title: Alterations in vitamin D status and anti-microbial peptide levels in patients in the intensive care unit with sepsis.
abstract: BACKGROUND
  Vitamin D insufficiency is common in hospitalized patients. Recent evidence suggests that vitamin D may enhance the innate immune response by induction of cathelicidin (LL-37), an endogenous antimicrobial peptide produced by macrophages and neutrophils. Thus, the relationship between vitamin D status and LL-37 production may be of importance for host immunity, but little data is available on this subject, especially in the setting of human sepsis syndrome and other critical illness.
  
  
  METHODS
  Plasma concentrations of 25-hydroxyvitamin D (25(OH)D), vitamin D binding protein (DBP) and LL-37 in critically ill adult subjects admitted to intensive care units (ICUs) with sepsis and without sepsis were compared to healthy controls.
  
  
  RESULTS
  Critically ill subjects had significantly lower plasma 25(OH)D concentrations compared to healthy controls. Mean plasma LL-37 levels were significantly lower in critically ill subjects compared to healthy controls. Vitamin D binding protein levels in plasma were significantly lower in critically ill subjects with sepsis compared to critically ill subjects without sepsis. There was a significant positive association between circulating 25(OH)D and LL-37 levels.
  
  
  CONCLUSIONS
  This study demonstrates an association between critical illness and lower 25(OH)D and DBP levels in critically ill patients as compared to healthy controls. It also establishes a positive association between vitamin D status and plasma LL-37, which suggests that systemic LL-37 levels may be regulated by vitamin D status. Optimal vitamin D status may be important for innate immunity especially in the setting of sepsis. Further invention studies to examine this association are warranted.
authors.affiliation: Division of Endocrinology, Diabetes & Lipids, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA. jengleo@gmail.com
authors.forename: Leo
authors.initials: L
authors.lastname: Jeng
authors.forename: Alexandra V
authors.initials: AV
authors.lastname: Yamshchikov
authors.forename: Suzanne E
authors.initials: SE
authors.lastname: Judd
authors.forename: Henry M
authors.initials: HM
authors.lastname: Blumberg
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Martin
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Ziegler
authors.forename: Vin
authors.initials: V
authors.lastname: Tangpricha
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000097:blood; D016022:Case-Control Studies; D054804:Cathelicidins / Q000097:blood*; D016638:Critical Illness; D003710:Demography; D005260:Female; D006262:Health; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D018805:Sepsis / Q000097:blood*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood*; D014809:Vitamin D-Binding Protein / Q000097:blood
chemical_list: D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; D014809:Vitamin D-Binding Protein; D014807:Vitamin D; C104450:25-hydroxyvitamin D