Accurate prediction of autologous stem cell apheresis yields using a double variable-dependent method assures systematic efficiency control of continuous flow collection procedures

Personalized Autologous Stem Cell Harvesting Improves Patient Collection Outcomes

OBJECTIVES

This study aims to demonstrate that utilizing a personalized approach to apheresis stem cell collection, can safely optimize the collection outcomes, especially in the context of poor mobilizers and high cell targets.

BACKGROUND

The optimal mobilization and harvesting of peripheral blood stem cells is critical to the success of the stem cell transplant. The ideal strategy that promotes better cell yields, with sustainable use of resources and assuring patient safety, should be pursued.

METHODS

PBSC collections for autologous stem cell transplant data according to a fixed-processed volume strategy (One Size Fits All) or individualized to patients CD34+ peripheral blood content and target approach (Custom-Tailored or CT) were retrospectively compared.

RESULTS

A total of 263 collections from 142 patients were assessed. The majority of patients were male, had multiple myeloma and were mobilized with isolated G-CSF. The CT strategy promoted a significantly higher CD34+ cell yield when the pre-collection CD34 was lower than 20/µl (1.02 ± 0.16 versus 1.36 ± 0.23, p < 0.001) and also a decrease in the proportion of mobilization cycles that needed 3 apheresis (31% versus 14%, p = 0.02). There was no difference in apheresis-related adverse events between the groups.

CONCLUSION

Tailoring the apheresis procedures to the patient-specific characteristics and objectives, can effectively promote better patient outcome.

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.

Predicting the CD34 content of mobilized peripheral blood leukapheresis products: single institution experience over 20 years

BACKGROUND AIMS

Since the standardization of CD34 measurement by flow cytometry, predictors of leukapheresis CD34 yield have played a pivotal role in planning donor leukaphereses. We describe here a single institution's experience with a multivariate predictor that was used for 2,929 products without alteration for 20 years.

METHODS

The ordinary least squares regression model variables included log peripheral CD34 count, collection duration (3- versus 4-hours), collection number, donor sex, and transplant type.

RESULTS

During the study period we changed flow cytometers twice and leukapheresis instruments once. During the Cobe Spectra era the predictor explained 90% of the variability in CD34 collection yield for autologous transplants (r2 = 0.90), and 70% for allogeneic transplants with an overall sensitivity to predict a CD34 yield of ≥ 1 × 106/kg of 97.7%, and specificity of 81.4%.

CONCLUSIONS

Implemented prospectively with real-time result reporting, the model allowed us to predict CD34 yield with both 3- and 4-hour collection scenarios. Given this guidance, 3-hour collections were selected by the clinical team 25% of the time, saving patient leukapheresis time and resources. When faced with a prediction of < 1 × 106 CD34/kg, the clinical team chose to defer collection 72% of the time. In instances where leukapheresis was performed despite a poor predicted outcome, 85% of patients collected on the Cobe Spectra, and 92% of patients collected on the Optia, failed to collect at least 1 × 106 CD34/kg. A revised model is tested retrospectively on Optia data, and suggestions for further improvements are discussed.

Predicting Successful Hematopoietic Stem Cell Collection in Healthy Allogeneic Donors

Introduction

Collection of peripheral blood stem cells (PBSCs) from healthy donors is a well-established process. We aimed to identify factors predictive of successful CD34+ PBSC collection and established a formula capable of predicting CD34+ cell yield.

Methods

We retrospectively evaluated 588 healthy adult donors (median age 29 years, range 18-69 years) at our institution from 2017 to 2022. The predicted minimal number of CD34+ cells was calculated as follows: (peripheral CD34+ cells/µL × adjusted collection efficiency of 30%) × total liters processed. This formula was further modified according to donor and recipient body weight (BW).

