Unrelated donor cord blood transplantation in adults with chronic myelogenous leukemia: results in nine patients from a single institution

The potential role of unrelated donor cord blood transplantation (UD-CBT) i n adults is not well established. We report the results of UD-CBT in nine a dult patients with chronic myeloid leukemia (CML). The median age was 27 ye ars (range, 19-41 years), and the median weight was 62 kg (range, 45-78 kg) , At transplant, six patients were in chronic phase (five in first, and one in second), two in blast crisis, and one in accelerated phase. Eight had r eceived intensive chemotherapy, and three had undergone autologous peripher al blood hematopoietic stem cell transplantation. Four had received interfe ron with no cytogenetic response, and only three underwent UD-CBT within 1 gear of diagnosis. After serological typing for class I antigens, and high- resolution DNA typing for DRB1, the degree of HLA match between patients an d cord blood (CB) units was 4/6 in six cases and 5/6 in three cases. The me dian number of nucleated cells infused was 1.7 x 10(7)/kg (range, 1.2 to 4. 9x10(7)/kg), and was above 2x10(7)/kg in only two cases. All patients recei ved thiotepa, busulfan, cyclophosphamide and anti-thymocyte globulin as con ditioning; cyclosporine and prednisone for graft-versus-host disease (GVHD) prophylaxis; and G-CSF from day +7 until engraftment, All seven evaluable cases engrafted, The median time to reach an absolute neutrophil count grea ter than or equal to0.5x10(9)/l and greater than or equal to 1x10(9)/l was 22 days (range, 19-52 days) and 28 days (range, 23-64 days), respectively. In the four patients evaluable for platelet recovery time to levels of grea ter than or equal to 20x10(9) platelets/l, greater than or equal to 50x10(9 ) platelets/l, and greater than or equal to 100x10(9) platelets/l, these ra nged from 50 to 128 days, 60 to 139 days, and 105 to 167 days, respectively . Three patients developed acute GVHD above grade II, and three of the five patients at risk developed extensive chronic GVHD. Four patients, all tran splanted in chronic phase, remain alive in molecular remission more than 18 , 19, 24 and 42 months after transplantation. These preliminary results sug gest that UD-CBT may be considered a reasonable alternative in adults with CML who lack an appropriate bone marrow donor.