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

BACKGROUND: 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. STUDY DESIGN AND METHODS: 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. RESULTS: 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. CONCLUSION: LVL procedures using Spectra Optia cMNC protocol was well tolerated and did not affect the manufacturing of tisa-cel.

MicroRNA and granulocyte-monocyte adsorption apheresis combotherapy after inadequate response to anti-TNF agents in ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC) is an inflammatory bowel disease characterized by chronic inflammation of the gastrointestinal tract, affecting millions of individuals throughout the world, and producing an impaired health-related quality of life. Granulocyte and monocyte apheresis (GMA) is a therapeutic option for UC management to induce remission by selective removal of activated leukocytes from bloodstream. Despite the knowledge of the important role of epigenetics in UC pathogenesis, and in the response to different treatments, nothing is known about the role of microRNAs in GMA therapy in UC patients. METHODS: Seven consecutively UC patients who started GMA in combo therapy with infliximab were recruited. Peripheral blood samples were taken before the apheresis session, at the start of the induction (S0) and at the end (S10). They were follow-up during the induction phase (10 sessions: 2 sessions for a week during 3 wk and 1 session for a week during 4 wk) of the treatment at a tertiary hospital (Hospital la Fe) and 6 mo after finishing the GMA induction therapy. MiRNA was extracted and analyzed by RT-PCR. R software and GraphPad were used. RESULTS: Clinical disease activity significantly decreased after induction therapy with GMA (median partial Mayo score 2 (IQR, 1-6) (P < .05). Fecal calprotectin value and CRP value significantly decreased after induction therapy. Five microRNAs modified their expression during GMA (unsupervised analysis): miR-342-3p, miR-215-5p, miR-376c-3p, miR-139-5p, and miR-150-5p. When a sub-analysis was performed in those patients who showed good response to apheresis treatment (n = 5), two microRNAs showed to be implicated: miR-215-5p and miR-365a-3p. These are preliminary but promising and novel results, as it is the first time, to our knowledge that microRNA profiles have been studied in the context of GMA treatment for IBD.

Vascular access for autologous peripheral blood stem cells collection by large volume leukapheresis: Single center experience.

INTRODUCTION: Peripheral blood stem cell (PBSC) harvesting requires reliable and safe vascular access. In our institution, a change of practice was implemented and the central venous catheter (CVC) placement for all autologous PBSC collections was abandoned in favor of a careful evaluation of peripheral venous access (PVA) for each individual patient. The aim of this prospective study was to evaluate the rate of patients with adequate peripheral veins for autologous PBSC collection and compare patient characteristics, collection efficacy, and complication rate between patients with PVA and CVC. METHOD: Peripheral veins were assessed by the apheresis nurse team in all patients referred between January 2020 and July 2021 to autologous PBSC collection. Only in case of difficult venous access, CVC was inserted. Large volume leukapheresis (LVL) procedures, which processed ≥3 total blood volumes, were performed. RESULTS: In 65 (57%) patients PVA was used, while 49 (43%) patients required placement of short-term CVC. Peripheral venous access was successfully used significantly more often in males (69.8%) (P = 0.010), and patients with multiple myeloma (71.0%) than in patients with non-Hodgkin's lymphoma (35.9%) and Hodgkin's lymphoma patients (33.3%) (P < 0.001). There was a significant difference in the type of prior administered chemotherapy; in the patients who received cytostatics free chemotherapy, PVA was used more often (75.0%) (P = 0.007). In terms of the efficacy and safety of LVLs, there were no differences between procedures performed using PVA and CVCs. CONCLUSION: Peripheral venous access is feasible for autologous PBSC collection in more than a half of patients, in particular in those with multiple myeloma. Changes in the treatment of multiple myeloma, using new proteasome inhibitors-based and immunomodulatory agents that do not adversely affect peripheral veins, have enabled the use of PVA even at the high blood flow rates required by LVL. Peripheral venous access is not associated with safety issues or with a lesser collection efficiency, and it is cost-effective as well. Each patient referred to autologous PBSC collection needs to be evaluated individually by the experienced apheresis team for the most appropriate venous access.

Therapeutic Leukocytapheresis to relieve priapism due to leukostasis in CML patients: Our experience in a tertiary care centre.

