[Bone marrow transplantation from unrelated donors in chronic myeloid leukemia: the results in 15 patients].

Background: Bone marrow transplantation (BMT) from a histocompatible donor is the only curative treatment in chronic myeloid leukemia (CML). Only a minority of patients dispose of an adequate donor from among his/her relatives. The remaining transplant receptors must look to unrelated donors (URD). The experience of the Escuela de Hematología Farreras Valentí (Farreras Valentí School of Hematology, Barcelona, Spain) in BMT from URD in CML in the first chronic phase is herein reported.

Methods: Fifteen patients (9 males and 6 females, median age 33 years; range 14-48 years) were transplanted from October 1988 to May 1994. Serologic identity was expressed in the A, B and D loci in 9 cases and minor incompatibility in 6. Conditioning included total body irradiation and cyclophosphamide in 14 patients and busulphan plus cyclophosphamide in 1. Partial and selective T lymphocyte depletion was performed by elutriation in 7 cases.

Results: Primary implant failure was detected in 2 out of 14 risk patients (14%) and secondary failure was observed in 3 out of 12 cases (25%). The actuarial probability of acute graft versus host disease (GVHD) was 55 +/- 15% at 7 weeks with a probability of appearance with an intensity of II-IV of 31 +/- 13%. Five out of 7 patients with a survival of greater than 100 days, developed chronic GVHD (71%). Ten presented fatal complications. In 5 cases, death was due to pulmonary problems. Recurrence of CML was not observed in any of the patients in the series. The probability of disease free survival at 2 years was 30 +/- 12%.

Conclusions: Bone marrow transplantation from an unrelated donor is an effective treatment for a proportion of patients with chronic myeloid leukemia although severe complications are frequent and originate a high mortality.