Advantages of non-cryopreserved autologous hematopoietic stem cell transplantation against a cryopreserved strategy

Application of biphasic mineralized collagen/polycaprolactone scaffolds in the repair of large load-bearing bone defects: A study in a sheep model

Objective

This study aims to evaluate the efficacy of biphasic mineralized collagen/polycaprolactone (bMC/PCL) scaffolds in repairing large load-bearing bone defects, particularly femoral defects, using a sheep model.

Methods

The bMC/PCL scaffolds were prepared by combining porous mineralized collagen/polycaprolactone (pMC/PCL) with compact mineralized collagen/polycaprolactone (cMC/PCL). The scaffolds were characterized using scanning electron microscopy to observe the microstructure and compression testing to assess mechanical properties. Twenty female sheep were selected to create a 20 mm femoral defect model, divided into a blank group (no material implanted) and an experimental group (bMC/PCL scaffolds implanted), with 10 sheep in each group. Bone healing and lower limb functional recovery were assessed at 1 month, 3 months, and 6 months postoperatively using Lane-Sandhu scores and visual analog scale scores for lameness. Additionally, bone repair progress was analyzed through X-ray, Micro-CT, and histological analyses.

Results

Compared with the blank group, the bMC/PCL scaffold group showed significant improvement in bone defect repair. At 3 and 6 months postoperatively, X-ray, Micro-CT scans, and histological staining indicated stable scaffold integration and gradual new bone formation. The Lane-Sandhu scores in the experimental group were 3.60 ± 0.548 and 4.00 ± 0.707 at 3 and 6 months, respectively, whereas the blank group experienced plate/screw breakage leading to fixation failure, with scores of 1, indicating better bone healing in the experimental group. The lameness scores in the experimental group were 2.71 ± 0.97 and 1.48 ± 0.86 at 3 and 6 months, respectively, significantly lower than those in the blank group (p < 0.0001 and p = 0.0002). Micro-CT analysis showed that bone volume to tissue volume ratio increased from 28.07 ± 9.22 % to 62.02 ± 11.82 %, bone mineral density increased from 0.392 ± 0.032 g/cm3 to 0.583 ± 0.125 g/cm3, trabecular thickness increased from 0.690 ± 0.224 mm to 1.049 ± 0.089 mm, and trabecular separation decreased from 2.766 ± 1.183 mm to 0.501 ± 0.268 mm at 3 and 6 months postoperatively.

Conclusion

This study evaluated the efficacy of bMC/PCL scaffolds in repairing large load-bearing bone defects. The bMC/PCL scaffolds demonstrated good bioactivity and mechanical properties, indicating promising clinical application prospects. Future studies should further verify the safety and efficacy of these scaffolds in a wider range of animal models to support their clinical application.

Significance statement

The bMC/PCL scaffolds offer a promising solution for large femoral bone defects, with potential for clinical use in orthopedic and trauma surgeries.

The translational potential of this article

The application of bMC/PCL scaffolds in clinical practice is expected to significantly advance the treatment of large bone defects, particularly weight-bearing bone defects. The study shows that bMC/PCL scaffolds have a significant impact on the repair of large weight-bearing bone defects and functional recovery, indicating their potential for application in orthopedics and trauma care. Specifically, the material's supportive role in weight-bearing bones offers new possibilities for its use in the repair of weight-bearing bone defects. Furthermore, the performance of bMC/PCL scaffolds in bone healing makes them an ideal candidate material for treating various bone defects, with broad clinical application prospects. Further clinical trials are necessary to confirm their safety and efficacy in human patients.

