Animal models for autoimmune liver disease--what is relevant for immune-mediated liver disease.

Autoimmune hepatitis (AIH) is a chronic autoimmune inflammation of the liver usually requiring lifelong immunosuppression. Steroids and azathioprine are the standard therapy, but the therapy is accompanied by strong side effects. Due to the fact that AIH is often recognized during the late course of disease, it is difficult to obtain knowledge about the immunological mechanisms responsible for initiation of the disease. Current AIH models have been helpful for understanding and modulating liver immune responses, but are not suited to study mechanisms in chronic AIH or to develop new therapies. While most common hepatitis models are more models of injury, transgenic AIH models deal with short-term hepatitis leading to tolerance, and models with natural antigens are either self-limited or have unknown target antigens. Therefore, new models with defined onset of AIH and a standardized course of disease are essential for a better understanding of the disease and to develop new therapies.