Association between HLA and red cell antigens. VI. Family studies

The reactivity of the HLA antigens A28, B7 and B8 on red blood cells (RBC) has been studied, and the inheritance of the strength of reactivity examined in 13 families where the HLA haplotypes could be determined. Examination of individuals possessing more than one of the three antigens showed that the antigens seemed to be expressed independently of each other on RBC. The family studies showed that the HLA reactivity of RBC does not invariably follow the HLA haplotype determining the particular antigen. It was also shown that heterozygosity/homozygosity did not seem to have much influence on the strength of reactivity. Our conclusion is that several factors are likely to be responsible for the great variation in HLA reactivity of RBC.