Anemias associated with chronic infection are characterized by what laboratory findings?

Anemias associated with chronic infection typically manifest as anemia of chronic disease (ACD). In this condition, the body responds to inflammation or infection by altering iron metabolism and hematopoiesis.

In ACD, there is usually a low serum iron concentration due to the sequestration of iron by macrophages and decreased erythropoiesis, which is a response to inflammatory cytokines. The total iron binding capacity (TIBC) is often low because of increased levels of hepcidin, a hormone that regulates iron homeostasis and prevents iron from being released from stores. This combination of low serum iron and low TIBC is a hallmark of anemia seen in chronic infections.

High ferritin levels may also be seen, as ferritin reflects the body's iron stores, which are often elevated in the context of inflammation. However, while low hemoglobin is a characteristic sign of anemia, it is the combination of low serum iron and low TIBC that specifically characterizes the anemic response to chronic infection.