Cytokine IL-1 beta but not IL-1 alpha promoter polymorphism is associated with Alzheimer disease in a population from the Canary Islands, Spain

Abstract

Aims: Previous studies have reported the presence of low-grade inflammation in Alzheimer disease (AD). Based on these data, our work attempts to investigate the effects of some promoter polymorphisms of pro-inflammatory cytokines [interleukin (IL)-1 alpha and IL-1 beta] on AD.

Patients and methods: A PCR-RFLP technique was used to analyze the promoter polymorphisms of both IL-1 alpha (-889 C/T) and IL-1 beta (-511 C/T) and the APOE genotype from the DNA samples of 282 patients (according to NINCDS-ADRDA criteria) and 312 control subjects.

Results: (i) The risk of developing AD in our population was associated with the IL-1 beta (-511 C/T) promoter polymorphism; (ii) such risk was independent of the risk factor allele in the APOE gene (APOE4); and (iii) the IL-1 alpha promoter polymorphism (-889 C/T) was not associated with the disease.

Conclusion: In our population, IL-1 beta promoter polymorphism (-511 C/T) is an independent risk factor for AD.