title: Melanocortin-1 Receptor Polymorphisms and the Risk of Complicated Sepsis After Trauma: A Candidate Gene Association Study.
abstract: The aim of the study was to determine if melanocortin-1 receptor (MC1R) single nucleotide polymorphisms (SNPs) are associated with complicated sepsis after trauma.
  
  
  
  Nosocomial infections are an important cause of morbidity and mortality after trauma. Several SNPs in inflammation-related genes have been associated with sepsis. MC1R is an anti-inflammatory mediator that may be involved in the immune response after trauma.
  
  
  
  We genotyped eight common MC1R SNPs in genomic DNA from subjects enrolled in a previously reported prospective cohort study. Subjects were adult trauma patients admitted to the intensive care unit at a Level 1 trauma center (2003-2005).
  
  
  
  A total of 1,246 subjects were included in the analysis. The majority were male (70%), severely injured (81%), and injured by a blunt mechanism (89%). Forty percent developed sepsis, and 23% developed complicated sepsis, which was defined as sepsis with organ dysfunction. In logistic regression analysis, with adjustments for age, sex, body mass index, injury severity score, red blood cell transfusion requirement, and mechanism of injury, the MC1RR163Q variant (rs885479) was associated with a lower risk of developing complicated sepsis (adjusted odds ratio [ORadj] = 0.48, 95% confidence interval [CI]: 0.28-0.81, P = 0.006). In a subgroup of 511 subjects with genome-wide SNP data, the association between the MC1RR163Q variant and complicated sepsis remained significant after adjusting for genetic substructure (by principal components) and the above clinical factors (ORadj = 0.30, 95% CI: 0.13-0.70, P = 0.005).
  
  
  
  MC1RR163Q is associated with a lower risk of complicated sepsis after trauma. Therapeutic targeting of MC1R may be beneficial for trauma patients at risk for complicated sepsis.
authors.affiliation: *Harborview Department of Surgery, University of Washington Medical Center, Seattle, Washington†Department of Surgery, University of Maryland Medical Center, Baltimore, Maryland‡Harborview Department of Medicine, University of Washington Medical Center, Seattle, Washington.
authors.forename: Max E
authors.initials: ME
authors.lastname: Seaton
authors.forename: Brodie A
authors.initials: BA
authors.lastname: Parent
authors.forename: Ravi F
authors.initials: RF
authors.lastname: Sood
authors.forename: Mark M
authors.initials: MM
authors.lastname: Wurfel
authors.forename: Lara A
authors.initials: LA
authors.lastname: Muffley
authors.forename: Grant E
authors.initials: GE
authors.lastname: O'Keefe
authors.forename: Nicole S
authors.initials: NS
authors.lastname: Gibran
mesh_terms: D000328:Adult; D003428:Cross Infection; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D025341:Principal Component Analysis; D011446:Prospective Studies; D044102:Receptor, Melanocortin, Type 1 / Q000235:genetics*; D012189:Retrospective Studies; D018805:Sepsis / Q000209:etiology / Q000235:genetics*; D014947:Wounds and Injuries / Q000150:complications / Q000235:genetics*; D055815:Young Adult
chemical_list: D044102:Receptor, Melanocortin, Type 1