Matched Donor Research Articles

Informed consent in the economic law field of additive manufacturing

Informed consent in the economic law field of additive manufacturing

Continuous and differential improvement in worldwide access to hematopoietic cell transplantation: activity has doubled in a decade with a notable increase in unrelated and non-identical related donors.

Promoting access to and excellence in hematopoietic cell transplantation (HCT) by collecting and disseminating data on global HCT activities is one of the principal activities of the Worldwide Network for Blood and Marrow Transplantation, a non-governmental organization in working relations with the World Health Organization. HCT activities are recorded annually by member societies, national registries and individual centers including indication, donor type (allogeneic/autologous), donor match and stem cell source (bone marrow/peripheral blood stem cells/cord blood). In 2018, 1,768 HCT teams in 89 countries (6 World Health Organization regions) reported 93,105 (48,680 autologous and 44,425 allogeneic) HCT. Major indications were plasma cell disorders and lymphoma for autologous, and acute leukemias and MDS/MPN for allogeneic HCT. HCT numbers increased from 48,709 in 2007. Notable increases were seen for autoimmune diseases in autologous and hemoglobinopathies in allogeneic HCT. The number of allogeneic HCT more than doubled with significant changes in donor match. While HCT from HLA-identical siblings has seen only limited growth, HCT from non-identical related donors showed significant increase worldwide. Strongest correlation between economic growth indicator of gross national income/capita and HCT activity/10 million population was observed for autologous HCT (correlation coefficient [r]=0.79). HCT from unrelated donors showed strong correlation (r=0.68), but only moderate correlation was detected from related donors (r=0.48 for HLA-identical sibling; r=0.45 for other). The use of HCT doubled in about a decade worldwide at different speed and with significant changes regarding donor match as a sign of improved access to HCT worldwide. Although narrowing, significant gaps remain between developing and non-developing countries.

Exploring Endocrine Signaling between Adipose Tissues and the Heart using Transfer Learning and Induced Pluripotent Stem Cell Models

Background: Because of the amount of evidence pointed toward obesity as a co-morbidity of heart disease, our goal in this study is to use a data-driven method to discover potential cross talk signals between adipose and cardiac tissues, which may reveal a physiological reason for this association. For this study, we hypothesized that adipose-cardiac crosstalk signaling can be found by unexpected co-expression between adipose tissue genes encoding secreted proteins and cardiac tissue genes and vice versa. By discovering new crosstalk signals between these two tissues, we can find new associations between heart disease and obesity. Methods: Cross-tissue correlations of gene expression have been used to identify candidate endocrine signals that mediate tissue crosstalk, which are otherwise diffcult to detect in circulation. However, the identification of significant cross-tissue gene co-expression is hindered by immense multiple-testing burden. Our goal here is to abstract gene expression patterns of tissues into eigengenes and then test their correlation with secreted protein coding genes across tissues in a pairwise fashion. We first used the NIH Common Fund Genotype-Tissue Expression data set (GTEx v8) which contains RNA seq gene expression data from matched tissues of over 17,000 transcriptomes, to learn the latent structure of gene expression across tissues. To do so, we used PLIER (pathway level information extractor), a matrix factorization algorithm to extract the latent targets as eigengenes that map to specific biological pathways in the target tissue (e.g., pathways in the heart in the case of adipose to heart crosstalk). The learned gene expression structure is then transferred to a smaller data set with matching donor adipose and heart transcript expression data, from which a correlation matrix is constructed to find significant relationships between source tissue crosstalk signals and target tissue eigengenes and nominate novel crosstalk signals. Results: Adipose to heart tissue cross talk correlations using PLIER derived latent eigengene targets revealed many adipokines that had strong correlations with pathways found in the heart tissue through similar gene expression. Among these strong correlations were eigengene targets that were wrapped in metabolism pathways particularly those of fatty acid, phospholipid, and protein metabolism. Adipokines that showed high significant and positive correlation with cardiac latent variable expression included Adiponectin (R = 0.32, p = 4.7e−13), Glutathione Peroxidase 3 (R = 0.34, p = 5e−15) and Galectin 9 (R = 0.37, p < 2.2e−16) among others. Based on these results, we nominated new potential relationships between adipose and cardiac tissue. Work is currently under way to validate these candidate crosstalk signals using human induced pluripotent stem cell (iPSC)-derived cardiomyocytes. Future Directions In conclusion, we have found strong evidence in silico to suggest a relationship between known secreted proteins from adipose tissue (adipokine) and the expression of important pathways (such as fatty acid and protein metabolism) in the heart. Based on the findings of these correlations between adipokines and latent eigengene pathways within the heart, our future directions will involved the understanding of potential downstream functional consequences mediated by the adipose secreted proteins in iPSC derived models. This project was supported in part by NIH award R03-OD032666 and the University of Colorado Translational Research Scholar Program to E.L. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Exploring Iodide and Hydrogen Sulfide as ROS Scavengers to Delay Acute Rejection in MHC-Defined Vascularized Composite Allografts.

