Association of the HLA-DRB1 alleles with characteristic MRI features of Asian multiple sclerosis

Background In Asian patients with multiple sclerosis ( MS), a paucity of brain lesions and longitudinally extensive spinal cord lesions (LESCLs) extending three or more vertebral segments are characteristic findings on magnetic resonance imaging (MRI). We aimed to disclose possible factors contributing to the development of such MRI features. Method Genotyping of HLA-DRB1 and -DPB1 alleles was performed in 121 consecutive Japanese patients with clinically definite MS based on the Poser criteria and 125 healthy controls. Possible factors associated with MRI features were determined by multiple logistic analysis. Patients with MS were classified based on the presence or absence of brain lesions fulfilling the Barkhof criteria (Barkhof brain lesions) and LESCLs. Barkhof brain lesion-negative (-) patients had a markedly lower frequency of HLA-DRB1*0901 than controls (P-corr < 0.05), whereas the frequency of DRB1*1501 was increased in the Barkhof brain lesion-positive (+) group, although this increase was not significant after correction. No Barkhof(-)LESCL(+) patients carried DRB1*0901 (P-corr < 0.05), despite this being the most common allele in Japanese. The Barkhof(-) LESCL(-) group showed a significant increase in the frequency of DRB1*0405 compared with controls (P-corr < 0.05). None of the DPB1 alleles were significantly different among the groups. Using multiple logistic analysis, the absence of oligoclonal bands was positively associated with an absence of Barkhof brain lesions, whereas a higher EDSS score was positively associated with the presence of LESCLs; however, the presence of anti-aquaporin-4 antibodies was not associated with either feature. Conclusion The characteristic MRI features in Asians are partly related to distinct HLA-DRB1 gene alleles and an absence of oligoclonal bands. Multiple Sclerosis 2008; 14: 1181-1190. http://msj.sagepub.com