A comparison of non-TBI and TBI conditioning regimens in bone marrow recipients undergoing match-unrelated transplantation in Hong Kong

Abstract

The present study investigated the effects of non-Total Body Irradiation (TBI) conditioning on the outcome of 8 patients (CML = 5 ; A M L = 3; Mean age 32.8 ± 3.3) undergoing Matched-Unrelated Bone Marrow Transplantation (MUD BMT) using busulfan (16 mg/kg) and cyclophosphamide (150 mg/kg). The outcome of 28 patients ( C M L = 16; AML = 7; Biphenotypic acute leukaemia = 2; ALL = 2 ; M D S = 1) using TBI (12Gy) containing regimen (Mean age 29.3 ± 1.7 ) were also analyzed. The number of days requiring TPN (due to oral mucositis) was significantly lower in the Bu-Cy group (18 ± 3.6 days) compared with the control (31.9 ± 4.1 days, p<0.05). There were no differences in neutrophil (ANC > 0.5 x 10 9/L) and platelet (>25 x 109/ L without transfusion) engraftments. The Bu-Cy group had less venoocclusive disease (VOD) (2/8 vs 11/28 in control) but more haemorrhagic cystitis (HC) (3/8 vs 5/28 in control) though the differences were not s i g n i ficant (p>0.05). Patients in the Bu-Cy group also had a signific a n t l y lower occurrence (1/8) of severe GVHD (Overall grade ³2) than the control group (18/28) (p<0.05). Transplant-related mortality (TRM) within 100 days after BMT was 0 in the Bu-Cy group but was 7 (out of 28) in the control (GVHD related = 4; Regimen-related toxicity = 2 ; Graft failure = 1). The difference, however, did not reach statistical sign i ficance (p>0.05). There was no difference in the occurrence of early graft failure in both groups of patients (1/8 in the Bu-Cy group vs 3/28 in the control). In conclusion, we have shown that the use of Bu-Cy during conditioning in MUD BMT had no adverse effect on neutrophil and platelet engraftments and did not increase the occurrence of graft failure. TBI based conditioning was associated with increased severity of oral mucositis and increased risk of VOD and severe GVHD and a higher transplant-related mortality.