An immunogenetic study of suppressor cell activity in autoimmune chronic active hepatitis.

Some patients with autoimmune chronic active hepatitis as well as their disease-free first degree relatives show decreased suppressor cell activity of peripheral blood T lymphocytes. Studies were therefore undertaken in families ascertained by the presence of a single chronic active hepatitis patient to determine if this abnormality of immune regulation represents a genetic phenotype simply controlled by a gene or genes at a putative disease susceptibility locus and, further, if this locus showed linkage to either the HLA or the immunoglobulin constant region loci. In addition to determining circulating autoantibody status and genotyping for HLA and immunoglobulin allotypes, suppressor T cells were evaluated by surface markers and by determining their ability to suppress IgG secretion in vitro. The results suggest that immunoregulatory dysfunction in autoimmune chronic active hepatitis is a familial abnormality, but that this abnormality occurs independent of circulating autoantibody status and of the segregation of genes for HLA or immunoglobulin allotypes.