Continuous Mononuclear Cell Collection Research Articles

Collection efficiency and safety of large-volume leukapheresis for the manufacturing of tisagenlecleucel.

In patients with relapsed or refractory B cell acute lymphoblastic leukemia or B cell non-Hodgkin lymphoma (r/r B-ALL/B-NHL) with low CD3+ cells in the peripheral blood (PB), sufficient CD3+ cell yield in a single day may not be obtained with normal-volume leukapheresis (NVL). Large-volume leukapheresis (LVL) refers to the processing of more than three times the total blood volume (TBV) in a single session for PB apheresis; however, the efficiency and safety of LVL for manufacturing of tisagenlecleucel (tisa-cel) remain unclear. This study aimed to investigate the tolerability of LVL. We retrospectively collected data on LVL (≥3-fold TBV) and NVL (<3-fold TBV) performed for patients with r/r B-ALL/B-NHL in our institution during November 2019 and September 2023. All procedures were performed using a continuous mononuclear cell collection (cMNC) protocol with the Spectra Optia. Although pre-apheresis CD3+ cells in the PB were significantly lower in LVL procedures (900 vs. 348/μL, p < .01), all patients could obtain sufficient CD3+ cell yield in a single day with a comparably successful rate of final products (including out-of-specification) between the two groups (97.2% vs. 100.0%, p = 1.00). The incidence and severity of citrate toxicity (no patients with grade ≥ 3) during procedures was not significantly different between the two groups (22.2% vs. 26.1%, p = .43) and no patient discontinued leukapheresis due to any complications. LVL procedures using Spectra Optia cMNC protocol was well tolerated and did not affect the manufacturing of tisa-cel.

Evaluating the efficiency and safety of large-volume leukapheresis using the Spectra Optia continuous mononuclear cell collection protocol for peripheral blood stem cell collection from healthy donors: A retrospective study.

Large-volume leukapheresis (LVL) refers to processing of more than three volumes of blood in a single session for peripheral blood stem cell collection. Recently, continuous mononuclear cell collection (cMNC) protocol has been developed using the Spectra Optia system, which is a widely used apheresis device. LVL using the novel protocol has been investigated in patients. However, the efficiency and safety of LVL in healthy donors using this protocol has not been characterized. Therefore, this study aimed to evaluate the efficiency and tolerability of CD34+ collection of LVL with the cMNC protocol in healthy donors. We retrospectively collected data on LVL (>3 total blood volume) and normal-volume leukapheresis (NVL) performed in healthy donors between October 2019 and December 2021. All procedures were performed using the cMNC protocol. Although pre-apheresis CD34+ cell count was lesser in LVL (23.5 vs. 58.0/μL, p < .001), CD34+ collection efficiency was comparable between LVL and NVL (61.2% vs. 61.4%, p = .966). Platelet loss was significantly higher in LVL compared to NVL (38.0% vs. 29.4%, p < .001), with no correlation between attrition of platelet and processing blood volume. Moreover, the incidence of citrate toxicity during procedures was comparable between the two groups (31.6% vs. 21.4%, p = .322). All LVL procedures could be completed without any adverse events. Allogeneic LVL procedure using Spectra Optia cMNC protocol was well tolerated by the donors and resulted in efficient collection of CD34+ cells, which was comparable to that of NVL.

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.

