Exogenous insulin-associated autoimmunity and the emergence of double diabetes in type 2 diabetes

Figure 2 Distribution of human leukocyte antigen-DRB1 and human leukocyte antigen-DQB1 alleles in the type 2 diabetes→ type 1 diabetes and type 2 diabetes→ type 1 diabetes groups. The upper panels display high-risk human leukocyte antigen (HLA)-DRB1 allele frequencies in each group, while the lower panels show HLA-DQB1 distributions. In the type 2 diabetes (T2D)→type 1 diabetes (T1D) group, DRB104:05 and DRB109:01, as well as DQB104:01 and DQB103:03, were predominant, consistent with classical T1D susceptibility haplotypes. In contrast, the T2D→T2D group exhibited a broader and more heterogeneous distribution of both DRB1 and DQB1 alleles, with no dominant autoimmune-associated patterns. T1D: Type 1 diabetes; T2D: Type 2 diabetes; HLA: Human leukocyte antigen.