Increased HLA—B Heterozygosity with Age

427 healthy individuals ranging in age from 16 to 101 years were tested for HLA-A and -B antigens. No significant differences were found for any particular antigen according to the age of the individual. However, a significant trend of increasing frequency with age was found for individuals possessing two detectable HLA-B antigens. An apparent trend of increasing frequencies for individuals possessing four HLA-A and -B antigens was not significant. These results concur with those of some previously published studies.