Stem cell transplants for patients with relapsed/refractory leukaemia

Today the indication for allogeneic stem cell transplantation for a high-risk leukaemia in first remission is well defined by most centres. In patients with primary refractory leukaemia the indication is controversially discussed. Similarly patients with relapse and advanced disease have a poor prognosis with chemotherapy, but also with transplantation. Finally more elderly patients with comorbidities seek help from transplantation, most of them in advanced and otherwise refractory disease. The results are reviewed.

The role of alloimmunity in the control of leukaemia has been defined and pretransplant conditioning treatment could be reduced to less intensive protocols. Graft-versus-leukaemia reactions have been demonstrated with the transfusion of donor lymphocytes. Using nonmyeloablative regimens allogeneic stem cell transplantation could be offered to elderly patients, the majority of patients with acute myeloid leukaemia and myelodysplastic syndromes. The use of antibodies and radio-immuno-therapy has improved the treatment of lymphoid malignancies. Cord blood transplants have shown improved results with double transplants. The superiority of maternal donors indicates a role of the donor's immune repertoire.

Taking advantage of alloimmune reactions and reduced intensity conditioning allogeneic stem cell transplantation has become successful even in elderly and fragile patients. The combination of molecular monitoring, targeted therapy and transplantation as a form of immunotherapy may improve the results of leukaemia treatment further.