From the Guidelines
Low serum transferrin levels are a significant indicator of potential iron deficiency or impaired liver function, and clinicians should investigate underlying causes through additional tests. When evaluating low serum transferrin, it is essential to consider the patient's overall clinical context, including symptoms, medical history, and other laboratory results. Transferrin is a protein that transports iron in the bloodstream, and low levels can occur in conditions like liver disease, malnutrition, protein-losing enteropathy, or chronic inflammation 1. This finding may suggest impaired liver function, as the liver is the primary site of transferrin synthesis. Some key points to consider when interpreting low serum transferrin levels include:
- Low transferrin often correlates with low serum iron and can contribute to anemia despite adequate iron stores, a condition known as anemia of chronic disease.
- Transferrin saturation (the percentage of transferrin bound to iron) is often more informative than the absolute transferrin level alone, with a saturation of less than 16% among adults often used to confirm iron deficiency 1.
- In patients with hypotransferrinemia due to a TF defect, transferrin supplementation by either plasma transfusion or apotransferrin infusion is recommended, along with monitoring of iron status to detect toxic iron loading early 1. Treatment should focus on addressing the underlying condition rather than directly supplementing transferrin, and monitoring transferrin levels can help track response to treatment of the primary disorder. In clinical practice, a comprehensive approach to diagnosing and managing low serum transferrin levels is crucial to ensure optimal patient outcomes, and this may involve collaboration with specialists such as hepatologists or hematologists.
From the Research
Low Serum Transferrin
- Low serum transferrin can be an indicator of iron deficiency and anemia, as seen in patients with chronic kidney disease (CKD) 2.
- Transferrin saturation, which is calculated by serum iron divided by total iron-binding capacity (TIBC), is also used to diagnose iron deficiency 3.
- However, low serum transferrin can also be associated with other conditions, such as acute-on-chronic organ failure and short-term mortality in decompensated cirrhosis 4.
- In patients with decompensated cirrhosis, low serum transferrin was found to correlate with the severity of organ failure, active alcoholism, and surrogates of systemic inflammation and macrophage activation 4.
Diagnosis and Treatment
- Iron deficiency and iron deficiency anemia can be diagnosed based on decreased levels of serum ferritin and transferrin saturation 5.
- Treatment for iron deficiency typically involves oral iron salts, but high-dose intravenous iron compounds are becoming increasingly popular, especially in cases where oral iron is not effective 6, 5.
- The choice of treatment depends on the underlying cause of the iron deficiency and the patient's overall health status.
Prognostic Significance
- Low serum transferrin has been found to be an independent predictor of short-term mortality in patients with decompensated cirrhosis 4.
- In CKD patients, low serum iron and low transferrin saturation were associated with an increased risk of anemia, even in patients with normal transferrin saturation 2.