Using a newly developed indirect T lymphocyte migration inhibition test, cell-mediated immunity to HBsAg and HBcAg was directly and simultaneously examined in a total of 21 patients with HBsAg-positive chronic liver disease (CLD), and in seven subjects whose sera contained anti-HBs (2 previous acute hepatitis B; 4 hepatitis B vaccine recipients and 1 chronic active hepatitis). T cell sensitization to HBcAg was invariably detected in the HBsAg-positive CLD patients tested (12/12), whereas T cell sensitization to HBsAg was not present in any of the patients (0/21). In contrast, T cell sensitization to HBsAg was present in all anti-HBs-positive subjects.

These results support the hypothesis that the cellular immune response to HBcAg, rather than to HBsAg, is implicated in the pathogenesis of HBsAg-positive CLD. Moreover, the observation that the addition of T cells from patients with HBsAg-positive CLD to T cells from anti-HBs positive subjects in a ratio of 1 to 9 reversed their sensitization to HBsAg, suggests that a hyperactivity of HBsAg-specific suppressor T cell population may be responsible for persistent HBs antigenemia.