title: Host risk factors for the development of reactive arthritis: a family study.
abstract: OBJECTIVE
  To determine if the same arthritogenic microorganisms can trigger reactive arthritis (ReA) in both HLA-B27 positive and HLA-B27 negative individuals. To determine risk factors (other than HLA-B27) for the development of ReA.
  
  
  METHODS
  Following a common food source outbreak of Salmonella enteritidis, 2 family groups of individuals with dysentery and new onset ReA signs and symptoms were identified. HLA typing was performed for all family members exposed to the dysenteric organism.
  
  
  RESULTS
  ReA occurred in HLA-B27 positive members of Family A. No member of Family B possessed HLA-B27 or CREG phenotype, but 3 members developed ReA. The HLA identical sibling of the proband in Family B developed dysentery but did not develop ReA.
  
  
  CONCLUSIONS
  In this epidemic, interaction of the microorganism with an HLA-B27 positive host predictably produced ReA but B27 was not necessary to produce it in other dysenteric patients. Host factors including amount of ingested microorganisms, age and sex but excluding HLA type may account for the differential development of ReA in the siblings in Family B.
authors.affiliation: Department of Medicine, St. Boniface Hospital, Winnipeg, Canada.
authors.forename: G T
authors.initials: GT
authors.lastname: Thomson
authors.forename: A
authors.initials: A
authors.lastname: Minenko
authors.forename: M L
authors.initials: ML
authors.lastname: Schroeder
mesh_terms: D001170:Arthritis, Infectious / Q000235:genetics* / Q000276:immunology*; D003429:Cross Reactions; D004196:Disease Outbreaks; D005260:Female; D015796:HLA-B27 Antigen / Q000032:analysis / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D006801:Humans; D008297:Male; D010375:Pedigree; D000091402:Prohibitins; D012307:Risk Factors; D012480:Salmonella Infections / Q000453:epidemiology
chemical_list: D015796:HLA-B27 Antigen; D015395:Histocompatibility Antigens Class I; C000717331:PHB2 protein, human; D000091402:Prohibitins