Immunological Disorders: (b) Immunodeficiencies and Gastrointestinal Complications of Organ Transplantation

In health, the gut immune system and microbe populations together with the systemic immune system interact in a tightly regulated way to develop and maintain optimal and non-damaging host defense at this critical interface of host and environment. Disordered immunity, arising either primarily (e.g. Primary Immunodeficiency Disorders – pids) or secondary to other conditions (e.g. Iatrogenic immunosuppressive states, infections such as HIV) often display prominent gastrointestinal manifestations, many with distinctive characteristics. In this Chapter, the gastrointestinal manifestations of a range of Primary Immunodeficiency disorders and those that arise in the context of organ transplantation are reviewed.