HLA-DR allele polymorphism and multiple sclerosis in Chinese populations: a meta-analysis

The association of human leukocyte antigen (HLA) genes and multiple sclerosis (MS) has been extensively investigated in Caucasians, but less so in Oriental races such as Chinese.

To review studies on association of HLA class II alleles with MS in the Chinese population.

An extensive search for published studies up to June 2010 was performed in the electronic databases. The meta-analysis facilities in the NCSS statistical package were utilized to analyze the findings in these studies. The odds ratios (ORs) of HLA-DR allele distributions in MS were analyzed against controls.

Eleven case-control studies were identified: nine genotyping and two serotyping studies. Six genotyping studies were suitable for HLA-DRB1 allele meta-analysis, which showed that HLA-DRB1*15 was associated with risk of MS in the combined group (308 cases and 407 controls; OR 1.39) while the HLA-DRB1*09 and HLA-DRB1*0901 alleles were protective. When the equivalent serotypes in these six studies were combined with the results from the two serotyping studies (431 cases and 652 controls) for a meta-analysis of HLA-DR serotypes, HLA-DR2 was a risk factor (OR 1.63) and HLA-DR9 was strongly protective in the combined group (OR 0.64).

Although limited data are available, our meta-analysis suggests that HLA-DR2/DRB1*15 are also associated with risk of MS in the Chinese population but less strongly so than in Western MS populations, whereas HLA-DR9 alleles appear to confer resistance in this population.