Donor Availability Research Articles

399 Methionine and Guanidinoacetic Acid Supplementation Throughout the Periconceptual Period of Gestation Alters Metabolite Concentrations and Fetal Development

Abstract Recent research reported changes in fetal growth due to increased methyl donor availability through periconceptual supplementation of the dam. We hypothesized that maternal supplementation of methionine (MET) or guanidinoacetic acid (GAA) during the periconceptual period will result in a methyl donor surplus or deficiency in maternal serum and ultimately influence fetal body and organ weight at d +63 gestation. The objectives of this study were to evaluate effects of methyl donor surplus or deficiency during the periconceptual period of gestation on metabolite concentrations in the heifer and the effects on early fetal development. Eighty MARC II heifers (n = 20 per treatment, initial BW = 346 ± 8 kg) were stratified by age and weight to one of four treatment groups to receive 100 g of supplement: ground corn carrier as control (CON), MET (10 g/d) in ground corn, GAA (40 g/d) in ground corn, and MET + GAA (10 g/d MET + 40 g/d GAA) in ground corn. Supplementation began 63 d before breeding (d –63) until d 63 of gestation (d +63), and serum samples were collected before feeding on d -63, at breeding, and d +63. Heifers were bred using male sexed semen from the same sire, and 35 heifers were confirmed pregnant (CON, n = 10; MET, n = 8; GAA, n = 7; MET + GAA, n =10) and harvested at d +63 of gestation to collect maternal and fetal samples. Data were analyzed as a 2 × 2 factorial design with 2 levels of MET and 2 levels of GAA. Methionine concentrations in maternal serum were greater (P = 0.05) in MET and MET + GAA supplemented heifers at d 0 and d +63 compared with CON and GAA at d -63, d 0, and d +63. There were no differences (P ≥ 0.15) in the concentration of GAA or creatine due to supplementation; however, both were decreased at breeding (P < 0.01) compared with d -63 and d +63. Fetuses from MET supplemented heifers had greater (P = 0.01) brain weight and Longissimus muscle than dams not receiving MET. We conclude that MET supplementation during the periconceptual period can alter methyl donor availability and increase fetal muscle development. USDA is an equal opportunity provider and employer.

Post-Transplant Cyclophosphamide Equalizes Clinical Outcomes of Allogeneic Hematopoietic Cell Transplantation across Racial and Ethnic Populations

Background Despite being the only curative option for many hematologic malignancies, allogeneic hematopoietic cell transplant (HCT) has been plagued by health disparities due to differences in access, donor availability, and outcomes across racial and ethnic minority populations (REM) (Gragert, NEJM, 2014). Even when a matched donor is available, HCT outcomes for REM patients are historically worse compared to non-Hispanic white (NHW) patients. (Landry, Stem Cell Investigation, 2021). The development of post-transplant cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis has led to increased use of HLA haploidentical (haplo) or mismatched unrelated donors (MMUD) with comparable outcomes to HLA matched HCT (McCurdy, Advances in Hematology, 2015). While PTCy allows for almost every transplant-eligible REM patient to have a suitable donor, there is limited data evaluating whether this transplant platform results in similar outcomes for REM patients compared to NHW patients. The aim of this study was to investigate if disparities in transplant outcomes still exist between REM patients and NHW patients who received an HLA mismatched transplant with PTCy. Methods We retrospectively analyzed 302 consecutive adult patients who underwent haplo or MMUD HCT with PTCy at Moffitt Cancer Center between 2014 and 2022. All endpoints were compared between four groups: NHW, Hispanic-White, Black, and Other (Asian, biracial, or multiracial.) Results In this cohort, 59% (n=178) of patients identified as NHW, 14% (n=41) as Hispanic-White, 16% (n=48) as Black, 7% (n=21) as biracial or multiracial, and 4% (n=11) identified as Asian. Most patients were male (57%). The median age of all patents was 58. The most common indication for transplant was acute myeloid leukemia (48%), myeloablative conditioning (MAC) was utilized in 42%, and 89% received peripheral blood stem cells grafts. REM patients were more likely to be <65 years of age (60% vs 66-90%, p<0.001), female (36% vs 50-54%, p=0.04), and receive MAC conditioning (33% vs 40-71%, p<0.001). Median follow-up was 21 months. In all clinical outcomes, no significant differences were observed between NHW and REM patients. At day 100, the cumulative incidence of Grade II-IV aGVHD was 37% [95% CI 30-44%] for NHW patients, 32% [95% CI, 18-46%] for Hispanic-White patients, 27% [95% CI, 15-40%] for Black patients, and 26% [95% CI, 13-41%] for patients of Other races (p= 0.38). The cumulative incidence of moderate to severe cGVHD at 2 years was 21% [95% CI 15-28%] for NHW patients, 25% [95% CI, 13-39%] for Hispanic-White, 17% [95% CI, 7.8-29%] for Black, and 27% [95% CI, 13-42%] for patients of Other races (p = 0.80). At 2 years, the probability of relapse was 25% [95% CI 19-32%] for NHW patients, 24% [95% CI, 12-39%] for Hispanic-White patients, 27% [95% CI, 15-40%] for Black patients, and 18% [95% CI, 7.1-33%] for patients of Other races (p = 0.97). During the same time interval, non-relapse mortality (NRM) for NHW patients, Hispanic-White patients, Black patients, and patients of Other races were 19% [95% CI, 13-25%], 15% [95% CI, 5.9-27%], 19% [95% CI, 9.4-32%], and 24% [95% CI, 11-40%] (p = 0.73), respectively. At 2 years, relapse free survival (RFS) was 56% [95% CI 49-64%] for NHW patients, 61% [95% CI, 47-79%] for Hispanic-White patients, 54% [95% CI, 41-71%] for Black patients, and 58% [95% CI, 43-78%] for patients of Other races (p = 0.77). Comparably, OS at 2 years for NHW, Hispanic-White patients, Black patients, and patients of Other races was 64% [95% CI, 57-72%], 72% [95% CI, 60-88%], 53% [95% CI, 40-71%], and 63% [95% CI, 49-83%] respectively after two years (p = 0.92). In multivariate analysis, race/ethnicity had no significant impact on incidence of Grade II-IV aGVHD (p= 0.40), moderate/severe cGVHD (p = 0.80), rates of relapse (p = 0.86), NRM (p= 0.77), RFS (p = 0.69), or OS (p = 0.64) (Table). Conclusions These results show that the use of HLA mismatched donor HCT with PTCy achieves comparable clinical outcomes between REM and NHW patients. Our study suggests that PTCy effectively contributes to equitable healthcare in the setting of allogeneic HCT for REM patients.

