[What should specialist in internal medicine be aware of in patients treated with biologics? : Infections and autoimmune phenomena].

Biologics that influence the immune system play a crucial role in the treatment of autoimmune and malignant diseases. Overall these drugs have revolutionized treatment as they demonstrate high efficacy and a relatively low amount of side effects. This leads to longer treatment of patients with a high quality of life. Side effects, especially longer-term side effects, become ever more important as patients are simultaneously seen by different physicians due to comorbidities. Infections, mainly of the upper airway or urogenital tract, represent the main side effect of immunosuppressive biologics, but atypical infections by fungi or mycobacteria may also occur. Biologics that enhance the immune response such as checkpoint inhibitors lead to autoimmune phenomena necessitating the interruption of treatment or immunosuppressive treatment.