Autologous Hematopoietic Progenitor Cell Infusion Adverse Event Associated with Apheresis Product Granulocyte Content

Introduction: Autologous hematopoietic progenitor cell (HPC) transplantation after high-dose chemotherapy has been used for several years in the treatment of various diseases.  Over the past few years, peripheral blood have become the standard hematopoietic progenitor cell source. This process requires frozen HPC graft storage in mechanical freezers or liquid nitrogen for their subsequent infusion. Addition of a cryoprotectant solution such as dimethylsulfoxide (DMSO) is required in order to prevent ice crystals formation during HPC freezing process. Clinical toxicity has been classically attributed to thawed HPC DMSO content. However, adverse events still have been described after DMSO removal. The amount of granulocytes in the apheresis product has been correlated to adverse event occurrence and severity. In this study, we evaluated correlation between pre leukapheresis peripheral blood granulocytes count and adverse event occurrence during thawed HPC infusion.

Patients and Methods: We retrospectively analyzed data from 361 patients submitted to autologous HPC transplantation from January 1999 to December 2013. HPC collection was performed with large volume leukapheresis, in a continuous-flow blood separator (Spectra, TerumoBCT, USA), with the mononuclear cell collection protocol, and ACD-A as anticoagulant solution. The apheresis product was diluted to maintain cell concentration less than 150x10⁹ cells/L or 300x10⁹ cells/L for storage in mechanical freezer or liquid nitrogen, respectively. A 5% DMSO solution was added to the HPC stored in mechanical freezer, whereas 10% DMSO was added for storage in liquid nitrogen. Complete blood count and CD34+ cell determination were performed in pre collection peripheral blood and the apheresis product. CD34+ cell determination was performed in the equipment Coulter Epics XL-MCL Flow Cytometer (Beckman Coulter, USA) according to the ISHAGE protocol. The HPC graft was thawed and infused without further manipulation. Infused volume limit was 10 ml/kg b.w or 40 mL of DMSO/day. Infusion was fractionated whenever required. Antihistamine drug and corticosteroid were given before all infusion. Adverse events included: nausea, vomiting, fever; hemodynamic, neurological, gastrointestinal, renal disorders; cardiac conduction disturbances, and hypersensitivity.

Results: The patients´ median age was 50±17 yo (min: 1 max: 86), weight 74±19 kg (10-143). The underlying diseases were: Multiple Myeloma, 105 (29%), NonHodgkin lymphoma, 99 (27%), Acute Myeloid Leukemia, 37 (10%), solid tumor and multiple sclerosis 32 (9%) each and Hodgkin Lymphoma, 30 (8%) patients. CBC median values: hemoglobin, 10.9±1.6 g/dl (9.8-12.0), platelet 74,2±86 x10⁹/L (44-138), white blood cell 20.8±18.3x10⁹/L(9.6-34.4), granulocyte 16.5±15.8x10⁹/L (6.6-28.9), and CD34+ cell, 23±79/mm³ (12-54).  Apheresis product median values: total volume  235±47 mL (215-256), white blood cell 175±113x10⁹/L (122-257), granulocyte 43.5±67.6x10⁹/L (13.4-93.9), and CD34+ 0.8±2.4x10⁹/L (0.4-2.0). Total nucleated cell collected was 5.7±4.5x10⁸/kg b.w (3.9-8.5), total CD34+ 2.5±7.3x10⁶/kg b.w (1.2-6.3). A total of 490 (74%) apheresis products were stored in mechanical freezer. A total of 289 thawed HPC infusions occurred in the study period. Adverse event occurred in 28 (10%) cases. The most common manifestations were hypertension and nausea/vomiting. Mild or moderate adverse event occurred in 26 infusions and severe adverse event in 02 cases. There was no difference in the infused HPC variables between patients with and without adverse event. However, significant difference was found in the apheresis product variables: median granulocyte count in the group with adverse reaction 74.7±52.5x10⁹/L (39.2-103.6) vs. 43.1±61.6x10⁹/L (12.6 to 89.2) in the group without adverse reaction, p=0.0158; total nucleated cells 8.1± 8.3x10⁸/kg b.w (5.8-13) vs. 5.8±4.7x10⁸/kg b.w (3.8-8.6), p=0.0033.

Conclusion: The apheresis product granulocyte count and total nucleated cells were correlated with adverse event during infusion of HPC cryopreserved without further manipulation after thawing.