Genetic susceptibility to autoimmune hepatitis is associated with the human leukocyte antigen haplotype Al-B8-DR3 and DR4. To date, only one study in Japan has considered the human leukocyte antigen DP locus in this disease, and no studies have been reported in whites. In this study we used a series of sequencespecific oligonucleotide probes to determine human leukocyte antigen DPBl genotypes in 101 unrelated white northern European patients and 105 racially and geographically matched controls. The aims of the study were twofold: first, to determine the degree of DPBencoded susceptibility to autoimmune hepatitis, and, second, to establish whether susceptibility can be extended to include human leukocyte antigen DPB. None of 17 DPBl alleles was significantly associated with the susceptibility to autoimmune hepatitis. Although one particular seven-locus haplotype Al-DPB1*0401 was significantly associated with the disease (27% vs. 7%, relative risk = 5.14, p < 0.0005), the association with this haplotype was weaker than that for the six-locus haplotype excluding DPB (40% vs. 11%, RR = 5.52, p < 0.0005). When the patients first seen at ages younger than 16 yr (pediatric patients) were considered separately, the greatest relative risk was for the seven-locus haplotype (41% vs. 7%; relative risk = 9.60, p < 0.0005). The results of this study further confirm that major histocompatibility complex-encoded susceptibility to autoimmune hepatitis is located at or close to the human leukocyte antigen DR locus; however, the Al-B8-DR3-DQ2-DPB1*0401 extended haplotype may be important in determining the age of onset and severity of disease. (HEPATOLOGY B8-DRB3*0101-DRB1*0301-DQAl*0501-DQB1*0201-1993;18:1334-1337.)
Susceptibility to autoimmune hepatitis (AIH) is associated with the genes of the major histocompatibility complex (MHC) on the short arm of human chromosome 6. Studies of whites have suggested that the AI-Btl-DR3 haplotype and DR4 may be independent risk factors for the disease (1-51, whereas in Japan-where Al-B8-DR3