HLA-DPB1*03 as Risk Allele and HLA-DPB1*04 as Protective Allele for Both Early- and Adult-Onset Multiple Sclerosis in a Hellenic Cohort

Background: Human Leucocyte Antigens (HLA) represent the genetic loci most strongly linked to Multiple Sclerosis (MS). Apart fromHLA-DRandHLA-DQ,HLA-DPalleles have been previously studied regarding their role in MS pathogenesis, but to a much lesser extent. Our objective was to investigate the risk/resistance influence ofHLA-DPB1alleles in Hellenic patients with early- and adult-onset MS (EOMS/AOMS), and possible associations with theHLA-DRB1*15:01risk allele.Methods: One hundred MS-patients (28 EOMS, 72 AOMS) fulfilling the McDonald-2010 criteria were enrolled. HLA genotyping was performed with standard low-resolution Sequence-Specific Oligonucleotide techniques. Demographics, clinical and laboratory data were statistically processed using well-defined parametric and nonparametric methods and the SPSSv22.0 software.Results: No significantHLA-DPB1differences were found between EOMS and AOMS patients for 23 distinctHLA-DPB1and 12HLA-DRB1alleles. TheHLA-DPB1*03allele frequency was found to be significantly increased, and theHLA-DPB1*02allele frequency significantly decreased, in AOMS patients compared to controls. TheHLA-DPB1*04allele was to be found significantly decreased in AOMS and EOMS patients compared to controls.Conclusions: Our study supports the previously reported risk susceptibility role of theHLA-DPB1*03allele in AOMS among Caucasians. Additionally, we report for the first time a protective role of theHLA-DPB1*04allele among Hellenic patients with both EOMS and AOMS.