Bioprinting Soft 3D Models of Hematopoiesis using Natural Silk Fibroin-Based Bioink Efficiently Supports Platelet Differentiation.

Hematopoietic stem and progenitor cells (HSPCs) continuously generate platelets throughout one's life. Inherited Platelet Disorders affect ≈ 3 million individuals worldwide and are characterized by defects in platelet formation or function. A critical challenge in the identification of these diseases lies in the absence of models that facilitate the study of hematopoiesis ex vivo. Here, a silk fibroin-based bioink is developed and designed for 3D bioprinting. This bioink replicates a soft and biomimetic environment, enabling the controlled differentiation of HSPCs into platelets. The formulation consisting of silk fibroin, gelatin, and alginate is fine-tuned to obtain a viscoelastic, shear-thinning, thixotropic bioink with the remarkable ability to rapidly recover after bioprinting and provide structural integrity and mechanical stability over long-term culture. Optical transparency allowed for high-resolution imaging of platelet generation, while the incorporation of enzymatic sensors allowed quantitative analysis of glycolytic metabolism during differentiation that is represented through measurable color changes. Bioprinting patient samples revealed a decrease in metabolic activity and platelet production in Inherited Platelet Disorders. These discoveries are instrumental in establishing reference ranges for classification and automating the assessment of treatment responses. This model has far-reaching implications for application in the research of blood-related diseases, prioritizing drug development strategies, and tailoring personalized therapies.

Recent insights into extracorporeal photopheresis for graft-versus-host disease.

INTRODUCTION: Extracorporeal Photopheresis (ECP) may be considered the unique large-scale cell therapy currently available. It is currently employed mainly as second-line treatment, especially in steroid-resistant or steroid-dependent Graft versus Host Disease (GvHD) with good results and very few limitations. AREAS COVERED: Many points need to be clarified regarding the ECP mechanism of action, that conditions the lack of uniqueness among the different centers, essentially cycle frequency, treatment duration, and the number of cells to be treated to obtain a response, according to the organs involved. Moreover, reliable biomarkers for prediction of response are lacking, as well as the best pharmacological combination. We will focus on the recent advances concerning ECP for GvHD treatment. We performed a systematic literature research in Pubmed and Embase as of September 2023. EXPERT OPINION: The recent studies on ECP mechanism of action along with the promising biomarkers of response, and the synergistic benefit of ECP in association with the new drugs render this therapy an important weapon for GvHD resistant to conventional treatment and can be proposed as a valid first-line therapy option with promising results. We believe that it should be used early in all categories of patients, considering its high safety profile.

Patient Blood Management after Hematopoietic Stem Cell Transplantation in a Pediatric Setting: Starting Low and Going Lower.

Despite the substantial transfusion requirements, there are few studies on the optimal transfusion strategy in pediatric patients undergoing hematopoietic stem cell transplantation (HSCT). Our study aimed to retrospectively analyze red blood cell (RBC) and platelet (PLT) transfusion practices during the first 100 days after HSCT at the pediatric hematology/oncology unit of our hospital between 2016 and 2019, due to a more restrictive approach adopted after 2016. We also evaluated the impact on patient outcomes. A total of 146 consecutive HSCT patients were analyzed. In patients without hemorrhagic complications, the Hb threshold for RBC transfusions decreased significantly from 2016 to 2017 (from 7.8 g/dL to 7.3 g/dL; p = 0.010), whereas it remained the same in 2017, 2018, and 2019 (7.3, 7.2, and 7.2 g/dL, respectively). Similarly, the PLT threshold decreased significantly from 2016 to 2017 (from 18,000 to 16,000/µL; p = 0.026) and further decreased in 2019 (15,000/µL). In patients without severe hemorrhagic complications, the number of RBC and PLT transfusions remained very low over time. No increase in 100-day and 180-day non-relapse mortality or adverse events was observed during the study period. No patient died due to hemorrhagic complications. Our preliminary observations support robust studies enrolling HSCT patients in patient blood management programs.

