From the Guidelines
Transferrin saturation should be maintained above 20% to ensure adequate iron availability for erythropoiesis, as evidenced by recent studies 1. Transferrin is a blood protein responsible for transporting iron throughout the body. This glycoprotein binds to iron in the intestines, carries it through the bloodstream, and delivers it to cells that need iron for essential functions like hemoglobin production and cellular metabolism.
Key Points
- Transferrin has a high affinity for iron, binding up to two iron atoms per molecule, which helps prevent free iron from causing oxidative damage in the body.
- When iron levels are low, transferrin saturation decreases, while in iron overload conditions, saturation increases.
- Clinically, transferrin levels and saturation percentages are important diagnostic markers for conditions like iron deficiency anemia (where transferrin levels increase) and hemochromatosis (where saturation is abnormally high).
- The liver primarily produces transferrin, and its synthesis increases when the body detects low iron stores.
- According to a recent study 1, the goal ferritin is 50 ng/mL, regardless of sex at birth, and a TSAT <20% has high sensitivity for diagnosing absolute or functional iron deficiency.
- Another study 1 highlights the importance of evaluating and managing anemia in patients with congestive heart failure, where iron deficiency is a common comorbidity.
Diagnosis and Management
- Serum ferritin assay and transferrin saturation are important in the assessment of patients with iron-restricted erythropoiesis 1.
- The % hypochromic reticulocytes and mean hemoglobin reticulocyte concentration (CHr) are assay options for the identification of iron-restricted erythropoiesis.
- A CHr value <30 pg appears to be the most predictive value for response to intravenous iron 1.
- Intravenous iron supplementation is recommended for patients with iron deficiency anemia, with a target hemoglobin increase of 1-2 g/dL within 4-8 weeks of therapy 1.
From the Research
Transferrin Overview
- Transferrin is a protein that plays a crucial role in iron transport and regulation in the body 2, 3, 4
- Transferrin saturation (TSAT) is a measure of the amount of iron bound to transferrin, and low TSAT levels can indicate iron deficiency 2, 4
Iron Deficiency and Transferrin
- Iron deficiency anemia is a common condition that can be treated with iron supplementation 2, 5, 6
- Transferrin saturation levels can be used to diagnose iron deficiency, particularly in patients with inflammation 2
- Low TSAT levels have been associated with increased morbidity and mortality in older adults with heart failure and anemia 4
Transferrin and Iron Overload
- Elevated transferrin-iron saturation can be a sign of iron overload disorders, such as hereditary hemochromatosis 3
- Iron overload can lead to end-organ damage, and diagnosis often involves genetic testing and imaging studies 3
Clinical Significance of Transferrin
- Transferrin levels can be used to monitor response to iron supplementation therapy 2, 5, 6
- Abnormal transferrin levels can be a sign of underlying conditions, such as chronic liver disease or malignancy 3
- Transferrin saturation levels can be used to guide treatment decisions in patients with iron deficiency anemia 2, 4