Analysis of first apheresis services in Ghana-Greater Accra Regional Hospital

BackgroundAt the combined American Society for Apheresis (ASFA) annual meeting and World Apheresis Association (WAA) Congress in 2014, it was observed that there were significant disparities with regard to the access of apheresis services within and across developing countries, with only few of such facilities available in Africa; notably South Africa and Nigeria. In 2019, Bone Marrow Transplantation (BMT) Unit-Ghana, acquired an apheresis machine. By the collaboration between BMT-Ghana, the Greater Accra Regional Hospital (GARH) and the Ministry of Health (Ghana), apheresis services is now available in Ghana. The aim of this paper is to present an analysis of apheresis services so far in Ghana. MethodA 12-month period from 2019 to 2021 was examined (less the period of the COVID-19 outbreak when the Unit was virtually at a standstill). The electronic database and hard copies of documented activities were analysed. Basic information on demographics and procedure types and counts was used. ResultsThe retrospective study encompassed data of 43 patients. Two (2) patients came from the West Africa sub-region (Nigeria and Cameroon) with the rest from 6 out of the 14 regions of Ghana (Greater Accra, Western, Central, Eastern, Ashanti, Volta). The essential nature of the apheresis services being the first in Ghana, brought patients as far as 315 km from the hinterlands to the Unit. Ages ranged from 2-52 years with a mean of 16.3 ± 15.3 years. Slightly more females (n = 23, 53%) received services than males (n = 20, 47%). Eighty-six percent (n = 37, 86%) of the patients were sickle cell patients referred to the Unit. Red Blood Cell exchange (RBCx) accounted for 87% (n = 40), of the 46 procedure counts followed by Continuous Mononuclear Cell Collection (CMNC) (n = 4, 9%) and lastly, Therapeutic Plasma Exchange (TPE) (n = 2, 4%). ConclusionGhana can now be counted among African countries offering apheresis services and the GARH is acknowledged as the only hospital in the country with this facility, thus improving patient care significantly.

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

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. 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. 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. 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.

Optimization of Autologous Hematopoietic Progenitor Stem Cell Apheresis Collection from Plerixafor-Mobilized Patients with Sickle Cell Disease