A Collaborative Model for Improving Patient Engagement and Access for Hematopoietic Stem Cell Transplant and Clinical Gene Therapy Trials for Patients with Sickle Cell Disease in the Upper Midwest United States

Introduction: Sickle cell disease (SCD) is the most common inherited hemoglobinopathy affecting populations across the United States. Several well-established patient-centered comprehensive care models have been in practice for preventive care and pain management. However, access to hematopoietic stem cell transplant (HSCT) and clinical trials for sickle cell gene therapies are limited, especially in pediatric and adult centers with limited HSCT-related resources. We describe a patient-centered collaborative model in the Upper Midwest United States to improve patient education and engagement as well as access to HSCT and gene therapy trials for patients with SCD. Collaborative Care Model: Since August 2021, centers across the Midwest meet monthly to improve access for HSCT and gene therapy as well as education about these therapies for individuals with SCD. The teams include: hematology and transplant teams from University of Minnesota, Comprehensive Sickle Cell Care team from Children's Hospital of Minneapolis, hematology and transplant team from Mayo Children's Hospital, hematology team from Essential Health, Duluth, Minnesota, hematology team from Sanford Children's Hospital Fargo and Sioux Falls and hematology team from Blank Children's Hospital, Des Moines, Iowa. This collaborative approach involves several stakeholders including an SCD community advocacy organization, hematology care providers across several rural as well as community/university hospitals, social workers, nurse coordinators, HSCT/gene therapy providers, as well as representatives from National Marrow Donor Program. Individual patient needs and available community support as well as institutional resources are discussed at length during monthly virtual meetings and a pre-intervention plan is established to ensure smooth transition of care to and from primary centers (Figure 1). Ongoing communication with the primary team helps with efficient transition of care after transplant as patients continue ongoing monitoring and care closer to home. Community partners help with early education of the families and provide necessary resources and support. Institutional partners like NMDP provide support with immune typing and discuss ongoing support and other resources available for providers and families. Results/Impact: Since the implementation of this collaborative model, there has been a steady increase in early referrals for education regarding HSCT and potential gene therapies trials for patients with SCD. There has been about 100% increase in new patient referrals since the implementation of this collaborative model compared to the average new referrals in the previous years (2021-22 vs 2018-19; Figure 2). Enrollment in HSCT as well as gene therapy clinical trials also has increased 2-3 folds since the implementation of the collaborative care model. It has helped established early discussion and longitudinal care and has also led to ongoing evaluation and discussions for availability of optimal donors, determining eligibility for HSCT and gene therapy trials as well as providing ongoing support and education to the sickle cell community and providers regarding the available therapies for SCD. This has also facilitated the transplant team establish earlier and better rapport with patients and their families and provide necessary education with an in-depth discussion regarding the potential benefits and risks of therapies such as HSCT and gene therapy. These discussions often occur over multiple visits and helps address psychological as well social barriers with a prospective evaluation. Additionally, the ongoing discussion among the providers helps with longitudinal monitoring of the patients and provide an assessment of the risks and benefits of therapies as the patient's disease course continues to evolve. This multi-stake holder collaborative approach continues to provide a well-established platform for discussion of newer therapies and access to open clinical trials, available resources for patients and families, and improve patient care and experience. The impact of this collaboration is noted in significant increase in early referrals and educational consults for HSCT and gene therapies, improved patient engagement as well as the acceptability and participation in clinical trials.