Hyperleukocytosis in leukemic patients may cause tumour lysis syndrome, disseminated intravascular coagulopathy, and leukostasis, resulting in decreased tissue perfusion and increasing the risk of mortality. Since the myeloid blasts are larger than lymphoid blasts and are less deformable, complications of leukostasis are seen more frequently in myeloid leukemia. Priapism is a less common complication associated with leukostasis in leukaemia patients that should be treated as soon as possible to avoid ischemic injuries. Although chemotherapeutic drugs such as hydroxyurea and imatinib are used to treat hyperleukocytosis in CML patients, leukocytapheresis (LCP) can achieve rapid cytoreduction. Prophylactic LCP could not offer any advantage over aggressive chemotherapy, but therapeutic leukocyte depletion has a proven role in patients having symptomatic leukostasis due to high tumour burden. Three patients with ischaemic priapism were reported at our institute's emergency department, where detumescence could not be achieved by distal shunting or aspiration with phenylephrine instillation. The procedure of therapeutic LCP was performed in all three patients on an emergency basis, which resolved painful priapism by rapid cytoreduction.

A critical time window for leukapheresis product transportation to manufacture clinical-grade dendritic cells with optimal anti-tumor activities.

BACKGROUND AIMS: Dendritic cell (DC)-based immunotherapy is a promising approach to treat cancer. However, key aspects governing the reproducible manufacturing of high-quality DC remain incompletely defined. Here, we show that the time window between leukapheresis and DC manufacturing is critical. METHODS: Transcriptomic profiling by RNA-seq was used to unbiasedly characterize cellular states during each step of DC manufacturing process, and functional assays were used to determine the anti-tumor activities of DC. RESULTS: During preclinical development of a DC-based cytotherapy platform, CUD-002 (NCT05270720), we found that DC quality varied among different batches, even though commonly used DC maturation markers CD80, CD83 and CD86 were indistinguishable. Multivariate analysis indicated that DC quality was negatively associated with the shipping time from the leukapheresis site to the manufacturing center. To investigate the potential effect of shipping time, we stored leukapheresis materials from three donors for 0, 1, 2 or 3 days before DC manufacturing. For each step, we carried out RNA-seq analysis to unbiasedly characterize cellular states. Integrated bioinformatic analyses indicated that longer storage time reduced the expression of several transcription factors to attenuate interferon pathways. CONCLUSIONS: Consistently, we found that 3-day storage of leukapheresis materials significantly lowered the efficiency to generate DC but also impaired DC responses to inflammatory signals, resulting in inferior antigen-presentation and cytotoxic T-cell activities. Thus, we recommend using leukapheresis materials within 48 h to manufacture therapeutic DCs.

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.

BACKGROUND: 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. STUDY DESIGN AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Leukapheresis for CAR-T cell production and therapy.

Chimeric antigen receptor (CAR) T-cell therapy is an effective, individualized immunotherapy, and novel treatment for hematologic malignancies. Six commercial CAR-T cell products are currently approved for lymphatic malignancies and multiple myeloma. In addition, an increasing number of clinical centres produce CAR-T cells on-site, which enable the administration of CAR-T cells on site. The CAR-T cell products are either fresh or cryopreserved. Manufacturing CAR-T cells is a complicated process that begins with leukapheresis to obtain T cells from the patient's peripheral blood. An optimal leukapheresis product is crucial step for a successful CAR-T cell therapy; therefore, it is imperative to understand the factors that may affect the quality or T cells. The leukapheresis for CAR-T cell production is well tolerated and safe for both paediatric and adult patients and CAR-Τ cell therapy presents high clinical response rate in many studies. CAR-T cell therapy is under continuous improvement, and it has transformed into an almost standard procedure in clinical haematology and stem cell transplantation facilities that provide both autologous and allogeneic stem cell transplantations. In patients suffering from advanced haematological malignancies, CAR-T cell therapy shows incredible antitumor efficacy. Even after a single infusion of autologous CD19-targeting CAR-T cells in patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL) and acute lymphoblastic leukaemia (ALL), long lasting remission is observed, and a fraction of the patients are being cured. Future novel constructs are being developed with better T cell persistence and better expansion. New next-generation CAR-T cells are currently designed to avoid toxicities such as cytokine release syndrome and neurotoxicity.

Use of subgroup-specific hematopoietic stem cell collection efficiencies to improve truncation calculations for large-volume leukapheresis procedures.