IntroductionAutologous hematopoietic progenitor cell (HPC)-based gene therapy and genome editing are emerging therapeutic strategies for patients with sickle cell disease (SCD). Given the high cell loss incurred during production of genetically modified HPCs, a large number of HPCs (10-15 x10 6 cells/kg) are required. Obtaining sufficient autologous HPCs from patients with SCD is a critical rate limiting step for the success of these novel genetic therapies. Plerixafor, a CXCR4 antagonist, has been shown to be safe and efficient for HPC mobilization in patients with SCD. However, impaired red blood cell (RBC) rheology and chronic inflammation associated with SCD make HPC apheresis collection challenging. For example, HPCs can potentially form aggregates with sickled RBCs traveling deep in the buffy coat upon density-based separation. In addition, elevated levels of activated platelets can increase cell clumping during apheresis. Thus, autologous HPC collection using standard apheresis setting is generally less efficient in patients with SCD and often associated with clumping and unstable cell interfaces during apheresis. It has been reported that standard HPC apheresis collections yield <0.7 x 10 6 CD34+ cells/kg per procedure in SCD patients despite adequate HPC mobilization (peak CD34 count 36-65/µL; Esrick, EB et al., 2018). To address these challenges, we modified our apheresis collection settings to improve the HPC collection efficiency and yield from plerixafor-mobilized patients with SCD.MethodsAdult patients with SCD who were enrolled on two clinical trials (NCT03226691 and NCT04443907) at St. Jude Children's Research Hospital and the National Heart, Lung and Blood Institute at the National Institutes of Health were included. Hydroxyurea was discontinued at least 2 weeks and an RBC exchange was performed 3-7 days prior to HPC mobilization. The participants received 240 µg/kg of Plerixafor subcutaneously, and underwent HPC collection 2-4 hours later using the Spectra Optia continuous mononuclear cell collection. Acid-citrate-dextrose-solution A was used for anticoagulation and calcium gluconate was infused during apheresis to prevent citrate-induced hypocalcemia symptoms. Up to 4 total blood volumes were processed for each collection with an adjusted collection preference (CP) of 10-40 and AC/Inlet ratio of 6-12. Collection efficiency (CE) 1 was calculated as CD34+ cell yield / [(pre-CD34 count + post-CD34 count)/2 x whole blood volume processed]. CE 2 was calculated as CD34+ cell yield / (pre-CD34 count x whole blood volume processed).ResultsWe performed 46 autologous HPC collections in 26 participants (age of 20 to 50 years). Mean (±1SD) pre-collection blood indices were: hematocrit (Hct) 27.4 ±3.8%, platelet count 226 ± 111 x10 9/L, and hemoglobin S 25.7 ± 6.0%, WBC count 13.82 ± 6.0 x10 9/L, and CD34+ cell count 62 ± 49 /µL. To address the altered HPC sedimentation and clumping associated with SCD, we targeted a deep buffy coat collection by lowing CP from standard 50 to 10-40, and used more anticoagulant by lowering Inlet/AC ratio from standard 12 to 6-12 respectively. The adjustments increased HPC yield, and 5.60 ± 5.48 x10 6/kg CD34+ cells were collected per procedure. The CE1 was 49.21 ± 28.34 % and CE2 42.74 ± 26.24%, which are comparable to autologous HPC CEs for non-SCD individuals. A deep collection led to highly efficient collections, although this tended to increase RBC contamination of the products (product Hct 6.0 ±2.2% versus < 3% for standard collection). Nevertheless, the participants experienced minimal loss of RBCs with a post-collection Hct of 26.6 ± 2.9%. Platelet loss was also relatively low, as demonstrated by a post-collection platelet count of 152 ± 69 x 10 9/L. No participants required platelet or blood transfusions, had bleeding or severe hypocalcemia-associated symptoms during and after the collections.ConclusionThe adjusted apheresis settings with a low buffy coat collection and increased anticoagulant dosage allowed safe and efficient autologous HPC collection in the patients with SCD. Further optimization of apheresis settings is required to increase HPC collection efficiency. DisclosuresSharma: Novartis: Other: Salary support paid to institution; Spotlight Therapeutics: Consultancy; Medexus Inc: Consultancy; CRISPR Therapeutics: Other, Research Funding; Vindico Medical Education: Honoraria; Vertex Pharmaceuticals/CRISPR Therapeutics: Other: Salary support paid to institution. Hankins: Bluebird Bio: Consultancy; UpToDate: Consultancy; Vindico Medical Education: Consultancy; Global Blood Therapeutics: Consultancy. Weiss: Cellarity Inc.: Consultancy; Novartis: Consultancy; Forma Therapeutics: Consultancy; Beam Therapeutics: Current holder of stock options in a privately-held company.

Comparison of prediction models for two different peripheral stem cell collection protocols in autologous patients. How to avoid errors in calculating total blood volume to process?

Introduction: Calculating accurate blood volume to process is a critical practice in apheresis planning; therefore, researchers try to develop dedicated prediction models. In this analysis, we have attempted to compare three algorithms for two different apheresis collection protocols. Methods: In a retrospective study, we have analyzed 137 apheresis procedures performed on 100 autologous patients. Apheresis procedures were performed with the Spectra Optia apheresis device with two protocols: mononuclear cell collection (MNC) and continuous mononuclear cell collection (cMNC). Three algorithms: a model based on mean collection efficiency (CE2), a linear regression model, and a power regression model were validated by plotting collected CD34 + cell dose versus predicted CD34 + cell dose. Results: All models showed high predictability for MNC procedure, a high correlation of predicted CD34 + yield and actual CD34 + yield ( R 2 = 0.9547; 0.9487; 0.9474 for CE2-based model, linear and power regression model, respectively). In contrast, alteration between models for the cMNC procedure was greater ( R 2 = 0.8049, 0.7970, and 0.8169) with a higher number of overpredictions. Further analysis revealed that for low CD34 + precounts blood volume to process, calculated with the three models, differ significantly up to fivefold times. Conclusions: Utilizing regression models may lead to calculation errors, which can affect undercollection, repetition of apheresis, or even mobilization failure. Contrary to regression models, the model based on mean CE2 gave the most accurate prediction both for MNC and cMNC procedures. Although new prediction algorithms are created, this simple formula remains a reliable tool that promotes careful planning of apheresis, thus improving patient safety.

