Bone marrow transplantation in thalassemia.

Since 1983, 350 patients aged 1 to 19 years with beta-homozygous thalassemia were given infusions of HLA-identical marrow after high doses of busulphan and cyclophosphamide. Survival and event-free survival leveled off about 1 year after bone marrow transplantation at 82% and 75%, respectively. In 172 consecutive patients who were treated with our current regimen since June 1985, a multivariate analysis demonstrated that portal fibrosis, hepatomegaly, and a history of inadequate chelation therapy were significantly associated with reduced probabilities of survival and event-free survival. The patients were divided into three classes on the basis of the presence of hepatomegaly, portal fibrosis, and inadequate chelation therapy. Class 1 had none of the factors and class 3 had all three factors; class 2 had different associations of two out of the three factors. For class 1 patients, the 3-year probabilities of survival and event-free survival were 97% and 94%, respectively. For class 2 patients, the probabilities were 86% and 83%, and for class 3 patients, 58% and 52%. Bone marrow transplantation from HLA-identical donors is followed by a high probability of event-free survival in thalassemic patients, particularly if they belong to class 1.