Vascularized composite allografts (VCA) face ischemic challenges due to their limited availability. Reperfusion following ischemia triggers oxidative stress and immune reactions, and scavenger molecules could mitigate ischemia-reperfusion injuries and, therefore, immune rejection. We compared two scavengers in a myocutaneous flap VCA model. In total, 18 myocutaneous flap transplants were performed in Major histocompatibility complex (MHC)-defined miniature swine. In the MATCH group (n = 9), donors and recipients had minor antigen mismatch, while the animals were fully mismatched in the MISMATCH group (n = 9). Grafts were pretreated with saline, sodium iodide (NaI), or hydrogen sulfide (H2S), stored at 4 °C for 3 h, and then transplanted. Flaps were monitored until clinical rejection without immunosuppression. In the MATCH group, flap survival did not significantly differ between the saline and hydrogen sulfide treatments (p = 0.483) but was reduced with the sodium iodide treatment (p = 0.007). In the MISMATCH group, survival was similar between the saline and hydrogen sulfide treatments (p = 0.483) but decreased with the sodium iodide treatment (p = 0.007). Rhabdomyolysis markers showed lower but non-significant levels in the experimental subgroups for both the MATCH and MISMATCH animals. This study provides insightful data for the field of antioxidant-based approaches in VCA and transplantation.

Effectiveness of blood transfusion to cats suffering flea infestation

Donation and transfusion of whole blood and its components in cats are relevant issues in veterinary practice. Blood transfusion to cats helps effectively treat anemia of diverse causes or at least stabilize a patient for further examinatons and searh of solutions for particular pathologies. Measures ensuring blood matching of donor and recipient cats must be conducted with the utmost care and thoroughness possible. At the very least, the blood group A/B/AB of both cats should be checked, and ideally further cross-sampling should be performed so as to detect Mik antigenes and other incompatibilities. Unlike dogs, cats have natural antibodies. Donor cats must be clinically healthy, vaccinated, 2–8 years old, weigh over 4 kg, with hematocrit over 30% (preferably more than 35%). Also, a donor cat should be examined for blood-transmitted infections, including feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), and Mycoplasma haemofelis (pathogen of infectious feline anemia). The article presents clinical cases of using blood transfusion to treat feline anemia and results of the conducted laboratory studies, showing effectiveness of the performed medical procedures. After blood transfusion, the cats had positive dynamics in the general clinical state and increases in the main morphological blood parameters up to the norm or to values close to it. However, the issue of posthemorrhagic anemia requires more in-depth research in each separate case, particularly regarding the underlying case, since it can return the animal’s state and its main morphological blood parameters to the initial level, with no recovery, or at least long remission. It was found that whole-blood transfusion to the recipient animals with flea invasion increased the number of red blood cells, hemoglobin content, and hematocrit, which positively affected blood oxygenation and redox processes in the recipient animals, and accordingly their general clinical state.

Transplant Candidates of 70+ Years Have Superior Survival If Receiving Pre-Emptively a Living Donor Kidney.

Background: The number of kidney transplant recipients over 70 years of age is increasing but detailed data on patient and graft survival in the modern era of immune suppression are few. Methods: A single-center cohort of patients of 70 years and older (n = 349) at time of kidney transplantation from 2010-2020 were followed until January 2023. Results: The median age was 73 years with a median follow-up of 4.3 years. Fifty percent of recipients of a living donor kidney (LDK, n = 143) received their graft pre-emptively. Cumulative death-censored graft survival was excellent in the LDK group and reached 98% at 5 years vs. 85% in the deceased donor kidney (DDK) group. Primary non-function (38%) and rejection (43%) were the major causes of graft loss in the first year after DDK transplantation. Rejection-related graft loss was 4.6% during follow-up. Median recipient survival was superior in the subgroup of pre-emptively transplanted LDK patients compared to non-pre-emptively LDK transplanted patients (11.1 versus 6.2 years). Non-pre-emptively transplanted patients had a significantly increased incidence of infection (HR 3.81, 1.46-9.96) and cardiovascular-related causes of death (HR 3.35, 1.16-9.71). Pre-emptive transplantation was also associated with a significantly improved graft survival in the DDK recipients but this result was confounded by significantly better HLA matching and younger donor age in this group. Conclusions: Pre-emptive LDK transplantation in patients of 70 years or older confers superior graft and recipient survival.

