Comparison of Cord Blood Transplant Outcome between U.S. Versus Non-U.S. Transplant Centers for Cord Blood from a Single Source.

Background: Cord blood transplantations (CBT) are performed in transplant centers (TC) worldwide; however, conditions for TC located around the world may be quite different, in particular, few studies have focused on CBT outcome in Asian TC. Factors such as patient populations, experiences, disease indications, available resources, and protocols may affect outcome as some have suggested.

Methods: In an effort to compare CBT performed by U.S. (n=129) and non-U.S. TC (n=63), a retrospective audited analysis was performed for all 192 patients with available engraftment and/or survival data using cord blood units (CBU) from a single source to minimize potential differences in quality.

Results: Kaplan-Meier estimates of engraftment for ANC500, platelet 20K and 50K were 91±3%, 80±5% and 74±5% for U.S. respectively, and 81±5%, 85±6%, and 81±7% for non-U.S. TC respectively. The relapse rate for the U.S. and non-U.S. TC were 26±5% and 17±5% respectively. TRM were 31±4% for U.S. TC and 22±5% for non-U.S. TC. The 3-year OS and DFS were 51±5% and 41±7% for U.S. and 68±6% and 61±7% for non-U.S. centers respectively. Factors including recipient age, CD34+ cell dose, #HLA matches, malignancy and wash status of the CBU were taken into consideration in a multivariate analysis which will be presented. In this study, non-U.S. TC were more likely to forego post-thaw wash of CB and perform CBT for benign indications, which appeared to affect outcome. Upon closer inspection of the individual TC, it appeared that there may be more heterogeneity in the TC results overseas, and that centers in the U.S. produced more consistent outcome. While it is possible that, due to many complex reasons, outcome at some non-U.S. TC may be somewhat uneven, many including several in Asia, produced outstanding results that rival the best TC anywhere.

Conclusion: It appears that many factors, including available resources, post-thaw wash, and CBT experience affect outcome, and outstanding outcome can be achieved, regardless of TC location.