Peripheral blood progenitor uncontrolled-rate freezing: a single pediatric center experience.
BACKGROUND
Controlled-rate freezing (CRF) followed by storage in liquid nitrogen is employed by most centers as the standard procedure for peripheral blood progenitor cell (PBPC) cryopreservation. Uncontrolled-rate freezing (URF) at -80 degrees C is more simple, time-saving, less expensive, and, possibly, as effective as CRF. The aim of this retrospective analysis was to compare CRF and URF in childhood transplantation.


METHODS
A total of 54 PBPC transplants performed in 39 children aged 3 to 16 years (median, 9.5 years) were analyzed: 23 transplants in 16 children with CRF versus 31 transplants performed in 23 children with -80 degrees C URF. All grafts contained at least 2 x 10(6) per kg unselected CD34+ cells, enumerated before freezing. Nucleated cells infused ranged from 1.32 x 10(8) to 4.3 x 10(8) per mL with a median of 3.1 x 10(8) per mL. Cryoprotectant solution consisted of a final dimethyl sulfoxide (DMSO) concentration of 10 percent DMSO with autologous plasma.


RESULTS
The two study groups did not differ in terms of timing of neutrophil and platelet recovery or transfusion requirements. Adverse events related to graft infusion, severe complications, and transplant-related mortality were not significantly different between CRF and URF groups. In both groups only mild adverse events were observed during graft administration. URF procedures, however, were simpler and less expensive. At a median follow-up of 72 months, no secondary myelodysplasia was observed in either group.


CONCLUSIONS
Our analysis suggests that URF is safe and effective in the pediatric population.
Iannalfi
Alberto
A
Stem Cell Transplantation Unit, Department of Hematology-Oncology, A. Meyer Pediatric Hospital, University of Florence, Florence, Italy. albertoiannalfi@yahoo.it
Bambi
Franco
F
Tintori
Veronica
V
Lacitignola
Laura
L
Bernini
Gabriella
G
Mariani
Maria Pia
MP
Sanvito
Maria Chiara
MC
Pagliai
Francesca
F
Brandigi
Francesco
F
Muscarella
Elisa
E
Tapinassi
Francesca
F
Faulkner
Lawrence
L
D000293:Adolescent; D001793:Blood Preservation / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D015925:Cryopreservation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D036102:Peripheral Blood Stem Cell Transplantation / Q000379:methods*; D015203:Reproducibility of Results; D016896:Treatment Outcome