Selection of Cord Blood Unit by CD34 Cell and GM-CFU Numbers and Allele-Level HLA Matching in Single Cord Blood Transplantation.

In Japan, only single-unit cord blood transplantations (CBTs) are typically performed, and their number has increased over the last 23 years, with ongoing improvement in results. In most cases, CBTs with multiple HLA mismatches are used, owing to a low HLA barrier, and lower engraftment rate is a problem that must be overcome. Here, as part of an effort to improve guidelines for the selection and processing of CB units for transplantation, we sought to assess the present status of CBT in Japan and to elucidate factors contributing to the favorable outcomes, focusing in particular on selection by cell components of CB unit and HLA allele matching.

Adverse events caused by cord blood infusion in Japan during a 5-year period.

Background And Objectives: In Japan, cord blood is used for more than half of all unrelated stem cell transplantations. The public cord blood banks (CBBs) have been collecting information on cord blood transplantation-related adverse events from physicians on a voluntary basis, without common definitions of the adverse reactions. The aims of this study were to compare two classification systems to improve the reporting system and to clarify the actual risk from cord blood infusion, which can then provide the impetus to take appropriate measures to reduce adverse events.