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.

Exosomal-miRNas expression and growth factors released by mononuclear cells of CLAD patients in response to extracorporeal photopheresis.

BACKGROUND: CLAD (Chronic Lung Allograft Dysfunction) remains a serious complication following lung transplantation. Some evidence shows that portions of Extracorporeal Photopheresis (ECP)-treated patients improve/stabilize their graft function. In spite of that, data concerning molecular mechanisms are still lacking. Aims of our study were to assess whether ECP effects are mediated by Mononuclear Cells (MNCs) modulation in term of microRNAs (miRNAs) expression and growth factors release. METHODS: Cells from leukapheresis of 16 CLAD patients, at time 0 and 6-months (10 cycles), were cultured for 48h ± PHA (10 ug/ml) or LPS (2 ug/ml). Expression levels of miR-146a-5p, miR-155-5p, miR-31-5p, miR181a-5p, miR-142-3p, miR-16-5p and miR-23b-5p in MNCs-exosomes were evaluated by qRT-PCR, while ELISA assessed different growth factors levels on culture supernatants. RESULTS: Our result showed miR-142-3p down-regulation (p = 0.02) in MNCs of ECP-patients after the 10 cycles and after LPS stimulation (p = 0.005). We also find miR-146a-5p up-regulation in cells after the 10 cycles stimulated with LPS (p = 0.03). Connective tissue growth factor (CTGF) levels significantly decreased in MNCs supernatant (p = 0.04). The effect of ECP is translated into frequency changes of Dendritic Cell (DC) subpopulations and a slight increase in T regulatory cells (Treg) number and a significant decrease in CTGF release. CONCLUSIONS: ECP might affect regulatory T cell functions, since both miR-142 and miR-146a have been shown to be involved in the regulation of suppressor regulatory T cell functions and DCs. On the other side ECP, possibly by regulating macrophage activation, is able to significantly down modulate CTGF release.

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.

A European Multi-Center Analysis of Extracorporeal Photopheresis as Therapy for Chronic Lung Allograft Dysfunction.

Extracorporeal photopheresis (ECP) is used by few lung transplant centers to treat chronic lung allograft dysfunction (CLAD). Although reported results suggest a beneficial effect on CLAD progression, evidence is limited to single center experiences. The aim of this study is to analyze outcomes of ECP in a large multicenter European cohort. The primary endpoint was patient survival after initiation of ECP. This study included 631 patients, 87% suffered from bronchiolitis obliterans syndrome (BOS), and 13% had restrictive allograft syndrome (RAS). Long-term stabilization was achieved in 42%, improvement in 9%, and no response in 26%. Within the first 12 months of therapy, 23% of patients died. Patients' survival after initiation of ECP at 5 years was 56% in stable, 70% in responders, and 35% in non-responders (p = 0.001). In multivariable Cox regression, both stabilization (HR: 0.48, CI: 0.27-0.86, p = 0.013) and response (HR: 0.11, CI: 0.04-0.35, p < 0.001) to ECP were associated with survival. Absolute FEV1 at baseline was also protective (HR: 0.09, CI: 0.01-0.94, p = 0.046). RAS phenotype was the only risk factor for mortality (HR: 2.11, 1.16-3.83, p = 0.006). This study provides long-term outcomes of ECP use in CLAD patients in the largest published cohort to date. Two-thirds of the cohort had a sustained response to ECP with excellent long-term results.

Mechanisms of Action of Extracorporeal Photopheresis in the Control of Bronchiolitis Obliterans Syndrome (BOS): Involvement of Circulating miRNAs.

Clinical evidence suggests an improvement or stabilization of lung function in a fraction of patients with bronchiolitis obliterans syndrome (BOS) treated by extracorporeal photopheresis (ECP); however, few studies have explored the epigenetic and molecular regulation of this therapy. The aim of present study was to evaluate whether a specific set of miRNAs were significantly regulated by ECP. Total RNA was isolated from serum of patients with established BOS grade 1-2 prior to the start and after 6 months of ECP treatment. We observed a significant downregulation of circulating hsa-miR-155-5p, hsa-miR-146a-5p and hsa-miR-31-5p in BOS patients at the start of ECP when compared to healthy subjects. In responders, increased miR-155-5p and decreased miR-23b-3p expression levels at 6 months were found. SMAD4 mRNA was found to be a common target of these two miRNAs in prediction pathways analysis, and a significant downregulation was found at 6 months in PBMCs of a subgroup of ECP-treated patients. According to previous evidence, the upregulation of miR-155 might be correlated with a pro-tolerogenic modulation of the immune system. Our analysis also suggests that SMAD4 might be a possible target for miR-155-5p. Further longitudinal studies are needed to address the possible role of miR-155 and its downstream targets.

