title: Behçet's disease in HLA-B*51 negative Germans and Turks shows association with HLA-Bw4-80I.
abstract: BACKGROUND
  Behçet's disease (BD) as systemic vasculitis of unknown etiology is associated with HLA-B*51 in European and Asian populations. HLA-A*26 was claimed as an additional BD susceptibility marker in Japanese and Greek patients. This study was performed to test for HLA associations in HLA-B*51 negative German and Turkish BD populations.
  
  
  METHODS
  In total, 65 German and 46 Turkish patients lacking HLA-B*51 were analyzed in comparison to healthy HLA-B*51 negative Germans (n = 1500) and Turks (n = 130). HLA-A/B genotypes were determined by SSOP. P-values with correction for multiple testing (p(c)), χ2-test and odds ratio (OR) were used for statistical evaluation.
  
  
  RESULTS
  HLA-A*26 was significantly more frequent in HLA-B*51- German patients [p(c) = 0.0076, OR = 3.23, 95% CI 1.63 to 6.39] than in respective controls. HLA-A*26 was also elevated in a smaller group of Turkish patients versus the controls. Significant association of HLA-Bw4 with isoleucine at amino-acid position 80 (HLA-Bw4-80I) was found in the HLA-B*51(-) German cohort of BD patients [p(c) = 0.0042, OR = 2.35, 95% CI 1.41 to 3.93) and in the Turkish patients in comparison to the respective controls [p = 0.025, OR = 2.17, 95% CI 1.09 to 4.31]. On the contrary, HLA-Bw4-80 T was reduced in both HLA-B*51(-) BD patient cohorts.
  
  
  CONCLUSIONS
  The study shows a significant association of HLA-Bw4-80I present on HLA-B*51 as well as on other B-locus molecules with BD. This indicates that distinctive Bw4 epitopes on HLA-B locus molecules could play a role in BD pathogenesis. The study also indicates an association with HLA-A*26 in German and Turkish BD patients as a genetic risk factor independent of HLA-B*51.
authors.forename: Alexandr Borisovich
authors.initials: AB
authors.lastname: Kuranov
authors.forename: Ina
authors.initials: I
authors.lastname: Kötter
authors.forename: Jörg Christoph
authors.initials: JC
authors.lastname: Henes
authors.forename: Saule Tleubaevna
authors.initials: ST
authors.lastname: Abisheva
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Steiert
authors.forename: Florian
authors.initials: F
authors.lastname: Riewerts
authors.forename: Kuvat Temirgalievich
authors.initials: KT
authors.lastname: Momynaliev
authors.forename: Claudia Anna
authors.initials: CA
authors.lastname: Müller
mesh_terms: D000483:Alleles; D001528:Behcet Syndrome / Q000235:genetics*; D016009:Chi-Square Distribution; D015331:Cohort Studies; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D005858:Germany; D015234:HLA-A Antigens / Q000235:genetics; D015235:HLA-B Antigens / Q000235:genetics*; D059949:HLA-B51 Antigen / Q000235:genetics*; D006801:Humans; D007532:Isoleucine / Q000235:genetics; D016017:Odds Ratio; D012307:Risk Factors; D014421:Turkey
chemical_list: D015234:HLA-A Antigens; C039683:HLA-A*26 antigen; D015235:HLA-B Antigens; D059949:HLA-B51 Antigen; C042388:HLA-Bw4 antigen; D007532:Isoleucine