Results

Median total collection was 8.0 × 106 CD34+ cells/kg BW (range 1.0-47.1 × 106 cells/kg BW) with 522 donors (89%) collecting ≥5.0 × 106 cells/kg of recipient BW. A second leukapheresis (LP) was performed in 49 donors. Need for two LPs was more common in female donors (OR 6.68, 95% CI, 2.62-17.05; p < 0.001), donors with higher age (OR for 10 years difference 1.53, 95% CI, 1.15-2.03, p = 0.003), donors with WBC count <30 × 109/L after 5 days of granulocyte-colony stimulating factor (G-CSF) stimulation (OR, 4.33; 95% CI, 1.59-11.83; p = 0.004), and a donor/recipient weight ratio <1 (OR 6.21, 95% CI, 2.69-14.34; p < 0.001). Predictive factors for optimal LP (i.e., ≥5.0 × 106 CD34+ cells/kg of recipient BW) were peripheral blood (PB) CD34+ cell count >50/µL (OR 12.82, range 6.34-25.92, p < 0.001), male donor (OR 2.77, range 1.06-7.23, p = 0.04), and a donor/recipient weight ratio >1 (OR 3.12, range 1.57-6.24, p = 0.001). WBC, platelets, hemoglobin, and age had no significant predictive value. Predicted versus observed number of CD34+ cells/kg BW collected demonstrated a very strong linear correlation (r = 0.925, 95% CI, 0.912-0.936, p < 0.0001).

Conclusions

Of the routinely monitored indicators in PBSC donors, CD34+ cell count in PB is the most important factor in predicting G-CSF-induced PBSC yields. Higher age, female sex, WBC <30 × 109/L, and a donor/recipient weight ratio <1 are useful indicators for identifying suboptimal mobilizers. The modified formula has shown successful and consistent performance in the prediction of key outcome measures including the minimum CD34+ cell collection, determination of the required length of apheresis, and whether a second day of PBSC collection was necessary to achieve the respective collection goal.

Peripheral Blood Allogeneic Stem Cell Mobilization: Can We Predict a Suboptimal Mobilization?

Allogeneic peripheral blood stem cells mobilization is now the basis of most stem cell transplants. In a very limited number of cases, mobilization is suboptimal leading to further collection procedures, to suboptimal cell doses infusion with delayed engraftment time, increased risks of transplant procedure and of related costs. To date we have no recognized and shared criteria for early estimating the probability of poor mobilization in healthy donors. We then analyzed allogeneic peripheral blood stem cell donations performed at the Fondazione Policlinico Universitario A.Gemelli IRCCS Hospital from January 2013 to December 2021 in order to identify premobilization factors associated with successful mobilization. The following data were collected: age, gender, weight, complete blood cell count at baseline, G-CSF dose, number of collection procedures, CD34+ cell count in peripheral blood on the first day of collection, CD34+ cell dose per kg body weight of recipient. Mobilization efficacy was defined according to the number of CD34+ cells in peripheral blood on day +5 of G-CSF administration. We classified donors as sub-optimal mobilizers or good mobilizers according to the achievement of the 50 CD34+ cell/μL threshold. We observed 30 suboptimal mobilizations in 158 allogeneic peripheral blood stem cell donations. Age and baseline white blood cell count were factors significantly associated with negative or positive impact on mobilization, respectively. We did not find significant differences in mobilization based on gender or G-CSF dose. Using cut-off values of 43 years and 5.5×10⁹/L WBC count, we built a suboptimal mobilization score: donors who reach 2, 1 or 0 points have a 46%, 16% or 4% probability of suboptimal mobilization, respectively. Our model explains 26% of the variability of mobilization confirming that most of the mobilization magnitude depends on genetically determined factors; however, suboptimal mobilization score is a simple tool providing an early assessment of mobilization efficacy before G-CSF administration begins in order to support allogeneic stem cells selection, mobilization and collection. Through a systematic review, we looked for confirmation of our findings. According to the published articles, all the variables we included in our model are confirmed to be strongly related to the success of mobilization. We believe that score system approach could be applied in clinical practice to assess the risk of mobilization failure at baseline allowing for a priori intervention.

