title: Association of HLA-DR5 (DR11) with systemic sclerosis (scleroderma) in Mexican patients.
abstract: OBJECTIVE
  To study the association between Major Histocompatibility Complex (MHC) haplotypes and systemic sclerosis (SSc) in Mexican mestizo patients.
  
  
  METHODS
  Class I, II and III MHC antigens were determined in 41 Mexican mestizo patients with SSc, 113 of their first degree relatives, and 85 ethnically matched controls. The significance of differences between patients and controls was tested by chi-square analysis with Yates' correction.
  
  
  RESULTS
  Frequencies of HLA-DR5 and HLA-DRw52 were found to be higher in SSc patients compared to ethnically matched healthy controls (p = 0.007, RR = 3.31; 95% confidence interval: 1.3-8.3 and p = 0.04, RR = 2.4; 95% confidence interval: 1.0-5.7, respectively). Sequence-specific oligotyping in DR5 positive individuals showed that 10 out of 41 patients had the DRB1*1104 subtype (24.3%) as compared to only 6 of the 85 healthy controls (7.0%) (p = 0.01, RR = 4.25). Subdividing patients according to their clinical features showed a significant increase of HLA-DR5 in diffuse (p = 0.013, RR = 3.89, 95% confidence interval: 1.27-12.0) and limited scleroderma (p = 0.0008), but not in the CREST syndrome. Segregation analysis obtained from the families showed that in the patients, DR5 was mostly part of the [HLAB35;DR5] haplotype as opposed to healthy controls.
  
  
  CONCLUSIONS
  These data support the role of DR5 (DRB1*1104) in the genetic susceptibility to develop scleroderma in Mexican patients and also sustain the notion of genetically determined clinical subgroups of SSc.
authors.affiliation: Department of Immunology and Rheumatology, Instituto Nacional de la Nutrición Salvador Zubirán, Mexico City, Mexico.
authors.forename: G
authors.initials: G
authors.lastname: Vargas-Alarcón
authors.forename: J
authors.initials: J
authors.lastname: Granados
authors.forename: G
authors.initials: G
authors.lastname: Ibañez de Kasep
authors.forename: J
authors.initials: J
authors.lastname: Alcocer-Varela
authors.forename: D
authors.initials: D
authors.lastname: Alarcón-Segovia
mesh_terms: D001483:Base Sequence; D006683:HLA-DQ Antigens / Q000235:genetics; D006684:HLA-DR Antigens / Q000235:genetics; D015805:HLA-DR5 Antigen / Q000032:analysis*; D006239:Haplotypes; D006801:Humans; D008800:Mexico / Q000208:ethnology; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes / Q000235:genetics; D010641:Phenotype; D012595:Scleroderma, Systemic / Q000208:ethnology* / Q000235:genetics / Q000276:immunology*
chemical_list: D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D015805:HLA-DR5 Antigen; D015345:Oligonucleotide Probes