Meta-analysis of the association between the interleukin-1A -889C/T polymorphism and Alzheimer's disease.

No clear consensus has been reached on the Interleukin-1A (IL-1A) -889C/T polymorphism and Alzheimer's disease (AD) risk. In this meta-analysis, 27 case-control studies were assessed to evaluate the possible association. Overall, positive associations of the IL-1A -889C/T polymorphism with AD risk were found in allele comparison T vs. C (OR = 1.09, 95% CI = 1.01-1.18), recessive model TT vs. CT + CC (OR = 1.21, 95% CI = 1.01-1.45), and homozygote comparison (TT vs. CC; OR = 1.32, 95% CI = 1.04-1.67). In subgroup analysis stratified by ethnicity, significant associations were demonstrated in Caucasians but not in Asians. In subgroup analysis according to the age of onset, the data showed a significant association in patients with late-onset AD in Caucasians but not in early-onset AD. In conclusion, this meta-analysis supports the idea that IL-1A -889C/T polymorphism is capable of causing AD and LOAD susceptibility in Caucasians but not in Asians.