Interpretation and Management
This patient does NOT have iron deficiency anemia—they have anemia of chronic disease (ACD) or functional iron deficiency, and routine iron supplementation is not recommended and may be harmful. 1
Understanding the Laboratory Pattern
Your patient presents with:
- Low serum iron (FE 35 mg/dL) - suggests limited circulating iron
- Low TIBC (206 mg/dL) - the critical distinguishing feature
- Elevated ferritin (352 ng/mL) - indicates adequate or excessive iron stores
This combination is pathognomonic for anemia of chronic disease, NOT iron deficiency anemia. 2
Key Diagnostic Distinctions
Iron Deficiency Anemia typically shows:
Anemia of Chronic Disease shows:
- Low serum iron
- Low or normal TIBC (<250 mg/dL) 2
- Normal to elevated ferritin 2
- The low TIBC has 97% predictive value for excluding iron deficiency 2
Clinical Approach
Do NOT Supplement with Iron
Iron supplementation should not be given when ferritin is normal or elevated, as it is potentially harmful and provides no benefit. 1 The elevated ferritin (352 ng/mL) indicates this patient has adequate total body iron stores that are simply sequestered due to inflammation. 1
Identify the Underlying Cause
The priority is finding and treating the underlying chronic inflammatory condition causing iron sequestration: 1
- Chronic infections (occult abscess, endocarditis, osteomyelitis)
- Inflammatory conditions (rheumatoid arthritis, inflammatory bowel disease, vasculitis)
- Malignancy (solid tumors, lymphoproliferative disorders)
- Chronic kidney disease 1
- Liver disease (hepatitis, cirrhosis) 1
Monitoring Parameters
Check the following to guide management:
- Complete blood count with MCV 1
- C-reactive protein or ESR to assess inflammation 1
- Transferrin saturation (calculate as: serum iron/TIBC × 100) 1
- Renal function (creatinine, eGFR) 1
- Targeted workup based on clinical suspicion 1
Special Circumstances Where Iron May Be Considered
Iron therapy might be appropriate ONLY in these specific scenarios despite elevated ferritin:
1. Functional Iron Deficiency with ESA Therapy
If the patient requires erythropoiesis-stimulating agents (ESAs) for chronic kidney disease or chemotherapy-induced anemia, intravenous iron may be beneficial even with ferritin up to 500-800 ng/mL to overcome functional iron deficiency. 1
- Transferrin saturation <20% suggests functional deficiency despite adequate stores 1
- Intravenous iron is superior to oral iron in this context 1
- Monitor to keep ferritin <800 ng/mL to avoid toxicity 1
2. Chronic Kidney Disease on Dialysis
Hemodialysis patients have unique iron requirements due to ongoing blood losses: 1
- Target TSAT ≥20% and ferritin ≥100 ng/mL 1
- Most require intravenous iron supplementation 1
- Monitor every 3 months and adjust accordingly 1
Critical Pitfalls to Avoid
Do not reflexively prescribe iron based solely on low serum iron. 1, 2 The TIBC is the critical discriminator—a low TIBC essentially rules out true iron deficiency. 2
Avoid iron overload. Giving iron when ferritin is already elevated (>300 ng/mL) risks toxicity, particularly hepatic and cardiac complications. 1
Do not use fecal occult blood testing as it is insensitive and non-specific for evaluating this type of anemia. 1
Treatment Algorithm
- Confirm the pattern: Low iron + Low TIBC + Elevated ferritin = ACD 2
- Withhold iron supplementation 1
- Investigate for underlying chronic disease (infection, inflammation, malignancy, CKD) 1
- Treat the underlying condition as the primary intervention 1
- Consider ESA therapy only if: 1
- Hemoglobin <10 g/dL with symptomatic anemia
- No active malignancy or recent stroke
- After trial of treating underlying condition
- If ESA therapy initiated, then consider IV iron (not oral) if TSAT <20% 1