[Gastrointestinal complications of the new immune checkpoint inhibitor therapies]

In recent years, immune checkpoint inhibitors (ICPI) have become established as an integral part of drug tumor therapy. They belong to a group of monoclonal antibodies that promote anti-cancer cell immune response. Inhibitory signaling pathways are interrupted by binding to CTLA-4 and PD-1 or PD-L1, which increases the activity of cytotoxic T lymphocytes and reduces the immunological tolerance to tumor cells.Diarrhea - a symptom of enterocolitis - is the most common side effect of ICPI therapy after dermatological phenomena. A combined CTLA-4 and PD-1 blockade may affect up to 44 % of patients. The symptoms of ICPI-associated colitis are similar to the clinical appearance of inflammatory bowel disease.The treatment of affected patients should follow a standardized approach. Both the European and American Oncology Societies offer specific recommendations for the diagnosis and treatment of ICPI-associated adverse reactions. Rapid immunosuppressant treatments, to include steroids and biologics, are necessary to reduce morbidity once differential diagnoses are excluded. It may then be possible to subsequently resume ICPI therapy.Immune-mediated hepatitis is a potential side effect which occurs about 6 to 14 weeks after initiation of therapy. It is usually asymptomatic and characterized by an increase in serum transaminases. Lipasemia, without clinical signs of acute pancreatitis, is a common laboratory finding, which usually has no therapeutic consequence.