What laboratory findings suggest the diagnosis of iron deficiency anemia?

In iron deficiency anemia, the laboratory findings typically reflect a depletion of iron stores and altered iron metabolism. The key indicators to support the diagnosis are decreased levels of ferritin and increased total iron binding capacity (TIBC).

Ferritin is a protein that stores iron, and its levels decrease when the body lacks sufficient iron. Consequently, a low ferritin level is a hallmark of iron deficiency. TIBC, on the other hand, measures the blood's capacity to bind iron with transferrin. When there is a deficiency of iron, the liver produces more transferrin to transport the limited available iron, leading to an elevation in TIBC.

Thus, in the case of iron deficiency anemia, one would expect to see decreased ferritin due to low iron stores and increased TIBC due to the body's compensatory mechanisms to maximize iron transport. This specific combination of findings is characteristic of iron deficiency anemia and underscores the body's response to insufficient iron availability for erythropoiesis (red blood cell production).

The other options do not align with the classical laboratory findings of iron deficiency anemia, indicating different states of iron metabolism or other types of anemia.