title: The interaction between HLA shared epitope alleles and smoking and its contribution to autoimmunity against several citrullinated antigens.
abstract: OBJECTIVE
  Recent data suggest that a gene-environment interaction between smoking and the HLA shared epitope alleles plays a role in shaping the autoimmune reaction to specific citrullinated antigens. This study was undertaken to determine the effects of HLA shared epitope alleles and tobacco exposure on the immune response against various citrullinated antigens. These associations were analyzed in the anti-citrullinated protein antibody (ACPA)-positive stratum to control for the possibility that the associations found are explained by the known interaction between HLA shared epitope alleles and tobacco exposure on ACPA status.
  
  
  METHODS
  In 661 patients with rheumatoid arthritis, reactivity against several citrullinated antigens from vimentin, fibrinogen, enolase, and myelin basic protein was determined by enzyme-linked immunosorbent assay. The effects of the HLA shared epitope alleles and tobacco exposure were assessed by logistic regression analysis. Biologic interaction was analyzed by investigating whether the effects of the risk factors combined exhibited departure from additivity.
  
  
  RESULTS
  A significant interaction between tobacco exposure and HLA shared epitope alleles was found for the presence of ACPA as reported previously. When these interaction effects were studied for several ACPA "fine specificities," significant interactions were noted for several citrullinated peptides. However, these interactions were not present after stratification for ACPA status, indicating that the interaction between tobacco exposure and HLA shared epitope alleles influences autoimmunity not to specific citrullinated antigens, but rather to ACPA development.
  
  
  CONCLUSIONS
  Our data indicate that the gene-environment interaction between HLA shared epitope alleles and smoking does not appear to shape the reactivity of the ACPA response. These data suggest that smoking promotes nonspecific citrullination rather than citrullination of specific antigens.
authors.affiliation: Leiden University Medical Center, Leiden, The Netherlands. a.willemze@lumc.nl
authors.forename: Annemiek
authors.initials: A
authors.lastname: Willemze
authors.forename: Diane
authors.initials: D
authors.lastname: van der Woude
authors.forename: Wendimagegn
authors.initials: W
authors.lastname: Ghidey
authors.forename: E W Nivine
authors.initials: EW
authors.lastname: Levarht
authors.forename: Gerrie
authors.initials: G
authors.lastname: Stoeken-Rijsbergen
authors.forename: Willem
authors.initials: W
authors.lastname: Verduyn
authors.forename: René R P
authors.initials: RR
authors.lastname: de Vries
authors.forename: Jeanine J
authors.initials: JJ
authors.lastname: Houwing-Duistermaat
authors.forename: Tom W J
authors.initials: TW
authors.lastname: Huizinga
authors.forename: Leendert A
authors.initials: LA
authors.lastname: Trouw
authors.forename: René E M
authors.initials: RE
authors.lastname: Toes
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000276:immunology; D001323:Autoantibodies / Q000235:genetics* / Q000276:immunology; D015551:Autoimmunity / Q000235:genetics / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000235:genetics* / Q000276:immunology; D005260:Female; D020022:Genetic Predisposition to Disease; D006680:HLA Antigens / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007075:Immunoglobulin M / Q000235:genetics / Q000276:immunology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D012907:Smoking / Q000235:genetics* / Q000276:immunology
chemical_list: D001323:Autoantibodies; D000939:Epitopes; D006680:HLA Antigens; D007075:Immunoglobulin M