Cryopreserved Umbilical Cord Mesenchymal Stem Cells Show Comparable Effects to Un-Cryopreserved Cells in Treating Osteoarthritis

Non-cryo and hypothermic preservations are two available options for short-term storage of living cells. For long-term cell storage, cryopreservation is an essential procedure as it prolongs the storage time, allowing for the transport and testing of cells, as well as the establishment of cell banks. But it is unclear whether cryopreservation reduces the therapeutic effects of human umbilical cord mesenchymal stem cells (hucMSCs) on osteoarthritis (OA). To investigate this, we compared the basic biological characteristics and the anti-OA efficacy of un-cryopreserved hucMSCs (UC-MSCs) and cryopreserved hucMSCs (C-MSCs). A mono-iodoacetate-induced rat OA model was established to evaluate the anti-OA properties of UC-MSCs and C-MSCs. And the conditioned medium of UC-MSCs (UC-CM) and cell freezing medium of C-MSCs (C-CFM) were collected for the mechanism study. No significant differences were found between UC-MSCs and C-MSCs in cell viability, immunophenotype, and trilineage differentiation capacity. In vivo, UC-MSCs and C-MSCs exhibited similar cartilage-repairing effects by attenuating pain and alleviating pathological changes in OA rat joints. In vitro, C-CFM and UC-CM promoted the proliferation of chondrocytes, improved the expression of anabolism-related molecules (Col2, COL2, and SOX9), and decreased the expression of catabolism-related molecules (Adamts5, Mmp13, Il6, COL10, and MMP13). These results indicated that UC-MSCs and C-MSCs had comparable anti-OA effects, and cryopreservation did not alter the anti-OA capability of hucMSCs, which provides further support for clinical use of C-MSCs in treating OA.

Non-cryopreserved autologous peripheral blood stem cell transplantation for multiple myeloma and lymphoma in countries with limited resources: practice considerations from the Worldwide Network for Blood and Marrow Transplantation

Autologous peripheral blood stem cell (PBSC) transplantation is a standard treatment of multiple myeloma (MM), Hodgkin lymphoma and various subtypes of non-Hodgkin lymphoma. Cryopreservation of hematopoietic stem cells is standard practice that allows time for delivery of conditioning regimen prior to cell infusion. The aim of this Worldwide Network for Blood & Marrow Transplantation (WBMT) work was to assess existing evidence on non-cryopreserved autologous transplants through a systematic review/meta-analysis, to study feasibility and safety of this approach. We searched PubMed, Web of Science and SCOPUS for studies that utilized non-cryopreserved autologous PBSC transplantation. Identified literature was reviewed for information on mobilization, apheresis, preservation and viability, conditioning regimen, engraftment, response, and survival. Results highlight collective experience from 19 transplant centers (1686 patients), that performed autologous transplants using non-cryopreserved PBSCs. The mean of infused CD34+ was 5.6 × 106/kg. Stem cell viability at transplantation was >90% in MM and >75% in lymphomas, after a storage time of 24-144 h at +4 °C. Mean time-to-neutrophil engraftment was 12 days and 15.3 days for platelets. Pooled proportion estimates of day 100 transplant-related mortality and graft failure were 1% and 0%, respectively. Non-cryopreservation of apheresed autologous PBSCs appears feasible and safe.

Orthobiologic Products: Preservation Options for Orthopedic Research and Clinical Applications

The biological products used in orthopedics include musculoskeletal allografts-such as bones, tendons, ligaments, and cartilage-as well as biological therapies. Musculoskeletal allografts support the body's healing process by utilizing preserved and sterilized donor tissue. These allografts are becoming increasingly common in surgical practice, allowing patients to avoid more invasive procedures and the risks associated with donor site morbidity. Bone grafting is one of the most frequently used procedures in orthopedics and traumatology. Biologic approaches aim to improve clinical outcomes by enhancing the body's natural healing capacity and reducing inflammation. They serve as an alternative to surgical interventions. While preliminary results from animal studies and small-scale clinical trials have been promising, the field of biologics still lacks robust clinical evidence supporting their efficacy. Biological therapies include PRP (platelet-rich plasma), mesenchymal stem cells (MSCs)/stromal cells/progenitor cells, bone marrow stem/stromal cells (BMSCs), adipose stem/stromal cells/progenitor cells (ASCs), cord blood (CB), and extracellular vesicles (EVs), including exosomes. The proper preservation and storage of these cellular therapies are essential for future use. Preservation techniques include cryopreservation, vitrification, lyophilization, and the use of cryoprotective agents (CPAs). The most commonly used CPA is DMSO (dimethyl sulfoxide). The highest success rates and post-thaw viability have been achieved by preserving PRP with a rate-controlled freezer using 6% DMSO and storing other cellular treatments using a rate-controlled freezer with 5% or 10% DMSO as the CPA. Extracellular vesicles (EVs) have shown the best results when lyophilized with 50 mM or 4% trehalose to prevent aggregation and stored at room temperature.