Post-transplant cyclophosphamide versus anti-thymocyte globulin after reduced intensity peripheral blood allogeneic cell transplantation in recipients of matched sibling or 10/10 HLA matched unrelated donors: final analysis of a randomized, open-label, multicenter, phase 2 trial

The use of post-transplantation cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis is not established after reduced intensity conditioning (RIC) hematopoietic stem cell transplantation (HSCT) from fully matched donors. This was a randomized, open-label, multicenter, phase 2 trial. All patients received a RIC regimen with fludarabine, intravenous busulfan for 2 days (Flu-Bu2), and a peripheral blood stem cell (PBSC) graft from a matched related or 10/10 HLA-matched unrelated donor. Patients were randomly assigned to receive anti-thymocyte globulin (ATG) 5 mg/kg plus standard GVHD prophylaxis or PTCy 50 mg/kg/d at days +3 and +4 plus standard GVHD prophylaxis. The primary endpoint was the composite endpoint of GVHD- and relapse-free survival (GRFS) at 12 months after HSCT. Eighty-nine patients were randomly assigned to receive either PTCy or control prophylaxis with ATG. At 12 months, disease-free survival was 65.9% in the PTCy group and 67.6% in the ATG group (P = 0.99). Cumulative incidence of relapse, non-relapse mortality, and overall survival were also comparable in the two groups. GRFS at 12 months was 54.5% in the PTCy group versus 43.2% in the ATG group (P = 0.27). The median time to neutrophil and platelet count recovery was significantly longer in the PTCy group compared to the ATG group. Except for day +30, where EORTC QLQ-C30 scores were significantly lower in the PTCy compared to the ATG group, the evolution with time was not different between the two groups. Although the primary objective was not met, PTCy is effective for GVHD prophylaxis in patients receiving Flu-Bu2 conditioning with a PBSC graft from a fully matched donor and was well tolerated in term of adverse events and quality of life. This trial was registered at clinicaltrials.gov: NCT02876679.

Design and Implementation of an Online Blood Donation System

Blood donation is a critical component of healthcare, saving countless lives each year. However, many regions, including Ghana, face chronic shortages of blood supply, often resulting in life-threatening delays for patients in need. Traditional blood donation methods are plagued with inefficiencies, causing delays in matching donors with recipients, and hindered by cumbersome paperwork that discourages potential donors. To address these challenges, this paper introduces an Online Blood Donation System, which offers an accessible, efficient, and secure platform for connecting blood donors with those in need. The project encompasses a comprehensive study, employing the Agile methodology, HTML, CSS, JavaScript, PHP, and MySQL, to design and develop the system. The system's objectives encompass facilitating blood donation, enhancing efficiency, increasing donor participation, ensuring data security, promoting awareness, and overall healthcare system improvement. This project aims to contribute to the healthcare sector by providing an innovative solution to blood donation challenges, ultimately saving lives and improving healthcare efficiency.

Recipient Pericardial Apolipoprotein Levels Might Be an Indicator of Worse Outcomes after Orthotopic Heart Transplantation.

End-stage heart failure (ESHF) leads to hypoperfusion and edema formation throughout the body and is accompanied by neurohormonal and immunological alterations. Orthotopic heart transplantation (HTX) has been used as a beneficial option for ESHF. Due to the shortage of donor hearts, the ideal matching and timing of donors and recipients has become more important. In this study, our aim was to explore the relationship between the clinical outcomes of HTX and the cytokine and apolipoprotein profiles of the recipient pericardial fluid obtained at heart transplantation after opening the pericardial sac. The clinical data and the interleukin, adipokine, and lipoprotein levels in the pericardial fluid of twenty HTX recipients were investigated. Outcome variables included primer graft dysfunction (PGD), the need for post-transplantation mechanical cardiac support (MCS), International Society for Heart and Lung Transplantation grade ≥2R rejection, and mortality. Recipient risk scores were also investigated. Leptin levels were significantly lower in patients with PGD than in those without PGD (median: 6.36 (IQR: 5.55-6.62) versus 7.54 (IQR = 6.71-10.44); p = 0.029). Higher ApoCII levels (median: 14.91 (IQR: 11.55-21.30) versus 10.31 (IQR = 10.02-13.07); p = 0.042) and ApoCIII levels (median: 60.32 (IQR: 43.00-81.66) versus 22.84 (IQR = 15.84-33.39); p = 0.005) were found in patients (n = 5) who died in the first 5 years after HTX. In patients who exhibited rejection (n = 4) in the first month after transplantation, the levels of adiponectin (median: 74.48 (IQR: 35.51-131.70) versus 29.96 (IQR: 19.86-42.28); p = 0.039), ApoCII (median: 20.11 (IQR: 13.06-23.54) versus 10.32 (IQR: 10.02-12.84); p = 0.007), and ApoCIII (median: 70.97 (IQR: 34.72-82.22) versus 26.33 (IQR: 17.18-40.17); p = 0.029) were higher than in the nonrejection group. Moreover, the pericardial thyroxine (T4) levels (median: 3.96 (IQR: 3.49-4.46) versus 4.69 (IQR: 4.23-5.77); p = 0.022) were lower in patients with rejection than in patients who did not develop rejection. Our results indicate that apolipoproteins can facilitate the monitoring of rejection and could be a useful tool in the forecasting of early and late complications.

