Viability and engraftment of hematopoietic progenitor cells after long-term cryopreservation: effect of diagnosis and percentage dimethyl sulfoxide concentration.
OBJECTIVE
We carried out a retrospective analysis of viability by diagnosis and dimethyl sulfoxide (DMSO) concentration in patients who had undergone autologous transplants using hematopoietic progenitor cells (HPC) after long-term storage (up to 17.8 years).


METHODS
Viability was tested using flow cytometry for HPC that were harvested and preserved using a controlled rate freezer and 5% or 10% DMSO with human serum albumin, then stored in liquid nitrogen. Data from 262 samples were analyzed (249 myeloma patients and 13 other diagnoses): 100 consecutively thawed samples with a storage time of <1 year (all 10% DMSO), 50 consecutive samples stored for 1-4.9 years (10% DMSO), 50 samples stored for 5-9 years (5% DMSO) and all samples stored and used for transplant after >9 years (60 samples, 5% DMSO; two samples, 10% DMSO).


RESULTS
No statistically significant difference in viability between the 5% DMSO and 10% DMSO groups was observed (P = 0.08), so the 1-4.9 years and 5-9 years were combined and the three groups (<1 year, 1-9 years and >9 years) were compared using an anova test. There was no difference in viability based on cryostorage period (P = 0.23) or between myeloma and other diagnoses (P = 0.45). No difference was seen in time to White blood cell (WBC) engraftment (P = 0.10) or to platelet engraftment between groups (P = 0.52).


CONCLUSIONS
These data suggest that long-term storage in 5% DMSO and human serum albumin is safe.
Veeraputhiran
Muthu
M
Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA. mkveeraputhiran@uams.edu
Theus
John W
JW
Pesek
Gina
G
Barlogie
Bart
B
Cottler-Fox
Michele
M
D018952:Antigens, CD34 / Q000096:biosynthesis; D001792:Blood Platelets / Q000502:physiology; D002452:Cell Count; D002470:Cell Survival; D015925:Cryopreservation; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D006085:Graft Survival; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells; D006801:Humans; D007962:Leukocytes / Q000502:physiology; D009101:Multiple Myeloma / Q000175:diagnosis / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D013997:Time Factors; D014182:Transplantation, Autologous
D018952:Antigens, CD34; D004121:Dimethyl Sulfoxide