Immunological mechanisms of corticosteroid therapy in chronic active hepatitis: analysis of peripheral blood suppressor T-cell and interleukin 2 activities.

To investigate the immunological mechanisms underlying corticosteroid therapy in chronic active hepatitis (CAH), in vitro effects of prednisolone on suppressor T-cell and interleukin 2 (IL-2) activities were examined in six corticosteroid therapy-effective and six therapy-ineffective patients with CAH prior to the therapy. Whereas low suppressor T-cell activity and decreased response to IL-2 in T cells were found in the corticosteroid therapy-effective group, these reductions recovered to the normal range when the activity or response was tested in the presence of prednisolone (1 and 10 micrograms/ml). Corresponding with these recoveries, suppressor T-cell activity arrived at normal values after corticosteroid therapy for 8 weeks. By contrast, in the corticosteroid-ineffective group, no apparent effects of prednisolone on suppressor T-cell activity and the response to IL-2 were observed. The relationship between the clinical effect of corticosteroid therapy and in vitro improvement in suppressor T-cell activity or in the response to IL-2 by prednisolone suggests that, in CAH, the corticosteroid effect is likely to be due to an immunomodulation in T-cell function.