Familial versus sporadic longevity and MHC markers

Area of Science:

• Immunogenetics
• Gerontology
• Human Genetics

Background:

• The genetic factors influencing human longevity are complex and not fully understood.
• Human Leukocyte Antigen (HLA) genes play a crucial role in immune response and have been implicated in various age-related conditions.
• Investigating HLA polymorphism in extremely aged populations can provide insights into the genetic basis of longevity.

Purpose of the Study:

• To investigate the association between HLA (Human Leukocyte Antigen) Class I and Class II allele frequencies and longevity in elderly populations.
• To compare HLA polymorphism in centenarians and nonagenarians with familial longevity against a younger control group.
• To explore the potential protective role of specific HLA alleles in exceptional aging.

Main Methods:

• Genotyping of HLA-A, HLA-B, and HLA-DRB1 alleles in elderly cohorts (centenarians and nonagenarians) and a control group.
• Statistical analysis to compare allele frequencies between groups.
• Assessment of haplotype sharing in familial nonagenarian sibling pairs.

Main Results:

• A significantly increased frequency of the HLA-DRB1*11 allele was observed in familial nonagenarians (18.3%) compared to controls (10%) and sporadic centenarians (11.8%).
• Rare HLA Class I alleles (A30, B70) showed significant differences from controls after statistical correction.
• No distortion in Mendelian sharing of haplotypes was found in familial nonagenarian sibling pairs.

Conclusions:

• The study suggests that the HLA-DRB1*11 allele may be associated with familial longevity, potentially through a protective effect in presenting immunogenic peptides.
• Longevity is heterogeneous, with genetic factors like specific HLA alleles contributing to exceptional aging, particularly in familial forms.
• The findings support the role of the immune system, specifically HLA genetics, in influencing lifespan and healthy aging.