title: HLA-A*01 is associated with late onset of Alzheimer's disease in Italian patients.
abstract: In this study, the distribution of HLA-A alleles was analyzed in Italian Alzheimer's Disease (AD)patients. Interaction between HLA alleles, APOE genotypes, age of onset, and gender were also analyzed. The results were compared to those obtained in healthy controls (HC). One hundred-seventy-three AD patients and 258 age-and-sex-matched healthy controls were enrolled in the study. AD patients were classified according to age at the onset of disease using quartiles of the distribution. HLA-A genotyping was performed by PCR-SSP; APOE genotyping was performed by RFLP. A correlation between late disease onset and HLA-A*01 was observed. Thus, HLA-A*01, calculated as number of alleles, was significantly more present in patients with age of onset > 74.0 years than in HC (20% vs 10.5%; p=0.014); the distribution of this allele was skewed also in patients 68.1-74 years of age (16.3%), even if the difference did not reach statistical significance. The relative risk ratio (RRR) of AD onset calculated by a multinomial logistic regression adjusted for sex and presence of APOE-4 confirmed a significant association of HLA-A*01 with AD onset > 74.0 years of age (RRR=2.2; 95%CI: 1.1-4.6; p=0.033). A high RRR (2.04) was also present in patients 68.1-74 years (p=0.064). Lower age of disease onset did not correlate with HLA-A*01. Data herein suggest that the presence of HLA-A*01 results in delayed AD development, even in patients carrying APOE-4. These results could offer new insights into the etiopathogenesis of Alzheimer's disease.
authors.affiliation: Laboratory of Molecular Medicine and Biotechnology, Don C. Gnocchi Foundation IRCCS, Milan, Italy.
authors.forename: F R
authors.initials: FR
authors.lastname: Guerini
authors.forename: C
authors.initials: C
authors.lastname: Tinelli
authors.forename: E
authors.initials: E
authors.lastname: Calabrese
authors.forename: C
authors.initials: C
authors.lastname: Agliardi
authors.forename: M
authors.initials: M
authors.lastname: Zanzottera
authors.forename: A
authors.initials: A
authors.lastname: De Silvestri
authors.forename: M
authors.initials: M
authors.lastname: Franceschi
authors.forename: L M E
authors.initials: LM
authors.lastname: Grimaldi
authors.forename: R
authors.initials: R
authors.lastname: Nemni
authors.forename: M
authors.initials: M
authors.lastname: Clerici
mesh_terms: D017668:Age of Onset; D000368:Aged; D000544:Alzheimer Disease / Q000208:ethnology / Q000235:genetics* / Q000276:immunology; D053327:Apolipoprotein E4 / Q000235:genetics; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D015234:HLA-A Antigens / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007558:Italy / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D053327:Apolipoprotein E4; D015234:HLA-A Antigens