HLA and non-HLA genes in Behcet s disease: a multicentric study in the Spanish population
Agradecer como siempre la inestimable ayuda, colaboración y trabajo de los doctores Norberto Ortego y Genaro Graña, tanto por su dedicación a la enfermedad como por su trato hacia la Asociación.
Marco Antonio Montes-Cano, Marta Conde-Jaldón, José Raul García-Lozano, Lourdes Ortiz-Fernández, Norberto Ortego-Centeno, María Jesús Castillo-Palma, Gerard Espinosa, Genaro Graña-Gil, Miguel Angel González-Gay, Ana Celia Barnosi-Marín, Roser Solans, Patricia Fanlo, Teresa Camps, Santos Castañeda, Juan Sánchez-Bursón, Antonio Núñez-Roldán, Javier Martín and María Francisca González-Escribano
According to genome wide association (GWA) studies as well as candidate gene approaches, Behcet s disease (BD) is associated with human leukocyte antigen (HLA)-A and HLA-B gene regions. The HLA-B51 has been consistently associated with the disease, but the role of other HLA class I molecules remains controversial. Recently, variants in non-HLA genes have also been associated with BD. The aims of this study were to further investigate the influence of the HLA region in BD and to explore the relationship with non-HLA genes recently described to be associated in other populations.
This study included 304 BD patients and 313 ethnically matched controls. HLA-A and HLA-B low resolution typing was carried out by PCR-SSOP Luminex. Eleven tag single nucleotide polymorphisms (SNPs) located outside of the HLA-region, previously described associated with the disease in GWA studies and having a minor allele frequency in Caucasians greater than 0.15 were genotyped using TaqMan assays. Phenotypic and genotypic frequencies were estimated by direct counting and distributions were compared using the chi2 test.
In addition to HLA-B*51, HLA-B*57 was found as a risk factor in BD, whereas, B*35 was found to be protective. Other HLA-A and B specificities were suggestive of association with the disease as risk (A*02 and A*24) or protective factors (A*03 and B*5
. Regarding the non-HLA genes, the three SNPs located in IL23R and one of the SNPs in IL10 were found to be significantly associated with susceptibility to BD in our population.
Different HLA specificities are associated with Behcet disease in addition to B*51. Other non-HLA genes, such as IL23R and IL-10, play a role in the susceptibility to the disease.