Study of association between interleukin-17 and interferon-gamma and recombinant human erythropoietin dose in patients undergoing peritoneal dialysis.

BACKGROUND: A common complication in patients undergoing peritoneal dialysis (PD) is a chronic inflammatory state and anemia that can be treating by recombinant human erythropoietin (rHuEPO). Higher required dose of rHuEPO could be expected in patients with higher cytokine levels. Additionally, it is known that peritoneal inflammation can be correlated with systemic inflammation and this could contribute to the compromised rHuEPO required dose in anemic patients with end stage renal disease (ESRD). Thus, the current study aimed to evaluate the association between levels of systemic and local interferon (IFN)-γ, interleukin (IL)-17 and other cytokines and the dose of rHuEPO used by patients undergoing PD for the correction of anemia. METHODS: Thirty-one patients under PD using rHuEPO were evaluated in this cross-sectional study. Plasma and dialysate levels of IL-2, IL-4, IL-6, IL-10, IL-17, tumour necrosis factor (TNF)-α and IFN-γ were determined using the Cytometric Bead Array TM kit (CBA; BD Bioscences, San Jose, CA). The relation between the levels of each cytokine levels and the tertiles of rHuEPO were plotted on box-plot graphics and then the medians of interleukins levels were compared by median comparison test. The significance level adopted was 5% and the analysis was performed by the softwares STATA (version 12.0) and GraphPad Prism 3.0. RESULTS: The median of IL-17 and IFN-γ plasma levels were significant higher in the group with higher rHuEPO dosage. However, this association was not observed in the dialysate levels, as well as was not observed a relationship between the other plasma and dialysate cytokines evaluated in this study and the dose of rHuEPO. CONCLUSIONS: Our study found increased IL-17 and IFN-γ plasma, but no dialysate levels, in patients receiving higher doses of rHuEPO, suggesting may exist a relationship between systemic inflammation of ESRD, and the necessary levels of rHuEPO for the correction of anemia in these patients.

Peritoneal dialysis and inflammation.

Peritoneal dialysis (PD) is a kidney replacement therapy for end stage renal disease (ESRD) patients. Despite being a lifesaving treatment, the rate of mortality in patients under PD is elevated, mainly due to the chronic peritoneal dysfunction which is characterized by inflammation, peritoneal fibrosis and neoangiogenesis. The inflammatory process is trigged and modulated by the type of the peritoneal dialysis solutions (PDSs) used during PD. Currently, different PDSs are commercially available: (i) the conventional solutions; (ii) solutions of neutral pH containing low concentration of glucose degradation products (GDPs); (iii) solutions with icodextrin; and (iv) solutions containing taurine. Therefore, the aim of this review is to describe the different types of peritoneal dialysis solutions used during PD and their relationship with systemic and intraperitoneal inflammation. Some studies suggested that solutions of neutral pH containing low concentration of GDPs, icodextrin and taurine have better biocompatibility and lower influence on the inflammatory process compared to the conventional one. On the other hand, the studies, in general, were performed with a small population and for a short period of time. Therefore, further well-designed and -controlled clinical trials with larger number of individuals are required in order to better understand the role of different peritoneal dialysis solution types in the development of inflammation in patients with chronic peritoneal dialysis. Accordingly, studies that are more well-designed, well-controlled and with a larger number of patients are needed to explain and define the role of different types of PDS in the inflammation development in patients with chronic peritoneal dialysis.