Further refinement of HLA-A by binding pocket structure revealed that the sequence Y(F/T)AVMENV(H/Q)Y, corresponding to HLA-A alleles A*03:01-02; *31:01; *32:02, was protective for AIH (OR: 0.3, P = 0.002).
Although HLA subtypes were comparable between these three collectives, the German patients were distinct from the Italian and North American patients with respect to DQ2 and from the North American patients with respect to B8-DR3-DQ2 HLA.A clinical correlation, e.g. difference in severity or treatability of AIH type 1, has yet to be determined.
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.