From the Guidelines
The patient's laboratory values are consistent with iron deficiency anemia, despite a normal ferritin level, which can be falsely elevated in inflammatory conditions, and treatment with oral iron supplementation is recommended. The patient has a low hemoglobin (8 g/dL) and low transferrin saturation (6%), indicating a lack of sufficient iron for erythropoiesis 1. The serum iron level is also low (14 μg/dL), further supporting the diagnosis of iron deficiency anemia. While the ferritin level (97 ng/mL) is within normal limits, it is not a definitive indicator of iron stores in this case, as it can be influenced by various factors, including inflammation 1.
The British Society of Gastroenterology guidelines recommend confirming iron deficiency with iron studies prior to investigation, and serum ferritin is considered the single most useful marker of iron deficiency anemia, but other blood tests, such as transferrin saturation, can be helpful if a false-normal ferritin is suspected 1. In this case, the low transferrin saturation and low serum iron levels support the diagnosis of iron deficiency anemia, despite the normal ferritin level.
Key points to consider in the management of this patient include:
- Initiating oral iron supplementation, typically ferrous sulfate 325 mg three times daily between meals with vitamin C to enhance absorption
- Monitoring hemoglobin levels to assess response to therapy, with a good response defined as a rise in hemoglobin of ≥10 g/L within a 2-week timeframe 1
- Continuing treatment for 3-6 months after hemoglobin normalizes to replenish iron stores
- Investigating the underlying cause of iron deficiency, including evaluation for gastrointestinal blood loss, malabsorption, or increased iron requirements
- Providing dietary counseling to increase iron-rich foods (red meat, leafy greens, beans) as an adjunct to supplementation.
From the Research
Interpretation of Laboratory Results
The patient's laboratory results show:
- Hemoglobin (Hgb) level of 8, which is below the normal range, indicating anemia 2
- Transferrin level of 162, which is a protein that binds to iron and transports it in the blood
- Percent saturation of transferrin of 6, which is low, indicating that there is not enough iron available to bind to transferrin 3
- Iron binding capacity of 227, which is high, indicating that there is a high capacity for iron to bind to transferrin, but not enough iron is available
- Ferritin level of 97, which is a protein that stores iron in the body, and is within the normal range, but may not accurately reflect iron stores in the presence of inflammation 2, 4
- Iron level of 14, which is low, indicating iron deficiency
Diagnosis and Treatment
Based on these results, the patient has iron-deficiency anemia, characterized by low hemoglobin, low iron, and low percent saturation of transferrin 2, 3. The ferritin level is within the normal range, but may not accurately reflect iron stores. The patient may benefit from iron supplementation, which can be administered orally or intravenously, depending on the severity of the deficiency and the patient's ability to tolerate oral iron 2, 3, 5.
Key Points
- Iron-deficiency anemia is a common condition that can cause symptoms such as fatigue, exercise intolerance, and difficulty concentrating 2
- Laboratory tests, including hemoglobin, iron, transferrin saturation, and ferritin, are used to diagnose iron deficiency and monitor treatment response 2, 3, 4
- Iron supplementation is the primary treatment for iron-deficiency anemia, and can be administered orally or intravenously 2, 3, 5
- The choice of iron supplementation depends on the severity of the deficiency, the patient's ability to tolerate oral iron, and the presence of underlying medical conditions 2, 3, 5