Analysis of 3,843 Unrelated Donors (URD) for 455 Allograft Candidates Reveals Low URD Availability with Marked Racial/ Ethnic Disparities: Major Implications for Transplant Center & Registry Operations

Introduction: Although hematologic malignancies patients (pts) often require urgent transplants, the degree to which unrelated donor (URD) availability is a barrier to prompt allografting is not established. Methods: We evaluated availability of requested URDs 1/2020-12/2022, overall & by pt ancestry, in 455 consecutive adults with acute leukemia, MDS or MPN who had a formal URD search & for whom ≥ 1 URDs were pursued for confirmatory typing (CT). We also examined donor location & Donor Readiness Score (DRS; the prediction of a donor's likelihood of availability for CT) by pt ancestry. We hypothesized that URD availability is a major barrier to transplant for underserved racial/ ethnic groups & this has not improved in the post-pandemic era. Results: Of 455 pts [median age 63 yrs, range 21-81; 250/455 (55%) with acute leukemia], 74% (335/455) had European (EURO) & 26% (120/455) non-European (non-EURO) ancestry. For these 455 pts, 3,843 URDs (median age 27 yrs, range 17-61; 1,951/3,843 [51%] male) were requested for CT or simultaneous CT-workup; 71% (2,730/3,843) of URDs were for EURO & 29% (1,113/3,843) for non-EURO pts; & 56% (2,140/3,843) were from domestic & 44% (1,703/3,843) international registries. Of 2,775 URDs with an assigned DRS, the median score was 63% (range 16-94%). URDs requested for non-EURO pts were more likely to be domestic [EUROs: 1,411/2,730 (52%) vs non-EUROs: 729/1,113 (65%), p < .001]. Also, URDs for non-EUROs had markedly lower median DRS (EUROs: 71% vs non-EUROs: 52%) with over 15x the proportion with DRS ≤ 30% [EUROs: 30/2,073 (1.5%) vs non-EUROs: 160/702 (23%), p < .001]. Table 1A-C outlines URD availability at CT & workup, overall & by pt ancestry. In summary: At CT, per pt: More non-EURO pts had greater than 10 URDs requested (p = .045), less than 5 URDs that agreed to CT (p < .001), & at least 5 URDs unavailable (p < .001), compared with EUROs.At workup, per pt: For over one-quarter (134/455, 29%), 3-5 URDs were requested. More non-EURO pts had less than 2 URDs that agreed to workup (p = .007) & at least 2 URDs unavailable (p = .017), compared with EUROs.At CT: Only half (2,036/3,843, 53%) of requested URDs were available for CT or CT-workup. URDs were less likely to agree to CT if requested for non-EURO pts ( vs EUROs), if domestic ( vs international), or if lower DRS (p < .001 for each).At workup: Of URDs requested for workup after CT, while 461/598 (77%) agreed, URDs requested for non-EURO pts were less likely to agree (p < .001).Overall: Availability of the 3,843 URDs requested for the 455 pts was low, with less than half available (Fig. 1A). Notably, URDs requested for non-EURO pts had lower availability (p < .001).By ancestry sub-type: African & non-Black Hispanic pts had the lowest URD availability.Over time: When examining 2020-2022, the worse URD availability for non-EURO pts is not improving in the post-pandemic era (Fig. 1B).URD provision: Of pts with ≥ 1 URD who agreed to workup, 12% did not have an URD available within 14 days of the 1st proposed collection date, & of 263 5-8/8 URD recipients for whom a primary URD was selected, over one third (103/263, 39%) were not transplanted with that donor. Of transplanted pts, as expected, non-EURO pts were less likely to receive 8/8 URDs (p < .001) &, for those who did, their URDs were older (p = .018), & 5-7/8 URDs requested for non-EUROs were more HLA-mismatched (p < .001). Conclusions: We demonstrate significant ongoing disparities in URD access that have major implications for transplant center & registry operations. Incorporating careful assessment of pt ancestry, transplant centers should pursue, & registries should permit, simultaneous pursuit of multiple URDs, especially for non-EURO pts, deciding at the outset what degree of HLA-mismatch will be accepted if an URD is desired but an 8/8 URD is unlikely (Davis et al, TCT 2023). Moreover, centers are ethically obliged to inform pts if timely URD procurement is unlikely, especially as these pts are commonly from underserved racial/ ethnic groups. Registries need to address high URD attrition, & prospective investigation of efforts to speed donor identification are needed. Finally, utilization of all alternative donors (5-7/8 URD, haploidentical & cord blood) is needed to facilitate donors for all in the time required for optimized transplantation.

Haploidentical Hematopoietic Cell Transplant with Post-Transplant Cyclophosphamide Expedites Donor-Derived Immune Reconstitution in a Pediatric Severe Aplastic Anemia Cohort

