Or in other words, which is the validity term of a frozen cord blood unit? How long can remain viable thefrom a frozen cord blood unit? Maintaining cell viability is the most important feature that condition the use or not of a cord blood unit for transplant.
So, providing an answer is one of the most important questions that both, physicians and parents, who have chosen for cord blood banking would like to have an answer.
For 23,5 years of storage in liquid nitrogen it has been proven the efficient recovery of stem and progenitor cells from a unit of frozen cord blood.
23,5 years, this is the current answer which can be given in accordance with published results of medical research1 on the oldest frozen specimen of umbilical cord blood, available in laboratory from Indiana University School of Medicine (IUSM), Indianapolis, Indiana.
At least 14 years of cryopreservation had the oldest frozen cord blood unit used in transplant
Besides the retrieval of viable stem and progenitor cells from frozen cord blood samples which was proven in laboratory, another important aspect is the validation of these results in real conditions, meaning in transplanted patients.
From this perspective, the oldest stored frozen cord blood unit which has been used for transplant in a patient had at least 14 years of cryopreservation, according to dr. Pablo Rubinstein1 . He is the founder of first public cord blood bank in the world, at New York Blood Center (in 1992).
In 2015 was published the successful real life story2 of a patient saved by transplantation of a cord blood unit frozen for 11 years . In the absence of a compatible donor, the use of umbilical cord blood for transplantation was the only chance of survival that could be given to a 37-year-old patient.
As a conclusion of this case, Wang Ruifeng, a researcher at Sichuan University, said:
"As long as umbilical cord blood does not enter a repetitive process of freezing and unfreezing, its shelf life is unlimited, said Wang Ruifeng, a researcher from Sichuan. Theoretically, after hundreds of years in storage, it can still be activated and put to use."
1.Hal E. Broxmeyer “How Long Can Cord Blood Be Stored?” September 2014