HLA-DRB1 and rheumatoid arthritis: In the recent Japanese study mentioned above [112], early RA patients carrying one or two copies of the SE-positive HLA-DRB1*04 allele (especially *0405) were more likely to be resistant to DMARD therapy (predominantly MTX) at two years (OR = 2.89, P = 0.011), an effect not seen with other SE-positive alleles.