A possible role of hepcidin in the pathogenesis of anemia among kidney allograft recipients.

Hepcidin is a small, defensin-like peptide whose production by hepatocytes is modulated in response to anemia, hypoxia, or inflammation. We studied correlations of hepcidin concentrations with markers of iron status, erythropoietin therapy, and markers of inflammation among 130 kidney allograft recipients. In addition, we assessed the prevalence of anemia and its relation to hepcidin. Soluble receptor of transferrin (sTfR), high-sensitivity C-reactive protein (hsCRP), TNF-alpha, interleukin (IL)-6, prohepcidin, and hepcidin were measured using commercially available kits. According to the WHO definition, the prevalence of anemia was 28%. Among anemic recipients we found a significantly higher values of serum creatinine, serum prohepcidin, hepcidin, (hsCRP), TNF-alpha, IL-6, ferritin, and proteinuria in addition to more frequent use of rapamycin and significantly lower use of CSA with lower CSA concentrations, as well as lower cholesterol, hemoglobin, and estimated glomerular filtration rate (eGFR) (by the Modification of Diet in Renal Disease equation). Serum prohepcidin significantly correlated with creatinine, GFR, time after transplantation, albumin, hsCRP, IL-6, and TNF-alpha, whereas hepcidin-25 correlated with serum iron, ferritin, hsCRP, IL-6, hemoglobin, transferrin saturation (TSAT), creatinine, and GFR. Multiple regression analysis showed that prohepcidin was independently related only to GFR and ferritin. Upon multiple regression analysis, predictors of serum hepcidin were eGFR, ferritin, and hsCRP, explaining 79% of the variation of hepcidin values. In conclusion, the prevalence of anemia was relatively high among a population of kidney allograft recipients. The pathogenesis of anemia is mulitfactorial. Elevated hepcidin levels among kidney transplant recipients may be due to low-grade inflammation, which is frequently encountered in this population, and mainly to impaired renal function, but it did not seem to be a major pathogenetic factor for anemia in this population.