HLA-DRB1 and Parkinson disease: In addition, a recent study analysed the binding of different alleles of class II MHC to peptides derived from autoantigens associated to PD and found a positive association between alleles HLA-DRB1*1501, HLA-DRB1*0304, and HLA-DRB5*0101 and the binding to autoantigens-derived peptides in PD patients (41).