HOMOZYGOUS MHC GENOTYPES AND LONGEVITY

To investigate the relevance of the major histocompatibility complex ( MHC) in longevity, we carried out a molecular analysis of the MHC in 4 32 unrelated healthy individuals. The comparison of individuals less t han or equal to 25 years and > 25 years showed that the 5.8-kb DQA1 al lele, which corresponds to HLA-DR53, was negatively associated with lo ngevity (p = 0.0035) resulting mainly from decreased homozygosity with age for that allele (p = 0.008), and restricted to males (p = 0.008). The difference was more striking for the 5.8 kb DQA1: 9.0 kb HSP70 ha plotype again only in males (26.3 vs. 6.2%; p = 0.017, OR = 5.4, 95% C I = 1.5-19.5). The oldest male subject homozygous for this DQA1: HSP70 haplotype was 54 years (p = 0.005). Comparing leukemic patients and h ealthy individuals with the same ethnic and geographical. origin, homo zygosity for these genotypes was more frequent in the young leukemic g roup. The results suggested the existence of recessive deleterious gen es in a segment of HLA-DR53 haplotypes.