Validation of a new automated irradiation system for off-line ECP.

Extracorporeal photopheresis (ECP) is a cell therapy originally employed for cutaneous T cell lymphoma and later for GvHD, solid organ rejection and other immunological diseases demonstrating an excellent safety profile. Mononuclear cell (MNCs) apoptosis triggered by UV-A light irradiation in the presence of 8-methoxypsoralene has a key role in priming the cells, ultimately leading to immunomodulation. We report preliminary data about an evaluation of the new automated irradiator device LUMILIGHT (Pelham Crescent srl) for off-line ECP. Fifteen MNCs samples collected by apheresis from 15 adult patients undergoing ECP at our Center were cultured immediately after irradiation along with untreated samples and evaluated at 24, 48 and 72 h timepoints for T cell apoptosis and viability by flow cytometry with Annexin V and Propide Iodidum staining. Post irradiation Hematocrit (HCT), calculated by the device, was compared with that of the automated cell counter. Bacterial contamination was also tested. In irradiated samples after 24-48 and 72 h, the average total apoptosis was 47 %, 70 % and 82 %, respectively, showing a significant difference from untreated samples; residual viable lymphocytes at 72 h were, on average, 18 %. The greatest initiation of apoptosis occurred from 48 h of irradiation onwards. Average early apoptosis of irradiated samples decreased over time (26 %, 17 % and 10 % at 24, 48 and 72 h, respectively). HCT measured by LUMILIGHT was over-estimated, possibly due to the low pre irradiation red blood cell contamination. Bacterial tests resulted negative. Our study showed the LUMILIGHT device to be a valid instrument for MNCs irradiation with good handling and no major technical problems as well as no adverse events in the patients. Our data need to be confirmed in larger studies.

A survey on preoperative autologous blood donation policy in bone marrow stem cell donors in Italy.

BACKGROUND: The high safety of homologous blood components, together with the introduction of the Patient Blood Management strategy, has led to the progressive abandonment of preoperative autologous blood donation (PAD) in surgery. Furthermore, recent scientific publications provide evidence about the non-usefulness of PAD in the collection of hematopoietic stem cells (HSC) from bone marrow (BM), also in consideration of harvest procedure safety. Nevertheless, no conclusive studies have been published yet. MATERIALS AND METHODS: Blood Establishments (BE) and Bone Marrow Collection Centers (BMCC) participated in a specific qualitative survey proposed by Italian National Blood and Transplant centers with the support of the relevant Italian Scientific Societies. The survey aimed at evaluating the policy adopted for PAD in related and unrelated adult HSC donors in Italy during the period 2018-2020. RESULTS: Forty-one BE corresponding to 37 BMCC filled in the questionnaire. Of 830 BM donors, 661 (80%) underwent 1063 PAD (mean 1.6 PAD/donor). The remaining 169 donors (20%) underwent BM harvest without PAD. No serious adverse events were reported for either donor group. In the case of ineligibility of donors for the PAD program, due to low hemoglobin values, 7/10 centers shifted donors to peripheral blood stem cell collection and three centers chose a different donor. Remarkably, only 51% of the PAD units requested were eventually transfused during the BM harvest process. Finally, the iron support policy among centers was heterogeneous. DISCUSSION: The results of this survey show that PAD is heterogeneously applied in Italian BMCC, as in other countries. However, all BMCC except two are willing to adopt a Patient Blood Management strategy as an alternative approach to adult related and unrelated BM donor harvests.

SARS-CoV-2 variants inactivation of plasma units using a riboflavin and ultraviolet light-based photochemical treatment.