Impact of Mobilization Strategies on Peripheral Blood Stem Cell Collection Efficiency and Product Quality: A Retrospective Single-Center Study

Autologous stem cell transplantation is routinely used in the management of several hematological diseases, solid tumors, and immune disorders. Peripheral blood stem cell (PBSC) collection performed by apheresis is the preferred source of stem cells. In this study, the potential impact of mobilization regimens on the performance of the Spectra Optia^® continuous mononuclear cell collection system was evaluated. We performed a retrospective data analysis for patients undergoing autologous PBSC collection at the Medical University Vienna, Vienna General Hospital between September 2016 and June 2018. Collections were divided into two main groups according to the mobilization regimen received: without (210 collections) or with (99 collections) plerixafor. Assessed variables included product characteristics and collection efficiency (CE). Overall, product characteristics were similar between the groups. Median CD34+ CE2 was 50.1% versus 53.0%, and CE1 was 66.9% versus 69.9% following mobilization without and with plerixafor, respectively; the difference was not statistically significant. Simple linear regression showed a very weak positive correlation between the mobilization method and CE1 or CE2 (mobilization with plerixafor increased CE2 by 4.106%). In conclusion, the Spectra Optia^® apheresis system led to high CE and a good quality of PBSC products when mobilization regimens with or without plerixafor were used.

Low hematocrit reduces the efficiency of CD34+ cell collection when using the Spectra Optia continuous mononuclear cell collection procedure

BACKGROUND

CD34⁺ cell collection efficiency (CE) is the determining factor when calculating processed blood volume (PBV) for leukapheresis (LP). However, the factors affecting CE in the continuous mononuclear cell collection (cMNC) protocol performed by the Spectra Optia apheresis system are not well established.

STUDY DESIGN AND METHODS

We retrospectively collected the data from 147 consecutive apheresis procedures across 106 healthy donors and 27 patients completed between July 2016 and December 2020 at the Okayama University Hospital. All procedures were performed using the Optia cMNC protocol.

RESULTS

The median CD34⁺ CE2 was significantly higher in the donor samples (64.3%) than in the patient samples (46.8%) (p < .0001). WBC counts, hematocrit, and platelet counts were all significantly higher in the donors than in the patients, and there was a moderate positive correlation between CD34⁺ CE2 and hematocrit (r = .47, p < .0001), with the equation of the line being y = 1.23x + 12.23. In contrast, there was only a very weak correlation between CD34⁺ CE2 and WBC or platelet count. In addition, low hematocrit correlated with an increased time to interface formation.

CONCLUSION

These data revealed the negative impact of low hematocrit on the efficiency of CD34⁺ cell collection when using the Optia cMNC protocol and suggest that hematocrit values should also be considered when determining PBV.

A simplified CD34+ based preharvest prediction tool for HPC(A) collection

BACKGROUND

Hematopoietic stem cell transplantation is an important treatment that is dependent on the collection of sufficient CD34+ hematopoietic progenitor cells. The peripheral blood CD34 count (PB CD34+ counts) measured by flow cytometry can be used in predicting CD34+ stem cell yields hours before the completion of collection. Previously described formulas to predict the yield have used many different variables. As such, there is currently no consensus on an industry-standard algorithm or formula.

STUDY DESIGN AND METHODS

Retrospective reviews of same-day PB CD34+ counts and the ensuing absolute CD34+ yields of mobilized donors (allogeneic and autologous) were used to develop and validate a formula using regression analysis to predict the CD34+ stem cell yield. A metric of prediction correlation, using root mean square error (RMSE), was used to assess the robustness of our prediction formula in addition to comparisons with two other published formulas, as well as subset analysis.

RESULTS

A formula in the form of y = mx^b with r = 0.95 and 95% confidence intervals was generated and validated. The ratio of actual to predicted yield demonstrated a high correlation coefficient (r = 0.96) with linear regression and overall RMSE of 228.4, which was lower than the two prior studies (calculated RMSE = 330.8 and 405.2). Subset analyses indicated male patients, lymphoma patients, and patients >60 years of age demonstrated lower RMSEs.

