In the presence of inflammation, how should iron status be interpreted and which tests help?

• A. Evaluate ferritin in isolation to assess iron status during inflammation.
• B. Evaluate transferrin saturation and CRP, and consider soluble transferrin receptor if needed.
• C. Rely solely on serum iron levels to define iron deficiency.
• D. Assume iron deficiency if ferritin is high, regardless of inflammation.

Answer: (B)

When inflammation is present, ferritin can rise as an acute‑phase reactant, which can mask true iron deficiency. Because of that, iron status can’t be interpreted from ferritin alone. The most informative approach is to assess iron availability with transferrin saturation (the ratio of serum iron to TIBC) while also measuring CRP to gauge the level of inflammation. CRP helps you interpret ferritin values in context—elevated ferritin with high CRP doesn’t exclude iron deficiency. If there’s still uncertainty after these tests, measuring soluble transferrin receptor can be helpful, since sTfR increases with iron deficiency and is less influenced by inflammation, aiding differentiation between true iron deficiency and anemia of inflammation. This combination provides a clearer picture of iron status during inflammatory states. Relying on serum iron alone is unreliable due to variability and inflammatory effects, and assuming iron deficiency from a high ferritin is incorrect when inflammation is present.