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.

A retrospective study assessing the characteristics of COVID-19 convalescent plasma donors and donations.

BACKGROUND: Although many trials are currently investigating the safety and efficacy of convalescent plasma (CP) in critically ill COVID-19 patients, there is a paucity of ongoing and published studies evaluating the CP donors' side. This retrospective study reports the first Italian experience on CP donors' selection and donations. METHODS: Patients aged 18-68 years who had recovered from COVID-19 at least 2 weeks previously were recruited between March 18 and June 30, 2020 in a study protocol at the Italian hospitals of Pavia and Mantova. RESULTS: During the study period, 494 of 512 donors recruited were judged eligible and underwent 504 plasmapheresis procedures. Eighty-five percent (437/512) of the CP donors were males. The average time between symptom recovery and CP donation was 36.6 (±20.0) days. Four hundred and eighty-eight plasmapheresis procedures (96.8%) were concluded and each unit was divided into two subunits (total 976) with an average volume of 316.2 (±22.7) mL. Ninety-three percent (460/494) of CP donors at the time of plasma donation had a neutralizing IgG titer ≥1:80. Plasmapheresis-related adverse reactions occurred in 2.6% (13/504) of cases; all the reactions were mild and none required therapeutic intervention. Donors' age and COVID-19 severity were positively associated with greater antibody responses. CONCLUSION: This study demonstrates the feasibility and safety of a pilot CP program conducted in Italy. The identification of factors (ie, age and severity of COVID-19) positively associated with higher neutralizing antibody titers at the time of donation may help to optimize the selection of CP donors.

Mortality reduction in 46 severe Covid-19 patients treated with hyperimmune plasma. A proof of concept single arm multicenter trial.

Hyperimmune plasma from Covid-19 convalescent is a potential treatment for severe Covid-19. We conducted a multicenter one arm proof of concept interventional study. Patients with Covid-19 disease with moderate-to-severe Acute Respiratory Distress Syndrome, elevated C-reactive Protein and need for mechanical ventilation and/or CPAP were enrolled. One to three 250-300 ml unit of hyperimmune plasma (neutralizing antibodies titer ≥1:160) were administered. Primary outcome was 7-days hospital mortality. Secondary outcomes were PaO2/FiO2, laboratory and radiologic changes, as well as weaning from mechanical ventilation and safety. The study observed 46 patients from March, 25 to April, 21 2020. Patients were aged 63, 61% male, of them, 30 were on CPAP and 7 intubated. PaO2/FiO2 was 128 (SD 47). Bilateral infiltrates on chest X-ray was present in 36 patients (84%). Symptoms and ARDS duration were 14 (SD 7) and 6 days (SD 3). Three patients (6.5%) died within 7 days as compared to an expected 15% from the National Statistics and 30% from a small concurrent cohort of 23 patients. The upper one-sided 90%CI was 13.9%, allowing to reject the null hypothesis of a 15% mortality. PaO2/FiO2 increased by 112 units (95%CI 82 to142) in survivors, the chest radiogram severity decreased in 23% (95%CI 5% to 42%); CRP, Ferritin and LDH decreased by 60, 36 and 20% respectively. Weaning from CPAP was obtained in 26/30 patients and 3/7 were extubated. Five serious adverse events occurred in 4 patients (2 likely, 2 possible treatment related). In conclusion, Hyperimmune plasma in Covid-19 shows promising benefits, to be confirmed in a randomized controlled trial. This proof of concept study could open to future developments including hyperimmune plasma banking, development of standardized pharmaceutical products and monoclonal antibodies.

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.

Plasma from donors recovered from the new Coronavirus 2019 as therapy for critical patients with COVID-19 (COVID-19 plasma study): a multicentre study protocol.

