A subgroup analysis arranged by the geographical regions showed HLA-A*26 is in fact associated with the onset of BD in Northeast Asia (OR = 2.11, 95% CI: 1.75-2.56), but not in the Middle East or in Europe.
HLA-A*29 and HLA-B*51 are associated with birdshot uveitis and Behçet's disease, respectively, and are used as a diagnostic criterion in patients with suspected disease, requiring their detection in diagnostic laboratories.
Our results confirm HLA-B*51 as a primary-association marker in predisposition to BD and suggest additional independent signals within the class I region, specifically in the genes HLA-A and HLA-B.
SNP mapping with logistic regression of the MHC identified the HLA-B/MICA region and the region between HLA-F and HLA-A as independently associated with BD (P < 1.7 × 10(-8)).
This GWAS highlights the premier genetic susceptibility locus for BD as the major histocompatibility complex itself, wherein reside two independent loci: HLA-B and HLA-A.
The significant increase of HLA-A*2602 and B*3901 in the patient group without HLA-B*51 suggests that these two alleles might also have some secondary influence on the onset of BD.
Since the B51 antigen has been recently identified to comprise nine alleles, B*5101-B*5109, we performed HLA-B51 allele genotyping by the polymerase chain reaction-sequencing based typing (PCR-SBT) method as well as serological HLA-A and -B typing among 21 Italian patients with Behçet's disease in order to investigate whether there is any correlation of one particular B51-associated allele with Behcet's disease.
Seventy-one Turkish patients with BD, diagnosed according to the International Study Group for Behçet's Disease criteria, were studied and compared with 600 healthy controls to determine not only frequencies of HLA-A, B, and DR antigens but also whether BD shows any distinct linkage disequilibrium (LD) patterns.
Ninety Japanese patients with Behçet's disease (BD) were typed for human leukocyte antigen (HLA)-DRB1, -DQA1-, -DQB1, and -DPB1 alleles by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and for HLA-A, -B, -C, -DR, and -DQ antigens by conventional serologic typing.
Frequency of HLA-A, B, and C antigens was studied in 184 patients with Behçet's disease to investigate the immunogenetically determined predisposition to this disease.