TNF and anemia (phenotype): Serum ferritin and TSAT have been reported to increase in peritoneal dialysis patients with anemia who are treated with ESA as the duration of peritoneal dialysis increases (13), which has been attributed to the effects of pro-inflammatory cytokines, such as tumor necrosis factor-α and interleukin-1, and uremic toxins, including polyamines, as well as parathyroid hormone (14, 15).