Guidelines for Anemia Management

Guidelines for Anemia Management

Iron is an essential nutrient that is needed by every human cell. It plays a valuable role in the transport and storage of oxygen and oxidative metabolism, and in cell growth and proliferation. The most important use of iron is the production of hemoglobin and myoglobin. Iron is very reactive and is needed for many metabolic processes but may also be potentially harmful. It can participate in several reactions that may produce free radicals, which can be damaging to cells. Because of this, both iron deficiency and iron overload are clinically significant. If too little iron is available, deficiency of iron-containing compounds may have deleterious effects on cells and tissues. If iron accumulates, toxicity may lead to organ damage and death.

Iron deficiency is the most common deficiency disease worldwide. More than 1 billion people have iron deficiency, and about 700 million people have iron deficiency anemia. An absolute iron deficiency occurs when an insufficient amount of iron is available to meet the body's requirements. The insufficiency may be due to inadequate iron intake, reduced bioavailability of dietary iron, increased utilization of iron, or chronic blood loss. Prolonged iron deficiency leads to iron deficiency anemia—a microcytic, hypochromic anemia in which there are inadequate iron stores.¹

With the advent of recombinant human erythropoietin therapy, functional iron deficiency has also been described. It is the most common cause of a poor response to erythropoietin therapy. Functional iron deficiency is defined as a condition in which there is a failure to release iron rapidly enough to keep pace with the demands of the bone marrow for erythropoiesis, despite adequate total body iron stores. In these cases, ferritin levels may be normal or high, but the supply of iron to the erythron is limited, as shown by a low transferrin saturation and an increased number of microcytic, hypochromic erythrocytes.¹

Functional iron deficiency has the following characteristics:

• Inadequate hemoglobin (Hb) response to erythropoietin
• Serum ferritin may be normal or high
• Transferrin saturation (TSAT) usually <20%
• Reduced mean corpuscular volume (MCV) or mean corpuscular hemoglobin concentration (MCHC) in severe cases

The differential diagnosis between functional and absolute iron deficiency is essential in order to understand iron indices in patients with chronic renal failure on hemodialysis.

Iron deficiency anemia is a serious public health problem that can impact all aspects of life and social activity. Many patients can be treated with oral iron preparations. However, there are subgroups in whom oral iron is not adequate to treat the iron deficiency. In these clinical situations, intravenous iron therapy is the preferred treatment. Venofer^® (iron sucrose injection, USP) is an alternative to oral or other parenteral iron therapy.