title: Interferon-gamma gene microsatellite polymorphisms in patients with biopsy-proven giant cell arteritis and isolated polymyalgia rheumatica.
abstract: OBJECTIVE
  Inflammatory cytokines are implicated in the pathogenesis of giant cell arteritis (GCA) and polymyalgia rheumatica (PMR). In this study we have examined the potential association of a CA repeat polymorphism in the first intron of the interferon gamma (IFN-gamma) gene with disease susceptibility and clinical expression of these conditions.
  
  
  METHODS
  Seventy-nine patients with isolated PMR, 59 biopsy-proven GCA patients and 129 ethnically matched controls from Lugo (NW Spain) were studied. Patients and controls were genotyped by molecular methods for the microsatellite dinucleotide (CA) repeat within the first intron of IFN-gamma gene.
  
  
  RESULTS
  No significant differences in the distribution of alleles for the IFN-gamma gene polymorphism between GCA and isolated PMR patients and controls were found. However, the frequency of IFN-gamma allele *4 (128 bp) was reduced in GCA patients (33.1%) compared with isolated PMR patients (46.2%). Also, GCA patients with visual ischemic manifestations exhibited a significantly reduced frequency of IFN-gamma allele *4 compared with those without visual manifestations (17.9% versus 42.5%; p = 0.05 [OR: 0.36, 95% CI: 0.13-1.00]). Moreover, allele *3 (126 bp) was over-represented in the GCA patients with visual ischemic manifestations (71.4% versus 44.4% in the remaining GCA patients; p = 0.01 [OR = 3.13, 95% CI: 1.27-7.68]).
  
  
  CONCLUSIONS
  In GCA, IFN-gamma functional polymorphisms are associated with clinical manifestations of severity rather than susceptibility to this vasculitis.
authors.affiliation: Division of Rheumatology, Hospital Xeral-Calde, Lugo, Spain. miguelaggay@hotmail.com
authors.forename: M A
authors.initials: MA
authors.lastname: Gonzalez-Gay
authors.forename: A H
authors.initials: AH
authors.lastname: Hajeer
authors.forename: A
authors.initials: A
authors.lastname: Dababneh
authors.forename: C
authors.initials: C
authors.lastname: Garcia-Porrua
authors.forename: M M
authors.initials: MM
authors.lastname: Amoli
authors.forename: J
authors.initials: J
authors.lastname: Llorca
authors.forename: W E R
authors.initials: WE
authors.lastname: Ollier
mesh_terms: D001706:Biopsy; D020022:Genetic Predisposition to Disease; D013700:Giant Cell Arteritis / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics*; D011110:Polymorphism, Genetic; D011111:Polymyalgia Rheumatica / Q000235:genetics* / Q000473:pathology
chemical_list: D007371:Interferon-gamma