HLA-DRB1 and systemic lupus erythematosus: We recently demonstrated that the HLA-DRB1*04 and HLA-DRB1*13 alleles alone and in particular the combination of these two alleles (HLA-DRB1*04/*13) were associated both with aPL of several specificities and with an increased risk of macrovascular events among SLE patients [12].