S. Miller

Alleles at four HLA class II loci determined by oligonucleotide hybridization and their associations in five ethnic groups

The use of polymerase chain reaction (PCR) and oligonucleotide hybridization offers a new approach for the definition of HLA class II alleles. It has been possible to determine 43 alleles of DRB1, four of DRB3, two of DRB4, four of DRB5, eight of DQA1, and 14 of DQB1. These alleles are inherited together in members of families and form closely associated groups which are found repeatedly and in characteristics patterns in different populations. We have determined the HLA class II alleles and analyzed their association in 431 healthy unrelated subjects including 161 North American Caucasians, 53 Latin Americans, 61 Blacks, 88 Chinese, and 68 Israeli Jews. For-locus haplotypes (DRB1; DRB3/4/5; DQA1; DQB1) were derived from 79 B cell lines and the analysis of segregation in 34 nuclear families. The B-cell lines yielded 37 and the families showed the same, and 20 other, haplotypic combinations. In addition to these 57 haplotypes, associated alleles were assigned in the unrelated panels following certain rules. The resulting haplotypes were assigned to groups known to share associated alleles. The groups were: (1) DR1, DR2, and DRw10 (13 haplotypes); (2) DR3 and DRw6 (26 haplotypes); (3) DR5 and DRw8 (24 haplotypes); (4) DR4, DR7, and DR9 (24 haplotypes). Their distribution in populations with different ethnic backgrounds was analyzed. The expressed DRB4 allele and its null mutant were determined by PCR and oligonucleotide hybridization. The different DR7 haplotypes resulting from these determinations were analyzed in a panel of 130 North American Caucasoids. This comprehensive analysis of class II HLA haplotypes in human populations should be useful in understanding the role of these genes and in various applications including anthropolgy, disease susceptibility, and transplantation of allogeneic organs and tissues.

Similar T-Cell Oligoclonality in Antimitochondrial Antibody-Positive and -Negative Primary Biliary Cirrhosis

Approximately 5% of patients with clinical and histological features suggestive of primary biliary cirrhosis do not have anti-mitochondrial antibodies that can be detected by current methodologies. Although the role of these autoantibodies in the pathogenesis of liver disease is uncertain, T lymphocytes within the portal tracts are felt to be important mediators of bile duct destruction. In order to investigate the hypothesis that a similar T-cell process may be involved in both antimitochondrial antibody-positive and -negative primary biliary cirrhosis, we characterized the oligoclonally expanded T cells in both types of patients by analysis of complementarity determining region 3 length in peripheral blood mononuclear cells. The distribution of oligoclonally expanded T cells was similar in both groups. This finding does not support a distinct T-cell-mediated pathogenesis for anti-mitochondrial antibody-positive and -negative primary biliary cirrhosis but rather suggests that similar processes may be involved in the immunopathogenesis of both.