CD33 and Alzheimer disease: Assessment of the association between the six SNPs and the likelihood of developing AD, while adjusting for age, gender, BMI, educational status and smoking showed a significant association with AD for rs1846190G>A (AG; OR = 0.042, P = 0.026 and AA; OR = 0.052, P = 0.031) in HLA-DRB1 and rs1354106T>G (GT; OR = 0.173, P = 0.005) in CD33 (Table 4).