title: Positive correlation between circulating cathelicidin antimicrobial peptide (hCAP18/LL-37) and 25-hydroxyvitamin D levels in healthy adults.
abstract: BACKGROUND
  Transcription of the cathelicidin antimicrobial peptide (CAMP) gene is induced by binding of the bioactive form of vitamin D, 1,25-dihydroxyvitamin D, to the vitamin D receptor. Significant levels of the protein hCAP18/LL-37 are found in the blood and may protect against infection and/or sepsis. We hypothesized that serum vitamin D levels may modulate the circulating levels of hCAP18. Only three studies have shown a positive correlation between circulating 25-hydroxyvitamin D and hCAP18 levels. Here we provide additional evidence for such a correlation in healthy, middle-aged adults.
  
  
  RESULTS
  Serum levels of 25-hydroxyvitamin D [25(OH)D] and plasma levels of hCAP18 were determined in 19 healthy middle-aged (mean of 50.1 years) adult men and women. Plasma hCAP18 concentrations correlated with serum 25(OH)D concentrations in subjects with 25(OH)D levels ≤ 32 ng/ml (r = 0.81, p < 0.005) but not in subjects with concentrations > 32 ng/ml (r = 0.19, p = 0.63).
  
  
  CONCLUSIONS
  We conclude that plasma hCAP18 levels correlate with serum 25(OH)D levels in subjects with concentrations of 25(OH)D ≤ 32 ng/ml as opposed to those with concentrations > 32 ng/ml and that vitamin D status may regulate systemic levels of hCAP18/LL-37.
authors.affiliation: USANA Health Sciences, Inc, 3838 West Parkway Boulevard, Salt Lake City UT 84120, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Dixon
authors.forename: Tyler
authors.initials: T
authors.lastname: Barker
authors.forename: Toni
authors.initials: T
authors.lastname: McKinnon
authors.forename: John
authors.initials: J
authors.lastname: Cuomo
authors.forename: Balz
authors.initials: B
authors.lastname: Frei
authors.forename: Niels
authors.initials: N
authors.lastname: Borregaard
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Gombart
mesh_terms: D000328:Adult; D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; D014807:Vitamin D; C104450:25-hydroxyvitamin D