Analysis of apheresis outcomes in a cohort of Chilean patients treated with autologous stem cell transplantation: A single center real-world experience

Adequate stem cell harvesting is required for autologous hematopoietic transplantation. In deficient mobilizer patients, the collection of stem cells can be challenging because of the impossibility of achieving satisfactory CD34 cell counts with GCSF + - chemotherapy. Plerixafor is a potent and expensive drug that promotes the release of stem cells from the medullary niche to the peripheral blood and allows satisfactory harvests. We performed a retrospective analysis of 370 patients with myeloma and lymphoma harvested at our institution. 99 % of patients achieved satisfactory apheresis using Plerixafor in 45 %. Satisfactory harvests were obtained in patients mobilized with GCSF or plerixafor. In patients who used plerixafor, it was necessary to perform fewer apheresis procedures (P = 0.05). In multivariate analysis, the only factor that predicted the need for plerixafor was the presence of less than 30,000 CD34 / ul on the day of apheresis (OR 0.3. p < 0.001). Since we adopted the plerixafor protocol guided by CD34 counts, the number of patients with harvest failure has decreased. In conclusion, the rational and standardized use of plerixafor favors satisfactory harvest in patients who require autologous transplantation in South-American patients.

American Society for Transplantation and Cellular Therapy International Affairs Committee: Report of the 4th Workshop on Quality as a Development Tool for Hematopoietic Cell Transplantation Programs at the 2023 Tandem BMT Meetings

We provide a summary of the 4th ASTCT International Workshop with presentations from experts from Chile ("Setting Up a Transplantation Program in Chile," by Dr Pablo Ramirez), Saudi Arabia ("Developing Quality Programs in North Africa," by Dr Amal Alseraihy), and Japan ("The Japanese Transplant Registry Unified Management Program [TRUMP]: Current Issues and the Future," by Dr Yoshiko Atsuta). Workshop objectives included: (1) recognizing the benefits and importance for low- and middle-income countries of developing quality criteria and programs beyond existing accreditation programs, such as the Foundation for the Accreditation of Cellular Therapy (FACT) and the Joint Accreditation Committee ISCT-Europe and EBMT (JACIE); (2) describing the relationships among monitoring outcomes, including mortality, improvement of care, data reporting, and associated costs; and (3) reviewing how quality structures have been implemented and are improving care worldwide.

Mesenchymal stem cell therapy in diabetic foot ulcer: An updated comprehensive review

Background

Diabetes has evolved into a worldwide public health issue. One of the most serious complications of diabetes is diabetic foot ulcer (DFU), which frequently creates a significant financial strain on patients and lowers their quality of life. Up until now, there has been no curative therapy for DFU, only symptomatic relief or an interruption in the disease's progression. Recent studies have focused attention on mesenchymal stem cells (MSCs), which provide innovative and potential treatment candidates for several illnesses as they can differentiate into various cell types. They are mostly extracted from the placenta, adipose tissue, umbilical cord (UC), and bone marrow (BM). Regardless of their origin, they show comparable features and small deviations. Our goal is to investigate MSCs' therapeutic effects, application obstacles, and patient benefit strategies for DFU therapy.

Methodology

A comprehensive search was conducted using specific keywords relating to DFU, MSCs, and connected topics in the databases of Medline, Scopus, Web of Science, and PubMed. The main focus of the selection criteria was on English-language literature that explored the relationship between DFU, MSCs, and related factors.

