title: Significant associations of HLA-B*5101 and B*5108, and lack of association of class II alleles with Behçet's disease in Italian patients.
abstract: Behçet's disease has been known to be strongly associated with human leukocyte antigen (HLA) B51, one of the split antigens of HLA-B5. An increased incidence of HLA-B51 in the patient group has also been reported in an Italian population. 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. In addition, HLA class II genotyping was performed by the PCR-restriction fragment length polymorphism (RFLP) method. As a result, only the phenotype frequency of the B51 antigen was found to be significantly increased in the patient group as compared to the ethnically matched control group by the corrected P-value analysis (71.4% in patients vs. 17.9% in controls; chi2 = 14.26, Pc = 0.0042, R.R. = 11.5). In the B51 allele genotyping, 11 out of 15 B51-positive patients were B*5101 and the remaining four were B*5108, whereas all of 5 normal controls were B*5101, showing significant association of each allele with Behçet's disease. No significant difference was observed between the patient and control groups in the HLA class II allelic distribution. This study revealed a strong association of Behçet's disease in Italian with B*5108 as well as B*5101, providing important insight into the molecular mechanism underlying an HLA association with Behçet's disease.
authors.affiliation: Department of Genetic Information, Tokai University School of Medicine, Bohseidai, Isehara, Kanagawa, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Kera
authors.forename: N
authors.initials: N
authors.lastname: Mizuki
authors.forename: M
authors.initials: M
authors.lastname: Ota
authors.forename: Y
authors.initials: Y
authors.lastname: Katsuyama
authors.forename: P
authors.initials: P
authors.lastname: Pivetti-Pezzi
authors.forename: S
authors.initials: S
authors.lastname: Ohno
authors.forename: H
authors.initials: H
authors.lastname: Inoko
mesh_terms: D000483:Alleles; D001528:Behcet Syndrome / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D005819:Genetic Markers; D015235:HLA-B Antigens / Q000235:genetics*; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D007558:Italy / Q000453:epidemiology
chemical_list: D005819:Genetic Markers; D015235:HLA-B Antigens; D000949:Histocompatibility Antigens Class II