Genetic variants in HLA-DP/DQ contribute to risk of acute myeloid leukemia: A case-control study in Chinese

Human leukocyte antigens (HLA) are heterodimeric cell surface molecules that bind short peptides derived from non-self and self proteins. Accumulative evidence showed that specific alleles of HLA class II were associated with the susceptibility to malignant tumors including acute leukemia. In this study, we investigated the association between four single nucleotide polymorphisms (SNPs) at HLA-DP/DQ and acute myeloid leukemia (AML) risk. We genotyped four SNPs in HLA-DP (rs3077 G > A and rs9277535 G > A) and HLA-DQ (rs2856718 A > G and rs7453920 G > A) in a case-control study of 545 AML cases and 1034 cancer-free controls using Tagman allelic discrimination assay. The associations between these SNPs and AML risk were estimated by computing the odds ratios (ORs) and their 95% confidence intervals (CIs) from multivariate logistic regression analysis. We found significant associations of the variant alleles in HLA-DP (rs3077 and rs9277535) and HLA-DQ rs7453920 with increased AML risk (adjusted OR = 1.29, 95%CI = 1.10-1.51for rs3077 in additive model; adjusted OR = 1.29, 95%CI = 1.11-1.51 for rs9277535 in additive model; adjusted OR = 3.18, 95%CI = 1.86-5.46 for rs7453920 in recessive model). When combining the effects of rs3077, rs9277535 and rs7453920, we found that AML risk was significantly increased with the increasing number of variant alleles of the three SNPs in a dose-dependent manner (P for trend < 0.001). Besides, we found multiplicative interaction between rs3077 and age (<= 45 years old and > 45 years old; P = 0.046). In conclusion, HLA-DP and HLA-DQ loci are candidate susceptibility regions for AML in Han Chinese.