Severe aplastic anemia (SAA) is a life-threatening, idiopathic process involving the immune-mediated destruction of hematopoietic stem cells. Treatment involves immunosuppressive therapy (IST) and/or allogeneic hematopoietic cell transplantation (HCT). The latter has recently been optimized with use of a post-transplant cyclophosphamide (PTCy) based graft-versus-host disease (GvHD) platform, permitting successful HCT with only half-HLA-matched haploidentical donors. In pediatrics, this platform results in >90% overall survival with low rates of GvHD and graft failure. However, reports on donor chimerism and immune reconstitution are limited. We hypothesized that a PTCy platform would expedite CD3 donor engraftment and CD4 T cell recovery. In a phase III clinical trial, we treated three cohorts of pediatric (age </=25 years) patients with SAA requiring alloHCT: MUD, MSD, and HAPLO. The MUD cohort included n=15 recipients of 7-8/8 HLA-matched unrelated donor grafts (n=5 7/8, n=10 8/8) with median age 14 years (range 2-17 years), following cyclophosphamide (Cy) 50 mg/kg, fludarabine (Flu) 200 mg/m 2, rabbit anti-thymocyte globulin (rATG) 9 mg/kg total dose rabbit and low dose total body irradiation (TBI) at 200 cGy. The MSD cohort included n=9 recipients of 8/8 HLA-matched sibling donor grafts with median age 15 years (range 12-24 years), following Cy 200 mg/kg and 9 mg/kg rATG. The HAPLO cohort included n=4 recipients of 4/8 HLA-matched related donor grafts with median age 8.5 years (range 2-21 years) following Cy 29 mg/kg, Flu 150 mg/m 2, 9 mg/kg rATG, and low dose TBI at 200 cGy. GvHD prophylaxis consisted of 30 days of mycophenolate mofetil, and 100 days of a calcineurin inhibitor (followed by an 8-10 week taper), with the HAPLO cohort additionally receiving post-transplant Cy (PTCy) 50 mg/kg/day on days +3 and +4. Peripheral blood lymphocyte counts and peripheral blood and bone marrow donor chimerism were evaluated on days +100, +180 and +365. Recipient characteristics were largely equivalent between cohorts, with 43% receiving IST prior to HCT. Clonality was overrepresented in the HAPLO cohort (2 of 4, 1 with monosomy 7 myelodysplastic syndrome and 1 with a large PNH clone), with only 2 of 15 in the MUD and none in the MSD cohorts. Active controlled infections at the time of HCT were additionally overrepresented in the HAPLO cohort, with disseminated pseudomonas in 1. The MUD cohort had 1 with Rhizopus invasive sinusitis (none in the MSD cohort). Achievement of neutrophil engraftment was statistically significantly delayed in the HAPLO cohort at a median of 17 days compared to 12 for MSD and 14 for MUD, p=0.004), however there were no episodes of primary or secondary graft failure. With only a single late death from intracranial hemorrhage in the MUD cohort, OS was equivalent at 2 years (100% in MSD and HAPLO cohorts, 93.3% in MUD). GvHD rates were low with only 1 (MUD) experiencing grade II acute GvHD, and 1 (MUD) experiencing mild chronic GvHD. Immune reconstitution varied by cohort with statistically significantly greater CD3 peripheral blood donor chimerism (p<0.001) as well as CD4 (p=0.04) and CD8 (p=0.03) T cell counts over time for the HAPLO recipients (CD3 chimerism in Fig 1, CD4 count in Fig 2; 2-way ANOVA fixed effects model). Considering a CD4 >200 cell/uL as clinically meaningful, we assessed the proportion of each cohort achieving this milestone at each timepoint. While each cohort had an increase in proportion achieving CD4>200 over time, the HAPLO cohort reached 50% with CD4 >200 at day +100, compared to 11% MUD and 0% MSD (p=0.09). At day +180, the proportion with CD4 >200 were 36% MUD, 25% MSD and 75% HAPLO (1 yr: 90% MUD, 100% MSD and HAPLO). Donor availability remains a challenge to successful transplant for patients with SAA, and haploidentical matches overcome donor limited accessibility. PTCy as GvHD prophylaxis is associated with low incidences of graft failure and severe GvHD. While PTCy might be anticipated to inhibit donor T cells and immune reconstitution, our data, albeit limited by small cohorts, demonstrates superior and more efficient CD3 donor engraftment and CD4 T cell count recovery following HAPLO HCT with PTCy compared to non-PTCy based MUD and MSD cohorts.

AMPK activation induces immunogenic cell death in AML

AbstractSurvival of patients with acute myeloid leukemia (AML) can be improved by allogeneic hematopoietic stem cell transplantation (allo-HSCT) because of the antileukemic activity of T and natural killer cells from the donor. However, the use of allo-HSCT is limited by donor availability, recipient age, and potential severe side effects. Similarly, the efficacy of immunotherapies directing autologous T cells against tumor cells, including T-cell recruiting antibodies, chimeric antigen receptor T-cell therapy, and immune checkpoint inhibitors are limited in AML because of multiple mechanisms of leukemia immune escape. This has prompted a search for novel immunostimulatory approaches. Here, we show that activation of adenosine 5′-monophosphate–activated protein kinase (AMPK), a master regulator of cellular energy balance, by the small molecule GSK621 induces calreticulin (CALR) membrane exposure in murine and human AML cells. When CALR is exposed on the cell surface, it serves as a damage-associated molecular pattern that stimulates immune responses. We found that GSK621-treated murine leukemia cells promote the activation and maturation of bone marrow–derived dendritic cells. Moreover, vaccination with GSK621-treated leukemia cells had a protective effect in syngeneic immunocompetent recipients bearing transplanted AMLs. This effect was lost in recipients depleted of CD4/CD8 T cells. Together, these results demonstrate that AMPK activation by GSK621 elicits traits of immunogenic cell death and promotes a robust immune response against leukemia. Pharmacologic AMPK activation thus represents a new potential target for improving the activity of immunotherapy in AML.

