The aim of this study was to determine the association of TNF-α (-308 G > A) polymorphism with AIH susceptibility and with TNF-α expression or clinical manifestations of AIH.
Increased frequencies of both HLA-DRB1*04:04:01 and *16:02:01:01 alleles (OR = 2.91; 95% CI = 1.08-7.84) and the haplotype (DRB1-TNFA-LTA) *04:04:01-G-A (OR = 5.33; 95% CI = 1.32-21.49) were observed in AIH patients.
The present findings suggest that the gene or genes conferring susceptibility to AIH lie in the region centromeric to the HLA A locus between HLA C and DRB1.
In conclusion, our data indicate that type 1 AIH predisposition in a Venezuelan mestizo population of different ethnic backgrounds is associated with DRB1*1301 and DRB1*0301 alleles.
These findings suggest that the DR4-specific sequence (Val 11 and His 13 at amino acid positions 11 and 13, respectively), but not particular Dw-associated DR4 sequence, in the first domain of the DRB1 chain contributes to susceptibility to autoimmune hepatitis among Japanese.
HLA-DRB1 alleles of 76 children with pAILD (autoimmune hepatitis [AIH], autoimmune sclerosing cholangitis [AISC], primary sclerosing cholangitis [PSC]) and of 50 healthy blood donors as control group were analyzed retrospectively.
These data indicate that anti-LKM antibodies in AIH and hepatitis C react with CYP2D6, as shown by their inhibitory activity, and that besides the known epitope 257-269 a further immunodominant epitope exists on CYP2D6 which is recognized by sera from patients with AIH II but hardly by sera from patients with hepatitis C.
The liver-kidney 'microsomal' autoantigen reactive with cytochrome P450 2D6 distinguishes two serological types of AIH that appear pathogenetically distinct.
Genetic susceptibility to type 1 autoimmune hepatitis is indicated by a preponderance of female subjects and strong associations with human leukocyte antigens (HLA) DRB1*0301 and DRB1*0401.
A significant association of autoimmune hepatitis with DRB1*0404 was found, (chi2Y=19.95, pc=0.002, RR=7.71), suggesting the presence of a susceptibility gene located at the DRB1 locus.
In subtypes of DR4, there was a trend of increase in the gene frequency of DRB1 0405 in patients with AIH versus healthy controls (21.9% vs 6.3%, P=0.04, but P(c) =0.08).
CD4 T cells from patients with type 2 AIH positive for the predisposing HLA allele DRB1*0701 recognize seven regions of CYP2D6, five of which are also recognized by CD8 T cells.
The genetic AIH risk factor HLA DRB1*03:01 was more frequent in younger patients, and DRB1*04:01 was more frequent in middle-aged patients without an obvious link to virus seropositivities.
Susceptibility for type 1 autoimmune hepatitis has been associated with the major histocompatibility alleles DRB1*0301, DRB3*0101, DRB1*0401, and DRB4*0103, whereas the DRB1*1501 allele may protect from the disease.
HLA alleles appear to influence the exact phenotype-the most interesting apparent association being between HLA-DRB1*0301-DQB1*0201, liver-kidney microsome autoantibodies (anti-CYP1A2), and autoimmune hepatitis.