From the Guidelines
Low transferrin levels with normal liver function are most likely indicative of iron deficiency, and the patient should be evaluated for iron deficiency anaemia. According to the British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults 1, serum markers of iron deficiency include low ferritin, low transferrin saturation, and low iron. A low transferrin level can be seen in iron deficiency, and it is essential to measure serum ferritin (SF) as it is the most specific test for iron deficiency in the absence of inflammation.
The guidelines suggest that an SF level of <15 μg/L is indicative of absent iron stores, while SF levels of less than 30 μg/L are generally indicative of low body iron stores 1. However, as SF is an acute phase protein, apparently normal levels may occur with iron deficiency in the context of an inflammatory disease process.
Key points to consider in the evaluation of low transferrin levels with normal liver function include:
- Measuring serum iron, total iron binding capacity (TIBC), ferritin, and transferrin saturation to confirm iron deficiency
- Evaluating for chronic inflammatory processes that may affect iron metabolism
- Considering other causes of low transferrin levels, such as protein malnutrition or genetic disorders
- Avoiding iron supplements unless specifically directed by a healthcare provider
- Regular monitoring of iron parameters to track progress
It is crucial to note that the specificity of serum markers for iron deficiency can be limited, and a comprehensive evaluation is necessary to determine the underlying cause of low transferrin levels 1.
From the Research
Low Transferrin Level with Normal Liver Function
- A low transferrin level can be an indicator of iron deficiency, even with normal liver function 2.
- Transferrin measurement outperforms iron measurement and saturation index in predicting iron deficiency 2.
- In cases of chronic liver disease, iron deficiency anemia can occur, and the diagnosis can be challenging due to the effects of liver disease on laboratory results 3.
- New parameters such as red blood cell ferritin, serum transferrin receptor test, and hepcidin have been studied for their utility in indicating true iron deficiency in combination with chronic liver disease 3.
- A study found that serum iron and TIBC give no additional information in the diagnosis of iron deficiency anemia and are redundant if serum ferritin is available 4.
- Elevated total iron-binding capacity can occur before a decrease in serum iron in iron-deficiency states, potentially as a compensatory mechanism to maintain normal erythropoiesis 5.
Diagnostic Considerations
- The diagnostic accuracy of serum iron and total iron binding capacity (TIBC) in detection of iron deficiency has been evaluated, with sensitivity and specificity of 63.5% and 38.6% for serum iron, and 64.5% and 42.8% for TIBC, respectively 4.
- Ferritin is considered the gold standard for diagnosing iron deficiency, with a specificity of 99% and sensitivity of 80% at a concentration of 30 ng/ml 4.
- Transferrin saturation can be determined by dividing serum iron by TIBC and multiplying by 100, but its diagnostic utility is limited compared to transferrin measurement alone 2, 4.