Peripheral Venous Access for Collection of Immune Effector Cells and Hematopoietic Stem Cells Is Feasible and Safe in Older Children and Young Adult Patients

Introduction: Collection of hematopoietic stem cells (HSC) for HSC transplantation (HSCT) and immune effector cells (IEC) for cellular manufacturing (e.g. CAR T-cells) in children and young adults has unique challenges. In order to maintain adequate flow rates, central venous catheters (CVCs) are often utilized at pediatric institutions. However, CVCs are associated with additional procedural risks (anesthetic complications, thrombotic events) and resource utilization (anesthesia, interventional radiology). In adults collection through peripheral venous catheter (PVC) access has become increasingly standard practice, but has not yet been routinely used in pediatrics. The aim of this study was to determine if it is feasible and safe to utilize PVC access in a select population of older children and young adults to reduce the need for CVC insertions. Methods: All individuals undergoing HSC and IEC collections at our institution (patients and sibling donors) between February 2019 and July 2020 were considered for PVC collection if in the treating physicians assessment the patient would be able to tolerate the procedure (arms outstretched for up to 6 hours) and venous vessels were deemed suitable for an 18 gauge PVC. For blood return patients received either a second PVC (minimum 20 gauge) or if present their port/central line was used. For patients screened after April 2020, assessment by ultrasound was performed prior to the procedure to determine venous vessel size. All patients had topical analgesia applied prior to PVC insertion. All collections were carried out using the Continuous mononuclear cell collection (CMNC) protocol on an Optia apheresis device. Collection-related parameters such as demographics, collection efficiency (CE2), collection time, flow rate and product quality were collected. Results: A total of 27 patients were screened for PVC collection from February 2019 until July 2020. The median age was 16.1 years (range 9.7-27.3) and median weight 67.7 kg (range 29.4-115.4). Ten out of 27 patients had ultrasound screening prior to collection on which one patient was deemed not suitable for PVC collection due to a venous anomaly. Cells were collected successfully by PVC in 24/26 (92%) of patients, 2/26 (8%) patients required CVC insertion after an unsuccessful PVC attempt due to inability to maintain an adequate flow rate. Average PVC collection flow rate was 50.3 ml/min (range 34-91) with median collection time of 244.5 min (range 87-397 min). Median collection efficiency (CE2) for CD3 cells was 59% (range 21-88), for CD34 cells 55% (range 28-69), product cell viability was 100%. Collection and product parameters were comparable to institutional collections performed utilizing CVCs. PVC collections were well tolerated, no patient had to stop the procedure due to discomfort or patient safety concerns. Conclusion: PVC collection of IEC and HSC is feasible and safe in older children and young adults. Ultrasound screening prior to PVC insertion and collection attempt can reduce failure rate and streamline the collection process. Disclosures Krueger: Novartis: Consultancy, Other: Travel support; no honoraria, Speakers Bureau; Kite, a Gilead Company: Other: Travel support; Atara: Other: Travel support.

Apheresis machines variably overestimate mononuclear cell collection volume.

Calculation of the actual number of CD34+ cells in the collection product is based on the volume of the collected product and its concentration of CD34+ cells measured in the lab. The number of CD34+ cells infused correlates closely with the pace of hematopoietic reconstitution following autologous or allogeneic stem cell transplantation. We studied peripheral blood stem cell collections in a single apheresis center with two Spectra Optia devices, using mononuclear cell collection or continuous mononuclear cell collection procedures. The collection volume displayed by the apheresis device was compared with the volume determined by a weight-based method. Fifty-two consecutive CD34 collections in 35 different donors (range 1-4 daily procedures per donor) were analyzed. The machines reported larger collection volumes (P < .001). The mean collection volume reported by the machine was 274.37 mL (range 162-396). The mean manually measured collection volume was 261.82 mL (range 155-371.40). Mean overestimation by machine was 12.53 mL (range -0.95 to 31.24; 95% confidence interval 10.94-14.11) or 4.88% (range -0.26 to 10.28). Median overestimation of the absolute number of CD34 was 10.29 × 106 (range -2.83 to 141.84 × 106 ). Both Spectra Optia machines overestimated the collection volume after peripheral blood stem cell collection. Although the mean variation falls within the expected range, in some cases, this overestimation may be clinically relevant if no other method of measurement is used.

