Comparison of Processing Reagents (Hespan and PrepaCyte-CB®) in Preparation of Cord Blood Units at the Saint Louis Cord Blood Bank

The Saint Louis Cord Blood Bank (SLCBB) is one of the largest public cord blood banks in the world. Prior to 2009 cord blood units (CBUs) at SLCBB were processed using Hespan (Hetastarch) for red cell and volume reduction. Since then PrepaCyte-CB has been substituted due to superior red cell reduction and colony forming unit recovery. Additionally, PrepaCyte-CB is compliant with FDA approved methods required for licensing of CBUs. As a consequence, units of both types exist and continue to be utilized for transplantation, raising important questions regarding potential impact of processing method on outcomes. Herein we report overall survival and engraftment characteristics of patients receiving CBUs as a function of processing methodology. This retrospective study was approved by the SLU IRB. Between 1/1999 and 11/2015 749 single unit transplants occurred. Out of these, 276 cases were excluded due to incomplete data. The remaining 473 transplants took place between 5/2000 and 11/2015, 410 with Hespan processed CBUs and 63 with PrepaCyte-CB processed CBUs. One year overall survival is shown in Figure 1, revealing no significant difference between preparation patient receiving cells from each processing regimen. Neutrophil engraftment arising from Hespan and PrepaCyte-CB CBUs was compared. Engraftment was defined as achievement of ≥500 absolute neutrophil count (ANC) by post-transplant day 42 (D42). Of the 473 cases, 75 had insufficient data for engraftment analysis. Importantly, these excluded charts included 87% Hespan and 13% PrepaCyte-CB units, the exact proportion encountered in the original total cohort, excluding introduction of bias. Ninety-five percent of cases (378/398) engrafted by D42; 20 patients (5%) did not, 1 of these died before D42. Thirty-six cases engrafted but died before D42. Figure 2 compares patient engraftment data for units processed with Hespan to those processed with PrepaCyte-CB. Median time to engraftment is similar, with interquartile ranges as shown.Figure 2D42 neutrophil engraftment state: prepacyte v. hespan.View Large Image Figure ViewerDownload Hi-res image Download (PPT) In the experience of the Saint Louis Cord Blood Bank, processing of donor cells using either Hespan or PrepaCyte-CB yields a product of equivalent reliability for engraftment of neutrophils, and equivalent one year overall survival. These conclusions are limited by the nature of retrospective analyses and potentially unknown reporting variance by transplant centers to CIBMTR. Additionally, the smaller number of PrepaCyte-CB units relative to Hespan are an additional consideration that could influence interpretation. Nevertheless, based on these data, use of both Hespan and PrepaCyte-CB processed CBUs continues to be appropriate.