BACKGROUND: Test the ability of Mirasol Pathogen Reduction Technology (PRT, Terumo BCT, Lakewood Co, USA) treatment with riboflavin and ultraviolet light (R + UV) in reducing SARS-CoV-2 infectivity while maintaining blood product quality. MATERIAL AND METHODS: SARS-CoV-2 strains were isolated and titrated to prepare cell free virus for plasma units infection. The units were then under treatment with Mirasol PRT. The infectious titers were determined before and after treatment with an in house microtitration assay on Vero E6 cells. Thirty-six plasma pool bags underwent PRT treatment. RESULTS: In all the experiments, the measured titer following riboflavin and UV treatment was below the limit of detection of microtitration assay for all the different SARS-CoV-2 strains. Despite the high copies number detected by RT-PCR for each viral strain after treatment, viruses were completely inactivated and not able to infect VERO E6 cells. CONCLUSION: Riboflavin and UV light treatment effectively reduced the virus titers of human plasma to the limit of detection in tissue culture, regardless of the strain. These data suggest that pathogen reduction in blood products highlight the safety of CP therapy procedures for critically ill COVID-19 patients, while maintaining blood product quality.

Photopheresis Abates the Anti-HLA Antibody Titer and Renal Failure Progression in Chronic Antibody-Mediated Rejection.

OBJECTIVE: Chronic renal antibody-mediated rejection (ABMR) is a common cause of allograft failure, but an effective therapy is not available. Extracorporeal photopheresis (ECP) has been proven successful in chronic lung and heart rejection, and graft versus host disease. The aim of this study was to evaluate the effectiveness of ECP in chronic ABMR patients. PATIENTS AND METHODS: We investigated ECP treatment in 14 patients with biopsy-proven chronic ABMR and stage 2-3 chronic renal failure. The primary aim was to e valuate the eGFR lowering after 1 year of ECP therapy. The ECP responders (R) showed eGFR reduction greater than 20% vs the basal levels. We also evaluated the effectiveness of ECP on proteinuria, anti-HLA antibodies (HLAab), interleukin 6 (IL-6) serum levels, and CD3, CD4, CD8, CD19, NK, Treg and T helper 17 (Th17) circulating cells. RESULTS: Three patients dropped out of the study. The R patients were eight (72.7%) out of the 11 remaining patients. Because ECP was not associated with any adverse reaction, the R patients continued such treatment for up to 3 years, showing a persisting eGFR stabilization. Twenty four hour proteinuria did not increase in the R patients over the follow-up when compared to the non-responder patients (NR). In the R patients, the HLAab levels were reduced and completely cleared in six out of eight patients when compared with the NR patients. The NR HLAab levels also increased after the discontinuation of the ECP. The ECP in the R patients showed a decrease in CD3, CD4, CD8, CD19, and NK circulating cells. The ECP treatment in the R patients also induced Tregs and Th17 cell increases, and a decrease of the IL-6 serum levels. CONCLUSIONS: ECP abates the HLAab titer and renal failure progression in patients with chronic renal ABMR, modulating the immune cellular and humoral responses.

Harnessing T Cells to Control Infections After Allogeneic Hematopoietic Stem Cell Transplantation.

Dramatic progress in the outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT) from alternative sources in pediatric patients has been registered over the past decade, providing a chance to cure children and adolescents in need of a transplant. Despite these advances, transplant-related mortality due to infectious complications remains a major problem, principally reflecting the inability of the depressed host immune system to limit infection replication and dissemination. In addition, development of multiple infections, a common occurrence after high-risk allo-HSCT, has important implications for overall survival. Prophylactic and preemptive pharmacotherapy is limited by toxicity and, to some extent, by lack of efficacy in breakthrough infections. T-cell reconstitution is a key requirement for effective infection control after HSCT. Consequently, T-cell immunotherapeutic strategies to boost pathogen-specific immunity may complement or represent an alternative to drug treatments. Pioneering proof of principle studies demonstrated that the administration of donor-derived T cells directed to human herpesviruses, on the basis of viral DNA monitoring, could effectively restore specific immunity and confer protection against viral infections. Since then, the field has evolved with implementation of techniques able to hasten production, allow for selection of specific cell subsets, and target multiple pathogens. This review provides a brief overview of current cellular therapeutic strategies to prevent or treat pathogen-related complications after HSCT, research carried out to increase efficacy and safety, including T-cell production for treatment of infections in patients with virus-naïve donors, results from clinical trials, and future developments to widen adoptive T-cell therapy access in the HSCT setting.