Results and Discussion

Numerous studies are being conducted and have demonstrated that MSCs can induce re-epithelialization and angiogenesis, decrease inflammation, contribute to immunological modulation, and subsequently promote DFU healing, making them a promising approach to treating DFU. This review article provides a general snapshot of DFU (including clinical presentation, risk factors and etiopathogenesis, and conventional treatment) and discusses the clinical progress of MSCs in the management of DFU, taking into consideration the side effects and challenges during the application of MSCs and how to overcome these challenges to achieve maximum benefits.

Conclusion

The incorporation of MSCs in the management of DFU highlights their potential as a feasible therapeutic strategy. Establishing a comprehensive understanding of the complex relationship between DFU pathophysiology, MSC therapies, and related obstacles is essential for optimizing therapy outcomes and maximizing patient benefits.

Autologous Stem Cell Transplant in Lymphoma Using a Noncryopreserved Platform: An Adapted Sequential Conditioning Maintaining Dose Intensity Does not Affect Transplantation Outcomes

BACKGROUND

Hematopoietic autologous stem cell transplantation (ASCT) is a validated therapeutic strategy for lymphoma treatment and precise well-tolerated conditioning. Several conditioning methods are available, but the most commonly used are CVB, BEAM, and ICE, which are conventionally administered in 6 to 7 days. Since 2015, our program has moved toward noncryopreserved platforms that require concise times; therefore, we have modified the conditioning by reducing it to 4 to 5 days. In this study, we show our experience.

METHODS

We compared ASCT performed in our program before and after 2015 in lymphoma patients. Between 2000 and 2014 and from 2015 to 2022, we performed 46 and 61 ASCT procedures, respectively.

RESULTS

Since 2015, we observed a greater number of infused stem cells, fewer episodes of febrile neutropenia (60% vs. 37% P = .008), shorter hospitalizations (30 vs. 18 days P = .001), faster engraftment (20 vs. 14 days P = .001) and better progression-free survival (72 vs. 44 months P = .002). Additionally, a prolonged overall survival was observed at these results, and this prolonged survival is difficult to interpret due to the short follow-up.

CONCLUSION

In conclusion, conditioning adjusted for a noncryopreserved strategy offers at least similar or even better results than the cryopreserved strategy. Prospective studies are warranted.

Hematopoietic cell transplants in resource-poor countries: challenges and opportunities

INTRODUCTION

Numbers of hematopoietic cell transplants continue to increase globally but most of this activity is in resource-rich countries. Limitations to increasing transplant activity in resource-poor countries include lack of sophisticated personnel and infrastructure, complexity in identifying and accessing donors, unavailability of some new drugs and high cost.

AREAS COVERED

We searched the biomedical literature for hematopoietic cell transplants and resource-rich and resource-poor countries. Recent advances which potentially make transplants more accessible in resource-poor countries include: (1) outpatient transplants; (2) grafts stored at 4°C; (3) less intensive pretransplant conditioning; (4) use of generic drugs; (5) less complex and costly donor access; and (6) increased collaboration with transplant centers in resource-rich countries.

EXPERT OPINION

We reviewed publications on the limitations and solutions discussed above. Paradoxically, most data we analyzed originate from resource-rich countries. We found no convincing epidemiological data to support a recent increased transplant rate in resource-poor countries yet but hope to see increases soon.

Adverse events, side effects and complications in mesenchymal stromal cell-based therapies

Numerous clinical studies have shown a wide clinical potential of mesenchymal stromal cells (MSCs) application. However, recent experience has accumulated numerous reports of adverse events and side effects associated with MSCs therapy. Furthermore, the strategies and methods of MSCs therapy did not change significantly in recent decades despite the clinical impact and awareness of potential complications. An extended understanding of limitations could lead to a wider clinical implementation of safe cell therapies and avoid harmful approaches. Therefore, our objective was to summarize the possible negative effects observed during MSCs-based therapies. We were also aimed to discuss the risks caused by weaknesses in cell processing, including isolation, culturing, and storage. Cell processing and cell culture could dramatically influence cell population profile, change protein expression and cell differentiation paving the way for future negative effects. Long-term cell culture led to accumulation of chromosomal abnormalities. Overdosed antibiotics in culture media enhanced the risk of mycoplasma contamination. Clinical trials reported thromboembolism and fibrosis as the most common adverse events of MSCs therapy. Their delayed manifestation generally depends on the patient's individual phenotype and requires specific awareness during the clinical trials with obligatory inclusion in the patient' informed consents. Finally we prepared the safety checklist, recommended for clinical specialists before administration or planning of MSCs therapy.

