The influence of cell concentration at cryopreservation on neutrophil engraftment after autologous peripheral blood stem cell transplantation

In patients with adequate CD34 cell collections, total leukocyte concentrations of 282 × 106/mL, freezing with 5% dimethyl sulfoxide and 6% hydroxyethylamide solution without a controlled-rate freezer, and storing cells at −80 °C yielded excellent engraftment. Further increases in cell concentration may delay engraftment, without affecting safety.