Reflections on methodical approaches to hematopoietic stem cell collection in children.

Pediatric peripheral blood stem cell collection (PBSC) is challenging because it has potentially more side effects than in adults due to the small body mass and unique physiology of children. The extracorporeal volume of the cell separator device, poor venous access and metabolic complications due to citrate toxicity are the main problems to face during PBSC collection. These aspects are more relevant in very low body weight (BW) children of 20 kg or lower. An efficient, experienced and well-prepared team of pediatricians, apheresis physicians and nurses, and physicians involved in CVC positioning is crucial to performing a safe PBSC collection. Despite the growing demand for PBSC collection in the pediatric setting, there is not an actual unique standardized detailed practice approach to be employed, therefore, on reflection, we believe that it is timely to draw up useful evidence-based recommendations on which guidelines can be developed for use by those groups with limited or no experience.

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

INTRODUCTION: At Hiwa Cancer Hospital (Sulaymaniyah, Iraqi Kurdistan) after the center was started by a cooperative project in June 2016, autologous transplantation was developed. PATIENTS AND METHODS: To develop the project, the capacity-building approach was adopted, with on-site training and coaching of personnel, educational meetings, lectures, on-the-job training, and the implementation of quality management planning. RESULTS: Here, we report initial results of peripheral-blood stem-cell mobilization and collection of the first 27 patients (age 12 to 61 years; 19 males and 8 females; multiple myeloma, n = 10; plasma cell leukemia, n = 1; Hodgkin lymphoma, n = 12; non-Hodgkin lymphoma, n = 3; and acute myeloid leukemia, n = 1). Only three (11.5%) of 26 patients experienced a failure of mobilization. A median of 6.1 × 106/kg CD34-positive cells per patient were collected (range, 2.4 to 20.8), with two apheretic runs. Twenty-four patients underwent autologous transplantation. All but one transplantation engrafted fully and steadily, with 0.5 and 1.0 × 109/L polymorphonucleates on day 10.5 (range, 8 to 12) and day 11 (range, 9 to 15), respectively, and with 20 and 50 × 109/L platelets on day 13 (range, 10 to 17) and day 17 (range, 2 to 44), respectively. More than 95% of patients are projected to survive 1 year after autograft. CONCLUSION: These data are the result of an Italian effort to establish in Iraqi Kurdistan a leading center for hemopoietic stem-cell transplantation. The capacity building approach was used, with on-site training and coaching as instruments for the development of provider ability and problem solving. With future limitations for immigration, this method will be helpful, especially in the field of high-technology medicine.

Automated red blood cell depletion in ABO incompatible grafts in the pediatric setting.

Bone marrow ABO incompatible transplantations require graft manipulation prior to infusion to avoid potentially lethal side effects. We analyzed the influence of pre-manipulation factors (temperature at arrival, transit time, time of storage at 4°C until processing and total time from collection to red blood cell depletion) on the graft quality of 21 red blood cell depletion procedures in ABO incompatible pediatric transplants. Bone marrow collections were processed using the Spectra Optia® (Terumo BCT) automated device. Temperature at arrival ranged between 4°C and 6°C, median transit time was 9.75h (range 0.33-28), median time of storage at 4°-6°C until processing was 1.8h (range 0.41-18.41) and median time from collection to RBC depletion was 21h (range1-39.4). Median percentage of red blood cell depletion was 97.7 (range 95.4-98.5), median mononuclear cells recovery was 92.2% (range 40-121.2), median CD34+ cell recovery was 93% (range 69.9-161.2), median cell viability was 97.7% (range 94-99.3) and median volume reduction was 83.9% (range 82-92). Graft quality was not significantly different between BM units median age. Our preliminary data show that when all good manifacturing practices are respected the post-manipulation graft quality is excellent also for those units processed after 24h.

