Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pathophysiol. Aug 15, 2015; 6(3): 62-72
Published online Aug 15, 2015. doi: 10.4291/wjgp.v6.i3.62
Iron deficiency anemia in inflammatory bowel disease
Sindhu Kaitha, Muhammad Bashir, Tauseef Ali
Sindhu Kaitha, Tauseef Ali, Department of Medicine, Section of Gastroenterology, Oklahoma University Health Sciences Center, Oklahoma City, OK 73104, United States
Muhammad Bashir, Department of Internal Medicine, Oklahoma University Health Sciences Center, Oklahoma City, OK 73104, United States
Author contributions: Kaitha S and Ali T conceived the idea; Kaitha S and Bashir M contributed to literature search and wrote the manuscript; Ali T supervised the project, performed critical review and proof reading of the manuscript.
Conflict-of-interest statement: Sindhu Kaitha, MD and Muhammad Bashir, MD have neither received fees for serving as a speaker nor have received research funding from any organization for this review article. Sindhu Kaitha, MD and Muhammad Bashir, MD are employees of University of Oklahoma Health Sciences Center and the institute has no conflict of interest with the article. Sindhu Kaitha, MD and Muhammad Bashir, MD do not own stocks and/or shares and/or patents in any organization that would have conflict of interest with this review article. Tauseef Ali, MD has received honorarium for serving as an advisory board member for Luitpold pharmaceuticals.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Tauseef Ali, MD, Assistant Professor, Department of Medicine, Section of Gastroenterology, Oklahoma University Health Sciences Center, Oklahoma, 601 NE 14th St, Oklahoma City, OK 73104, United States.
Telephone: +1-405-4712653 Fax: +1-405-2715803
Received: January 29, 2015
Peer-review started: January 29, 2015
First decision: April 27, 2015
Revised: May 9, 2015
Accepted: June 15, 2015
Article in press: June 16, 2015
Published online: August 15, 2015

Anemia is a common extraintestinal manifestation of inflammatory bowel disease (IBD) and is frequently overlooked as a complication. Patients with IBD are commonly found to have iron deficiency anemia (IDA) secondary to chronic blood loss, and impaired iron absorption due to tissue inflammation. Patients with iron deficiency may not always manifest with signs and symptoms; so, hemoglobin levels in patients with IBD must be regularly monitored for earlier detection of anemia. IDA in IBD is associated with poor quality of life, necessitating prompt diagnosis and appropriate treatment. IDA is often associated with inflammation in patients with IBD. Thus, commonly used laboratory parameters are inadequate to diagnose IDA, and newer iron indices, such as reticulocyte hemoglobin content or percentage of hypochromic red cells or zinc protoporphyrin, are required to differentiate IDA from anemia of chronic disease. Oral iron preparations are available and are used in patients with mild disease activity. These preparations are inexpensive and convenient, but can produce gastrointestinal side effects, such as abdominal pain and diarrhea, that limit their use and patient compliance. These preparations are partly absorbed due to inflammation. Non-absorbed iron can be toxic and worsen IBD disease activity. Although cost-effective intravenous iron formulations are widely available and have improved safety profiles, physicians are reluctant to use them. We present a review of the pathophysiologic mechanisms of IDA in IBD, improved diagnostic and therapeutic strategies, efficacy, and safety of iron replacement in IBD.

Keywords: Iron deficiency anemia, Inflammatory bowel disease, Hepcidin, Ferritin, Oral iron, Intravenous iron

Core tip: Iron deficiency anemia (IDA) is increasingly recognized as a common complication in patients with inflammatory bowel disease (IBD). IDA has a significant impact on quality of life and health care costs. This comprehensive review article discusses the latest advances in understanding the pathophysiologic mechanisms involved in development of IDA in patients with IBD, and reviews new diagnostic tests and therapeutic options with high safety indexes for the management of IDA. This article aims at increasing physician awareness and understanding of the complex mechanisms involved in IDA, and the current cutting-edge approach for the management of IDA in patients with IBD.