title: Is interleukin-6 -174 genotype associated with the development of septicemia in preterm infants?
abstract: OBJECTIVE
  Systemic infection affects one quarter of preterm infants. Defense from infection is in part mediated by the cytokine interleukin-6 (IL-6). We tested the hypothesis that the IL-6 -174 GG genotype, associated with lower IL-6 response to inflammation, is also associated with the development of septicemia in preterm infants.
  
  
  METHODS
  The study group comprised 157 infants who were born at < or =32 weeks. Genotype distribution (34% [54] GG, 46% [72] GC, 20% [31] CC) and C allele frequency (0.43; 95% confidence interval [CI]: 0.37-0.48) were similar to the UK adult population. Among the patients who developed bacterially confirmed septicemia (n = 51 [33%]), there was a significantly higher prevalence of the IL-6 -174 GG genotype than that observed in those who did not develop infection (47% vs 28% for GG: odds ratio [OR]: 2.3; 95% CI: 1.1-4.5). This association remained statistically significant (OR: 2.7; 95% CI: 1.2-6.3) after multiple binary logistic regression adjustment for other significant predictors of the development of septicemia. Late infection alone was similarly associated with GG genotype (septicemia 47% vs no septicemia 29% for GG: OR: 2.2; 95% CI: 1.1-4.3).
  
  
  CONCLUSIONS
  Variation in the IL-6 gene seems to influence the defense against bacterial pathogens in the very preterm infant.
authors.affiliation: Department of Child Health, University of Bristol, Bristol, United Kingdom. david.harding@bristol.ac.uk
authors.forename: David
authors.initials: D
authors.lastname: Harding
authors.forename: Sukhbir
authors.initials: S
authors.lastname: Dhamrait
authors.forename: Ann
authors.initials: A
authors.lastname: Millar
authors.forename: Steve
authors.initials: S
authors.lastname: Humphries
authors.forename: Neil
authors.initials: N
authors.lastname: Marlow
authors.forename: Andrew
authors.initials: A
authors.lastname: Whitelaw
authors.forename: Hugh
authors.initials: H
authors.lastname: Montgomery
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D015331:Cohort Studies; D004200:Diseases in Twins / Q000453:epidemiology; D004739:England / Q000453:epidemiology; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D015850:Interleukin-6 / Q000235:genetics / Q000502:physiology*; D008297:Male; D020125:Mutation, Missense; D017354:Point Mutation; D011446:Prospective Studies; D018805:Sepsis / Q000453:epidemiology / Q000235:genetics*; D016037:Single-Blind Method
chemical_list: D015850:Interleukin-6