How to Collect the Minimum-Targeted CD3+ Cells for CAR-T Therapy- the Bern Approach

Introduction: An autologous CD3+ cell collection is the first step required for a CAR-T therapy. Up to now, in the commercial setting, one of the available models predicting the time or processed patient blood volume needed in order to gain the minimum-targeted absolute count of CD3+ cells relies on a formula provided by Novartis (Reference Model - RM), which assumes these parameters to be inversely proportional. We here aimed to develop a refined and more precise model, which enables to predict the needed processed blood volume in patients with low pre-apheresis peripheral CD3+ counts for gaining the targeted CD3+ cell count of e.g. 1.0x10⁹, using the patient's pre-apheresis peripheral CD3+ cell values, the collected absolute CD3+ cell counts, and the effectively processed blood volumes (Bern model - BM). Methods: We analyzed 16 lymphocyte apheresis procedures in adult patients (ALL: n=1; B-cell lymphomas: n=15) with a median age of 70.5 years (r 25 - 81 years) performed at the University Hospital Bern, Switzerland, for the production of Kymriah® (Novartis) in the period from December 2018 till July 2019. All cell collections were performed on the Spectra Optia (Terumo BCT©) device. Continuous Mononuclear Cell Collection (CMNC) procedure was used. We measured the peripheral CD3+ cell counts of the patients' blood and the collected products by means of multi-parameter flow cytometry (BD FACSCanto II). The inversely proportional function (RM) did not fit well our data, which was the trigger to look for an alternative function. Best fit of the series of data points and establishing of the function calculation has been performed by using Excel 2019 statistics, using power function modeling. Results: The median peripheral CD3+ cell level at start of apheresis was 1.29x10⁹/ml (r 0.11x10⁹/ml - 2.66x10⁹/ml). Low peripheral CD3+ counts (defined as &lt; 0.7x10⁹/ml) were found in 5 out of 16 patients, whereas 11 patients showed normal peripheral CD3+ counts. Interestingly, in our hands lymphocyte collections at low pre-apheresis CD3+ counts was successful reaching the target &gt;1.0x10⁹ CD3+ cells defined by the manufacturer. The median collection duration was 176 minutes (r 114 - 286 minutes) and the median ratio of processed blood volume to WBV (patient whole blood volume) was 3.1 (r 1.50 - 6.70). There was a significant negative correlation between CD3+ cell levels and blood volume processed/WBV (Spearman rank correlation, r: -0.92, p=0.0285). The median collected CD3+ cell number in the lymphocyte harvests was 6.43 x109 (r 1.88x109 - 11.90x109), fulfilling the required minimum of CD3+ cells in all 16 patients. In Figure 1, each data point labeled by 1-9 or A- G represents an individual patient. The function of RM y=2.5x-1 (plotted in gray) is the intuitive, inverse proportional model provided by Novartis to calculate the minimum targeted cell count for production of Kymriah®. The function of BM y=2.167x-0,759 (plotted in blue) is our empiric model best fitting to our patients' data. Both models provide numerically similar results in case of normal pre-apheresis CD3+ cell counts, but differ significantly in the area of low pre-apheresis CD3+ values. To illustrate all similarities and differences between BM and RM in a single plot, one can present this relation as follows: BM = 2.167(pCD3+)-0,759 is equal to 2.5(pCD3+) -1(RM) * 0.8671(pCD3+)0,241 where pCD3+ is the pre-apheresis CD3+ cell count expressed in 109 cells/ ml. Using this approach we obtain the following final formula: BM = RM * BF where BF (Bern Factor) is defined here as 0.8671 * (pCD3+)0.241. Figure 2 presents a graphic illustration of the formula for the BF. The function in Figure 2 is linking the RM and BM. For low CD3+ values, the BF is lower than for the normal CD3+ values. Conclusion: In the area of lower pre-apheresis CD3+ values, lymphocyte apheresis showed to be more efficient than expected by the manufacturer's model and the collection could be performed faster than assumed. According to our data the function y=2.167x-0,759 is more precise for calculating the needed processed blood volume for gaining the minimum required CD3+ cell count of 1.0x10⁹. Further investigations are needed to evaluate the applicability of the above Bern Model to predict processed blood volumes in patients with low peripheral CD3+ counts and to explain the phenomenon why the collection seems less efficient for patients with normal peripheral CD3+ cells. Disclosures Jalowiec: Pfizer: Other: Travel grant; Amgen: Other: Travel grant; Novartis: Other: Travel grant. Baerlocher:Novartis: Research Funding. Zeerleder:Alexion: Speakers Bureau; Jazz Pharma: Speakers Bureau; Sanofi/Genzyme: Speakers Bureau.

