Occurrence and severity of adverse events after autologous hematopoietic progenitor cell infusion are related to the amount of granulocytes in the apheresis product.

Background: Adverse events (AEs) after hematopoietic progenitor cell (HPC) infusion are rare but might be life-threatening. These reactions have traditionally been associated with the amount of infused cryoprotectant, but persistence of such events after dimethyl sulfoxide (DMSO) depletion has questioned this assumption.

Study Design And Methods: The incidence of AEs on a cohort of 460 patients (490 HPC infusions) undergoing autologous DMSO-reduced HPC transplantation was prospectively evaluated. HPCs were collected from adult patients with various hematologic or solid malignancies. After quality control (QC) on fresh apheresis products and subsequent cryopreservation, HPC grafts were thawed and washed at the cell therapy facility. QC was performed on each graft after washing, and clinical data were collected for each infusion.

Results: AEs were reported in 66 cases (13.5%) and were graded according to the NCI-CTC scale from 1 to 4. Although none of the factors associated with patient characteristics or infusion procedure were different between the two groups (no AE vs. occurrence of AE), it was found that the absolute number of granulocytes measured before freezing was considerably higher in the AE group. Furthermore, within this group, there was a strong correlation between the amount of granulocytes and the grading of the reaction.

Conclusion: This survey demonstrates that AEs occurring in the setting of DMSO-reduced HPC grafts are directly related to the amount of granulocytes and thus emphasizes the need for high-quality apheresis products so as to improve the safety of HPC infusion.