Collection of peripheral blood progenitor cells on Day 4 is feasible and effective while reducing granulocyte-colony-stimulating factor exposure to healthy donors

Single Apheresis Session on the 4th Day of Granulocyte Colony-Stimulating Factor Administration Seems Convenient to Collect Enough Peripheral Blood Stem Cells from Healthy Donors

Background

To minimize adverse events of peripheral blood stem cell (PBSC) collection in healthy donors, it is reasonable to limit the total dose of granulocyte colony-stimulating factor (G-CSF) and/or the number of apheresis days without decreasing of PBSCs yield. Therefore, we have started to collect G-CSF induced PBSCs on day 4 instead of on day 5. So, we retrospectively aimed to investigate the results of this 4-day G-CSF administration.

Study Design and Methods

Seventy-six healthy donors who performed on G-CSF induced PBSCs donation consecutively between January 2020 and July 2022 were included in this study. G-CSF (filgrastim) at 2 × 5 µg/kg/day subcutaneously was applied. Apheresis started on day 4.

Results

Sixty-nine (90.8%) of 76 donors provided enough PBSCs on day 4 apheresis session. Younger age (p = 0.004), higher PB CD34+ cell count on the 4th day of G-CSF (p < 0.001), and male donor (p = 0.010) were correlated with increased amounts of PBSCs yield. Univariate and multivariate logistic regression analyses to predict very good mobilizers (collected PBSCs ≥8 × 106/kg after the first apheresis) were performed. In multivariate logistic regression analyses, male sex (p = 0.004), PB CD34+ cell count ≥100/µL on the 4th day of G-CSF (p < 0.001), and glomerular filtration rate ≥115 mL/min (p = 0.031) were found to be independent predicting factors to demonstrate very good mobilizer.

Conclusion

It seems that starting the apheresis on the 4th day of G-CSF administration is effective and to provide minimal G-CSF exposure in healthy donors.

Scoping Review of Factors Associated with Stem Cell Mobilization and Collection in Allogeneic Stem Cell Donors

There is wide interindividual variation in the efficacy of CD34+ cell mobilization and collection in healthy allogenic hematopoietic stem cell donors. Donor characteristics, blood cell counts, and various factors related to mobilization and collection have been associated with blood CD34+ cell count and CD34+ cell yield after granulocyte colony-stimulating factor (G-CSF) mobilization and collection. Given the heterogenous nature of the literature reporting these associations, in this scoping review we clarify the determinants of CD34+ count and yield. Studies published between 2000 and 2023 reporting allogeneic donors undergoing G-CSF mobilization and peripheral blood stem cell (PBSC) collection were evaluated. Eligible studies were those that assessed blood CD34+ cell count or CD34+ cell yield in the first PBSC collection after mobilization with 4 or 5 days of G-CSF treatment. Associations were recorded between these outcomes and donor factors (age, sex, weight, ethnicity), mobilization factors (G-CSF scheduling or dose), collection factors (venous access, processed blood volume [PBV]) or laboratory factors (blood cell counts at baseline or after mobilization). The 52 studies evaluated between 15 and 20,884 donors. Forty-three studies were retrospective, 33 assessed blood CD34+ cell counts, and 39 assessed CD34+ cell yield from PBSCs. Blood CD34+ cell counts consistently predicted CD34+ cell yield. Younger donors usually had higher blood CD34+ cell counts and CD34+ cell yield. Most studies that investigated the effect of donor ancestry found that donors of non-European ancestry had higher blood CD34+ cell counts after mobilization and higher CD34+ cell yields from collection. The poor consensus about the best predictors of blood CD34+ cell count and yield necessitates further prospective studies, particularly of the role of donor ancestry. The current focus on donor sex as a major predictor requires re-evaluation.

Is an earlier strategy for harvesting peripheral blood stem cells in healthy allogeneic donors feasible?

INTRODUCTION

Peripheral blood stem cells (PBSC) mobilization with granulocyte colony stimulating factor (G-CSF) for healthy donors is generally performed at 5th day. However, earlier collection is sometimes feasible, raising the question of whether to initiate apheresis early to limit further G-CSF exposure, while considering the risk of mobilization failure. In the current study, we examined the factors predicting successful 4th day collection and developed a model that can be used practically.

PATIENTS AND METHODS

The study was carried out by obtaining the data of PBSC mobilizations performed between January 2009 and September 2022 in our transplantation center.

