Anti-TNF levels and anti-drug antibodies, immunosuppressants and clinical outcomes in inflammatory bowel disease.

The anti-tumor necrosis factor-α (TNF) antibodies have revolutionized the management of ulcerative colitis and Crohn's disease. The development of assays to allow for the measurements of serum drug levels and anti-drug antibodies have provided a more objective means of therapeutic decision making, particularly among patients losing response to treatment. Additionally, more evidence is emerging that indicates the relationship between drug levels and response to therapy including clinical response, mucosal healing and sustained remission. The use of combination therapies of the anti-TNF agents and the thiopurine immunosuppressants may also decrease immunogenicity to the anti-TNF agents and potentiate response to therapy. With more evidence emerging evidence of the importance of therapeutic drug levels and anti-drug antibodies, clinicians may be able to better optimize the current arsenal of inflammatory bowel disease therapeutics to achieve greater rates of durable remission and improved quality of life.