Association between baseline serum hepcidin levels and infection in kidney transplant recipients: Potential role for iron overload

Transpl Infect Dis. 2018 Feb;20(1). doi: 10.1111/tid.12807. Epub 2018 Jan 10.

Abstract

Background: The liver-synthesized peptide hepcidin is a key regulator of iron metabolism and correlates with total iron stores. We analyzed the association between pre-transplant hepcidin-25 levels and infection after kidney transplantation (KT).

Methods: Serum hepcidin-25 levels were measured at baseline by high-sensitivity ELISA in 91 patients undergoing KT at our institution between December 2011 and March 2013. The impact of this biomarker on the incidence of post-transplant infection (excluding lower urinary tract infection) during the first year was assessed by Cox regression.

Results: Mean hepcidin-25 level was 82.3 ± 67.4 ng/mL and strongly correlated with serum ferritin (Spearman's rho = 0.703; P < .001). There were no significant differences in hepcidin-25 levels between patients with or without overall infection (96.4 ± 67.5 vs 72.6 ± 66.7 ng/mL; P = .101). Such difference was evident for opportunistic (128.9 ± 75.0 vs 73.0 ± 62.3 ng/mL; P = .003) and, to a lesser extent, surgical-site infection (107.5 ± 73.3 vs 76.5 ± 65.2 ng/mL; P = .087). Patients with hepcidin-25 levels ≥72.5 ng/mL had higher 12-month cumulative incidence of overall infection (51.2% vs 29.2%; P = .032). After multivariate adjustment, hepcidin-25 ≥72.5 ng/mL acted as an independent risk factor for overall (adjusted hazard ratio [aHR] 3.86; 95% confidence interval [CI] 1.49-9.96; P = .005) and opportunistic infection (aHR 4.32; 95% CI 1.18-15.75; P = .027).

Conclusion: Elevated baseline serum hepcidin-25 levels were associated with increased risk of infection after KT, suggesting a role for iron overload in the individual susceptibility to post-transplant infection.

Keywords: hepcidin-25; infection; iron metabolism; iron overload; kidney transplantation.

MeSH terms

  • Adult
  • Aged
  • Bacterial Infections / etiology*
  • Bacterial Infections / microbiology
  • Biomarkers
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Ferritins / blood
  • Hepcidins / blood*
  • Humans
  • Incidence
  • Iron / blood*
  • Iron / metabolism
  • Iron Overload / blood*
  • Iron Overload / etiology
  • Kidney Transplantation / adverse effects*
  • Liver
  • Male
  • Middle Aged
  • Opportunistic Infections / etiology
  • Opportunistic Infections / microbiology
  • Risk Factors
  • Transplant Recipients
  • Urinary Tract Infections

Substances

  • Biomarkers
  • Hepcidins
  • Ferritins
  • Iron