How can iron deficiency anemia be distinguished from anemia of chronic infection?

To distinguish iron deficiency anemia from anemia of chronic infection, the total iron-binding capacity (TIBC) is a particularly useful diagnostic parameter. In iron deficiency anemia, TIBC is typically elevated because the body is actively trying to increase the transport of iron in response to its deficit. The liver produces more transferrin, which binds to iron, leading to an increased binding capacity.

In contrast, in anemia of chronic infection, the TIBC is often decreased or normal. This is due to the interplay of inflammatory cytokines, such as hepcidin, which regulate iron metabolism and lead to iron sequestration within macrophages and a reduction in transferrin synthesis.

Thus, measuring TIBC can help differentiate between these two types of anemia: a high TIBC suggests iron deficiency, while a low or normal TIBC indicates anemia of chronic infection. This differentiation is essential for determining the appropriate treatment and management plan for the patient.