5 years DKMS Chile: approach, results and impact of the first unrelated stem cell donor center in Chile.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is performed worldwide to treat blood cancer and other life-threatening blood disorders. As successful transplantation requires an HLA-compatible donor, unrelated donor centers and registries have been established worldwide to identify donors for patients without a family match. Ethnic minorities are underrepresented in large donor registries. Matching probabilities are higher when donors and patients share the same ethnic background, making it desirable to increase the diversity of the global donor pool by recruiting donors in new regions. Here, we report the establishment and the first 5 years of operation of the first unrelated stem cell donor center in Chile, a high-income country in South America with a population of over 19 million. We used online and in-person donor recruitment practices through patient appeals and donor drives in companies, universities, the armed forces, and public services. After confirmatory typing donors were subjected to medical work-up and cleared for donation. We recruited almost 170,000 donors in 5 years. There were 1,488 requests received for confirmatory typing and donor availability checks, of which 333 resulted in medical work-up, leading to 194 stem cell collections. Products were shipped to Chile (48.5%) and abroad. Even when the COVID-19 pandemic challenged our activities, the number of donors recruited and shipped stem cell products remained steady. In Chile there was an almost 8-fold increase in unrelated donor transplantation activity from 16 procedures in 2016-2018 to 124 procedures in 2019-2021, mainly for pediatric patients following the center's establishment. We estimate that 49.6% of Chilean patients would find at least one matched unrelated donor in the global DKMS donor pool. Establishing a DKMS donor center in Chile has significantly increased donor availability for Chilean patients and contributed to an increase of unrelated donor stem cell transplant activity.

The Current Status of Allogenic Islet Cell Transplantation.

Type 1 Diabetes (T1D) is an autoimmune destruction of pancreatic beta cells. The development of the Edmonton Protocol for islet transplantation in 2000 revolutionized T1D treatment and offered a glimpse at a cure for the disease. In 2022, the 20-year follow-up findings of islet cell transplantation demonstrated the long-term safety of islet cell transplantation despite chronic immunosuppression. The Edmonton Protocol, however, remains limited by two obstacles: scarce organ donor availability and risks associated with chronic immunosuppression. To overcome these challenges, the search has begun for an alternative cell source. In 2006, pluripotency genomic factors, coined "Yamanaka Factors," were discovered, which reprogram mature somatic cells back to their embryonic, pluripotent form (iPSC). iPSCs can then be differentiated into specialized cell types, including islet cells. This discovery has opened a gateway to a personalized medicine approach to treating diabetes, circumventing the issues of donor supply and immunosuppression. In this review, we present a brief history of allogenic islet cell transplantation from the early days of pancreatic remnant transplantation to present work on encapsulating stem cell-derived cells. We review data on long-term outcomes and the ongoing challenges of allogenic islet cell and stem cell-derived islet cell transplant.

Microtransplantation, an option to explore in hematological malignancies: A review article

Abstract Hematopoietic stem cell transplant remains a valuable option for a variety of hematological malignancies, but it has its limitations given the patient’s old age, availability of donors, and the risk of morbidity and mortality associated with the procedure like graft-versus-host disease. Microtransplantation (MT) is nonengrafting allogeneic cellular therapy performed by infusing human leukocyte antigen-mismatched allogeneic peripheral blood CD34+ stem cells mobilized with granulocyte colony-stimulating factor after chemotherapy or targeted therapy. A state of transient microchimerism without engraftment will exist postinfusion, and the patient will benefit from graft-versus-tumor effect without being at high risk for graft-versus-host disease. A total of 600 patients with a diagnosis of acute myeloid leukemia, Philadelphia positive acute lymphoblastic leukemia, myelodysplastic syndrome, Hodgkin, and non-Hodgkin’s lymphomas were included in the 11 articles in this review. The results show improved overall survival and progression-free survival, which suggest MT as a valid option to be investigated further in prospective controlled studies. The improved outcomes could be explained by combined recipient-versus-tumor and graft-versus-tumor effects as the patient immune system is preserved, natural killer cells anti-leukemic effect within MT infusion and the effects of regulatory T cells. The major toxicity is myelosuppression, while nonhematologic toxicities are rare.

Impact of various detergent-based immersion and perfusion decellularization strategies on the novel caprine pancreas derived extracellular matrix scaffold.

Limited availability of the organs donors has facilitated the establishment of xenogeneic organ sources for transplantation. Numerous studies have decellularized several organs and assessed their implantability in order to provide such organs. Among all the decellularized organs studies for xenotransplantation, the pancreas has garnered very limited amount of research. The presently offered alternatives for pancreas transplantation are unable to liberate patients from donor dependence. The rat and mice pancreas are not of an accurate size for transplantation but can only be used for in-vitro studies mimicking in-vivo immune response in humans, while the porcine pancreas can cause zoonotic diseases as it carries porcine endogenous retrovirus (PERV- A/B/C). Therefore, we propose caprine pancreas as a substitute for these organs, which not only reduces donor dependence but also poses no risk of zoonosis. Upon decellularization the extracellular matrix (ECM) of different tissues responds differently to the detergents used for decellularization at physical and physiological level; this necessitates a comprehensive analysis of each tissue independently. This study investigates the impact of decellularization by ionic (SDS and SDC), non-ionic (Triton X-100 and Tween-20), and zwitterionic detergents (CHAPS). All these five detergents have been used to decellularize caprine pancreas via immersion (ID) and perfusion (PD) set-up. In this study, an extensive comparison of these two configurations (ID and PD) with regard to each detergent has been conducted. The final obtained scaffold with each set-up has been evaluated for the left-over cytosolic content, ECM components like sGAG, collagen, and fibronectin were estimated via Prussian blue and Immunohistochemical staining respectively, and finally for the tensile strength and antimicrobial activity. All the detergents performed consistently superior in PD than in ID. Conclusively, PD with SDS, SDC, and TX-100 successfully decellularizes caprine pancreatic tissue while retaining ECM architecture and mechanical properties. This research demonstrates the viability of caprine pancreatic tissue as a substitute scaffold for porcine organs and provides optimal decellularization protocol for this xenogeneic tissue. This research aims to establish a foundation for further investigations into potential regenerative strategies using this ECM in combination with other factors.

