Autoimmune hepatitis (AIH), a liver disease causing destruction of the hepatocytes which are then replaced by fibrous tissue. AIH is characterised by hypergammaglobulinaemia which is mainly due to elevation of IgG with moderate increases in IgA and IgM. AIH affect female predominantly and is subdivided into types 1, 2 and 3 based on the antibody profile. Type 1 is associated with the presence of smooth muscle and/or antinuclear antibodies. Type 2 (LKM and/or LC-1) and type 3 (anti-SLA/LP) are discussed elsewhere.

Image: Rodent stomach showing smooth muscle antibody staining. The antibody is directed against a variety of cytoskeletal proteins which includes desmin, F-actin. tubulin and vimentin and can be detected using tissues comprised of cellular structures containing these antigens (walls of artieries, intergastric glands and muscularis muscosa layer of the stomach).