RESULTS

A total of 141 healthy donors with a median donor age of 32 (18-64) were included. Adequate mobilization was achieved in 115 (81.6 %) patients. Median peripheral CD34 + cell count was 69.4/μL in the adequate mobilization group and 46/μL in the mobilization failure group (p < 0001). Multivariate analysis revealed that donor/recipient weight ratio and the 4th day peripheral CD34 + cell count≥ 50/μL were independent markers for 4th day collection success. A predictive model of our center including these parameters was available with 0.765 sensitivity and 0.968 specificity [(AUC):0.948 (95 % CI, 0.90-0.99), p < 0.001].

CONCLUSION

The result of the current study shows that peripheral 4th day collection can be performed in selected donors, taking into account peripheral CD34+ cell count and donor/recipient weight ratio. In addition, using these indicators, new predictive models can be created that may assist clinicians in daily practice.

Stem Cells Collection and Mobilization in Adult Autologous/Allogeneic Transplantation: Critical Points and Future Challenges

Achieving successful hematopoietic stem cell transplantation (HSCT) relies on two fundamental pillars: effective mobilization and efficient collection through apheresis to attain the optimal graft dose. These cornerstones pave the way for enhanced patient outcomes. The primary challenges encountered by the clinical unit and collection facility within a transplant program encompass augmenting mobilization efficiency to optimize the harvest of target cell populations, implementing robust monitoring and predictive strategies for mobilization, streamlining the apheresis procedure to minimize collection duration while ensuring adequate yield, prioritizing patient comfort by reducing the overall collection time, guaranteeing the quality and purity of stem cell products to optimize graft function and transplant success, and facilitating seamless coordination between diverse entities involved in the HSCT process. In this review, we aim to address key questions and provide insights into the critical aspects of mobilizing and collecting hematopoietic stem cells for transplantation purposes.

Collection efficiency in apheresis

Significant advances in procedural information displayed by current apheresis machines have been made, but analyses of cell collection efficiency (CE) still rely on calculations done by apheresis professionals. Accordingly, understanding CE equations can support the optimization of apheresis techniques and identification of incidents that could impact the procedure's effectiveness. This report summarizes classical and novel CE analyses applied to apheresis exemplified by an actual case of hematopoietic progenitor cell collection. In addition to the apheresis yield and most common CE1 and CE2 formulas, we present the instantaneous and corrected CE, fold enrichment, collection throughput, collection rate and its variants, average inlet rate, classical and adjusted captured cells, recruitment pool, recruitment factor, recruitment coefficient, blood component loss, predictive apheresis yield, and performance ratio calculations. Moreover, the mathematical relationship between these CE equations is also shown, which can be helpful in many apheresis procedures.

Medical and ethical considerations on hematopoietic stem cells mobilization for healthy donors

Hematopoietic stem cell transplantation is a common procedure potentially beneficial to many individuals with cancer, hematological, or inherited disorders, and has highlighted the need of related or unrelated donors to perform allograft. Donation of hematopoietic stem cells, either through bone marrow harvest or peripheral blood stem cell collection, is well-established and widespread. Over the past two decades, the peripheral blood stem cell collection by aphaeresis has become the main source of hematopoietic stem cells for transplantation, due to faster engraftment and practicability and lower risk of relapse for high-risk patients. For peripheral blood stem cell donation, donors require mobilization of hematopoietic stem cells from bone marrow into the blood stream. This is performed by growth factors injections. This article is a review of reported applications of growth factors (original granulocyte colony stimulating factor and its biosimilars), for healthy donors' peripheral blood stem cell mobilization, in terms of toxicity, side effects, efficacy and follow-up. There is still an ethical dilemma for clinicians involved in allograft, because they expose healthy donors to drugs. It is important to dispel some of the critical concerns regarding their use in healthy volunteers, particularly because they receive no personal therapeutic benefit from this procedure.

Healthy donor hematopoietic stem cell mobilization with biosimilar granulocyte-colony-stimulating factor: safety, efficacy, and graft performance

BACKGROUND

Biosimilar granulocyte-colony-stimulating factors (G-CSFs) have been available in the European Union since 2008, and Sandoz' biosimilar filgrastim was approved in the United States in March 2015 for all of the reference product's indications except acute radiation syndrome. Biosimilar G-CSFs have been largely embraced by the medical community, except for some reservations about healthy-donor stem cell mobilization, for which use outside of clinical studies was cautioned against by some members of the scientific community.

