title: Association of HLA loci alleles and antigens in Saudi patients with vitiligo.
abstract: HLA complex is composed of several closely linked loci, each containing several alleles, yielding a high expression of polymorphism. Vitiligo, a commonly acquired dermatological disorder, has been associated with different HLA antigens in different ethnic groups. In this study, HLA classes I (HLA-A, B, and C) and II (HLA-DR, DQ) antigens/alleles were analyzed in a group of 80 Saudi subjects consisting of vitiligo patients (40) and matched controls (40). The frequency of antigens of various HLA loci was tested using two-stage microcytotoxicity assays, while the frequency of alleles of HLA-DR was screened by polymerase chain reaction/sequence specific primers (PCR/SSP) method. The frequencies of HLA-B7, B15, Bw6, Cw6, Cw7, and DRB4*010101 were found to be significantly higher in vitiligo patients compared to controls [P = 0.029, 0.015, 0.033, 0.009, 0.043, and 0.015, respectively, with relative risk (RR) > or = 3, etiologic fraction (EF) > or = 0.4]. On the other hand, HLA-A9, B5, DQ1, and DRB3*010101 were significantly decreased in vitiligo patients compared to healthy Saudis [P = 0.008, 0.004, 0.028, and 0.04, respectively, with RR < 1 and preventive fraction (PF) < 0.5]. Among the patients, the highest allele frequency was noted for DRB4*010101(70%), while in controls it was for DRB3*010101 (72.5%). These results for antigens and allele frequency of various HLA Loci in vitiligo patients and control subjects suggested that HLA-B7, Bw6, Cw6, Cw7, and DRB4*010101 could be susceptible to vitiligo, while HLA-A9, B5, DQ1, and DRB3*010101 might be negatively associated with the development of vitiligo in Saudis.
authors.affiliation: Department of Dermatology, Armed Forces Hospital, Riyadh 11159, Saudi Arabia.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Abanmi
authors.forename: Fahad
authors.initials: F
authors.lastname: Al Harthi
authors.forename: Riyadh
authors.initials: R
authors.lastname: Al Baqami
authors.forename: Saleh
authors.initials: S
authors.lastname: Al Assaf
authors.forename: Abdulrahman
authors.initials: A
authors.lastname: Zouman
authors.forename: Misbahul
authors.initials: M
authors.lastname: Arfin
authors.forename: Mohammad
authors.initials: M
authors.lastname: Tariq
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D015235:HLA-B Antigens / Q000235:genetics; D059910:HLA-B15 Antigen; D015793:HLA-B7 Antigen / Q000235:genetics; D015236:HLA-C Antigens / Q000235:genetics; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012529:Saudi Arabia; D014820:Vitiligo / Q000208:ethnology / Q000235:genetics / Q000276:immunology*
chemical_list: D015235:HLA-B Antigens; D059910:HLA-B15 Antigen; D015793:HLA-B7 Antigen; C038652:HLA-Bw6 antigen; D015236:HLA-C Antigens; C528994:HLA-C*06 antigen; C040178:HLA-C*70 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C487016:HLA-DRB4*01:01 antigen; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II