PURPOSE: A critical component of optimizing peripheral blood (PB) hematopoietic stem cell (HSC) collections is accurately determining the processed blood volume required to collect the targeted number of HSCs. Fundamental to most truncation equations employed to determine this volume is the procedure's estimated collection efficiency (CE), which is typically applied uniformly across all HSC collections. Few studies have explored the utility of using different CEs in subpopulations of donors that have substantially different CEs than the institutional average. METHODS: Initial procedures from 343 autologous and 179 allogeneic HSC collections performed from 2018 to 2021 were retrospectively analyzed. Predictive equations were developed to determine theoretical truncation rates in various donor subgroups. RESULTS: Quantitative variables (pre-procedure cell counts) and qualitative variables (relatedness to recipient, gender, method of venous access, and mobilization strategy) were found to significantly impact CE. However, much of the variability in CE between donors could not be explained by the variables assessed. Analyses of procedures with high pre-collection PB cell counts identified lower CE values for these donors' truncation equations which still allow truncation but minimize risk of collecting less CD34+ cells than requested. CONCLUSIONS: Individualized CE does not substantially improve truncation volume calculations over use of a fixed CE and adds complexity to these calculations. The optimal fixed CE varies between autologous and allogeneic donors, and donors with high pre-collection PB cell counts in either of these groups. This model will be clinically validated and continuously refined through analysis of future HSC collections.

Variable recovery of cryopreserved hematopoietic stem cells and leukocyte subpopulations in leukapheresis products.

INTRODUCTION: Due to the expansion of cell therapy using not only haematopoietic stem cells (HSC) but also other leukocyte subpopulations, the loss of these cells in cryopreserved apheresis products needs to be evaluated. Various factors that could negatively affect post-thaw recovery, such as leukapheresis product characteristics, storage time and cryopreservation protocols have been identified. METHODS: The post-thaw recovery of HSCs, lymphocytes, NK cells and monocytes, as well as the factors that could adversely affect it were analysed in autologous and allogeneic leukapheresis products. RESULTS: The lowest post-thaw recovery was observed in autologous and allogeneic CD34+ cells, with the median of 73.7% and 68.1%, respectively. In leukocyte subpopulation, the lowest post-thaw recovery was observed for CD14+ cells, both autologous and allogeneic. The highest post-thaw recovery was observed for CD3+/CD8+ cells in autologous, and for CD19+ cells in allogeneic samples. The statistically significant difference was observed between autologous and allogeneic PBSC products for CD3+ cell recovery (P = 0.031) and CD3+/CD8+ cell recovery (P = 0.009). The evaluation of factors that could adversely affect the post-thaw recovery in autologous samples showed weak negative correlations between platelet concentration and CD3+ recovery, as well as between storage time and CD3+CD8+ recovery. In allogeneic samples, a strong negative correlation was observed only between the percentage of granulocytes and CD3+, CD3+/CD8+ and CD3+/CD4+ cell recoveries. CONCLUSION: Since various post-thaw recoveries of leukocyte subpopulations were observed, the cell therapy manufacturing centers should evaluate how their cryopreservation method and other factors affect the recovery of cell population of interest in their settings.

Improved enrichment of circulating tumor cells from diagnostic leukapheresis product.

The median number of circulating tumor cells (CTCs) detected in 7.5 mL of peripheral blood by CellSearch (PB-CS) in patients with metastatic prostate cancer is in the order of 1-10, which means many samples have insufficient tumor cells for comprehensive characterization. A significant increase is obtained through diagnostic leukapheresis (DLA), however, only 2%-3% of the DLA product can be processed per CellSearch test, limiting the gain. We processed aliquots from 30 DLA products of metastatic prostate cancer patients consisting of 0.2 × 109 leukocytes using CellSearch (DLA-CS) as well as the newly introduced reduced enrichment reagent protocol (RER), which uses 10-fold less enrichment reagents than DLA-CS. The number of tumor cells and the total number of captured cells were determined using the CellTracks Analyzer. Additionally, for six DLA samples, a 1.0 × 109 leukocyte aliquot was processed (RER+), using twofold less enrichment reagents than DLA-CS. A median 2.7-fold reduction in leukocyte co-enrichment was found between DLA-CS and RER methods without any loss in tumor cell recovery (Wilcoxon Signed Ranks Test, p = 0.953). Using 1.0 × 109 leukocyte aliquots a fourfold increase in tumor cells was found compared to DLA-CS and a 19-fold increase compared to PB-CS was obtained. The here-introduced RER protocol results in a higher final sample purity without any loss in tumor cell recovery while using 10-fold less CellSearch capture reagent. With this improved method, 26% of the leukapheresis sample can now be processed using reagents from a single CellSearch test, enabling the obtainment of a sufficient number of CTCs for comprehensive characterization in most metastatic prostate cancer patients.