Performance prediction algorithm for autologous PBSC collection in adults and pediatric patients using large volume leukapheresis.

The number of CD34+ cells collected in apheresis procedures depends mainly on the collection efficiency of the device and the blood volume processed. Large volume leukapheresis (LVL) can improve CD34+ cell yield and has previously been investigated using the COBE Spectra device (Terumo BCT, USA). This was a retrospective analysis of LVL performance in patients undergoing continuous mononuclear cell collection (CMNC) using the new Spectra Optia apheresis system (Terumo BCT, USA) at the University Hospital Center, Zagreb, from March 2016 to September 2016. CD34+ cell yield predictability, determined using a customized algorithm, was also assessed. In total, 67 procedures performed in 46 adults and 14 performed in 11 children were included in the analysis. In adults, 30 (65.2%) patients successfully reached their target preapheresis CD34+ cell count on day 1, with a median (interquartile range [IQR]) CD34+ collected cell dose of 4.8 × 106 /kg (2.3-10.6 × 106 /kg). In the pediatric group, 81.8% successfully collected the target CD34+ cell dose on the first day, with a median (IQR) CD34+ collected cell dose of 11.1 × 106 /kg (3.2-16.3 × 106 /kg). The customized algorithm showed a strong and significant linear correlation with actual CD34+ cell dose (P < 0.0001). The results of this study support the use of LVL and the customized prediction algorithm in apheresis procedures. The ability to tailor the procedure to meet the needs of the individual patient may help to minimize the blood volume processed, shorten the duration, reduce the volume of infused anticoagulants, and improve patient comfort.

A dual strategy to optimize hematopoietic progenitor cell collections: validation of a simple prediction algorithm and use of collect flow rates guided by mononuclear cell count.

Previous prediction algorithms to achieve target CD34+ goals have not been widely adopted, with many centers still using a set volume to process for hematopoietic progenitor cell collections. This may be because previous algorithms are challenging to implement. Additionally, no study has yet examined the utility of adjusting the collect flow rate (CFR) based on the donor's preprocedure total mononuclear cell (MNC) count, which correlates with CD34+ yield. In this retrospective analysis of mobilized allogeneic donors collected using MNC (COBE Spectra, Terumo BCT) or continuous mononuclear cell collection (CMNC) (Spectra Optia, Terumo BCT) procedures, we validated a one-step prediction algorithm to achieve the target CD34+ product dose (Appendix S1, available as supporting information in the online version of this paper). The COBE Spectra MNC Collect Flow Tool (Appendix S2, available as supporting information in the online version of this paper) was used to select the collect flow rate for both MNC and CMNC procedures. Procedural collection efficiency (CE) was compared to that of historical procedures utilizing fixed CFRs (1.0-1.5 mL/min). Ninety-three percent of collections achieved the target CD34+ goal using our algorithm-calculated process volumes. The remaining 7% of cases had CEs lower than the algorithm CE (0.40), and thus were below goal. Second, an MNC-based CFR improved MNC and CD34+ CEs in patients with higher MNC counts compared to our historical controls. We validated that this simple, single-step prediction algorithm achieves the target CD34+ goal in most HPC collections. Secondly, we showed that an MNC-based CFR for hematopoietic progenitor cell collections improves CE at higher MNCs; this may be preferable to a WBC-based CFR because of variability of MNC counts at a given WBC count.

