MPO and granulomatosis with polyangiitis: MPO-ANCA positivity has also been found to be associated with HLA-DQA and DQB1 loci in GPA and MPA [68,70], DRB1*0901 [81,82], DRB1*1302 [83], DQA1*0302 [84], and DQB1*0303 [81] in MPA in East Asian cohorts, and HLA-DQ in EGPA in Europeans [71].