CONCLUSION

We have demonstrated a simple yet robust formula that can be used prospectively to accurately predict the CD34+ stem cell yield in both autologous and allogeneic donors, which also accounts for recipient weight.

Leukapheresis cell concentration adjustment required for a successful recovery of HSC after cryopreservation

The recovering of an adequate number of hematopoietic stem cells after cryopreservation is considered pivotal for successful transplantation. Various factors could influence the recovery of HSC following processing and cryopreservation. Therefore, leukapheresis product from thirty patients was cryopreserved in 10% DMSO in cryopreservation bags for their autologous bone marrow transplantation, and 2 ml were cryopreserved in cryovials for post-thaw viability assessment by flow cytometry. The percentage of viable HSCs recovered post-cryopreservation in leukapheresis product was significantly influenced by the concentration of the total nucleated cells cryopreserved per volume. Patients receiving a higher rate of viable HSCs resulted in earlier engraftment of both neutrophils and platelets, so they have been discharged earlier from the hospital. Furthermore, Storage temperature and duration played a role in the recovery of these cells and for the support of the findings, age of the patient at the time of collection did not show any impact on the recovery of this HSC post-cryopreservation. In conclusion, various influencing factors must be taken into consideration during the cryopreservation of HSCs, especially for poor mobilizing patients with a low number of collected hematopoietic stem cells.

Validation of a formula predictive of peripheral blood stem cell yield and successful collection in healthy allogeneic donors

BACKGROUND

An efficient mobilization and collection of peripheral blood stem cells (PBSCs) are crucial to optimize engraftment in the recipient. We aim to validate a formula that predicted CD34⁺ cell yield and to describe variables that correlated with high yield mobilization and collection in healthy donors.

METHODS

We retrospectively analyzed clinical and laboratory data from healthy donors who underwent PBSC collection from 2006 to 2015. The predicted number of collected cells was calculated using the following formula: Total number of CD34⁺ (cells×10⁶/kg) yield=[(peripheral CD34⁺ cells/μL)×(0.43)/recipient body weight (kg)]×total liters processed.

RESULTS

We evaluated 338 collections from 307 allogeneic PBSC donors. The predicted versus the observed number of CD34⁺ cells/kg collected yielded an r-value of 0.775 (0.726-0.816; p<0.0001). Overall, 55.7% donors had an acceptable mobilization level. Donors with a body weight <67kg were less likely to yield a satisfactory CD34⁺ cell count (OR=0.44; 95% CI 0.24-0.81), while a white blood cell (WBC) count >40×10⁹/L (OR=3.69; 2.11-6.46) and platelet count ≥200×10⁹/L (OR=2.09; 1.26-3.47) on the day of collection predicted a good level of mobilization. Predictors of a CD34⁺ cell yield/kg of ≥4×10⁶ with only one apheresis session were: circulating CD34⁺ cells/μL >40 (OR=16; 6.94-36.93), hemoglobin ≥14g/dL (OR=3.40; 1.53-7.57), WBC >40×10⁹/L (OR=4.61; 2.10-10.10) on the first collection day, and a positive delta weight between donor and recipient (OR=3.10; 1.36-7.06).

CONCLUSION

The formula for predicting CD34⁺ cell yield is accurate and suggests the optimal length of time for successful leukapheresis. Validation of the predictors of successful mobilization will help to further refine PBSC leukapheresis procedures.

Initial Results of Peripheral-Blood Stem-Cell Mobilization, Collection, Cryopreservation, and Engraftment After Autologous Transplantation Confirm That the Capacity-Building Approach Offers Good Chances of Success in Critical Contexts: A Kurdish-Italian Cooperative Project at the Hiwa Cancer Hospital, Sulaymaniyah

Introduction

At Hiwa Cancer Hospital (Sulaymaniyah, Iraqi Kurdistan) after the center was started by a cooperative project in June 2016, autologous transplantation was developed.