Since the end of 2019, a new coronavirus strain has been reported in the Chinese province of Wuhan, indicated as 2019-nCoV or SARS-CoV-2. In February 2020, the first case of transmission on Italian soil was reported. On March 09, 2020, at the time of protocol design, the Italian Ministry of Health reported 10,149 people who had contracted the virus; of these, 8514 were positive, of which 5038 were hospitalized with symptoms (59.2%) and 877 in intensive care (10.3%), while the remaining 2599 were in home isolation; 631 were deceased (6.2%) and 1004 healed (9.9%). To date there are no studies in the literature that demonstrate its feasibility and efficacy in the context of the worldwide SARS-CoV-2 epidemic. Based upon the little existing evidence, we planned to assess the efficacy of the infusion of hyperimmune plasma in COVID-19 patients in a one-arm proof-of-concept clinical trial. The primary objective of our study is to evaluate the efficacy of the administration of plasma taken from convalescent donors of COVID-19 to critically ill patients with COVID-19 in terms of their survival. Death from any cause will be considered. The main limit of this study is its one-arm proof-of-concept design with only 43 patients enrolled. However, in the absence of previous evidence, larger and/or randomized trials did not appear to be ethically acceptable. Moreover, the results from this study, if encouraging, will allow us to plan further informed large clinical trials. Trial registration: NCT04321421 March 23, 2020.

Automated mononuclear cell collection: a feasibility study employing a new software for extracorporeal photopheresis.

BACKGROUND AND OBJECTIVES: Very recently, Fresenius Kabi, improved the software (autoMNC lymphocytes, SW 04.03.08) for mononuclear cells (MNCs) collection with the aim to ameliorate the quality of harvest, employing the automated autoMNC lymphocytes software SW 04.03.09. Herein, we report the results of an observational study evaluating the feasibility of MNCs collection in patients undergoing extracorporeal photopheresis (ECP) at our centre, using the new COM.TEC software 04.03.08c for MNC collection, afterwards integrated in the software 04.03.09, available on the market since November 2018. MATERIALS AND METHODS: Thirty adult patients (21 males and 9 females) with GvHD, Chronic Lung Allograft Dysfunction or renal rejection, were consecutively enrolled to undergo 1 ECP procedure by the offline technique, according to our internal protocol, processing 1·5 blood volumes. Feasibility of collection was defined as: Hct in collection bag ≤5%, MNCs purity (percentage of MNCs/bag) ≥80%, MNCs collection efficiency (CE2) ≥60%, patient's platelet depletion ≤50%. RESULTS: Thirty ECP procedures were evaluated. Feasibility (defined by the four parameters previously described) of MNCs collection was observed in 1 out of the 30 harvests analysed. Median Hct in the product was 3·45% (IQR: 2·6-5·0), and median MNCs purity was 97·2% (IQR 89·1-98·6). Median CE2 for MNCs was 21·4% (IQR: 11·9-41·2), and median patient's platelet depletion was 36·2% (IQR 21·9-51·4). CONCLUSION: The autoMNC lymphocytes software SW 04.03.08c for MNCs collection in ECP setting demonstrated to collect a good quality product in terms of purity and RBC contamination even if the collection efficiency and platelet contamination must be improved.

Platelet lysate loaded electrospun scaffolds: Effect of nanofiber types on wound healing.

In healthy individuals, wound healing is a highly efficient process. However, interruptions of normal healing give rise to chronic wounds, characterized by inflammation with impaired angiogenesis and re-epithelialization. The aim of this work was the design and the development of electrospun nanofibrous scaffolds based on sodium alginate (SA) and pullulan (PUL) and loaded with human platelet lysate (PL) intended for skin reparation, to take the advantage of nanofibrous scaffolds (with improved physical structure) and of SA as biopolymer. Two preparation approaches have been used to load PL in the scaffolds: as component of the PUL/SA matrix, to be electrospun, or as coating component, to cover the previously prepared electrospun PUL based membranes. A preformulation study to assess pullulan entanglement concentration and alginate or citric acid critical concentration, to obtain electrospun nanofibers, has been performed. The preparation process allowed to obtain insoluble systems starting from aqueous solutions and these were able to act as scaffolds for tissue engineering with suitable mechanical properties and PL release. PL loading in PUL/SA matrix nanofibers did not substantially modify the nanofiber morphology before crosslinking, while the crosslinking process, in presence of PL, determined less sharp nanofibers probably due to an increase in hydrophilicity caused by PL proteins. On the contrary, the coated nanofibers showed an increase in diameters due to PL loading. The two different approaches affected the fiber dimension and scaffold elasticity, especially for PL loaded systems. Anyhow, these differences were not crucial for fibroblast adhesion and proliferation which were mainly influenced by PL loading. In particular, fibroblasts presented different conformation and orientation mainly due to the presence of PL. This caused a cell random orientation compatible to a fibroblast-to-myofibroblast transition that could enhance wound healing.