title: IL-1RN gene polymorphism is associated with peri-implantitis.
abstract: OBJECTIVE
  Interleukin (IL)-1alpha, IL-1beta and their natural specific inhibitor IL-1 receptor antagonist (IL-1ra) play a key role in the regulation of the inflammatory response in periodontal tissues. Polymorphisms in the IL-1 gene cluster have been associated with severe adult periodontitis. We aimed to investigate the IL-1 gene cluster polymorphisms in patients with peri-implantitis.
  
  
  METHODS
  The study included 120 North Caucasian individuals. A total of 71 patients (mean age 68 years, 76% smokers) demonstrating peri-implantitis at one or more implants as evidenced by bleeding and/or pus on probing and bone loss amounting to >3 threads on Brånemark implants and 49 controls (mean age 66 years, 45% smokers) with clinical healthy mucosa and no bone loss around the implants were recruited for the study. The titanium implants, ad modum Brånemark, had been in function for at least 2 years. Mouthwash samples were collected and used for genotyping of the bi-allelic polymorphisms IL-1A(-889), IL-1B(+3953), IL-1B(-511) and a variable number of tandem repeat IL-1RN gene polymorphisms using PCR technique.
  
  
  RESULTS
  Significant differences were found in the carriage rate of allele 2 in the IL-1RN gene between peri-implantitis patients and controls (56.5% vs. 33.3%, respectively; odds ratios (OR) 2.6; 95% confidence interval (CI) 1.2-5.6; P=0.015). Logistic regression analysis taking smoking, gender and age into account confirmed the association between the IL-1RN allele 2 carriers and peri-implantitis (OR 3; 95% CI 1.2-7.6; P=0.02).
  
  
  CONCLUSIONS
  Our results provide evidence that IL-1RN gene polymorphism is associated with peri-implantitis and may represent a risk factor for this disease.
authors.affiliation: Department of Oral Microbiology, ACTA Amsterdam, Amsterdam, The Netherlands.
authors.forename: Marja L
authors.initials: ML
authors.lastname: Laine
authors.forename: Asa
authors.initials: A
authors.lastname: Leonhardt
authors.forename: Ann-Marie
authors.initials: AM
authors.lastname: Roos-Jansåker
authors.forename: A Salvador
authors.initials: AS
authors.lastname: Peña
authors.forename: Arie Jan
authors.initials: AJ
authors.lastname: van Winkelhoff
authors.forename: Edwin G
authors.initials: EG
authors.lastname: Winkel
authors.forename: Stefan
authors.initials: S
authors.lastname: Renvert
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D015921:Dental Implants; D004812:Epidemiologic Methods; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010510:Periodontal Diseases / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects
chemical_list: D015921:Dental Implants; D007375:Interleukin-1