Prevalence of baseline hypocalcemia and symptomatic hypocalcemia during leukapheresis.

Symptoms of hypocalcemia are reported in up to 50% of patients undergoing leukapheresis procedures. There is no set standard of practice for administering calcium supplementation in the prevention or treatment of hypocalcemia symptoms. The goal of this descriptive, retrospective study was to determine the prevalence of baseline hypocalcemia and symptomatic hypocalcemia during leukapheresis with acid citrate dextrose solution A and to identify patient characteristics associated with symptomatic hypocalcemia. Three percent of patients were found to have hypocalcemia before leukapheresis with 35% experiencing hypocalcemia symptoms during leukapheresis. Older age, higher albumin levels, and longer procedure time were associated with increased risk of hypocalcemia symptoms.

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.

Managing leukapheresis in adult and pediatric patients eligible for chimeric antigen receptor T-cell therapy: suggestions from an Italian Expert Panel.

Chimeric antigen receptor (CAR) T-cell therapy relies on T cells engineered to target specific tumor antigens such as CD-19 in B-cell malignancies. In this setting, the commercially available products have offered a potential long-term cure for both pediatric and adult patients. Yet manufacturing CAR T cells is a cumbersome, multistep process, the success of which strictly depends on the characteristics of the starting material, i.e., lymphocyte collection yield and composition. These, in turn, might be affected by patient factors such as age, performance status, comorbidities, and previous therapies. Ideally, CAR T-cell therapies are a one-off treatment; therefore, optimization and the possible standardization of the leukapheresis procedure is critical, also in view of the novel CAR T cells currently under investigation for hematological malignancies and solid tumors. The most recent Best Practice recommendations for the management of children and adults undergoing CAR T-cell therapy provide a comprehensive guide to their use. However, their application in local practice is not straightforward and some grey areas remain. An Italian Expert Panel of apheresis specialists and hematologists from the centers authorized to administer CAR T-cell therapy took part in a detailed discussion on the following: 1) pre-apheresis patient evaluation; 2) management of the leukapheresis procedure, also in special situations represented by low lymphocyte count, peripheral blastosis, pediatric population <25 kg, and the COVID-19 outbreak; and 3) release and cryopreservation of the apheresis unit. This article presents some of the important challenges that must be faced to optimize the leukapheresis procedure and offers suggestions as to how to improve it, some of which are specific to the Italian setting.

Recent advances in microfluidic cell separation to enable centrifugation-free, low extracorporeal volume leukapheresis in pediatric patients.

Leukapheresis is a common extracorporeal procedure for leukodepletion and cellular collection. During the procedure, a patient's blood is passed through an apheresis machine to separate white blood cells (WBCs) from red blood cells (RBCs) and platelets (PLTs), which are then returned to the patient. Although it is well-tolerated by adults and older children, leukapheresis poses a significant risk to neonates and low-weight infants because the extracorporeal volume (ECV) of a typical leukapheresis circuit represents a particularly large fraction of their total blood volume. The reliance of existing apheresis technology on centrifugation for separating blood cells limits the degree to which the circuit ECV could be miniaturized. The rapidly advancing field of microfluidic cell separation holds excellent promise for devices with competitive separation performance and void volumes that are orders of magnitude smaller than their centrifugation-based counterparts. This review discusses recent advancements in the field, focusing on passive separation methods that could potentially be adapted to perform leukapheresis. We first outline the performance requirements that any separation method must meet to replace centrifugation-based methods successfully. We then provide an overview of the passive separation methods that can remove WBCs from whole blood, focusing on the technological advancements made in the last decade. We describe and compare standard performance metrics, including blood dilution requirements, WBC separation efficiency, RBC and PLT loss, and processing throughput, and discuss the potential of each separation method for future use as a high-throughput microfluidic leukapheresis platform. Finally, we outline the primary common challenges that must still be overcome for these novel microfluidic technologies to enable centrifugation-free, low-ECV leukapheresis in the pediatric setting.

The effect of the time from diagnosis to induction therapy on prognosis in patients with acute leukemia undergoing leukapheresis for symptomatic hyperleukocytosis.

