Spontaneous graft-versus-host disease following autologous peripheral blood progenitor cell transplantation in chronic myeloid leukaemia

Myeloablation followed by haemopoietic reconstitution using autologous peripheral blood progenitor cells (PBPC) is applicable to some patients with CML, particularly where there is no allogeneic stem cell donor available, and interferon alpha has failed to achieve a significant cytogenetic response. Cells lacking the Philadelphia (Ph) chromosome can be collected at the early phase of myeloid recovery after intensive chemotherapy, and reconstitution after autografting can be associated with prolonged suppression of the Ph positive clone. It is possible that mechanisms other than this 'in vivo purge' may contribute to disease control, for example an autologous graft-versus-leukaemia effect. We report two patients in whom significant autologous graft-versus-host disease (auto-GVHD) has occurred, which has not previously been described as a spontaneous event after PBPC autograft for CML. We postulate that mononuclear cells collected in an early phase of recovery after intense myelosuppression have the capacity to produce self-reactivity after autografting. These cells, which may include autoreactive T lymphocytes or antigen-presenting dendritic cells, might mediate a useful graft-versus-leukaemia effect.