Autoimmune hepatitis, primary sclerosing cholangitis, and inflammatory bowel disease. Sequential overlap syndrome: a twist to the mosaic of autoimmunity.

Autoimmune liver diseases can overlap resulting in a new entity, phenotypically different from those pathologies that converge, and that demonstrates the complexity of our immune system. Sequential overlap syndrome is the consecutive presentation, separated by a variable period of time, of two liver autoimmune diseases, mostly autoimmune hepatitis and primary biliary cholangitis. This syndrome constitutes a challenge both in its diagnosis and in its treatment given the exceptional nature of its presentation. The theory of a mosaic of autoimmunity is proposed to describe this phenomenon.