A Novel Method for Isolation of Pluripotent Stem Cells from Human Umbilical Cord Blood.

Very small embryonic-like cells (VSELs) are a population of very rare pluripotent stem cells isolated in adult murine bone marrow and many other tissues and organs, including umbilical cord blood (UCB). VSEL existence is still not universally accepted by the scientific community, so for this purpose, we sought to investigate whether presumptive VSELs (pVSELs) could be isolated from human UCB with an improved protocol based on the isolation of enriched progenitor cells by depletion of nonprogenitor cells with magnetic separation. Progenitor cells, likely including VSELs, cultured with retinoic acid were able to form dense colonies and cystic embryoid bodies and to differentiate toward the ecto-meso-endoderm lineages as shown by the positivity to specific markers. VSEL differentiative potential toward mesodermal lineage was further demonstrated in vitro upon exposure to an established inductive protocol, which induced the acquisition of renal progenitor cell phenotype. VSEL-derived renal progenitors showed regenerative potential in a cisplatin model of acute kidney injury by restoring renal function and tubular structure through induction of proliferation of endogenous renal cells. The data presented here foster the great debate that surrounds VSELs and, more in general, the existence of cells endowed with pluripotent features in adult tissues. In fact, the possibility to find and isolate subpopulations of cells that fully fit all the criteria utilized to define pluripotency remains, nowadays, almost unproven. Thus, efforts to better characterize the phenotype of these intriguing cells are crucial to understand their possible applications for regenerative and precision medicine purposes.

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

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

Extracorporeal photopheresis for bronchiolitis obliterans syndrome after allogeneic stem cell transplant: An emerging therapeutic approach?

Bronchiolitis obliterans syndrome (BOS) is the main manifestation of pulmonary GVHD. It has often a dramatic and fast evolution and current treatment (change or increase in immunosuppression, macrolides and inhaled therapy) is poor with high mortality rates. In this scenario, extracorporeal photopheresis (ECP) bursts as a new immunomodulatory approach with a different philosophical purpose. In fact, available data show that ECP treatment is intended to delay the inflammatory process and consequently respiratory lung function decline, rather than reverse the damage itself. Preliminary results reported in literature show that ECP may effectively improve/slow lung function decline in cGVHD patients with BOS after standard treatment failure. Further studies are needed to confirm the efficacy of ECP, assess the optimal schedule and consider it for early treatment.

In Vitro and In Vivo Differentiation of Progenitor Stem Cells Obtained After Mechanical Digestion of Human Dental Pulp.

Human population is facing a revolutionary change in the demographic structure with an increasing number of elderly people requiring an unmet need to ensure a smooth aging process and dental care is certainly an important aspect that has to be considered. To date, dentistry has been conservative and the need of transferring the scientific models of regenerative dentistry into clinical practice is becoming a necessity. The aim of this study was to characterize the differentiation commitment (in vitro) and the clinical grafting ability (in vivo) of a population of progenitor stem cells obtained after mechanical digestion of dental pulp with an innovative system recently developed. This approach was successfully used in previous studies to obtain a clinical-grade ready to use dental pulp fragments that could be grafted in autologous tissues to obtain bone. We are thus showing that micro grafts resulting from mechanical digestion contain stem cells with a mesenchymal phenotype, able to differentiate toward different cell types and to generate new bone in patients. We are providing data for the establishment of standardized and routinely oral surgery approaches, having outlined the cellular properties of human stem cells obtained from the dental pulp. This method can represent a valid tool for both regenerative medicine and tissue engineering purposes not only applicable to the cranio-maxillofacial region but, likely, to different bone pathologies for a fastening and healing recovering of patients. J. Cell. Physiol. 232: 548-555, 2017. © 2016 Wiley Periodicals, Inc.

Autologous immuno magnetically selected CD133+ stem cells in the treatment of no-option critical limb ischemia: clinical and contrast enhanced ultrasound assessed results in eight patients.

