Anemia and iron deficiency in Crohn’s disease

ABSTRACT

Introduction: Anemia is a common extraintestinal complication of Crohn’s disease (CD) mainly caused by iron deficiency, that affects the quality of life in CD patients. Elucidation of the etiology and pathology of iron-deficiency anemia (IDA) and anemia of chronic diseases (ACD) has developed in recent years. Common biochemical parameters of iron status are insufficient for assessment of patients with anemia and CD. Thus, novel iron indices are required for accurate assessment in IDA patients with CD. Oral iron supplementation for IDA treatment is common and is associated with minor gastrointestinal side effects. Intravenous substitution improves safety profiles but may be not tolerable in some patients. Fortunately, additional therapies for anemia of active CD have emerged in recent years.

Area covered: Here, we propose the review article on the link among anemia, iron deficiency, and Crohn’s disease. We discuss the current diagnosis and therapy of anemia and iron deficiency in CD and propose the new directions for future research.

Expert commentary: Exploring pathogeneses and treatments of anemia and iron deficiency in Crohn’s disease will develop potential tools for early diagnosis and effective treatment of anemia in CD patients, and improve their life quality.

KEYWORDS:

• Anemia
• iron deficiency
• Crohn’s disease
• Iron-Deficiency Anemia (IDA)
• Anemia of Chronic Diseases (ACD)

Article Highlights

• Anemia was one of the most prevalent systemic complications of IBD and impaired the quality of life, and the most common etiologies of anemia in CD patients are I iron-deficiency anemia (IDA) and anemia of chronic diseases (ACD).

• Factors contribute to anemia and iron deficiency, including impaired iron intake, inherent dietary restrictions, and levels of hepcidin, erythrocyte deficiency, reduced life span, and cytokines.

• Diagnostic methods of IDA and ACD, such as ferritin, transferrin saturation (TfS), soluble transferrin receptor (sTfR), total iron- binding capacity (TIBC), mean corpuscular volume (MCV), the percentage of hypochromic red cells (% HYPO), cytometry of the reticulocyte hemoglobin content (CHr), and serum iron.

• Treatment of iron deficiency and anemia, including oral iron supplementation and intravenous (IV) iron. Novel treatments are being investigated and developed for anemia patients with CD, and they work by regulating iron metabolism.

Declaration of Interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript.

Additional information

Funding

This work was supported by grants from the Teaching and Research Project 2015 Renji College of Clinical Medicine (No. 5032.20) and the National Science Foundation of China (No. 81470820). We thank LetPub (www.letpub.com) for its linguistic assistance during the preparation of this manuscript.