Association of HLA-DRB1 polymorphism with Alzheimer's disease: a replication and meta-analysis.

Genome-wide association studies (GWAS) have identified one single-nucleotide polymorphism (SNP) rs9271192 within HLA-DRB1 as a risk factor for Alzheimer's disease (AD) in Caucasians. The effect of rs9271192 on AD needed to be verified in other ethnic cohorts. In order to evaluate the association between HLA-DRB1 rs9271192 polymorphism and late-onset AD (LOAD) in the Northern Han Chinese population, we recruited 982 LOAD patients and 1344 sex-and age-matched healthy controls. The results showed that HLA-DRB1 rs9271192 was associated with LOAD (genotype P = 0.015, allele P = 0.04). The results of logistic regression revealed the C allele homozygosity strongly increased the risk of LOAD under a recessive model in the total sample (P = 0.004, OR = 2.069, 95% CI = 1.262-3.434). When these data were stratified by apolipoprotein E (APOE) epsilon 4 status, the observed association was confined to APOE e4 non-carriers (additive model: P=0.048, OR = 1.191, 95% CI = 1.001-1.417; recessive model: P < 0.001, OR = 2.601, 95% CI = 1.519-4.566). Furthermore, metaanalysis after sensitive analysis confirmed that rs9271192 within HLA-DRB1 increased the risk of LOAD (OR = 1.12, 95% CI = 1.08-1.15). To summarize, the C allele in HLA-DRB1 rs9271192 may be an independent risk factor for LOAD.