Non-cryopreserved peripheral blood stem cells as a safe and effective alternative for autologous transplantation in multiple myeloma

BACKGROUND

Autologous stem cell transplantation is the standard procedure for multiple myeloma and the grafts are usually cryopreserved. Previous studies reported advantages in the use of fresh peripheral blood stem cells (PBSC) autotransplantation compared to cryopreservation of the grafts. This study compared the transplant-related outcomes of two graft preservation methods: fresh storage (4°C/72 h) and cryopreservation (-80°C).

STUDY DESIGN AND METHODS

We performed an analysis of 45 patients with multiple myeloma under autotransplantation (17 fresh and 28 cryopreserved) from 2017 to 2021. Fresh PBSC were maintained in the refrigerator for three days in a concentration up to 300 × 10³ TNC/μL. Cryopreserved PBSC were concentrated by plasma reduction after centrifugation (950 g/10 min/4°C) and an equal volume of cryoprotection solution was added for a final concentration of 300 × 10³ TNC/μL, 5% DMSO, 6% hydroxyethyl starch, and 3% human albumin.

RESULTS

Neutrophil engraftment was significantly faster with fresh PBSCs (10 vs. 11.5 days, p = 0.045). Adverse effects were more common in cryopreserved PBSC transplantation (75% vs. 35.3% patients; p = 0.013). Post transplantation hospital stay was 20 and 22 days for fresh and cryopreserved PBSCs respectively (p = 0.091). There was no difference in platelet engraftment time (10.5 days for both; p = 0.133), number of antibiotics used after transplantation (3 for fresh and 2.5 for cryopreserved; p = 0.828), days of antibiotic use after transplantation (12.2 days for fresh and 13.3 days for cryopreserved, p = 0.579), and overall survival (p = 0.736).

CONCLUSION

The infusion of fresh PBSC refrigerated for up to three days is effective and safe for autologous transplantation in patients with multiple myeloma, which is a useful alternative to cryopreserved PBSC.

Cryopreserved versus non-cryopreserved stem cell autografts in multiple myeloma a restrospective cohort study

The use of non-cryopreserved hematopoietic stem cells (HSC) can be an alternative to the traditional cryopreserved infusions of HSCs in autologous stem cell transplantation (aHSCT). After high-dose melphalan conditioning (HDM), we sought to compare time to engraftment, overall survival, and safety in multiple myeloma (MM) patients undergoing a first aHSCT after high-dose melphalan conditioning (HDM). We conducted a cohort study from March 2018 to December 2019. Of all autologous transplants performed during this period, 105 were for MM as the first consolidation. Fifty-one patients received a cryopreserved graft; the remaining 54 patients received a fresh infusion. General clinical characteristics were similar between these two groups. Cell viability was higher in non-cryopreserved grafts (95% vs. 86% p < 0.01). Four deaths occurred during hospitalization in the cryopreserved group, one in the non-cryopreserved group. The cumulative incidence of neutrophil and platelet engraftment on D + 25 was higher in the non-cryopreserved compared to the cryopreserved group (98% vs 90% p < 0.01 and 96.2% vs 72.54% p < 0.01 respectively). Additionally, the hospital length of stay was reduced by 4 days for patients for the non-cryopreserved cohort. In summary, the use of non-cryopreserved HSCs after HDM is safe and effective compared to patients who received a cryopreserved graft.

Autologous Stem Cell Transplantation in Multiple Myeloma: Where Are We and Where Do We Want to Go?