Alternative Versus Matched Donor Allogeneic Hematopoietic Transplantation for Afro-Caribbean and Latin American HTLV1-Associated Adult T Cell Leukemia/Lymphoma

Alternative Versus Matched Donor Allogeneic Hematopoietic Transplantation for Afro-Caribbean and Latin American HTLV1-Associated Adult T Cell Leukemia/Lymphoma

Comparing between HLA-matched sibling donor allogenic HSCT and non-sibling matched related donor allogenic HSCT outcome in pediatric patients; single center retrospective study.

Extended family donor search other than siblings may yield an HLA matched donor in communities with high rate of consanguinity. The outcome of patients who are transplanted from non-sibling matched related donors (NS-MRD) including engraftment and graft versus host disease (GVHD) are scarce in comparison with matched sibling donor (MSD). We retrospectively reviewed the outcome of all our pediatric hematopoietic stem cell transplantation (HSCT) patients who had non-sibling matched related donor and controlled them with matched sibling donor HSCT (based on age, indication of HSCT, conditioning regimen, GVHD prophylaxis, serotherapy, stem cell source and cytomegalovirus status). A total of 76 patients were reviewed during study period. Thirty patients (39.5%) in NS-MRD arm and 46 patients in MSD (60.5%) were identified after matching in age, disease, and conditioning regimens. All patients had similar approach including stem cell source and GVHD prophylaxis (CNI + 2nd agent). Out of the NS-MRD group, 18 patients (59%) had one of their parents as a donor and the rest as second degree relatives. Both groups were equally distributed and were homogeneous. Both groups had no statistically significant difference in outcome including engraftment, GVHD and Chimerism tests results. GVHD was seen in (13%) NS-MRD patients compared to (11%) in MSD patients. All patients remain alive with median follow up of 1249 days (431-3525). This study showed no significant difference in allogenic HSCT outcomes between matched sibling donors and non-sibling matched related donors and support using the same management approach in terms of conditioning therapy, GVHD prophylaxis, and serotherapy only if indicated.

Recruiting refugees and migrants as potential hematopoietic stem cell donors to serve patients of comparable ethnicities with rare human leucocyte antigen patterns - The BluStar.NRW project in North Western Germany

Currently, approximately 19 million people with a migration background live in Germany. The majority of those descend from regions where the population has a genetically different distribution of HLA antigens when compared to the HLA frequencies usually found in North Western Europe. In case of severe haematological disorders of these individuals, allogeneic stem cell transplantation may be the treatment of choice. However, finding appropriate histocompatible hematopoietic stem cell donors continues to be a major challenge. If no matching sibling donors are available, there are only few suitable donors with a similar genetic background available in international blood stem cell donor registries.The “BluStar.NRW” project aimed to recruit new blood and hematopoietic stem cell donors with a migration background and to noticeably increase the number of suitable donors for patients within this group. Since December 2017, a total number of 9100 blood and stem cell donors with a migration background were recruited and typed for this project. HLA typing for HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1 was performed by Next Generation Sequencing. We assessed the proportion of rare alleles according to HLA frequency tables, as defined by a frequency of <1:1000. The rare HLA allele frequencies according to HLA frequency tables of the BluStar.NRW cohort were compared with a matched control donor cohort: Rare HLA-A, -B, -C, -DRB1 and -DQB1 alleles occurred three times more frequent than in the control group, but rare HLA-DPB1 alleles occurred more frequently in the control cohort. This difference was highly significant for all HLA alleles (p < 0.0001 for HLA-A, -B, -C, -DRB1, -DPB1; p = 0.0002 for HLA-DQB1). In addition, the distribution of rare alleles differed between the two groups. To date, 29 work-ups were initiated, 12 PBSC, one BM and three DLI were collected so far out of the BluStar.NRW cohort. The apheresis probability is twofold higher (0.18% vs. 0.07%) compared to the control group which clearly shows a serious medical need. However, 13 work-ups were cancelled in the BluStar.NRW donor cohort which represents an almost twice as higher cancellation rate (45% vs. 25%).This single registry analysis with a large sample cohort clearly indicates that hematopoietic stem cell donors with a migration background represent an adequate donor pool to serve patients of comparable ethnicity.

