Objective: To describe the results of allogeneic stem cell transplantation after non-myeloblative conditioning in high-risk patients with a haematological malignancy.
Design: Prospective and descriptive.
Method: In the Utrecht University Medical Centre 21 patients in an advanced stage of various haematological malignancies were treated with allogeneic stem cell transplantation following non-myeloablative conditioning. The patients were either younger than 55 but unsuitable for standard allogeneic stem cell transplantation because of co-existing disease, or between the ages of 55 and 70, and they had to have either a HLA-identical donor relative or a donor in which there was only one mismatched antigen. They were treated with a combination of fludarabine and a low dose of total body irradiation, followed by the administration of an unmanipulated stem cell transplantated.
Results: Engraftment of the stem cells was rapid in all patients but one, and 9 patients already showed complete donor cell chimerism 4 weeks after the infusion of stem cells. A total of 12 patients ultimately became completely donor chimeric, one of whom had received donor leucocytes; 7 patients were still mixed chimeric, with > 80% donor cells. 13 patients developed acute 'graft-versus-host disease' (GVHD), but in 10 of these it was mild and transitory. After a median follow-up of 9 months, 5 patients (24%) had died, 4 as a result of disease progression and one from a cause related to the transplantation.
Conclusion: Allogeneic stem cell transplantation following non-myelaoblative conditioning is a convenient mode of therapy with a low mortality related to the transplantation. It is particularly suitable for the treatment of older patients at high risk with regard to their disease.