OBJECTIVES: Demonstrate the safety and effectiveness of highly purified CD133+ autologous stem cells in critical limb ischemia (CLI). DESIGN: Prospective single-center not randomized. Clinicaltrials.gov identifier: NCT01595776 METHODS: Eight patients with a history of stable CLI were enrolled in a period of 2 years. After bone marrow stimulation and single leukapheresis collection, CD133+ immunomagnetic cell selection was performed. CD133+ cells in buffer phosphate suspension was administered intramuscularly. Muscular and arterial contrast enhanced ultra sound (CEUS), lesion evolution and pain management were assessed preoperatively and 3, 6 and 12 months after the implant. RESULTS: No patient had early or late complications related to the procedure. Two patients (25 %) didn't get any relief from the treatment and underwent major amputation. Six patients (75 %) had a complete healing of the wounds, rest pain cessation and walking recovery. An increase in CEUS values was shown in all eight patients at 6 months and in the six clinical healed patients at 12 months and had statistical relevance. CONCLUSIONS: Highly purified autologous CD133+ cells can stimulate neo-angiogenesis, as based on clinical and CEUS data.

A New Medical Device Rigeneracons Allows to Obtain Viable Micro-Grafts From Mechanical Disaggregation of Human Tissues.

Autologous graft is considered the gold standard of graft materials; however, this approach is still limited due to both small amount of tissue that can be collected and to reduced cell viability of cells that can be obtained. The aim of this preliminary study was to demonstrate the efficacy of an innovative medical device called Rigeneracons® (CE certified Class I) to provide autologous micro-grafts immediately available to be used in the clinical practice. Moreover, Rigeneracons® is an instrument able to create micro-grafts enriched of progenitors cells which maintain their regenerative and differentiation potential. We reported preliminary data about viability cell of samples derived from different kind of human tissues, such as periosteum, cardiac atrial appendage biopsy, and lateral rectus muscle of eyeball and disaggregated by Rigeneracons®. In all cases we observed that micro-grafts obtained by Rigeneracons® displayed high cell viability. Furthermore, by cell characterization of periosteum samples, we also evidenced an high positivity to mesenchymal cell markers, suggesting an optimal regenerative potential.

Successful T-cell-depleted haploidentical hematopoietic stem cell transplantation in a child with dyskeratosis congenita after a fludarabine-based conditioning regimen.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only cure for marrow failure associated with dyskeratosis congenita (DC). Data on transplants from alternative donors are limited. We describe a boy with DC and severe aplastic anemia who underwent haploidentical T-cell depleted HSCT using a reduced-intensity conditioning regimen. He underwent engraftment without toxicity or GVHD. His posttransplant course was complicated by EBV reactivation, treated with rituximab and EBV-specific T lymphocytes. After 26 months, he is in complete chimerism, with normal blood count and no sign of GVHD or pulmonary dysfunction. To the best of our knowledge, this is the first report of DC successfully treated with allogeneic HSCT from a haploidentical family donor.

Allogeneic lethally irradiated cord blood mononuclear cells in no-option critical limb ischemia: a "box of rain".

Critical limb ischemia (CLI) is burdened by a 40% major amputation rate, and a 5-year life expectancy <50%. We report the first in-human injection of lethally γ-irradiated non-human leukocyte antigen (HLA)-matched cord blood (CB)-derived mononuclear cells in a no-option CLI patient, to induce therapeutic neo-angiogenesis, with evidence of successful outcome supported by clinical findings (ulcer healing and pain relief), instrumental assessment (transcutaneous O2 pressure, ankle/brachial index, and contrast-enhanced ultrasonography), and histological demonstration of muscular tissue repair and capillary network expansion. If our approach will be confirmed, the huge number of CB units currently discarded might be redirected toward regenerative medicine purposes, leading to cutting-edge solutions for important unmet clinical needs, such as ischemic diseases, which remain the main cause of disability and mortality in western countries.