Influence of major histocompatibility complex region genes on human longevity among Okinawan-Japanese centenarians and nonagenarians.

The frequencies of 80 HLA antigen phenotypes in 82 centenarians and 20 nonagenarians in Okinawa, Japan, were compared with those in other healthy adults in various age-brackets. Subjects aged over 90 had an extremely low frequency of HLA-DRw9 and an increased frequency of DR1. In this age-group the relative risk of corrected (for number of antigens) p value for HLA-DRw9 were 5.2 and 0.0001, respectively; those for HLA-DR1 were 13.3 and 0.0367, respectively. Since a high frequency of DRw9 and a low frequency of DR1 are associated with autoimmune or immune deficiency diseases, the genetic protection against these disorders may contribute to longevity.