Transient Iron Resistance in Severe Iron Deficiency Anemia.

Iron deficiency is the primary cause of anemia in the United States. Occasionally the anemia is severe enough to require transfusion of blood products. Anecdotal case reports described a state of transient iron intolerance in patients with profound, prolonged iron deficiency. We are presenting a study, evaluating in a prospective fashion how the iron parameters of patients with severe iron deficiency respond to blood transfusion and compare this to the trajectory of patients with other causes of anemia.

We included nineteen consecutive patients admitted to the medical floors with the diagnosis of anemia. Six of them had severe iron deficiency. The remaining part of the cohort carried the diagnosis of refractory anemia or anemia of chronic disease. We evaluated serum iron level, total iron binding capacity (TIBC), transferrin, and ferritin levels immediately prior to the transfusion of two units PRBCs and then six, twelve, twenty four, and forty eight hours after the completion of the transfusion, and correlated them to the pre- and post-transfusional IL-1, IL-2, IL-6, IL-10, IL-18, MIB-1β, MCP-1, erythropoietin, and hepcidin values of severely iron deficient patients and patients with other causes of their anemia.

Patients with severe iron deficiency anemia showed a transient peak of the serum iron levels immediately after completion of blood transfusion. This normalized after 24 hours. In the not severely iron deficient population, no peak in the serum iron levels was observed. The remaining iron parameters, namely TIBC, transferrin, and ferritin remained unchanged. The transient elevation of the serum iron levels correlated with changes in the level of different cytokines.

Severely iron deficient patients show a transient intolerance to externally, parenterally delivered iron, that normalizes within 24 hours.

No relevant conflicts of interest to declare.