A Supportive Role of Mesenchymal Stem Cells on Insulin-Producing Langerhans Islets with a Specific Emphasis on The Secretome.

Type 1 Diabetes (T1D) is a chronic autoimmune disease characterized by a gradual destruction of insulin-producing β-cells in the endocrine pancreas due to innate and specific immune responses, leading to impaired glucose homeostasis. T1D patients usually require regular insulin injections after meals to maintain normal serum glucose levels. In severe cases, pancreas or Langerhans islet transplantation can assist in reaching a sufficient β-mass to normalize glucose homeostasis. The latter procedure is limited because of low donor availability, high islet loss, and immune rejection. There is still a need to develop new technologies to improve islet survival and implantation and to keep the islets functional. Mesenchymal stem cells (MSCs) are multipotent non-hematopoietic progenitor cells with high plasticity that can support human pancreatic islet function both in vitro and in vivo and islet co-transplantation with MSCs is more effective than islet transplantation alone in attenuating diabetes progression. The beneficial effect of MSCs on islet function is due to a combined effect on angiogenesis, suppression of immune responses, and secretion of growth factors essential for islet survival and function. In this review, various aspects of MSCs related to islet function and diabetes are described.

Comparative genomics sheds light on transcription factor-mediated regulation in the extreme acidophilic Acidithiobacillia representatives

Extreme acidophiles thrive in acidic environments, confront a multitude of challenges, and demonstrate remarkable adaptability in their metabolism to cope with the ever-changing environmental fluctuations, which encompass variations in temperature, pH levels, and the availability of electron acceptors and donors. The survival and proliferation of members within the Acidithiobacillia class rely on the deployment of transcriptional regulatory systems linked to essential physiological traits. The study of these transcriptional regulatory systems provides valuable insights into critical processes, such as energy metabolism and nutrient assimilation, and how they integrate into major genetic-metabolic circuits. In this study, we examined the transcriptional regulatory repertoires and potential interactions of forty-three Acidithiobacillia complete and draft genomes, encompassing nine species. To investigate the function and diversity of Transcription Factors (TFs) and their DNA Binding Sites (DBSs), we conducted a genome-wide comparative analysis, which allowed us to identify these regulatory elements in representatives of Acidithiobacillia. We classified TFs into gene families and compared their occurrence among all representatives, revealing conservation patterns across the class. The results identified conserved regulators for several pathways, including iron and sulfur oxidation, the main pathways for energy acquisition, providing new evidence for viable regulatory interactions and branch-specific conservation in Acidithiobacillia. The identification of TFs and DBSs not only corroborates existing experimental information for selected species, but also introduces novel candidates for experimental validation. Moreover, these promising candidates have the potential for further extension to new representatives within the class.

Substrate-dependent strategies to mitigate sulfate inhibition on microbial reductive dechlorination of polychlorinated biphenyls

Sulfate widely co-exists with polychlorinated biphenyls (PCBs) at various concentrations in the subsurface environment. Previous studies have suggested that sulfate often hampers microbial degradation of aliphatic chlorinated solvents such as chloroethenes. However, the impact of sulfate on microbial reductive dechlorination of aromatic PCBs and the underlying mechanisms have received limited attention. Likewise, strategies to mitigate such inhibition remain scarce. Here we found that the mechanisms and mitigation strategies of sulfate inhibition on PCB dechlorination were substrate-dependent. Under electron donor-limiting conditions, even a low concentration of sulfate (2 mM) resulted in a decreased PCB dechlorination rate by 88.7% in a co-culture comprising Dehalococcoides mccartyi CG1 and the sulfate-reducing bacterium Desulfovibrio desulfuricans F1, an inhibition which was attributed to the competition for electron donor between sulfate reduction and PCB dechlorination. As expected, re-amendment of 5 mM lactate effectively re-initiated PCB dechlorination. However, in the presence of a higher concentration of sulfate (5 mM), the PCB dechlorination rate in the co-culture was 77.7% lower than in the control, even with excessive electron donor supply. This inhibition was linked to high concentration of sulfide (∼5 mM) produced from sulfate reduction, as suggested by high availability of electron donor, recovery of dechlorination activity after removal of sulfide, and negligible influence of sulfate on PCB dechlorination in the axenic culture of D. mccartyi CG1. Indeed, sulfide (>5 mM) was found to directly suppress expression of PCB-dechlorinating reductive dehalogenase gene. The highest transcriptional level of pcbA1 was 2.9 ± 0.3 transcripts·cell−1 in the presence of ∼5 mM sulfide, which was increased to 37.4 ± 5.0 transcripts·cell−1 when sulfide was removed. Under this scenario, introduction of ferrous salts (5 mM) efficiently alleviated sulfide inhibition on PCB dechlorination. Interestingly, the augmentation of methanogens in the co-culture was also effective in mitigating sulfide inhibition on PCB dechlorination, offering a new approach to protect Dehalococcoides under sulfide stress. Collectively, these findings deepen our understanding of the influence of sulfate on microbial reductive dechlorination of PCBs and contribute to developing appropriate strategies based on geochemical conditions to alleviate sulfate inhibition during bioremediation of PCB-contaminated sites.

