Pathogenesis, diagnosis and treatment of anaemia in immune-mediated gastrointestinal disorders.

Immune-mediated disorders affecting the gastrointestinal (GI) tract may compromise GI integrity, interfere with the absorption of nutrients and cause bleeding and inflammation. All these features contribute to the pathogenesis of anaemia, the most prevalent extra-intestinal manifestation of immune-mediated GI disorders. Anaemia is most commonly due to iron deficiency and/or inflammation, but vitamin deficiencies and, more infrequently, autoimmune haemolysis or drug-induced myelosuppression can be involved. Here we address several issues related to the differential diagnosis and treatment of anaemia in immune-mediated GI disorders, giving particular relevance to the problem of iron deficiency anaemia associated with inflammation. It is emphasized how, in most cases, anaemias due to iron or vitamin deficiencies are best treated by parenteral administration of the deficient factor(s), and how the available high dose intravenous (IV) iron formulations can reduce ambulatory and social costs of IV iron supplementation, while improving patient's compliance to treatment. Actual and future treatment possibilities for anaemia of inflammation, involving the use of erythropoiesis stimulating agents, biologicals and hepcidin inhibitors are discussed.