Evaluation of the new continuous mononuclear cell collection protocol versus an older version on two different apheresis machines.

Cell separators are routinely used to collect CD34+ blood stem cells in the context of customized stem cell transplantation procedures. The Spectra Optia (Terumo BCT) is a novel development of the precursor instrument, the Cobe Spectra (Terumo BCT). In this report, 146 autologous and 42 allogeneic donors undergoing apheresis on the Cobe Spectra using the mononuclear cell (MNC) program 4.7 or on the Spectra Optia using the new continuous mononuclear cell (cMNC) program 11.2 are compared. Viability of cells and collection efficacy within the apheresis products was comparable for autologous and allogeneic products collected with the MNC or cMNC method. However, we found a reduced duration of the apheresis procedure and lower hematocrit within the apheresis products when using the cMNC in autologous and allogeneic donors. Moreover, allogeneic donors collected substantially more CD34+ cells per kilogram of body weight when using the cMNC method. Differences in platelets before and after apheresis were substantially smaller in this cohort when compared to the cohort collected with the MNC method. Neutrophil and platelet engraftment after autologous or allogeneic transplantation with a product collected with the MNC procedure was comparable to a transplantation with a product processed according to the cMNC method. Comparison of the MNC (Cobe Spectra) and the cMNC (Spectra Optia) methods demonstrated an equal performance and outcome. However, advantages were present using the cMNC method with respect to apheresis duration and hematocrit within the apheresis product (autologous/allogeneic donors) and numbers of CD34+ cells collected, especially in allogeneic donors.

Evaluation of a new continuous mononuclear cell collection procedure in a single transplant center cohort enriched for AL amyloidosis patients

BackgroundThe Spectra Optia continuous mononuclear cell (CMNC) program is newly available, and herein validated in a single-center cohort enriched with AL amyloidosis patients to collect a target CD34+ yield of 2.5 × 106 cells/kg within 2 days. MethodsConsecutive autologous transplant patients in 2016 are included. Patients undergo leukapheresis with Optia CMNC and Spectra v4.7 over a 2-day cycle. Data collection includes collection efficiency, adverse events and engraftment kinetics. Results36 leukapheresis procedures on 18 patients are included. The diagnoses are AL amyloidosis (9), myeloma (7), lymphoma (2), and scleroderma (1). Median age is 60; 12 are men. Plerixafor was employed pre-emptively in 6 cycles. Median blood CD34+ on Day 1 of leukapheresis was 46 cells/uL. Median number of blood volumes processed on Day 1 was 3.1. All collection cycles were completed within 2 days; only one in a heavily pretreated lymphoma patient did not reach the target requiring a second mobilization attempt. Mean collection efficiencies were comparable between the two devices. There were 2 adverse events: tubing rupture on the Optia; and one case of hypotension. All 18 patients underwent high-dose chemotherapy: median cell dose infused was 7.7 × 106 CD34+ cells/kg. Median days to neutrophil and platelet engraftment were 10 and 13 respectively. ConclusionThe Optia CMNC collection protocol is safe and effective in a small single-center autologous stem cell transplant cohort enriched for high-risk patients with AL amyloidosis and cardiac involvement. Caution is needed for tubing setup because there is less cumulative experience with Optia.

