The predominant association of HLA DRB1*13 with type 1 autoimmune hepatitis in Brazil and Argentina suggests that HLA DRB1*13 favors the presentation of triggering antigens that are common to this region, and the hepatitis A virus may be one of several such agents, may be this can explain the prevalence of type 1 AIH among our children and not type 2 as we are also endemic area for Hepatitis A. This evidence concerns the gene HLA-DRB1 and hepatitis A virus infection.