A 58-year-old woman with rheumatoid arthritis has a hemoglobin of 9 g/dL, serum ferritin of 400 ng/mL, low serum iron, and normal marrow iron stores. The hormone responsible for this pattern acts on which molecule to trap iron within macrophages and enterocytes?

• A Ferroportin ✓
• B Transferrin receptor
• C H-ferritin mRNA
• D Divalent metal transporter 1

Explanation

Inflammation raises interleukin-6, which drives hepatic hepcidin synthesis. Hepcidin binds ferroportin, the sole cellular iron exporter on macrophages, hepatocytes, and enterocyte basolateral surfaces, triggering its internalization and degradation. Export stops, so macrophage iron accumulates while plasma iron falls, producing the anemia of chronic disease with high ferritin and low serum iron. DMT1 handles apical uptake from the gut lumen and is regulated by HIF mechanisms, not hepcidin.

Reference: Williams Hematology, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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