[Impact of immune disorders in digestive pathology]

The digestive tract has a special immune system where predominate the secretory factors of IgA. The IgA secreted by the plasma cells of the digestive mucosa is dimeric and is poured into the intestinal lumen after being attached to a protein of epithelial orgin. These facts lead to defence reactions of a special type. The digestive consequences of a quantitative abnormality of this system (hypogammaglobulinemia) or qualitative abnormality such as alpha heavy chain disease or Whipple's disease, are briefly reviewed. The consequences of an abnormal response of this system are considered in the light of present knowledge concerning coeliac disease. On the whole, these recent studies should lead to a revision of the idea of digestive allergy.