The introduction of high-dose therapy in the 1990s as well as the development of drugs such as thalidomide, lenalidomide, and bortezomib in the 2000s led to an impressive improvement in outcome of patients with multiple myeloma (MM) eligible for autologous stem cell transplantation (ASCT). Clinical trials conducted in the first ten years of the twenty-first century established as standard therapy for these patients a therapeutic approach including induction, single or double ASCT, consolidation, and maintenance therapy. More recently, incorporating second-generation proteasome inhibitors carfilzomib and monoclonal antibody daratumumab into each phase of treatment significantly improved the efficacy of ASCT in terms of measurable residual disease (MRD) negativity, Progression Free Survival (PFS), and Overall Survival (OS). The availability of techniques such as multiparameter flow cytometry (MFC) and next-generation sequencing (NGS) for MRD assessment allowed the design of MRD-based response-adjusted trials that will define, in particular, the role of consolidation and maintenance therapies. In this review, we will provide an overview of the most recent evidence and the future prospects of ASCT in MM patients.

Effects of cell concentration, time of fresh storage, and cryopreservation on peripheral blood stem cells: PBSC fresh storage and cryopreservation

INTRODUCTION

Peripheral blood stem cells are widely used in autologous or allogeneic transplantation. The quality of the product directly impacts clinical outcomes, and the cell quality and/or functionality may be influenced by the storage conditions as time, temperature, total nucleated cells (TNC) concentration and cryopreservation requirement.

OBJECTIVE

To verify the effects of time, cell concentration, and cryopreservation/thawing in the viability and functionality of stem cells for transplantation.

METHODS

We evaluated TNC, CD45⁺ viable cells, CD34⁺ viable cells, and cell viability and functionality of 11 samples. Measurements were performed immediately and 24 h, 48 h, 72 h, and 96 h after sample collection at high and low TNC concentrations. The same parameters were also evaluated after cryopreservation and thawing of the samples.

RESULT

Duration of storage and TNC concentration exhibited a negative effect on cell quality (CD45⁺ viable cells, CD34⁺ viable cells and functionality). Moreover, the association of these parameters increased the negative effect on graft quality. Cryopreservation and thawing also negatively affected the collected sample regarding viable CD34⁺ cells (recovery 66.2 %), viable CD45⁺ cells (recovery 56.8 %), and 7-AAD viability. No significant losses in viable CD45⁺/CD34⁺ cells and functionality were observed in the first 24 h in both TNC conditions.

CONCLUSION

These results emphasize the importance to consider carefully the storage conditions until transplantation, measuring TNC/μL until 24 h after collection (diluting the product when TNC > 300 × 10³/μL) and infusing fresh graft as soon as possible.

Winter is coming: the future of cryopreservation

The preservative effects of low temperature on biological materials have been long recognised, and cryopreservation is now widely used in biomedicine, including in organ transplantation, regenerative medicine and drug discovery. The lack of organs for transplantation constitutes a major medical challenge, stemming largely from the inability to preserve donated organs until a suitable recipient is found. Here, we review the latest cryopreservation methods and applications. We describe the main challenges-scaling up to large volumes and complex tissues, preventing ice formation and mitigating cryoprotectant toxicity-discuss advantages and disadvantages of current methods and outline prospects for the future of the field.

Non-cryopreserved hematopoietic stem cells in autograft patients with lymphoma: a matched-pair analysis comparing a single center experience with the use of cryopreserved stem cells reported to the European Society for Blood and Marrow Transplantation registry

BACKGROUND AIMS

Around 50 000 autologous stem cell transplantations are done each year worldwide using cryopreserved peripheral blood stem cells (PBSCs). Cryopreservation is time-consuming and expensive. Since 2007, several retrospective studies have shown that PBSCs can be stored at 4°C for 2-3 days, allowing autologous stem cell transplantation in patients with multiple myeloma receiving high-dose melphalan. Data with non-cryopreserved PBSCs in patients autografted for lymphoma following longer pre-conditioning regimens are limited. In addition, no controlled comparison has been able to detect unforeseen differences.

METHODS

The authors compared outcomes of 94 consecutive adult patients with lymphoma (66 with Hodgkin lymphoma) autografted in our department in Oran (Algeria) using PBSCs stored at 4°C, from 2009 to 2018, with patients receiving cryopreserved stem cells reported to the European Society for Blood and Marrow Transplantation registry. Patients autografted in Oran were matched with patients receiving cryopreserved PBSCs in the registry (four controls per patient in Oran).

