Iron and Total Iron-binding Capacity (TIBC) – 001321

Serum iron is increased in hemosiderosis, hemolytic anemias especially thalassemia, sideroachrestic anemias, hepatitis, acute hepatic necrosis, hemochromatosis, and with inappropriate iron therapy. Iron may reach high levels with iron poisoning. Some patients who receive multiple transfusions (eg, some hemolytic anemias, thalassemia, renal dialysis patients) will have increased serum iron levels.

Serum iron is decreased with insufficient dietary iron, chronic blood loss (including the hemolytic anemias paroxysmal nocturnal hemoglobinuria), inadequate absorption of iron and impaired release of iron stores as in inflammation, infection and chronic diseases. The combination of low iron, high TIBC and/or transferrin and low saturation indicates iron deficiency. Without all of these findings together, iron deficiency is unproven.² Low ferritin supports the diagnosis of iron deficiency. Detection of iron deficiency may lead to detection of adenocarcinoma of gastrointestinal tract, a point which cannot be overemphasized. In recovery from pernicious anemia, especially just after B₁₂ dose, iron levels are low. In fact, the drop in serum iron 1 to several days after the Schilling test flushing dose of vitamin B₁₂ may be more useful in diagnosis than the radioactivity of the 24-hour urine collection. Serum iron is reported to drop with acute infarct of myocardium.