STUDY DESIGN AND METHODS

In a two-center safety surveillance study (National Clinical Trial NCT01766934), 245 healthy volunteer stem cell donors were enrolled. Of 244 donors who began mobilization with twice-daily Sandoz biosimilar filgrastim, 242 received a full (n = 241) or partial (n = 1) course of G-CSF and underwent apheresis. Efficacy and safety were assessed and are reported here.

RESULTS

Biosimilar filgrastim was accompanied by the typical G-CSF class-related adverse effects of expected frequency and severity. Median mobilization for CD34-positive stem cells was 97/µL (range, 20-347/µL); after one apheresis (91%) or two aphereses (9%) from all but three donors (1.2%), cell doses in excess of the typical 4 × 10⁶ CD34-positive cells/kg of the recipient had been collected (range, 3-52 × 10⁶ /kg). Biochemical and hematologic alterations were consistent with previous reports; all had normalized by the first follow-up 1 month after mobilization. Stem cell products engrafted with typical probability and kinetics for G-CSF-mobilized stem cell products.

CONCLUSION

These data support the use of biosimilar filgrastim for healthy-donor stem cell mobilization as safe and effective.

Comparison between intermittent and continuous spectra optia leukapheresis systems for autologous peripheral blood stem cell collection

Terumo BCT recently introduced a new system for mononuclear cell (MNC) collection that uses a Spectra Optia apheresis machine equipped with a redesigned disposable kit and software program (version 11.2). It allows for the continuous collection of MNCs, unlike the original Spectra Optia system (version 7.2), which included a chamber for two-step cell separation. The aim of this study was to compare the two apheresis systems in regard to specific performance parameters. A retrospective data analysis of 150 patients who had undergone peripheral blood stem cell collection between March of 2014 and May of 2015 at our institution was performed. For the matched comparison, patients were divided into two groups by diagnosis and by previous forms of therapy received: a homogeneous group of patients with multiple myeloma (MM) that had received first line therapy ("MM" group, n = 88) and a heterogeneous group that included all of the other patients ("other" group, n = 62). No significant differences in CD34+ collection yields between both collection regimens were found (p_MM  = 0.19, p_other  = 0.74) in either group. Moreover, similar performance ratios (collected/predicted CD34+ cell number in %) were observed (p_MM  = 0.89, p_other  = 0.1). No relevant variations in platelet or hemoglobin loss were found between the two systems. We conclude that the new continuous Spectra Optia MNC system is equally efficient in collecting CD34+ cells and can be used without sacrificing collection efficiency levels when treating a broad variety of autologous patients. J. Clin. Apheresis 32:27-34, 2017. © 2016 Wiley Periodicals, Inc.

[Short-term effects of hemogram in healthy donors after peripheral blood stem cell collection]

目的

探讨连续外周血造血干细胞（PBSC）采集对异基因造血干细胞供者外周血细胞计数的影响以及供者对连续采集的耐受性。

方法

166名于2013至2014年在浙江大学医学院附属第一医院血液科捐献PBSC的亲缘异基因供者，男86名，女80名，中位年龄40.5（15.0~60.0）岁。动员方案为G-CSF 5~10 µg·kg⁻¹·d⁻¹皮下注射至采集结束。于PBSC动员前、采集前、采集1次及2次后检测供者外周血以及采集物中WBC、PLT、HGB。

结果

连续2次PBSC采集后供者外周血HGB中位数由145（94~181）g/L降至138（93~167）g/L（P<0.05），PLT中位数由231（105~490）×10⁹/L降至95（39~210）× 10⁹/L（P<0.05），WBC差异无统计学意义（P>0.05）。采集物中HGB与供者外周血HGB降幅呈低度正相关（r=0.297，P=0.017），采集物中PLT与供者外周血PLT降幅高度相关（r=0.719，P<0.001）。不同年龄组供者在PBSC采集后的HGB降幅两两比较差异无统计学意义（P≥0.05）。PLT差异无统计学意义（P>0.05）。不同体重指数供者在PBSC采集1次及2次后外周血HGB降幅差异均有统计学意义（P=0.003，P<0.001），体重指数<18.5 kg/m²的偏瘦组供者HGB下降最明显（P<0.05）。

结论

健康异基因造血干细胞供者在连续PBSC采集过程中HGB轻度下降，对于偏瘦供者应调整采集参数以保证安全。采集PBSC会使血小板减少的风险增加，减少的程度与年龄及体重指数无关，且均可耐受。