There are many known reasons for resistance, of which iron deficiency is the main factor, followed by infection, malnutrition, secondary hyperparathyropathy, and EPO resistance can also be induced by autoimmune diseases, aluminum poisoning and angiotensin converting enzyme inhibitors (Jacobs et al., 1985; Freyssinier et al., 1999; Kashii et al., 2000; Bouscary et al., 2003; Bohlius et al., 2005). Here, EPO is linked to infection.