LB-Q1 and LB-Q2: two determinants defined in the primed lymphocyte test and independent of HLA-D/DR, MB/LB-E, or SB.

The primed lymphocyte test (PLT) was used to prepare reagents between HLA-D/DR identical individuals. Two sets of primed lymphocytes were obtained which recognized the new determinants referred to as LB-Q1 and LB-Q2, respectively. LB-Q2 is significantly associated with HLA-A1, -B8, and -D/DR3. Nevertheless, LB-Q1 and LB-Q2 seem to be distinct from any of the established HLA antigens. No association with any of the alleles of the SB system was observed. A recombination between HLA-D/DR and HLA-B suggested that the locus encoding LB-Q2 is situated on the telomeric side of HLA-D/DR.