Donor's ability to comprehend and carefully assess the benefits and risks of donation in living donor liver transplantation: a Pakistani perspective - a short communication.

Patients unlikely to obtain deceased donor liver transplantation (DDLT) are offered living donor liver transplantation (LDLT) as an alternative. The success of LDLT is bound to the availability of altruistic donors who undergo smooth and safe surgery. Donor morbidity is reported to be up to 20-30%, while donor mortality is only 0.1-0.5%. Globally, LDLT poses numerous ethical concerns regarding living donors, such as autonomy, non-maleficence, and beneficence. The donor's comprehension of information is a serious issue in LDLT. The donors may underestimate the risk of morbidity and mortality, as well as can ignore the long-term psychological consequences. Furthermore, donor voluntariness may be questionable as the donors may agree to donate under severe family pressure or emotional attachment. We propose open communication with all the donors, ensuring that they should not be subjected to any undue pressure or emotional lability. Donor knowledge and understanding of potential complications and the psychosocial aspect can be augmented by good communication. We also suggest that the donors' education and psychological evaluation should be done in a friendly environment with complete privacy. Interventions should be aimed at improving communication and independent decision-making with the use of e-health educational tools for comprehension assessment.

Biomarkers for Kidney-Transplant Rejection: A Short Review Study.

Kidney transplantation is the preferred treatment for end-stage renal failure, but the limited availability of donors and the risk of immune rejection pose significant challenges. Early detection of acute renal rejection is a critical step to increasing the lifespan of the transplanted kidney. Investigating the clinical, genetic, and histopathological markers correlated to acute renal rejection, as well as finding noninvasive markers for early detection, is urgently needed. It is also crucial to identify which markers are associated with different types of acute renal rejection to manage treatment effectively. This short review summarizes recent studies that investigated various markers, including genomics, histopathology, and clinical markers, to differentiate between different types of acute kidney rejection. Our review identifies the markers that can aid in the early detection of acute renal rejection, potentially leading to better treatment and prognosis for renal-transplant patients.

Survey of blood collection and transfusion practices among institutions in Africa.

Dramatic improvements in blood transfusion have occurred during the last two decades. Transfusion medicine services and practices in Africa remain underexplored. A survey of blood bank/transfusion medicine (BBTM) practices, available blood products, blood product source(s), pre-transfusion testing, and blood donor infectious disease testing methodologies across Africa was performed using the American Society for Clinical Pathology (ASCP) listserv. Survey recipients included hospital-based laboratories/blood banks, national transfusion medicine services, and free-standing laboratories (collectively referred to as institutions). Responses from a total of 81 institutions across 22 countries were analyzed. All 81 institutions provide at least one type of blood product-whole blood, red blood cells (RBCs), platelets, plasma, and cryoprecipitate, with whole blood (90.1%, 73 of 81) and RBCs (79.0%, 64 of 81) most common, while cryoprecipitate is least common (12.4%, 10 of 81). Only five countries had a responding institution that provides all types of products. Among institutions that collect blood onsite, the most common sources of blood products are patients' family members (94.1%, 48 of 51) and pre-screened on-demand volunteer donors (82.4%, 42 of 51). The most commonly screened infectious agents are HIV and hepatitis B virus (both 81.5%), while 70.4% (57 of 81) test for hepatitis C virus (HCV) and Treponema pallidum. This study highlights significant variability and restrictions in blood product availability, pre-transfusion testing, and blood donor infectious disease testing across Africa. Further studies are needed to ascertain barriers to improving blood donor availability, blood product safety, and infectious disease testing.

Existence of HLA-Mismatched Unrelated Donors Closes the Gap in Donor Availability Regardless of Recipient Ancestry

In patients without a matched sibling donor (MSD) or well-matched unrelated donor (MUD), hematopoietic cell transplantation (HCT) can still be successful when using an HLA-mismatched unrelated donor (MMUD) in combination with post-transplantation cyclophosphamide (PTCy), abatacept, or other novel approaches. This may allow clinicians to choose a suitable donor from a wide range of donor options while optimizing other donor selection characteristics, including donor age. We hypothesized that allowing for a 5/8 HLA match level considering high-resolution matching at HLA-A, -B, -C and -DRB1, there is a potential to close the donor availability gap for all patients regardless of their race/ethnicity. In this work, we estimate the likelihood of matching for all racial/ethnic groups at different HLA match thresholds. Our study aimed to assess the potential for identifying an available MUD or MMUD in the National Marrow Donor Program (NMDP)/Be The Match (BTM) donor registry for 21 detailed and 5 broad racial/ethnic groups, using high-resolution HLA matching for HLA-A, -B, -C, and -DRB1 at various levels (8/8, 7/8, 6/8, and 5/8). We used donor registry population data from the NMDP/BTM in 2020 and redistributed the donor registry data according to existing population ratios, accounting for demonstrated donor availability. Finally, we used a genetic model at the population level to estimate the match likelihood for detailed and broad racial/ethnic groups. Likelihood of 8/8 HLA match ranging from 16% to 74% were obtained for various detailed racial/ethnic groups with available donors age ≤35 years. When considering more mismatches in the HLA loci, registry coverage became >99% with a 5/8 HLA match level for donors of all ages or those age ≤35 years, with HLA-DPB1 T cell epitope permissive matching, or when searching for donors outside of their racial/ethnic group. Our registry models demonstrate the potential for using MMUDs at various HLA match levels to study whether this will expand access to HCT across racial/ethnic groups. Expanded donor options may erase the donor availability gap for all patients while allowing for selection of MMUDs with favorable characteristics, such as younger age.

