HLA antigens associated with properdin factor B allotype BfF1.

Linkage disequilibrium has been described between HLA-B antigens and allotypes of properdin factor B (Bf). The association between HLA-B and DR antigens and the rare allotype BfF1 was investigated. In 27 HLA-A, B and DR typed individuals only one person was found who was DR3 negative but five who were B18 negative. Family studies showed that in nine cases B18, BfF1 and DR3 segregated as a haplotype; in another family which was B18 negative, BfF1 and DR3 segregated together. It is infered that the Bf locus is more strongly associated with HLA-DR than with HLA-B.