Occurrence of paternal and maternal HLA-B/D recombinants in a single family.

Two B/D recombinant offspring in one family were identified by HLA-A,B,C,D, and DR typing with the Eighth International Workshop sera and cells, intrafamily MLC and PLT test. Restimulation of cells primed against the four parental haplotypes showed good discrimination between family members who shared the D alleles and those who did not. When the B/D recombinant haplotypes were primed, accelerated proliferative response was observed only with cells sharing the HLA-D region. Cells that shared with the priming cells the HLA-A to B interval but differed for the D region did not restimulate. These results demonstrated the role of HLA-D disparity in evoking secondary proliferative response and showed that the determinant(s) mapping between HLA-A and B did not restimulate.