Controlled-rate versus uncontrolled-rate cryopreservation of peripheral blood progenitor cells: a prospective multicenter study. Group for Cryobiology and Biology of Bone Marrow Transplantation (CBTMO), Spain.
OBJECTIVE
Cryopreservation of hemopoietic progenitors for transplantation has been traditionally performed by the use of a controlled-rate freezer. Several groups have reported successful cryopreservation of progenitor cells at -80 degrees C without a controlled-rate freezer. In an attempt to elucidate whether both methods are equally efficient, we compared controlled-rate versus uncontrolled cryopreservation of peripheral blood progenitor cells (PBPC) in a prospective, multicenter study.


METHODS
Apheresis products from patients undergoing PBPC mobilization were split into two aliquots, and cryopreserved simultaneously by both methods, in autologous plasma plus 10% dimethylsulfoxide. Controlled-rate samples were placed into a programmable freezer with a cooling rate of 1-2 degrees C/min. Uncontrolled-rate samples were directly introduced into a -80 degrees C mechanical freezer. After thawing, cell counts, assays for viability, clonogenic cultures and CD34+ cell enumeration were performed.


RESULTS
A total of 105 cases were included. No significant differences were found in viability (mean 88.8 +/- 13% in the controlled-rate group vs. 89.7 +/- 12% in the uncontrolled-rate group), nucleated cell loss (23.5 +/- 23% vs. 23 +/- 22%), mononuclear cell loss (19 +/- 23% vs. 19.1 +/- 22%), and loss of CD34+ cells (34.3 +/- 33% vs. 28.6 +/- 34%). On the other hand, recovery of granulomonocytic colony-forming units (CFU-GM), was significantly better with the controlled-rate technique, than with the non-controlled-rate method (104.3 +/- 95 vs. 86.5 +/- 80, respectively; p = 0.048).


CONCLUSIONS
Our results indicate that both techniques are suitable for cryopreservation of PBPC, although a better recovery of committed progenitors is achieved by the controlled-rate method. Therefore, the use of controlled-rate freezer should probably be recommended.
Perez-Oteyza
J
J
Department of Hematology, Hospital Ramon y Cajal, Madrid, Spain. jaime.perez@hrc.es
Bornstein
R
R
Corral
M
M
Hermosa
V
V
Alegre
A
A
Torrabadella
M
M
Ramos
P
P
Garcia
J
J
Odriozola
J
J
Navarro
J L
JL
D001793:Blood Preservation / Q000295:instrumentation / Q000379:methods*; D002470:Cell Survival; D003114:Colony-Forming Units Assay; D015925:Cryopreservation / Q000295:instrumentation / Q000379:methods*; D005069:Evaluation Studies as Topic; D019337:Hematologic Neoplasms / Q000097:blood / Q000628:therapy; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D009369:Neoplasms / Q000097:blood / Q000628:therapy; D011446:Prospective Studies; D013030:Spain / Q000453:epidemiology