Apheresis days required for harvesting CD34+ cells predicts hematopoietic recovery and survival following autologous transplantation

Is neutropenic fever an obstacle to effective stem cell harvesting?

INTRODUCTION

Autologous stem cell transplantation (ASCT) is a well-established consolidation treatment for many hematologic cancers which delivers prolonged survival. A subset of patients' adequate stem cell harvest is not achievable with a solitary use of granulocyte colony-stimulating agents (G-CSF). Generally, chemomobilization is employed for patients failing G-CSF and its most feared complication febrile neutropenia (FN).

MATERIALS AND METHODS

Here, we aimed to investigate the impact of the FN in chemomobilization on apheresis outcomes and engraftment. One hundred and eighty-three patients with the diagnosis of lymphoma or myeloma who underwent chemomobilization between 2015 and 2020 were included in the study.

RESULTS

Forty-three patients experienced FN. All patients received G-CSF. All myeloma patients were mobilized with 4 g/m2 cyclophosphamide, but it was heterogeneous for lymphoma patients. The precollection blood counts, harvested CD34+ hematopoietic stem cells (HSCs)/kg, apheresis count, and engraftment durations were recorded. Preapheresis leukocyte and platelet were lower in the FN group (P = 0,004 and P = 0,001). Peripheral CD34 HSCs and total harvested CD34 HSCs were similar among groups (P = 0.25 and P = 0.9). More apheresis was needed in the FN group, but it was not significant (P = 0.07). Undergoing ASCT was similar (P = 0.7); however, platelet and neutrophil engraftment durations were slower in the FN group (P = 0.05 and P = 0.001).

CONCLUSION

Harvesting sufficient CD34+ HSCs from patients with FN is still feasible; however, FN treatment should begin promptly, and further apheresis sessions may be required.

Cost saving, patient centered algorithm for progenitor cell mobilization for autologous hematopoietic cell transplantation

Administration of plerixafor with granulocyte-colony stimulating factor (G-CSF) mobilizes CD34+ cells much more effectively than G-CSF alone, but cost generally limits plerixafor use to patients at high risk of insufficient CD34+ cell collection based on low peripheral blood (PB) CD34+ counts following 4 days of G-CSF. We analyzed costs associated with administering plerixafor to patients with higher day 4 CD34+ cell counts to decrease apheresis days and explored the use of a fixed split dose of plerixafor instead of weight-based dosing. We analyzed 235 patients with plasma cell disorders or non-Hodgkin's lymphoma who underwent progenitor cell mobilization and autologous hematopoietic cell transplantation (AHCT) between March 2014 and December 2017. Two hundred ten (89%) received G-CSF plus Plerixafor and 25 (11%) received G-CSF alone. Overall, 180 patients (77%) collected in 1 day, 53 (22%) in 2 days and 2 (1%) in 3 days. Based on our data, we present a probabilistic algorithm to identify patients likely to require more than one day of collection using G-CSF alone. CD34+ cell yield, ANC and platelet recovery were not significantly different between fixed and standard dose plerixafor. Plerixafor enabled collection in 1 day and with estimated savings of $5000, compared to patients who did not receive plerixafor and required collection for three days. While collection and processing costs and patient populations vary among institutions, our results suggest re-evaluation of current algorithms.

Neutropenic fever during peripheral blood progenitor cell mobilization is associated with decreased CD34+ cell collection and increased apheresis collection days

BACKGROUND

Peripheral blood progenitor cell (PBPC) mobilization with chemotherapy in addition to Granulocyte-Colony Stimulating Factor (G-CSF) improves cell collection compared to G-CSF alone; however, it is associated with increased risk of neutropenic fever (NF).

METHODS

We analyzed risk factors for post-priming NF and NF association with autologous stem cell transplant outcomes. Between 1998 and 2008, 593 adult patients with lymphoma underwent PBPC mobilization with etoposide and G-CSF.

RESULTS

Median age was 51 years (range 18-77) and 372 (63%) were male. Diagnoses were 457 (77%) non-Hodgkin lymphoma and 136 (23%) Hodgkin lymphoma. Of 554 (93%) transplanted patients, majority were in complete or partial remission at time of transplant (88%). Overall, 141 (24%) patients were hospitalized for NF. Nine patients (6%) had bacteremia, 4 (3%) had pneumonia, 2 (<1%) had herpes simplex viral infections, and the remaining 126 (90%) had no identified infection source. NF patients had lower likelihood of proceeding to transplant (86% vs. 96%, P < .001), lower CD34+ cell dose collection (median 7.23 × 106 CD34+ cells/kg vs. 8.98 × 106 CD34+ cells/kg, P = .002), and were more likely to require > 4 days of apheresis (48% vs. 37%, P < .001). NF was associated with a higher 30-day readmission rate following transplant hospitalization (17% vs. 9%, P = .012).

CONCLUSION

NF during etoposide priming is associated with lower likelihood of proceeding to transplant, lower CD34+ cell dose collection, more apheresis days required for collection and a higher 30-day readmission rate following transplant discharge.

Relapse risk after autologous stem cell transplantation in patients with lymphoma based on CD34+ cell dose

It is unclear whether higher CD34 + cell doses infused for ASCT have any influence on survival or relapse in patients with lymphoma. We analyzed the correlation of infused CD34 + cell dose with relapse, survival, and hematopoietic recovery in 146 consecutive patients undergoing ASCT for lymphoma. Higher doses (>5 × 10⁶/kg) were significantly correlated with earlier hematopoietic recovery, fewer infectious episodes, lower transfusion needs. No differences were observed in lymphoma outcomes (4-year relapse incidence of 38% [95%CI: 29%-48%] in the lower dose group versus 51% [95%CI: 30%-69%] in the higher dose group, 10-year OS probabilities of 58% [95%CI: 48%-68%] versus 75% [95%CI: 59%-91%], 10-year DFS probabilities of 47% [95%CI: 37%-57%] versus 42% [95%CI: 23%-61%], p = NS for all outcomes). In this series, a higher infused CD34 + cell dose did not correlate with survival or relapse but correlated with earlier hematopoietic recovery and lower resource consumption.