for refractory IBD. Future research is needed to answer important questions, such as the long-term risk of malignancies, safety during pregnancy, when to discontinue and when to switch anti-TNF therapy, as well as to determine the balance between therapeutic and toxic effects.