Anemia of inflammation

Area of Science:

• Hematology
• Immunology
• Internal Medicine

Background:

• Anemia of inflammation (AI), or anemia of chronic disease (ACD), is the most frequent anemia in hospitalized and chronically ill patients.
• It is prevalent in conditions with prolonged immune activation like infection, autoimmune diseases, cancer, chronic kidney disease, heart failure, pulmonary diseases, and obesity.

Purpose of the Study:

• To review the mechanisms, diagnosis, and treatment of anemia of inflammation.
• To discuss challenges in diagnosing AI, especially with coexisting iron deficiency.
• To explore current and future therapeutic strategies for AI.

Main Methods:

• Literature review of mechanisms, diagnosis, and treatment of anemia of inflammation.
• Analysis of the role of inflammation-inducible cytokines and hepcidin in iron homeostasis.
• Examination of factors contributing to AI, including erythrocyte half-life and erythropoietin response.

Main Results:

• Inflammation disrupts iron absorption and retention, leading to iron-restricted erythropoiesis.
• Shortened erythrocyte lifespan, blunted erythropoietin response, and inhibited erythroid differentiation also contribute to AI.
• Diagnosis is typically by exclusion, supported by altered iron indices (hypoferremia, hyperferritinemia), but coexisting iron deficiency complicates diagnosis.

Conclusions:

• Current treatments for AI involve addressing the underlying disease and often include iron therapy and erythropoiesis-stimulating agents.
• Future therapies may involve antagonizing hepcidin to redistribute iron for erythropoiesis.
• Optimal AI treatment requires a better understanding of its contribution to morbidity and the impact of treatment on patient prognosis.