Evaluation of the Impact of a New Cooling Cell Processor System on Islet Cell Isolation Facility.

Standard cell therapy equipment, including the gold standard cell processor to purify human islets for clinical transplantation, is rarely refrigerated, potentially exposing cells to elevated temperatures during the centrifugation step. Custom cooling systems have a direct benefit on human islet viability and function. The current study was designed to test the effectiveness of a newly developed, readily available cooled cell processor system requiring minimal modifications and to evaluate its impact on human cell viability and the GMP cleanroom environment.The cooler system, a mechanically refrigerated heat exchanger set at -30 °C was used to deliver cooled medical grade dry air to the cell processor bowl through a hole drilled in the centrifuge cover. With the limited availability of pancreas donors in Qatar, system validation was done with continuous density gradient purification of pooled human bone marrow buffy coat. Sterility, turbulence, and particle count were measured in class C and class B clean room environments. No turbulence developed around the cooled cell processor, and no excess 0.5 µm and 5 µm airborne particulates were generated as per cleanroom GMP standards. At the beginning and end of the collection steps, the temperature rose respectively to 21.50 °C ± 0.34 °C and 21.93 °C ± 0.20 °C in the non-cooled cell processor and to only 10.9 °C ± 0.17 °C and 11.16 °C ± 0.35 °C in the cooled- cell processor (p <0.05). The cooled cell processor led to both improved recovery (98%) of the mononuclear cell fraction and viability (100% ± 2%) post-processing. The new cooling system effectively reduces the heat produced by the cell processor while having no particulate impact on the GMP clean room environment. The cooled cell processor described here is an inexpensive ($16,000 without including taxes, customs clearance, and transportation) and minimally invasive method to provide robust cooling. Currently, this technology in the GMP cell therapy facilityis being applied to human islet cell isolation and transplantation for the clinical program.

Haploidentical transplant with posttransplant cyclophosphamide vs matched related and unrelated donor transplant in acute myeloid leukemia and myelodysplastic neoplasm

Hematopoietic cell transplantation from haploidentical donors (haploHCT) has facilitated treatment of AML and MDS by increasing donor availability and became more feasible since the introduction of post-transplant cyclophosphamide (ptCY). In our single-center retrospective analysis including 213 patients with AML or MDS, we compare the outcome of haploHCT (n = 40) with ptCY with HCT from HLA-identical MRD (n = 105) and MUD (n = 68). At 2 years after transplantation, overall survival (OS) after haploHCT was not significantly different (0.59; 95% confidence interval 0.44–0.79) compared to MRD (0.77; 0.67–0.88) and MUD transplantation (0.72; 0.64–0.82, p = 0.51). While progression-free survival (PFS) was also not significantly different (haploHCT: 0.60; 0.46–0.78, MRD: 0.55; 0.44–0.69, MUD: 0.64; 0.55–0.74, p = 0.64), non-relapse mortality (NRM) was significantly higher after haploHCT (0.18; 0.08–0.33) vs. MRD (0.029; 0.005–0.09) and MUD (0.06; 0.02–0.12, p < 0.05). Higher NRM was mainly caused by a higher rate of fatal infections, while deaths related to GvHD or other non-relapse reasons were rare in all groups. As most fatal infections occurred early and were bacterial related, one potential risk factor among many was identified in the significantly longer time to neutrophil engraftment after haploHCT with a median of 16 days (interquartile range; 14.8–20.0) vs. 12 days (10.0–13.0) for MRD and 11 days (10.0–13.0) for MUD (p = 0.01).

Perinatal S-Adenosylmethionine Supplementation Represses PSEN1 Expression by the Cellular Epigenetic Memory of CpG and Non-CpG Methylation in Adult TgCRD8 Mice.

DNA methylation, the main epigenetic modification regulating gene expression, plays a role in the pathophysiology of neurodegeneration. Previous evidence indicates that 5'-flanking hypomethylation of PSEN1, a gene involved in the amyloidogenic pathway in Alzheimer's disease (AD), boosts the AD-like phenotype in transgenic TgCRND8 mice. Supplementation with S-adenosylmethionine (SAM), the methyl donor in the DNA methylation reactions, reverts the pathological phenotype. Several studies indicate that epigenetic signatures, driving the shift between normal and diseased aging, can be acquired during the first stages of life, even in utero, and manifest phenotypically later on in life. Therefore, we decided to test whether SAM supplementation during the perinatal period (i.e., supplementing the mothers from mating to weaning) could exert a protective role towards AD-like symptom manifestation. We therefore compared the effect of post-weaning vs. perinatal SAM treatment in TgCRND8 mice by assessing PSEN1 methylation and expression and the development of amyloid plaques. We found that short-term perinatal supplementation was as effective as the longer post-weaning supplementation in repressing PSEN1 expression and amyloid deposition in adult mice. These results highlight the importance of epigenetic memory and methyl donor availability during early life to promote healthy aging and stress the functional role of non-CpG methylation.