Today we’ll be discussing how many cord blood units should be stored. Cord blood is an important source of hematopoietic stem cells and has several advantages over bone marrow for transplantation including less strict human leukocyte antigen or HLA matching criteria.
The greater the size of the cord blood bank, the greater the probability of finding a match for the patients’ HLA markers. Large cord blood banks, however, are not cost-effective.
Mr. Boo wrote an editorial in the journal TRANSFUSION and has this to say:
“Public cord blood banking has positively impacted accssess to transplant for many, especially for those who cannot find an adult donor. But the cost of public baking is challenging the industry. Studies need to help address the question of what is the minimum registry size today.”
Dr. Shin and colleagues recently estimated the minimum number of cord blood units needed in Korea for allogeneic hematopoietic transplantations by determining the HLA allele and haplotype frequencies for over 17,000 cord blood donor units.
Using over 1000 patients who had received unrelated hematopoietic stem cell transplantations to compute the probability of matching, Dr. Shin’s research team found that for 6 HLA markers to match, only 47% of patients would find a match if half a million cord blood units were hypothetically stored. However, 95% of patients would be able to find a suitable match with 5 of 6 markers matching with a cord blood inventory of 51,000 units in Korea.
Dr. Shin notes:
“51,000 is the minimum number because we only consider the HLA diversity of Koreans. Total nucleated cell count should also be considered. In addition, the level of resolution of HLA typing could be considered.”
Mr. Boo also stated that studies such as these help to address the minimal cord blood registry needed; however, that number will continue to evolve as the success of cord blood transplantation is evaluated.
He further notes
“An ideal inventory size may be difficult to attain in many countries. For the foreseeable future, however, publically banked cord blood units represent an important alternative for many patients around the globe who cannot find a suitable adult donor match.”
We’ll be back with another edition of Transfusion News on March 30th. Thanks for joining us.
References
1. Boo M. Current challenges for public cord blood banks. Transfusion 2014;54:499-500.
2. Yoon JH, Oh S, Shin S, Park JS, Roh EY, Song EY, Park MH, Han KS. The minimum number of cord blood units needed for Koreans is 51,000. Transfusion 2014;54:504-8.