INTRODUCTION: Our study investigated leukapheresis's effect on delayed induction therapy outcomes in patients with acute leukemia presenting with symptomatic hyperleukocytosis. METHODS: This retrospective cohort study included 30 adult patients diagnosed with acute leukemia who underwent leukapheresis for leukostasis. The patients were divided into the first 24 h and >24 h groups, according to the time from diagnosis to induction therapy (TDT). RESULTS: There was no significant difference between the TDT groups regarding complete remission (CR), 4-week mortality, and overall survival (OS) at a median follow-up of 409 days. Tumor lysis syndrome, disseminated intravascular coagulation, and hemoglobin levels were significant in early mortality. In univariate analysis, age, hemoglobin levels, patients' eligibility for intensive chemotherapy, and achieving CR were critical factors for OS. CONCLUSION: The study findings suggest that waiting for the clinical and laboratory results may be a safe and reasonable approach before assigning patients the best treatment option with leukapheresis.

Clinical characteristics and outcomes of children with newly diagnosed acute myeloid leukemia and hyperleukocytosis managed with different cytoreductive methods.

BACKGROUND: Hyperleukocytosis in patients with acute myeloid leukemia (AML) has been associated with worse outcomes. For cytoreduction, leukapheresis has been used but its clinical utility is unknown, and low-dose cytarabine (LD-cytarabine) is used as an alternative method. METHODS: Children with newly diagnosed AML treated between 1997 and 2017 in institutional protocols were studied. Hyperleukocytosis was defined as a leukocyte count of ≥100 × 109 /L at diagnosis. Clinical characteristics, early complications, survival data, and effects of cytoreductive methods were reviewed. Among 324 children with newly diagnosed AML, 49 (15.1%) presented with hyperleukocytosis. Initial management of hyperleukocytosis included leukapheresis or exchange transfusion (n = 16, considered as one group), LD-cytarabine (n = 18), hydroxyurea (n = 1), and no leukoreduction (n = 14). RESULTS: Compared with patients who received leukapheresis, the percentage decrease in leukocyte counts following intervention was greater among those who received LD-cytarabine (48% vs. 75%; p = .02), with longer median time from diagnosis to initiation of protocol therapy (28.1 vs. 95.2 hours; p < .001). The incidence of infection was higher in patients (38%) who had leukapheresis than those who receive LD-cytarabine (0%) or leukoreduction with protocol therapy (14%) (p = .008). No differences were noted in the outcomes among the intervention groups. Although patients with hyperleukocytosis had higher incidences of pulmonary and metabolic complications than did those without, no early deaths occurred, and the complete remission, event-free survival, overall survival rates, and outcomes of both groups were similar. CONCLUSION: LD-cytarabine treatment appears to be a safe and effective means of cytoreduction for children with AML and hyperleukocytosis.

Successful stem cell collection for atypical teratoid rhabdoid tumor in an extremely low-body weight child: A case report.

The use of peripheral blood hematopoietic stem cells for bone marrow reconstitution after myeloablative therapy is well established in children with malignant disorders. However, the peripheral blood hematopoietic stem cells collection in very low-body weight (≤10 kg) children remains a significant challenge because of technical and clinical issues. A male newborn affected by atypical teratoid rhabdoid tumor, diagnosed prenatally, received two cycles of chemotherapy following surgical resection. After an interdisciplinary discussion, it was decided to intensify the treatment with high-dose chemotherapy followed by autologous stem cell transplantation. After 7 days of G-CSF administration the patient underwent hematopoietic progenitor cells-apheresis collection. The procedure was performed in the pediatric intensive care unit, using two central venous catheters and Spectra Optia device. The cell collection procedure was completed in 200 min, during which time 3.9 total blood volumes were processed. During apheresis we did not observe electrolyte alterations. No adverse events were recorded during or immediately following the cell collection procedure. Our report describes the feasibility of performing large volume leukapheresis without complications in an extremely low-body weight patient weighing 4.5 kg using the Spectra Optia apheresis device. No catheter-related problems occurred, and apheresis was completed without any adverse event. In conclusion, we believe that very low-body weight pediatric patients need a multidisciplinary approach to manage central venous access, hemodynamic monitoring, cell collection, prevention of metabolic complications to improve safety, feasibility, and efficiency of stem cell collection procedures.

A secondary CD34+ acute lymphoblastic leukemia unmasked and mobilized by G-CSF in an autologous stem cell donor with testicular cancer.