Longevity Matching for Living Donor Renal Transplantation

This study identifies the effect of individual donor and recipient characteristics on graft survival in living-donor kidney transplantation (LDKT) using a recently described novel measure, kidney life years (KLYs). The Organ Procurement and Transplantation Network/United Network for Organ Sharing database was used to identify first-time kidney-only LDKT recipients between 1987 and 2020 who did not experience death with a functioning graft (DWFG) and were not missing relevant information (n=87,290). Patient characteristics were evaluated using Cox and multiple regression analyses, with the dependent variable being KLYs. An equation for expected KLYs based on patient characteristics was created using regression coefficients. The equation was validated using bootstrapped Pearson correlations and then applied to the DWFG group for comparison. Based on statistical significance from Cox and multiple linear regression analyses, 9 of the original 18 variables were selected for inclusion in the equation. Variables with notable impact included HLA match points (0.021 KLYs; 95% CI: [0.019,0.024]; P ≤ .001), Donor Age (-0.030 KLYs; 95% CI: [-0.035,-0.025]; P ≤ .001), and Donor African American Ethnicity (-2.356 KLYs; 95% CI: [-2.552,-2.159]; P ≤ .001). Equation validation was supported, given a negative correlation (r=-0.071; P ≤ .001) between expected KLY change and observed graft failure. Expected KLY change was found to be greater in those who eventually DWFG when compared with all other LDKTs (t=-5.735, P ≤ .001). Increasing HLA match points may be more beneficial for graft longevity than minimizing donor age in comparisons using realistic between-donor differences. Additionally, greater average expected KLYs in those who ultimately DWFG may illustrate an opportunity for improved donor-recipient matching.

Donor and recipient age matching improves outcomes after deceased donor liver transplantation

Donor and recipient age matching improves outcomes after deceased donor liver transplantation

Analysis of Human Leukocyte Antigen Frequency among Renal Transplant Recipients and Donors in Nepal

ABSTRACT Background and Objectives: Kidney transplants are effective for advanced renal failure, but graft rejection can occur when the recipient’s immune system misidentifies the kidney as a foreign object. Human leukocyte antigen (HLA), a component of the host’s immunological defense system, acts as a barrier to graft rejection. Selecting potential kidney recipients and donors for transplantation requires careful consideration of histocompatibility for the HLA-A, HLA-B, and HLA-DRB1 antigens. Mismatches between donors and recipients prolong transplant therapy, leading to lower graft survival and higher mortality. The objective of the study was to analyze HLA-A, HLA-B, and HLA-DRB1 antigens frequency in live-related renal transplant recipients and donors visiting the Department of Histocompatibility and Immunopathology at the National Public Health Laboratory, Teku, Kathmandu, Nepal. Methods: A retrospective study was conducted by using data from 104 renal transplant recipients and donors whose samples had previously been collected, processed, and analyzed to identify the Class I loci (HLA-A and HLA-B) and Class II loci (DRB1) between November 2021 and February 2024. Results: The study found that the majority of donors were female, and the majority of recipients were male. In this study, 10, 17, and 12 different HLA-A, B, and DRB1 alleles were found in recipients and donors. Alleles found more frequently are A*11 (25.00%), A*24 (23.08%), sB*15 (22.60%), B*35 (12.98%), DRB1*15 (22.60%), and DRB1*12 (21.63%). Conclusions: The study suggests that both donors and recipients of renal transplants in Nepal have a diverse HLA antigen distribution, which could aid in selecting a genetically closer group as potential matched donors for transplant recipients.

Haploidentical Stem Cell Transplantation: Half Match but More Hope!-Single Centre Experience from Western India.

