title: HLA-A*9, a probable secondary susceptibility marker to ankylosing spondylitis in Basque patients.
abstract: HLA-B27 is strongly associated to ankylosing spondylitis (AS). The objective of our study was to analyze HLA-B27 association, B27 subtype distribution and frequency of other HLA class I and DR antigens in a group of Basque AS patients. HLA class I antigens were typed serologically and HLA-B27 and A9 subtypes were determined by DNA typing in samples from 46 patients with AS, 54 B27-positive spondyloarthropathies, 82 healthy subjects and 20 B27-positive controls. A class I HLA 9.2 kb PvuII restriction fragment length polymorphism (RFLP), previously associated with AS, was analyzed in a representative group of patients and controls. We found that HLA-B*2705 conferred a relative risk of 126 for AS in this group. HLA-A9 (A*2402) allele was significantly increased in AS patients compared with healthy controls and B27-positive control group (Pcorr<0.0001) and also increased in patients affected with peripheral arthritis. No association between class I HLA 9.2 Kb RFLP and AS was found. These results suggest that HLA-A*9 allele itself or another linked gene could act as a secondary and independent susceptibility allele to AS.
authors: Immunology Section, Hospital Ntra Sra. de Anánzazu, San Sebastian, Guipúzcoa, Spain.
authors: M D
authors: MD
authors: de Juan
authors: A
authors: A
authors: Reta
authors: J
authors: J
authors: Cancio
authors: J
authors: J
authors: Belzunegui
authors: E
authors: E
authors: Cuadrado
mesh_terms: D000483:Alleles; D015415:Biomarkers; D015252:Deoxyribonucleases, Type II Site-Specific; D004198:Disease Susceptibility; D005260:Female; D015234:HLA-A Antigens / Q000235:genetics*; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D000949:Histocompatibility Antigens Class II / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D013030:Spain; D013167:Spondylitis, Ankylosing / Q000235:genetics*
chemical_list: D015415:Biomarkers; D015234:HLA-A Antigens; C037709:HLA-A9 antigen; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; C025630:CAGCTG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific