HLA-DRB1 and systemic lupus erythematosus: In East Asian SLE the MHC risk is also strong, but may be slightly simpler than in EURs, the predominant risk arising from the extended haplotypes including HLA-DRB1*15:02 in LD with DQA1*01 and DQB1*05 or *06 alleles (9,10).