With the success of post-transplant cyclophosphamide based platform and improved clinical care, the number of haploidentical stem cell transplants (HaploSCT) have surged over the last decade. However, data from India is scarce. We aimed to evaluate the outcome of haploSCT at our centre. Since the inception of government schemes, many patients at our centre are able to undergo transplantation at subsidized cost. We conducted a retrospective analysis of the haploidentical transplants performed between January 2015 and November 2022. Fifty patients were eligible for this study. Patient details were obtained from case files. The graft versus host disease (GVHD) prophylaxis was post-transplant Cyclophosphamide (PTCy) with Mycophenolate-mofetil and Cyclosporine/tacrolimus/sirolimus. All patients were transfused peripheral blood stem cells from donors. Post-transplant, patients continued regular follow up as per schedule. Supportive care was given as per unit protocol. Overall survival (OS) was calculated using the Kaplan-Meier method. Fifty patients underwent haploSCT. A total of fifty patients with a median age of 20years (range 3-53years) underwent haploidentical HSCT from a family donor. Twenty three (46%) patients were > 18years age and 82% were males. Indications for transplant included both benign and malignant hematological diseases. Most common conditioning regimen used was Fludarabine + Busulphan + Cyclophosphamide (n = 38, 76%). Thirty five patients (70%) engrafted successfully. In the patients who had successful engraftment, the median time to neutrophil engraftment was 16days (range 10-20days) and platelet engraftment was 18days (range 10-32). Fourteen patients developed acute GVHD (28%), and three patients developed chronic GVHD (6%). The median follow-up was 30months and the two-year OS was 43% with a median OS of 17months. Twenty-one (adult = 9, pediatric = 12) out of 50 patients (42%) are alive and on regular follow-up. HaploSCT with a PTCy platform is a cost-effective, promising modality of treatment in patients who have no suitable matched donors and are not affording matched unrelated transplants. At our centre, we were able to achieve acceptable results with use of generic medications at affordable cost. Transplant Related Mortality (TRM) rates were comparable to other centres, however, multi-drug resistant bacterial infection remains a challenge in performing haploidentical HSCT in developing countries.

Sex Differences in Cardiac Transplantation.

The goal of this review was to summarize contemporary evidence surrounding sex differences in heart transplantation (HT). Women have steadily comprised approximately 25% of waitlist candidates and HT recipients. This disparity is likely multifactorial with possible explanations including barriers in referral to advanced heart failure providers, implicit bias, and concerns surrounding sensitization. Women continue to experience higher waitlist mortality at the highest priority tiers. After HT, there are differences in post-transplant complications and outcomes. Future areas of study should include sex differences in noninvasive surveillance, renal outcomes after transplantation, and patient-reported outcomes. There are important sex-specific considerations that impact candidate selection, donor matching, waitlist and post-transplant outcomes. Concerted efforts are needed to improve referral patterns to ensure transplantation is allocated equally.

Prime Editing Efficiently and Precisely Corrects Causative Mutation in Chronic Granulomatous Disease, Restoring Myeloid Function: Toward Development of a Prime Edited Autologous Hematopoietic Stem Cell Therapy

Chronic granulomatous disease (CGD) is an inherited primary immunodeficiency characterized by a lack of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in phagocytic myeloid cells such as neutrophils. NADPH oxidase produces reactive oxygen species (ROS) that directly kill bacteria and fungi to control infection. CGD patients lack this ability to control infection, which results in chronic and severe infections, inflammation, autoimmunity, poor quality of life, and reduced lifespan. Current standard care for CGD is antimicrobial prophylaxis and aggressive management of infection. For patients with a suitable human leukocyte antigen (HLA) matched donor, an allogeneic hematopoietic stem cell (HSC) transplant (allo-HSCT) offers a curative approach. However, many patients do not have access to HLA matched donors and allo-HSCT also carries a risk of GvHD and graft rejection. P47phox-deficient CGD, the most common autosomal recessive CGD, is caused by mutations in the NCF1 gene, which encodes the p47phox protein, a subunit of the NADPH oxidase complex. Approximately 80% of p47phox-deficient CGD patients carry the same homozygous mutation, a 2 nucleotide GT deletion (delGT) in exon 2 of NCF1 which is correctable using Prime Editing. Transplantation of Prime Edited patient autologous CD34 + cells, in which the delGT mutation has been corrected with Prime Editing, may provide a curative treatment for p47phox-deficient CGD patients. To evaluate whether correction of the delGT NCF1 mutation in CGD patient CD34 + cells restores p47phox protein expression and NADPH oxidase activity in myeloid progeny, Prime Editors were designed to correct this mutation precisely and efficiently. The Prime Editors were delivered to CD34 + cells from two p47phox-deficient CGD patients homozygous for delGT NCF1. In both studies, ≧75% of Prime Edited patient CD34 + cells carried at least 1 corrected allele as determined by ddPCR and DNA sequencing analyses. Myeloid progeny differentiated from Prime Edited patient CD34 + cells had restored p47phox protein expression and NADPH oxidase activity to ~80% of normal healthy donors as determined by multiple ROS detection assays. To evaluate reproducibility, Prime Editors were delivered to CD34 + cells from 6 different healthy donors. On average, greater than 90% of CD34 + cells were Prime Edited across 6 donors in independent experiments. To confirm that Prime Edited CD34 + cells retain stem cell multipotency, engraftment, and hematopoietic reconstitution properties, Prime Edited and mock treated CD34 + cells from three different donors were transplanted into immunodeficient mice. Sixteen weeks after CD34 + cell transplantation, &amp;gt;87% of long-term hematopoietic stem cells (LT-HSC) that repopulated the bone marrow had at least 1 allele corrected. There were no significant differences between ‘electroporation only’ mock treated and Prime Editor electroporated human CD34 + cells with respect to long-term CD34 + cell engraftment, human CD45 + blood cell chimerism, hematopoietic multilineage blood cell reconstitution and biodistribution, or LT-HSC cell potency. Across these studies, &amp;gt;95% human CD45 + cell chimerism was achieved with Prime Edited CD34 + cells. Despite high on-target correction of the delGT mutation in NCF1, off-target editing, unintended editing, and chromosomal rearrangements (larger deletions or translocation) events were not detected using a robust suite of genome-wide assays. In summary, Prime Editing corrects a mutation that causes the most common autosomal recessive from of CGD; correction of this delGT mutation at NCF1 restores NADPH oxidase activity and function in myeloid progeny of Prime Edited CGD CD34 + cells; and Prime Edited long-term HSCs retain multipotency and functionality in vivo. These results support the development of a Prime Edited CGD patient autologous CD34 + cell therapy as a potential curative approach for p47phox-deficient CGD patients.