RESULTS

Neutrophil engraftment was significantly faster with cryopreserved PBSCs (P = 0.003). By day 10, only 17% of patients receiving non-cryopreserved PBSCs engrafted versus 48% for cryopreserved PBSCs. Likewise, platelet recovery to 20 000/mm³ was significantly faster in patients receiving cryopreserved PBSCs (P = 0.01). However, all patients in both groups had recovered by day 20. There were no significant differences in non-relapse mortality (9% versus 7%, P = 0.4), relapse incidence (22% versus 32%, P = 0.13), progression-free survival (70% versus 61%, P = 0.4) or overall survival (85% versus 75%, P = 0.3).

CONCLUSIONS

This analysis suggests that, in patients with lymphoma receiving pre-transplant regimens such as carmustine, etoposide, cytarabine and melphalan, PBSCs stored at 4°C for up to 6 days can be used safely in centers with no cryopreservation facility. However, the kinetics of hematopoietic recovery showed a significant, albeit small, delay in engraftment for both neutrophils and platelets, which favors the use of cryopreservation if available.

Outcomes of Non-Cryopreserved Versus Cryopreserved Peripheral Blood Stem Cells for Autologous Stem Cell Transplantation in Multiple Myeloma

BACKGROUND Autologous stem cell transplantation (ASCT) has become a standard procedure in multiple myeloma (MM) patients. Cryopreservation (CRYO) of stem cells may be associated with adverse reactions of dimethyl sulfoxide. Previous studies showed that stem cell storage at 4°C (non-cryopreserved [NC] method) may have some advantages. This analysis focused on comparing the transplant-related outcomes of the 2 preservation methods. MATERIAL AND METHODS This was a cohort study of consecutive MM patients who underwent ASCT at Chiang Mai University from 2014 to 2019. Primary outcomes were time to neutrophil and platelet engraftment. Key secondary outcomes were the incidence of infusion reactions, duration of hospitalization, cost, and survival. RESULTS A total of 42 MM patients underwent ASCT. Of these, 26 patients and 16 patients underwent NC and CRYO stem cell collections, respectively. There was no difference in time to neutrophil engraftment (median 12 vs. 10.5 days, P=0.203) or platelet engraftment (median 14 vs. 12 days, P=0.809) between groups. The incidence of infusion reactions and duration of hospitalization were similar in both groups. The average cost of ASCT was 10% lower in the NC group. There was no difference in progression-free survival (median 16 vs. 22 months, P=0.701) or overall survival between NC and CRYO groups. CONCLUSIONS ASCT in MM using the NC preservation method is effective and safe compared to the CRYO method in both short-term and survival outcomes.

Autologous stem cell transplant for high-risk neuroblastoma: Achieving cure with low-cost adaptations

BACKGROUND

The majority of patients in low- and middle-income countries (LMIC) are unable to receive optimal therapy, including autologous stem cell transplant (ASCT) for high-risk neuroblastoma. Management is intensive and multidisciplinary; survival is often poor. We report a single-center outcome of high-risk neuroblastoma, with adaptations optimized for LMIC.

PROCEDURE

The study was retrospective. Patients were treated on the backbone of the high-risk neuroblastoma study-1 of SIOP-Europe (HR-NBL1/SIOPEN) protocol with ASCT. Adaptations incorporated to decrease cost, requirement for inpatient admission, infections, and faster engraftment included (a) optional outpatient administration for rapid-COJEC, (b) two sessions of stem-cell apheresis, (c) storing stem cells at 2-6°C without cryopreservation for up to 7 days, (d) no central lines, (e) no antibacterial/antifungal/antiviral prophylaxis, (f) omitting formal assessment of cardiac/renal/pulmonary functions before ASCT, and (g) administration of pegylated granulocyte colony-stimulating factor on Day +4.

