Which iron-related lab value tends to be elevated in cases of anemia of chronic disease?

In cases of anemia of chronic disease, serum ferritin levels are typically elevated. This occurs due to the body's response to chronic inflammation or illness, wherein iron stores are sequestered by the reticuloendothelial system, leading to increased ferritin. Despite the high ferritin levels indicating that iron stores are adequate or even high, the bioavailability of iron for erythropoiesis is actually diminished due to various inflammatory cytokines that affect iron metabolism and utilization.

In chronic disease, although iron may be sequestered, the production of transferrin, which facilitates iron transport, is decreased. Therefore, transferrin saturation is often low, and total iron-binding capacity (TIBC) is also commonly reduced, reflecting a decrease in the available iron for erythropoiesis. Serum iron levels tend to be low as well, indicating a lack of circulating iron due to the sequestration process.

This unique pattern, with elevated ferritin but low serum iron, TIBC, and transferrin saturation, helps differentiate anemia of chronic disease from other types of anemia, such as iron deficiency anemia, which typically presents with low ferritin and high TIBC. Thus, the increase in serum ferritin during anemia of chronic disease serves as a