title: Low plasma level of cathelicidin antimicrobial peptide (hCAP18) predicts increased infectious disease mortality in patients undergoing hemodialysis.
abstract: BACKGROUND
  Human cathelicidin antimicrobial protein (hCAP18) is an antimicrobial and immunomodulatory peptide that has pleiotropic effects and is transcriptionally regulated by vitamin D. Because the administration of vitamin D analogues has been linked to decreased mortality among patients with end-stage renal disease, we hypothesized that low hCAP18 levels would identify those who are at increased risk of death attributable to infection while undergoing hemodialysis.
  
  
  METHODS
  We performed a case-control study nested in a prospective cohort of patients (n = 10,044) initiating incident hemodialysis. Case patients (n = 81) were those who died of an infectious disease within 1 year; control patients (n = 198) were those who survived at least 1 year while undergoing dialysis.
  
  
  RESULTS
  Mean (+/-SD) baseline levels of hCAP18 in case patients and control patients were 539 +/- 278 ng/mL and 650 +/- 343 ng/mL, respectively (P = .006). hCAP18 levels had a modest correlation with 1,25-dihydroxyvitamin D levels r = 0.23; P = .053) but not with 25-hydroxyvitamin D levels r = -0.06; P = .44). Patients with hCAP18 levels in the lowest tertile had a 2-fold increased risk (odds ratio, 2.1; 95% confidence interval, 1.2-3.5) of death attributable to infection; after multivariable adjustment, this relationship remained statistically significant (odds ratio, 3.7; 95% confidence interval, 1.2-11.2).
  
  
  CONCLUSIONS
  In individuals initiating chronic hemodialysis, low baseline levels of hCAP18, a vitamin D-regulated antimicrobial protein, are independently associated with an increased risk of death attributable to infection.
authors.affiliation: Department of Medicine, Division of Hematology/Oncology, Cedars-Sinai Medical Center, David Geffen School of Medicine at Univeristy of California, Los Angeles, USA.
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Gombart
authors.forename: Ishir
authors.initials: I
authors.lastname: Bhan
authors.forename: Niels
authors.initials: N
authors.lastname: Borregaard
authors.forename: Hector
authors.initials: H
authors.lastname: Tamez
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Camargo
authors.forename: H Phillip
authors.initials: HP
authors.lastname: Koeffler
authors.forename: Ravi
authors.initials: R
authors.lastname: Thadhani
mesh_terms: D000368:Aged; D023181:Antimicrobial Cationic Peptides / Q000097:blood*; D016022:Case-Control Studies; D054804:Cathelicidins; D015331:Cohort Studies; D003141:Communicable Diseases / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D006435:Renal Dialysis / Q000009:adverse effects*; D012307:Risk Factors; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D; C104450:25-hydroxyvitamin D