An association of drb11501 with westeern type multiple sclerosis in Japanease

In Caucasians, the statistically strong association between HLA-DRB11501 and multiple sclerosis (MS) was well established. Whereas it is controversial in Japanese patients with MS. In this study the polymorphism of HLA-DRB1, -DRB3 and -DRB5 genes as well as magnetic resonance imaging(MRI) of the brain and spinal cord were studied in 57 Japanese patients with MS. According to the clinical findings, 23 patients who showed a relapsing-remitting course and a selective involvement of the optic nerve and spinal cord with minimal brainstem signs were classified as Asian type MS. The other 34 patients demonstrating an involvement of multiple sites in the central nervous system were classified as Western type MS. Asian type MS showed a significantly lower number of brain lesions on MRI than did Western type, while Asian type MS showed a significantly higher frequency of gadolinium-enhanced lesions on the spinal cord MRI than did Western type(47% vs. 17%). Among the DRb chain genes examined, only the frequency of the DR2-associated DRB11501 allele and DRB50101 allele were found to be significantly higher in Western type(41.2%) than in either Asian type(0%) or healthy controls(14.2%). Heterogeneity in the immunogenetic background and in the MRI features between the two subtypes of MS thus suggests the presence of two etiologically distinct MS in Asians.