HLA-DRB1*15:01 and multiple sclerosis: a female association?

Background: The association between multiple sclerosis (MS) and the HLA-DRB1*15: 01 haplotype has been proven to be strong, but its molecular basis remains unclear. Vitamin D receptor (VDR) gene variants and sex have been proposed to modulate this association. Objectives: 1) Test the association of...

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Bibliographic Details
Authors: Irizar, Haritz, Muñoz Culla, Maider, Zuriarrain, Olaia, Goyenechea Soto, Estibaliz, Castillo Triviño, Tamara, Prada, Alvaro, Sáenz Cuesta, Matías, De Juan, Dolores, López de Munain Arregui, Adolfo José, Olascoaga, Javier, Otaegui Bichot, David
Format: article
Publication Date:2011
Country:España
Institution:Universidad del País Vasco
Repository:Addi. Archivo Digital para la Docencia y la Investigación
OAI Identifier:oai:addi.ehu.eus:10810/65045
Online Access:http://hdl.handle.net/10810/65045
Access Level:Open access
Keyword:HLA-DRB1*15:01
HLA II gene expression
multiple sclerosis
sex
VDR
Description
Summary:Background: The association between multiple sclerosis (MS) and the HLA-DRB1*15: 01 haplotype has been proven to be strong, but its molecular basis remains unclear. Vitamin D receptor (VDR) gene variants and sex have been proposed to modulate this association. Objectives: 1) Test the association of MS with *15:01 and VDR variants; 2) check whether VDR variants and/or sex modulate the risk conferred by *15:01; 3) study whether *15:01, VDR variants and/or sex affect HLA II gene expression. Methods: Peripheral blood from 364 MS patients and 513 healthy controls was obtained and DNA and total RNA were extracted from leukocytes. HLA-DRB1, DRB5 and DQA1 gene expression measurements and *15:01 genotyping were performed by qPCR. VDR variants were genotyped by PCR-RFLP. Results: Our data confirms that the *15:01 haplotype confers a higher risk of suffering from MS (OR = 1.364; 95% CI = 1.107-1.681). No association was found between VDR variants and MS, but they were shown to moderately modulate the risk conferred by *15:01. Sex confers a much stronger modulation and the *15:01-MS association seems to be female specific. A higher *15:01 frequency has been observed in Basques (45.1%). *15:01 positive samples showed a significant overexpression of DRB1 (p < 0.001), DRB5 (p < 0.001) and DQA1 (p = 0.004) in patients. DRB1 (p = 0.004) and DRB5 (p < 0.001) were also overexpressed in *15:01 controls. Conclusions: We confirm the *15:01-MS association and support that it is female specific. The relevance of ethnic origin on association studies has also been highlighted. HLA-DRB1*15:01 seems to be a haplotype consistently linked to high HLA II gene expression.