From the Guidelines
Anemia of chronic disease is characterized by decreased total iron binding capacity (TIBC) and increased ferritin levels, as stated in the most recent and highest quality study 1. This distinction is crucial in differentiating anemia of chronic disease (ACD) from iron deficiency anemia (IDA). In ACD, the body's inflammatory response leads to increased hepcidin production, which in turn causes iron sequestration within macrophages, resulting in a functional iron deficiency despite adequate or elevated iron stores. The increased ferritin levels in ACD are a result of ferritin being an acute phase reactant that rises during inflammation.
Key Laboratory Findings
- Decreased TIBC: This occurs because inflammation reduces transferrin production, a key component of TIBC.
- Increased ferritin levels: Ferritin is an acute phase reactant that increases during inflammation, indicating the presence of an inflammatory process.
- Normal or slightly reduced serum iron: Despite adequate iron stores, the iron is sequestered and not available for erythropoiesis.
- Low transferrin saturation: This is a result of the decreased transferrin production and the sequestration of iron. These laboratory findings are essential in diagnosing ACD and differentiating it from other types of anemia, such as IDA.
Treatment Approach
The treatment of ACD should focus on addressing the underlying chronic condition rather than iron supplementation, as the problem is iron sequestration rather than iron deficiency 1. However, in cases where iron deficiency is also present, iron supplementation may be necessary. The European Crohn's and Colitis Organization (ECCO) guidelines recommend intravenous iron as the first-line treatment for patients with clinically active IBD, previous intolerance to oral iron, or hemoglobin below 100 g/L 1.
Monitoring and Maintenance
Regular monitoring of serum ferritin, transferrin saturation, and hemoglobin levels is crucial in managing ACD. Re-treatment with intravenous iron should be initiated as soon as serum ferritin drops below 100 mg/L or hemoglobin below 12 or 13 g/dL, according to gender 1. This approach ensures that the patient's iron stores are maintained, and anemia is prevented or treated effectively.
From the Research
Anemia of Chronic Disease Characteristics
- Anemia of chronic disease is characterized by decreased serum iron and increased ferritin levels 2, 3, 4.
- Total iron-binding capacity (TIBC) is often decreased in anemia of chronic disease 3.
- The disorder is mediated by inflammatory cytokines, which lead to increased hepcidin synthesis and subsequent hypoferremia 2, 4, 5.
- Anemia of chronic disease is often normocytic and normochromic, and is the most prevalent type of anemia after iron deficiency anemia 5.
Pathophysiology
- The pathogenesis of anemia of chronic disease involves alterations in iron metabolism, including increased ferritin and decreased serum iron 6, 2.
- Inflammatory cytokines, such as IL-6, IL-1, TNF alpha, and TGF beta, play a crucial role in the development of anemia of chronic disease 3, 5.
- Hepcidin is the master regulator of iron homeostasis, and its synthesis is stimulated by inflammation 4, 5.
Diagnosis and Treatment
- Diagnosis of anemia of chronic disease depends on the ability to correlate clinical pathways of the underlying disease with the patient's ferrokinetic state 6.
- Treatment options include erythropoiesis-stimulating agents, blood transfusion, and iron supplementation, in addition to treating the underlying disease 6, 4, 5.
- Controlling the underlying disease and correcting anemia are the primary goals of treatment 5.