Which cytokine is used to treat anemia secondary to chronic kidney disease?

Erythropoietin is the correct choice for treating anemia secondary to chronic kidney disease because it is a hormone that stimulates the production of red blood cells in the bone marrow. In chronic kidney disease, the kidneys often produce insufficient amounts of erythropoietin due to their impaired function, leading to anemia. Administering erythropoietin can help increase red blood cell levels and alleviate the symptoms associated with anemia.

The other options do not have a direct role in the management of anemia related to chronic kidney disease. Alpha-interferon is primarily used in the treatment of viral infections and certain cancers, while interleukin-2 is mainly involved in immune responses and cancer treatment. Interleukin-11 does have some roles in hematopoiesis, but it is not specifically utilized for treating kidney disease-related anemia as effectively as erythropoietin. Thus, its function does not directly address the primary issue at hand.