The relationship between HLA-DR3 and T-cell regulation of immunoglobulin production in primary sclerosing cholangitis.

Immunoglobulin production in vitro, its control by concanavalin A-activated suppressor T-cells, and the relationship between abnormalities in nonantigen-specific suppression and histocompatibility antigens have been studied in 20 patients with primary sclerosing cholangitis (PSC). Suppression of IgG, IgM, and IgA synthesis was impaired in 12 patients with PSC alone, but was normal in 8 with PSC and associated ulcerative colitis (UC). The HLA antigens B8 and DR3 were increased in frequency in both groups of patients, but an association between DR3, and to a lesser extent B8, and defective suppressor T-cell function was only observed in the patients with PSC alone. These results not only provide further evidence of an association between HLA DR3 and impaired nonantigen-specific suppression but also indicate the genetic complexity of this association and its specificity, being found in this study in only one subgroup of patients with PSC.