Measurable Residual Disease As Assessed By Flow Cytometry As Predictor of Survival in Pediatric AML Patients

Introduction Pediatric acute myeloid leukemia (pedAML) is a heterogeneous group of hematological malignancies classified according to morphology, immunophenotyping, and genomics. The optimal adjustment of therapy based on level of response is not well defined. Aim: Herein, we present the results of a retrospective study aiming to analyze the prognostic value of measurable residual disease (MRD) as determined by flow cytometry (FC-MRD) in pediatric AML. Patients and Methods All pediatric and adolescent patients (aged 0-18 years old) with AML treated in our unit between 1/2013-6/2023 were included in this study. French American British (FAB) morphological classification, immune-phenotype analysis, and molecular characterization were performed on diagnosis, and all patients were treated according to AML-BFM protocols. Final risk classification was based on evaluation of response and on genetic abnormalities at diagnosis. MRD was assessed by FC-MRD after Induction 1 and 2, and, either after course 5 or before hematopoietic stem cell transplantation (HSCT). Complete Remission (CR) was defined as regenerative or normocellular bone marrow with &amp;lt;5% blasts; in peripheral blood ≥1.0x10 9/L neutrophil granulocytes and ≥80x10 9/L thrombocytes or Remission with partial regeneration ( CRp: regenerative or normocellular bone marrow with &amp;lt;5% blasts; in the blood: ≥1.0x10 9/L leukocytes, ≥0.5x10 9/L, neutrophil granulocytes and ≥50x10 9/L, self-sustained platelets), lasting at least 4weeks; no extramedullary disease. Overall survival (OS) was defined as the time interval from the treatment initiation date to the date of death due to any cause. Progressive free survival (PFS) was defined as the time interval from the response date to the date of disease relapse or death due to any cause. The probabilities of OS and PFS were estimated with the Kaplan-Meier method. Results Overall, there were 52 patients (median age at diagnosis:7 years, 37males/15 females) diagnosed with AML, of whom: 40 patients with de novo AML, 5 patients with therapy- or myelodysplasia-related AML and 7 patients with mixed-lineage leukemia. Cytogenetics were considered favorable for 16 (31.0%), intermediate for 4 (7.6%), and adverse for 32 (61.4%) patients. Standard-risk patients (n=16) received only chemotherapy, whereas all high-risk patients, and intermediate-risk patients with available matched donors, underwent HSCT should they have reached remission. Forty-four patients (84.6%) achieved complete response (CR). Among these patients, 43 patients (97.7%) achieved CR after 1 course of induction, and 1 patient (2.3%) required at least 2 courses. Twenty-four patients (46.1%) underwent HSCT during either their first (20/24) or second (4/24) CR. Overall, 12 patients (23.07%) died, 4 patients due to resistant disease, 3 patients due to relapse, 2 patients due to serious complications upon diagnosis, 1 patient due to infection and 2 patients due to transplant-related complications. With a median follow-up time of 3.7 years (range 0.1-11.1years), the five-year OS and PFS of the entire cohort was 74.0% and 70.0%, respectively. The level of FC-MRD was a significant prognostic factor for OS and PFS. More specifically, achievement of FC-MRD &amp;lt; 0.1% at all time points was associated with a significant improvement in PFS and OS. (figure 1). FC-MRD ≥ 0.1% after course 5 or before HSCT was the only independent adverse prognostic factor that was statistically significant for both progression-free (P=0.001) and overall survival (P&amp;lt;0.001) (figure1). Conclusions We investigated the association between FC-MRD and survival in Greek pediatric patients with AML. In our cohort, achieving an MRD status &amp;lt;0.1% according to FC is associated with significant improvement in the outcome of pediatric patients with AML.

