"The gastrointestinal tract is not merely an organ involved in the absorbing and transporting of food into the body, but it functions also as a physical barrier against the external macromolecules and microbes as the first line of defence. In addition, the gastrointestinal mucosa with its lymphoid elements, named gut-associated lymphoid tissue (GALT) as an immune organ, has the ability to protect the host from harmful organisms or local antigens. At the same time, the GALT plays a central role in the development of induced tolerance against harmless products of digestion and the normal intestinal flora, which may be immunogenic. This book is devoted to briefly summarizing the newest advances in the field of gastrointestinal immunology. Papers are dealing with the morphology and function of the GALT, then various clinical entities with presumed immunopathogenesis such as Helicobacter pylori and hepatitis virus infections, as well as gluten sensitive enteropathy, inflammatory bowel diseases and autoimmune hepatitis are discussed. Finally, the problems of liver and pancreas transplantation are outlined. The book is offered for gastroenterologists, immunologists, physiologists and internists."