Continuous Mononuclear Cell Collection (cMNC) protocol impact on hematopoietic stem cell collections in donors with negative collection predictors

BackgroundRecently, novel protocol utilizing Continuous Mononuclear Cell Collection (cMNC) have been introduced for leukapheresis. We compared the efficacy of cMNC with an older protocol – mononuclear cell collection (MNC) for CD34+ cell collection in unrelated donors with negative stem cell collection predictors. Material and methodsRetrospective data from a series of 258 consecutive unrelated hematopoietic stem cell donors was included in this single-center study (80 donors collected with cMNC and 178 with MNC). The donors with poor predictors for collection such as low number of circulating CD34+ cells and/or weight disproportion were assigned to the cMNC arm. ResultsThe cMNC protocol yielded a higher number of CD34 + cells per donor body weight (7.63 × 106/kg vs 6.82 × 106/kg, p = 0.027). One apheresis was sufficient for collection of target cell number in 89% individuals from both groups despite negative predictors in the cMNC group. In donors with CD34 + cell count <100/μL and a body weight disproportion between donor and recipient one apheresis was sufficient in 83% of donors in cMNC group and in 58% in MNC group (p = 0.0345) with collection efficiency CE2% values of 61% for cMNC and 62% for MNC (p = 0.77). ConclusioncMNC protocol is more efficient in donors with low pre-apheresis CD34+ cell count and weight disproportion between donor and recipient. This suggests that the use of cMNC in unrelated donors could possibly further improve the results of HSC collections.

Comparison of the Terumo BCT MNC and Cmnc Protocols for Peripheral Blood Stem Cell Collections

Background: Terumo BCT recently offered a new method of peripheral blood stem cell (PBSC) collection using the Spectra Optia¨, an apheresis instrument. The new protocol includes a continuous mononuclear cell collection (CMNC) as opposed to an older version, the mononuclear cell collection (MNC), which involves an additional step where product pools through a cell separation insert. Our institution has used both methods and the purpose of this study was to compare the CMNC to the MNC protocol, including run times and PBSC product characteristics.Methods: A retrospective review and comparison of parameters from 120 collection procedures using the MNC insert and 60 collection procedures using the CMNC insert was done using the t-test. Data from patients/donors (including 20 allogeneic donors) as well as procedure details including run time, flow cytometry marker for stem cells (CD34)-positive (CD34+) throughput, CD34+ collection efficiency (CE%), platelet loss (plt loss/total blood volume [TBV]), and collection product characteristics were included in the analysis.Results: The MNC donor group included 12 allogeneic donors, which is comparable to the 8 allogeneic donors in the CMNC group. Donor weight and patient weight was not significantly different between the two groups. Pre-procedure laboratory values (WBC, percentage of lymphocytes [lymph%], percentage of monocytes [MNC%], and platelet count) were also similar between the two groups.Run time was found to be significantly shorter using the CMNC protocol compared to the MNC protocol. Product volume was also significantly lower in the CMNC group compared to the MNC group. Although the volume was lower, the CMNC product had significantly higher white blood cell count (WBC), MNC%, and lymph% when compared to the MNC product. The CD34+ throughput was significantly higher in the CMNC group than the MNC group. The CD34+ CE% was found to be slightly increased in the CMNC group, though not significantly. The platelet loss was nearly identical in both protocols when normalized for total blood volume. Product hematocrit (HCT%) was significantly higher using the CMNC protocol; however, the red blood cell volume never exceeded 20 mL due to the lower product volume with the CMNC protocol. The numerical results are summarized in the Table.Conclusion: The CMNC protocol collects a smaller volume of a purer product when compared to the MNC protocol with comparable platelet and red blood cell loss. Staff members who perform apheresis procedures are pleased by the shorter run time. [Display omitted] DisclosuresRoig:Terumo BCT: Employment.