The Impact of Variability among Banks on the Quality of Umbilical Cord Blood for Transplantation.

INTRODUCTION

As the frequency of umbilical cord blood (UCB) stem cell transplantation has increased, the quality of UCB available in banks is an important part of the success of UCB stem cell transplants.

METHODS

UCB units from outside banks were received in the Clinical Cell Therapy Laboratory where accompanying documentation, transfusion-transmitted disease test results, histocompatibility and ABO typing results, medical history, sterility testing, and processing records including cell counts were reviewed. Deviations were categorized based on cord blood regulations and the potential impact of deviations using a system developed to categorize according to the medical history, quality control testing, or labeling and documentation and for their potential risk to the patient.

RESULTS

Between January 1, 2001 and December 31, 2003, 268 UCB units were received for transplantation from 14 UCB banks. Of these 268 units, 151 (56%) from 12 banks (86%) had a total of 246 quality issues (Table). Most (54%) of the issues were in quality control. Examples included: 21 units with transmissible diseases tests that were incomplete, pending, or with positive results; 4 with a positive microbiological screening culture at the shipping UCB bank from a sample obtained prior to cryopreservation; 20 from mothers thought to be colonized with group B streptococcus; 31 from mothers who received antibiotics during labor; and 7 units arrived with inadequate temperature monitoring so it could not be documented that the units were maintained at an acceptable temperature. 11 units had questionable quality control test results for cell viability < 50% (2), poor CFU growth (2), nucleated red cell content > 20% (5), leaking segment (1) and confirmatory HLA typing not performed from attached segment (1). Of the 132 units with quality control issues, 25 (19%) were likely to pose a risk to patients. Documentation was inadequate for five units because related records did not have a complete numbering system. Reports of transmissible disease testing, cell content, donor medical history, or other details were sent on sheets of paper that did not contain the unique number of the UCB unit or other identifying information to assure that the data on that page were from the unit in question. Very few (4%) medical history issues posed a risk to patients. Examples of the medical history issues included: maternal exposure to malaria, recent tattoo, body piercing, maternal HIV risk factors, and maternal history of herpes, chlamydia, human papilloma virus (HPV) or use of donor sperm for the pregnancy.

CONCLUSION

Because standards have evolved over time, UCB banks contain units that have different levels of quality. Some units have been placed in the usable inventory with incomplete test results and/or documentation or that may not meet the banks own current criteria. Since many are only recognized after a transplant decision has been made, information about any quality or operating procedure deviation should be provided in sufficient detail and at the initiation of the search process so that transplant physicians can consider these quality issues when making a transplant decision.