Patients and Methods

To develop the project, the capacity-building approach was adopted, with on-site training and coaching of personnel, educational meetings, lectures, on-the-job training, and the implementation of quality management planning.

Results

Here, we report initial results of peripheral-blood stem-cell mobilization and collection of the first 27 patients (age 12 to 61 years; 19 males and 8 females; multiple myeloma, n = 10; plasma cell leukemia, n = 1; Hodgkin lymphoma, n = 12; non-Hodgkin lymphoma, n = 3; and acute myeloid leukemia, n = 1). Only three (11.5%) of 26 patients experienced a failure of mobilization. A median of 6.1 × 10⁶/kg CD34-positive cells per patient were collected (range, 2.4 to 20.8), with two apheretic runs. Twenty-four patients underwent autologous transplantation. All but one transplantation engrafted fully and steadily, with 0.5 and 1.0 × 10⁹/L polymorphonucleates on day 10.5 (range, 8 to 12) and day 11 (range, 9 to 15), respectively, and with 20 and 50 × 10⁹/L platelets on day 13 (range, 10 to 17) and day 17 (range, 2 to 44), respectively. More than 95% of patients are projected to survive 1 year after autograft.

Conclusion

These data are the result of an Italian effort to establish in Iraqi Kurdistan a leading center for hemopoietic stem-cell transplantation. The capacity building approach was used, with on-site training and coaching as instruments for the development of provider ability and problem solving. With future limitations for immigration, this method will be helpful, especially in the field of high-technology medicine.

The Start-Up of the first Hematopoietic Stem Cell Transplantation Center in the Iraqi Kurdistan: a Capacity-Building Cooperative Project by the Hiwa Cancer Hospital, Sulaymaniyah, and the Italian Agency for Development Cooperation: an Innovative Approach

We describe the entire process leading to the start-up of a hematopoietic stem cell transplantation center at the Hiwa Cancer Hospital, in the city of Sulaymaniyah, Kurdistan Iraqi Region. This capacity building project was funded by the Italian Development Cooperation Agency and implemented with the support of the volunteer work of Italian professionals, either physicians, nurses, biologists and technicians. The intervention started in April 2016, was based exclusively on training and coaching on site, that represent a significant innovative approach, and led to a first autologous transplant in June 2016 and to the first allogeneic transplant in October. At the time of reporting, 9 months from the initiation of the project, 18 patients have been transplanted, 15 with an autologous and 3 with an allogeneic graft. The center at the HCH represents the first transplantation center in Kurdistan and the second in wide Iraq. We conclude that international development cooperation may play an important role also in the field of high-technology medicine, and contribute to improved local centers capabilities through country to country scientific exchanges. The methodology to realize this project is innovative, since HSCT experts are brought as volunteers to the center(s) to be started, while traditionally it is the opposite, i.e. the local professionals to be trained are brought to the specialized center(s).

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.

Mobilization of healthy donors with plerixafor affects the cellular composition of T-cell receptor (TCR)-αβ/CD19-depleted haploidentical stem cell grafts

BACKGROUND

HLA-haploidentical hematopoietic stem cell transplantation (HSCT) is suitable for patients lacking related or unrelated HLA-matched donors. Herein, we investigated whether plerixafor (MZ), as an adjunct to G-CSF, facilitated the collection of mega-doses of hematopoietic stem cells (HSC) for TCR-αβ/CD19-depleted haploidentical HSCT, and how this agent affects the cellular graft composition.

METHODS

Ninety healthy donors were evaluated. Single-dose MZ was given to 30 'poor mobilizers' (PM) failing to attain ≥40 CD34+ HSCs/μL after 4 daily G-CSF doses and/or with predicted apheresis yields ≤12.0x106 CD34+ cells/kg recipient's body weight.

