Pathophysiology and therapeutic management of anemia in gastrointestinal disorders

ABSTRACT

Introduction

Anemia is a common complication of gastrointestinal (GI) disorders, with a prevalence up to 60% in celiac disease (CeD) and inflammatory bowel disease (IBD). Iron deficiency anemia (IDA) is the most prevalent form of anemia in these conditions, but chronic inflammation and vitamin B12 deficiency represent other common contributing mechanisms, especially in IBD.

Areas covered

We discuss the pathogenesis of anemia in various medical GI disorders, the sometime problematic distinction between IDA, anemia of inflammation (AI) and the association of the two, and therapeutic and preventive measures that can be useful for the management of anemia in GI disorders. Unfortunately, with the exception of IDA and AI in IBD, large RCT concerning the treatment of anemia in GI disorders are lacking.

Expert opinion

Anemia management strategies in GI disorders are outlined, with a focus on the main prevention, diagnostic, and therapeutic measures. Specific problems and situations such as the role of gluten-free diet for IDA treatment in CeD, the choice between oral and parenteral supplementation of iron or vitamin B12 in carential anemias, the use of endoscopic procedures to stop bleeding in intestinal angiodysplasia and preventive/treatment strategies for NSAID-associated GI bleeding are discussed.

KEYWORDS:

• Autoimmune gastritis
• celiac disease
• Crohn’s disease
• gastrointestinal bleeding
• iron
• ulcerative colitis

Acknowledgments

None stated.

Article highlights

• Anemia is a common and debilitating extraintestinal manifestation of many gastrointestinal (GI) tract disorders, with the highest reported prevalence of celiac disease (CeD) and inflammatory bowel disease (IBD).

• Iron deficiency anemia (IDA) is the most common form of anemia in GI disorders due to either blood loss or malabsorption, followed by vitamin B12 deficiency in autoimmune atrophic gastritis (AAG) and anemia of inflammation in IBD.

• Unexplained IDA or IDA refractory to oral iron supplementation can be the initial manifestations of a GI disorder, thereby requiring a proactive case-finding strategy based on the serological evaluation for AAG and CeD and the histological examination of gastric and duodenal biopsies.

• More sensitive and specific diagnostic tests are needed to ensure the correct characterization of anemia in GI disorders; these include the determination of serum hepcidin concentration for iron deficiency and for anemia of inflammation, serum holotranscobalamin, and red blood cell folate concentrations for vitamin B12 and folate deficiencies.

• Since most cases of GI disorder-associated anemia are carentials, they can be effectively treated by supplementation of the missing factor; parenteral supplementation can be needed in more severe cases or when oral supplementation will be likely ineffective because of malabsorption or side effects.

Declaration of financial/other relationships

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. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

All authors significantly participated in the drafting or critical revision of the manuscript for important intellectual content and provided approval of the final submitted version.

Guarantor of the article

Gaetano Bergamaschi, Antonio Di Sabatino

Additional information

Funding

This paper was not funded.