Generation of autologous immunity to acute myeloid leukaemia and maintenance of complete remission following interferon-alpha treatment.

Interferon-alpha (IFN-alpha) is established as part of the treatment for chronic myeloid leukaemia, although its precise mode of action remains largely unknown. Its use in acute myeloid leukaemia (AML) has been limited. We have previously documented autologous cytolytic activity against AML blasts in patients after autologous bone marrow transplantation. Here we present a patient with poor-risk AML who relapsed from first complete remission (CR) and was unwilling to undergo high-dose chemotherapy with stem cell rescue. In second chemotherapy-induced CR, the patient had no evidence of antileukaemia cytolytic activity in an in vitro assay, and she commenced IFN-alpha (Roferon). She subsequently developed high levels of leukaemia-specific cytotoxicity, and has remained in second CR for two years. These findings support the use of IFN-alpha in patients with poor-risk AML, and suggest that one mechanism of action may be immunological.