RESULTS

MZ significantly increased CD34+ counts in PM. Naïve/memory T and B cells, as well as natural killer (NK) cells, myeloid/plasmacytoid dendritic cells (DCs), were unchanged compared with baseline. MZ did not further promote the G-CSF-induced mobilization of CD16+ monocytes and the down-regulation of IFN-γ production by T cells. HSC grafts harvested after G-CSF + MZ were enriched in myeloid and plasmacytoid DCs, but contained low numbers of pro-inflammatory 6-sulfo-LacNAc+ (Slan)-DCs. Finally, children transplanted with G-CSF + MZ-mobilized grafts received greater numbers of monocytes, myeloid and plasmacytoid DCs, but lower numbers of NK cells, NK-like T cells and Slan-DCs.

CONCLUSIONS

MZ facilitates the collection of mega-doses of CD34+ HSCs for haploidentical HSCT, while affecting graft composition.

Peripheral blood stem cell yield calculated using preapheresis absolute CD34+ cell count, peripheral blood volume processed, and donor body weight accurately predicts actual yield at multiple centers

BACKGROUND

Accurate prediction of stem cell yield is important for planning leukapheresis procedures. A formula has been published (Pierelli et al., Vox Sang 2006;91:126-34) to estimate the CD34+ dose collected on the first day of leukapheresis that was based on the preapheresis peripheral blood (PB) CD34+ counts, the blood volume processed, and the donor's weight. The aim of this study was to assess the predictive value of this formula.

STUDY DESIGN AND METHODS

Data were retrospectively collected on 1126 consecutive PB stem cell harvests conducted at five institutions. Information on age, sex, diagnosis, weight, preapheresis absolute peripheral CD34+ count, total blood volume processed, and CD34+ cells harvested per kilogram of body weight on the first day of apheresis was collected.

RESULTS

Among donors at least 18 years old, Pearson's correlation coefficient (r) between actual yield (AY) and predicted yield (PY) was 0.76. To characterize this correlation, AY and PY were classified as being within the conventionally acceptable CD34+ doses (>2 × 10(6) -5 × 10(6) cells/kg), below this range (≤2 × 10(6) cells/kg), or above it (>5 × 10(6) cells/kg). The positive predictive value (PPV) of PY was estimated considering the distribution of AY as the "gold standard." PPV was relatively high for PY of more than 5 × 10(6) cells/kg (85%), moderate for PY of not more than 2 × 10(6) cells/kg (72%), and low for PY more than 2 × 10(6) to 5 × 10(6) cells/kg (56%). A consistent pattern was observed within institutions.

CONCLUSION

The formula of Pierelli et al. is associated with a PPV that is high, moderate, and relatively low for the corresponding predicted CD34+ doses.

An algorithm based on peripheral CD34+ cells and hemoglobin concentration provides a better optimization of apheresis than the application of a fixed CD34 threshold

BACKGROUND

Optimization of peripheral blood stem cell (PBSC) collection for autologous bone marrow transplantation is necessary for a good standard of care and cost-effectiveness. An algorithm was validated for prediction of the day of maximum peripheral CD34+ cell concentration after mobilization chemotherapy (Day(CD34peak)).

STUDY DESIGN AND METHODS

This study compared mobilization and collection variables of a cohort of patients where apheresis was started at the Day(CD34peak) predicted by the algorithm with a patient group where PBSCs were collected when PB CD34+ cell concentration reached 10 per microL per day (Day(CD34threshold)). Day(CD34peak) was calculated according to the equation Day(CD34peak) = -0.41 x Hb(D0) + 0.99 x Day(CD34threshold) + 7.8 (with Hb(D0) representing the hemoglobin value on Day 0).

RESULTS

The mean number of apheresis procedures per patient based on the Day(CD34threshold) was 1.74, but decreased to 1.35 when applying the new method (Day(CD34peak)). For lymphomas, the mean number of apheresis procedures decreased from 1.98 to 1.47 (p = 0.03), while in patients with multiple myeloma it did not change significantly (1.23 and 1.26, respectively). Age and primary disease influenced the number of apheresis procedures needed to achieve the collection target.

CONCLUSION

The application of our algorithm can lower the number of apheresis procedures by improving the timing, especially in patients suffering from malignant lymphomas with a poor marrow potential after several chemotherapy lines.