title: Serum iron parameters in the early post-transplant period and infection risk in kidney transplant recipients.
abstract: BACKGROUND
  The impact of iron metabolism on the risk of infectious complications has been demonstrated in various immunosuppressed populations. However, no previous studies have assessed this potential association in kidney transplant (KT) recipients.
  
  
  METHODS
  We prospectively analyzed 228 patients undergoing KT at our institution from November 2008 to February 2011. Serum iron parameters (iron level, ferritin, total iron-binding capacity, unsaturated iron-binding capacity, transferrin, and transferrin saturation) were assessed within the first 2 weeks after transplantation (median interval, 3 days; interquartile [Q1 -Q3 ] range, 1-6 days), and before the occurrence of the first infectious episode (median interval, 26 days; Q1 -Q3 range, 11-76 days). Primary outcome was the occurrence of any episode of infection during the first year. Multivariate-adjusted hazard ratios (aHRs) were estimated by Cox regression models.
  
  
  RESULTS
  Patients with ferritin level ≥ 500 ng/mL had higher incidence rates (per 1000 transplant-days) of overall infection (P = 0.017), bacterial infection (P = 0.002), and bloodstream infection (P = 0.011) during the first post-transplant year. One-year infection-free survival rate was lower in these recipients (26% vs. 41%; P = 0.004). On multivariate analysis, after adjusting for potential confounders, ferritin emerged as an independent predictor of overall infection (aHR [per unitary increment], 1.001; P = 0.006), and bacterial infection (aHR [per unitary increment], 1.001; P = 0.020).
  
  
  CONCLUSIONS
  Monitoring of serum iron parameters in the early post-transplant period may be useful in predicting the occurrence of infection in KT recipients, although further studies should be carried out to confirm this preliminary finding.
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Fernández-Ruiz
authors.forename: F
authors.initials: F
authors.lastname: López-Medrano
authors.forename: A
authors.initials: A
authors.lastname: Andrés
authors.forename: J M
authors.initials: JM
authors.lastname: Morales
authors.forename: C
authors.initials: C
authors.lastname: Lumbreras
authors.forename: R
authors.initials: R
authors.lastname: San-Juan
authors.forename: N
authors.initials: N
authors.lastname: Polanco
authors.forename: E
authors.initials: E
authors.lastname: González
authors.forename: J M
authors.initials: JM
authors.lastname: Aguado
mesh_terms: D000328:Adult; D000368:Aged; D001424:Bacterial Infections / Q000097:blood / Q000453:epidemiology*; D018572:Disease-Free Survival; D005260:Female; D005293:Ferritins / Q000097:blood*; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007501:Iron / Q000097:blood*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D018805:Sepsis / Q000097:blood / Q000453:epidemiology*; D014168:Transferrin / Q000378:metabolism*
chemical_list: D014168:Transferrin; D005293:Ferritins; D007501:Iron
keywords: ferritin; infection; iron-binding capacity; kidney transplantation; serum iron parameters; transferrin