BACKGROUND: Late complications of chemotherapy include treatment-related secondary leukemias. We describe an unusual case of a new treatment-related acute lymphoblastic leukemia (t-ALL) that was unmasked and mobilized by G-CSF during autologous hematopoietic progenitor cell collection (HPCC) in a young man with testicular cancer. METHODS: Electronic chart review of the patient medical history and pertinent laboratory findings. Patient CD34 and blast results were compared to 4249 autologous and 437 allogeneic HPCC performed between 2004 and 2022. In autologous donors, the %blast and %CD34 were compared by linear regression and paired t-test using commercial software. RESULTS: The patient was a 21-year-old male with relapsed testicular cancer referred for G-CSF cytokine-only mobilization and autologous HPCC. His pre-mobilization WBC count and differential were normal. On the day of HPCC, his WBC = 37.9 K/mcL with 12% blasts and 9.75% circulating CD34+ cells. The patient was admitted 9 days after HPCC with a normal WBC count and 15% blasts. He was diagnosed with a pro-B t-ALL bearing an t(4:11)(q21:q23) translocation and KMT2A-AF4 rearrangement. Upon review, this patient had the highest %CD34 among 4686 HPCC and was the only donor with %CD34 > 1% after a cytokine-only mobilization. CONCLUSION: We report a case of t-ALL that mimicked CD34+ HPC and was mobilized by high-dose G-CSF. Up to 70% of secondary leukemias bear 11q23/KMT2A rearrangements, which occur at the multipotent stem cell stage and can result in myeloid and lymphoid leukemias. Donors who have received past chemotherapy, especially with topoisomerase II inhibitors, are at increased risk for 11q23/KMT2A leukemias.

Safety and performance of the Spectra Optia apheresis system for white blood cell depletion in patients with elevated white blood cell counts.

BACKGROUND: For the past 30 years, white blood cell depletion (WBCD) or leukocytapheresis has been conducted to rapidly reduce excessive circulating white blood cell (WBC) concentrations in patients at risk for or with symptoms of leukostasis due to hyperleukocytosis. The goal of leukocytapheresis is to prevent or treat acute complications from leukostasis, thereby enabling patients to receive potentially curative chemotherapy. METHODS: This report details the results from a retrospective and a prospective clinical study conducted in the European Union and the People's Republic of China, which assessed the use of the Spectra Optia Apheresis System for leukocytapheresis in patients with hyperleukocytosis. The primary objective of both studies was to the assess the safety and performance of the WBCD procedure in patients with elevated WBC counts. RESULTS: Data were collected from 72 participants completing 87 WBCD procedures. The mean percent change in participant WBC counts post-procedure was 50.3 ± 21.2% and the collection efficiency (CE1) of the WBCD procedures was 53.7 ± 19.8%. Sixty-one participants (95.3%) experienced a total of 279 adverse events (AEs) with the majority of the AEs related to post-procedure changes in laboratory values, which is an anticipated AE in this patient population. CONCLUSION: The data collected within these studies indicate that the WBCD procedure is safe and well tolerated in patients with hyperleukocytosis as evaluated by percent decrease in WBC count, CE1, and AE incidence.

A case of ulcerative colitis-related postoperative enteritis treated with granulocyte and monocyte apheresis.

A 46-year-old man, receiving continuous steroid therapy for refractory ulcerative colitis with an insufficient response to anti-tumor necrosis factor-α therapy, presented with left buttock pain. He was diagnosed with steroidal left femoral head necrosis, and total proctocolectomy with permanent ileostomy was performed. At 6 months postoperatively, the patient developed general fatigue, abdominal pain, and severe ileostomy diarrhea. Computed tomography revealed continuous intestinal edema from the descending duodenal leg to the upper jejunum. Gastrointestinal endoscopy revealed deep ulcers, coarse mucosa, and duodenal erosion. Based on clinical progress, findings, and pathology, the patient was diagnosed with ulcerative colitis-related postoperative enteritis. Although 5-aminosalicylic acid treatment was initiated, his symptoms persisted, bloody diarrhea from colostomy was observed. Subsequently, granulocyte and monocyte apheresis treatment was added. Symptoms and endoscopic findings improved with granulocyte and monocyte apheresis. Azathioprine was introduced as maintenance therapy, and no sign of recurrence was observed. Although ulcerative colitis-related postoperative enteritis has no definitive treatment, granulocyte and monocyte apheresis may be considered for initial treatment.