Increased immunoglobulin production in vitro in healthy HLA-B8-positive persons.

The histocompatibility antigens B8 and DR3 are associated with several autoimmune diseases, and immune hyper-responsiveness has been believed to be one factor in the pathogenesis of these diseases. In the present study we compared the in vitro immunoglobulin production of healthy HLA-B8-positive individuals with that of HLA-B8-negative individuals. In HLA-B8-positive persons a higher number of pokeweed mitogen (PWM)-stimulated Ig-secreting cells was obtained. When the cells were stimulated with PWM in the presence of a physiological concentration of hydrocortisone (HC), the secretion of IgG was significantly higher in HLA-B8-positive individuals. This finding indicates that the PWM-stimulated IgG secretion in healthy HLA-B8-positive individuals is more sensitive for the enhancing action of HC.