RESULTS

Over 5 years 9 months, 35 patients with high-risk neuroblastoma were treated. Rapid-COJEC was administered over a median duration of 80 days (interquartile range: 77, 83). Conditioning regimen included melphalan (n = 7), oral busulfan-melphalan (Bu/Mel; n = 6), or intravenous Bu/Mel (n = 22). The median viability of stem cells stored for 6 days (n = 28) was 93% (range: 88-99). Two (5.7%) patients had ASCT-related mortality. The 3-year overall and event-free survival was 41% and 39%, respectively. A relapse occurred in 20 (57%) patients. Treatment abandonment was observed in one (3%) patient.

CONCLUSIONS

Administration of therapy in a disciplined time frame along with low-cost adaptations enables to manage high-risk neuroblastoma with low abandonment and an encouraging survival in LMIC. Stem cells can be stored safely without cryopreservation for up to 7 days.

Non-cryopreserved peripheral blood stem cells autologous transplantation in multiple myeloma: Bicentric study

OBJECTIVES

The objective of this study is to evaluate the toxicity of autologous transplantation of non-frozen peripheral blood stem cells in Moroccan patients with multiple myeloma.

MATERIAL AND METHODS

This was a bicentric retrospective study conducted in the Clinical Haematology Department of Mohammed V Military Teaching Hospital and at the Al Madina Clinic in Casablanca. The study period was from January 2015 to June 2019. All patients with multiple myeloma who had undergone an autologous peripheral stem cell transplant without freezing were included. Mobilisation was performed with lenograstim alone and the collected stem cells were stored for 24-48hours in a blood bank refrigerator at a temperature of 4°C. After standard conditioning with high-dose melphalan, the peripheral blood stem cells were reinjected 24 h following conditioning.

RESULTS

Over the study period, 55 patients received an autologous transplant using non-frozen peripheral blood stem cells. The median richness of the CD34 cells collected was 4.5×10⁶ CD34/kg (range: 2-12.2). The time required for neutrophil recovery was 12 days (range: 7-19). The time required for platelet recovery was 14 days (range: 9-32). The mortality rate within 100 days post-transplant was 3.6%. We did not observe any cases of graft failure.

CONCLUSION

Our study finds good feasibility and low toxicity of autologous peripheral stem cell transplantation without freezing in patients with multiple myeloma.

SUL-109 Protects Hematopoietic Stem Cells from Apoptosis Induced by Short-Term Hypothermic Preservation and Maintains Their Engraftment Potential

The newly developed 6-hydroxychromanol derivate SUL-109 was shown to provide protection during hypothermic storage of several cell lines, but has not been evaluated in hematopoietic stem cells (HSCs). Hypothermic preservation of HSCs would be preferred over short-term cryopreservation to prevent cell loss during freezing/thawing and would be particularly useful for short-term storage, such as during conditioning of patients or transport of HSC transplants. Here we cultured human CD34⁺ umbilical cord blood (UCB) cells and lineage-depleted (Lin^-) Balb/c bone marrow (BM) cells for up to 7 days in serum-free HSC expansion medium with hematopoietic growth factors. SUL-109-containing cultures were stored at 4°C for 3 to 14 days. The UCB cells were tested for viability, cell cycle, and reactive oxygen species (ROS). DMSO-cryopreserved Lin^- BM cells or Lin^- BM cells maintained for 14 days at 4°C were transplanted into RAG2^-/- Balb/c mice and engraftment was followed for 6 months. The addition of SUL-109 during the hypothermic storage of expanded CD34⁺ UCB cells provided a significant improvement in cell survival of the immature CD34⁺/CD38^- fraction after 7 days of hypothermic storage through scavenging of hypothermia-induced ROS and was able to preserve the multilineage capacity of human CD34⁺ UCB cells for up to 14 days of cold storage. In addition, SUL-109 protected murine BM Lin^- cells from 14 days of hypothermic preservation and maintained their engraftment potential after transplantation in immune-deficient RAG2^-/- mice. Our data indicate that SUL-109 is a promising novel chemical for use as a protective agent during cold storage of human and murine HSCs to prevent hypothermia-induced apoptosis and promote cell viability.