MARROW TRANSPLANTATION IN PATIENTS WITH THALASSEMIA RESPONSIVE TO IRON CHELATION-THERAPY

Background. Patients with homozygous beta-thalassemia, who have a good prognosis during treatment with conventional therapy, appear to have an especially high probability of hematologic cure with bone marrow tr ansplantation, although the morbidity and mortality associated with su ch treatment are not established. Methods. The records of all patients with thalassemia who received bone marrow transplants from HLA-identi cal donors in Pesaro, Italy, were examined from October 1982 through M ay 1992. Detailed evaluation of the outcome was conducted in the 89 pa tients identified as being in class 1 according to the Pesaro classifi cation, in which hepatomegaly, portal fibrosis, and the inadequacy of iron chelation therapy are considered independent risk factors, and th e patients are classified as being in class 1 if none of these factors are present, class 2 if one or two of the factors are present, and cl ass 3 if all three factors are present. Sixty-four of the patients had been prepared for transplantation with a drug regimen in current use that includes busulfan and cyclophosphamide followed by cyclosporine a s prophylaxis against acute graft-versus-host disease (protocol 6). Re sults. There were seven deaths, all within 101 days of transplantation . Two of the 64 patients treated according to protocol 6 died. The pro babilities of survival, rejection-free survival, death from causes unr elated to rejection, and rejection were 0.92, 0.85, 0.06, and 0.08, re spectively, in the total group and 0.97, 0.93, 0.03, and 0.04 in the 6 4 patients treated according to protocol 6. Preliminary evidence sugge sts that there was useful unloading of tissue iron deposits. Conclusio ns. The high probability of cure with little early or late morbidity a nd mortality suggests that patients with class 1 thalassemia who have HLA-identical donors available should be treated by bone marrow transp lantation. However, this was not a controlled trial, so we cannot dire ctly compare the outcome with that of conventional treatment.