Optimizing Outcomes with Myeloablative Conditioning in Older Patients: Efficacy and Safety of Precision Engineered Orca-T in Patients > 55 Years Old with Hematologic Malignancies

Background Allogeneic hematopoietic stem cell transplants (alloSCT) offer the only curative treatment for many hematological cancers but carry the risk of significant toxicity including graft versus host disease (GvHD). Additionally, while the use of a myeloablative conditioning (MAC) regimen optimizes disease control, it can increase the complications associated with transplant and non-relapse mortality. Therefore, older patients are often deemed unfit for MAC and relegated to treatment with reduced intensity conditioning (RIC) regimens, which result in a higher incidence of relapse. Orca-T is a high-precision cell therapy biologic that includes stem and immune cells, derived from allogeneic donors, that leverages highly purified, polyclonal donor regulatory T cells to control alloreactive immune responses. The specific subsets selected in the Orca-T manufacturing process retain cells with therapeutic benefit while removing those that pose potential risks, allowing for intensification of concomitant chemotherapy and resulting in overall positive outcomes to date in the phase 1b trial (NCT04013685). To assess the safety and efficacy in an older patient population, we compared outcomes in those at least 55 years old to younger patients treated with Orca-T, receiving chemotherapy-based MAC with tacrolimus as single-agent GvHD prophylaxis. Methods As of 6/02/23, 38 patients ≥18 to &amp;lt;55 (younger) and 25 patients ≥55 years of age (older) received Orca-T as part of a multicenter Phase 1b single-arm trial and had the following diagnosis: acute myeloid, lymphoid or mixed phenotype leukemia in CR/CRi, myelodysplastic syndrome or chronic myeloid leukemia that was in chronic phase. Patients with active disease at the time of transplantation and patients with myelofibrosis were not included in this analysis. Patients received a myeloablative regimen consisting of intravenous busulfan, fludarabine, and thiotepa (BFT) prior to Orca-T, followed by single-agent GvHD prophylaxis with tacrolimus, and had an 8/8 related or unrelated matched donor. Donors were matched via DNA-based high-resolution typing of HLA-A, -B, -C, and -DRB1. Results Orca-T was successfully manufactured at a centralized GMP facility, distributed and infused at study sites throughout the U.S. Vein-to-vein time (i.e. time between end of donor apheresis to start of recipient's Orca-T infusion) was &amp;lt; 72 hours for all patients, majority &amp;lt; 60 hours. Median age was 47 in the younger group and 59 in the older group. The younger group was 50% female, and the older group was 36% female. The percentage that were of Hispanic or Latino ethnicity were 11% in the younger group, and 12% in the older group. 8%, 74% and 11% vs 12%, 44% and 32% had ALL, AML and MDS in the younger and older groups, respectively. A greater proportion of patients in the younger group had a baseline HCT-CI score of 0 (53%), while more had a baseline HCT-CI score of 4 (12%) in the older group. The median duration of follow-up for both groups was 12 months (Table). Disease free survival at 1 year was similar in both groups at 89% in the younger patients and 86% in the older patients (Figure). Modified GRFS* rate at 12 months among patients in the younger group was 86% compared to 77% in the older group. Non-relapse mortality at 1 year was 0% in both of these groups who received BFT MAC. Overall survival was high at 100% and 96% at 12 months in the younger and older patients, respectively. There were two patients &amp;gt; 65 when they received Orca-T; both remain alive without evidence of grade 3-4 acute GvHD, moderate to severe cGvHD, or relapse to date. Only 2 patients experienced grade 3 mucositis (no grade 4-5) and 1 younger patient (2.6%) and 1 older patient (4.0%) required total parenteral nutrition. Conclusions Our analysis suggests that Orca-T cell therapy represents a reduced toxicity alternative to conventional transplant and is well-tolerated by patients 55 and older, with comparable clinical outcomes to those 18 - &amp;lt; 55. In both patient groups, relapse incidence was low, with high GRFS. Remarkably, non-relapse mortality was zero at 1 year with excellent overall survival , suggesting that this regimen could potentially improve outcomes for older patients. An ongoing Phase 3 trial evaluating Orca-T vs. standard of care is currently enrolling throughout the United States.