Iron Treatment May Be Difficult in Inflammatory Diseases: Inflammatory Bowel Disease as a Paradigm

Abstract

Iron plays a key role in many physiological processes; cells need a very exact quantity of iron. In patients with inflammatory bowel disease, anaemia is a unique example of multifactorial origins, frequently being the result of a combination of iron deficiency and anaemia of chronic disease. The main cause of iron deficiency is the activity of the disease. Therefore, the first aim should be to reach complete clinical remission. The iron supplementation route should be determined according to symptoms, severity of anaemia and taking into account comorbidities and individual risks. Oral iron can only be used in patients with mild anaemia, whose disease is inactive and who have not been previously intolerant to oral iron. Intravenous iron should be the first line treatment in patients with moderate-severe anaemia, in patients with active disease, in patients with poor tolerance to oral iron and when erythropoietin agents or a fast response is needed. Erythropoietin is used in a few patients with anaemia to overcome functional iron deficiency, and blood transfusion is being restricted to refractory cases or acute life-threatening situations.

Keywords: inflammatory bowel disease; intravenous iron; iron deficiency; iron deficiency anemia; oral iron.

Figure 1

Diagnosis of types of anaemia. MCV: mean corpuscular volume, N: normal, IDA: iron deficiency anaemia, FID: functional iron deficiency, ACD: anaemia of chronic disease, MDS: myelodysplastic syndrome, sTfR: soluble transferrin receptor.