What is the management plan for a 73-year-old male with Chronic Kidney Disease (CKD) stage 2, iron deficiency anemia, and lab results showing low Ferritin, low serum iron, elevated Total Iron-Binding Capacity (TIBC), and low iron saturation percentage?

Iron Deficiency Anemia in CKD Stage 2

This patient has absolute iron deficiency anemia and should be treated with iron supplementation, with intravenous iron being the preferred route for optimal correction, particularly given his CKD status. 1, 2

Laboratory Interpretation

Your patient's labs clearly indicate absolute iron deficiency:

• Ferritin 27 ng/mL (severely depleted iron stores; <100 ng/mL defines absolute deficiency in CKD) 2
• Transferrin saturation 24% (borderline low; <20% is definitive for iron deficiency in CKD) 3, 2
• Elevated TIBC 270 (consistent with iron deficiency as the body attempts to capture more iron) 3

These values meet criteria for absolute iron deficiency rather than functional iron deficiency or anemia of chronic disease. 3, 2

Critical Next Step: Rule Out GI Blood Loss

Before initiating iron therapy, you must evaluate for gastrointestinal malignancy as a source of chronic blood loss, especially in a 73-year-old male with iron deficiency. 3 Referral to gastroenterology for endoscopic evaluation is mandatory in this age group with new-onset iron deficiency. 3

Iron Replacement Strategy

First-Line: Intravenous Iron (Preferred)

IV iron is superior to oral iron for CKD patients and should be your first choice: 1, 4

• Dosing regimen: Administer 500-1,000 mg of iron dextran as a single IV infusion after a 25 mg test dose 3, OR give 100-125 mg IV weekly for 8-10 doses 3
• Alternative IV formulations: Iron gluconate (250 mg twice monthly for 3 months) or iron sucrose are also effective 3, 4
• Monitoring: Check hemoglobin and iron parameters 2 weeks after completing the iron course 1
• Expected response: Studies show mean hemoglobin increases of 1.8 g/dL with IV iron alone in CKD patients, with 55% reaching target hemoglobin of 12 g/dL without requiring erythropoietin 4

Alternative: Oral Iron (Less Effective in CKD)

If IV iron is not feasible, oral iron can be attempted but has significant limitations: 3

• Dosing: At least 200 mg elemental iron daily 3
• Major caveat: Oral iron absorption is impaired in CKD due to hepcidin upregulation, even at stage 2 3, 2
• Compliance issues: GI side effects (dyspepsia, constipation) lead to poor adherence 3
• Drug interactions: Proton pump inhibitors and H2-blockers further reduce absorption 3
• Consider alternate-day dosing rather than daily to minimize hepcidin-mediated absorption blockade 3

Target Iron Parameters

Treatment goals: 3, 1

• Transferrin saturation >20% (ideally >30%)
• Ferritin 100-500 ng/mL
• Hemoglobin 11-12 g/dL

Avoid over-supplementation: Withhold IV iron if ferritin exceeds 500 ng/mL or TSAT exceeds 30-50% 3, 1

When to Consider ESA Therapy

Do NOT start erythropoietin-stimulating agents (ESAs) initially. 1 First, complete a trial of IV iron therapy and reassess hemoglobin response. 1, 4 Only consider ESAs if:

• Hemoglobin fails to improve adequately after completing IV iron course 1
• All correctable causes of anemia have been addressed 1
• Iron stores are optimized (TSAT >20%, ferritin >100 ng/mL) 3

Monitoring Schedule

• Iron parameters and hemoglobin: Every 3 months once stable 3, 1
• Renal function: Monitor creatinine and GFR given CKD diagnosis 3
• Thyroid function: Should be checked as part of comprehensive anemia evaluation in elderly patients 3

Common Pitfalls to Avoid

• Don't assume anemia is solely due to CKD at stage 2: Iron deficiency is a distinct, treatable cause that must be addressed first 2, 4
• Don't rely on oral iron in CKD patients: Even at stage 2, absorption is compromised and unlikely to maintain adequate iron stores 3
• Don't skip the GI evaluation: Missing an underlying malignancy has devastating consequences 3
• Don't start ESAs before optimizing iron: This wastes resources and exposes patients to unnecessary ESA-related risks 1