A prospective study of posttransplant cyclophosphamide for unrelated donor peripheral blood stem cell transplant with special attention to graft content and the impact of a higher γδ T cell dose.

Posttransplant cyclophosphamide (PtCy) has been shown to decrease post-hematopoietic stem cell transplant acute and chronic graft-versus-host disease (GVHD). In this study, PtCy was used in 44 patients along with mycophenolate and tacrolimus with HLA matched (29) and mismatched (15) unrelated donors to determine the impact of graft content on outcome; thus, all patients had flow cytometric analysis of their graft content including the number of B cells, NK cells, and various T cell subsets. Higher γδ T cell dose was associated with the development of acute GVHD (p = .0038). For PtCy, further studies of the cell product along with further graft manipulation, such as selective γδ T cell depletion, could potentially improve outcomes.

A Prospective, Randomized Trial Examining the Use of G-CSF Versus No G-CSF in Patients Post-Autologous Transplantation.

Contemporary, prospective data regarding the impact of granulocyte-colony stimulating factor (G-CSF) on outcomes after autologous hematopoietic stem cell transplantation (Auto-HSCT) in an era when stem cell grafts are more qualitatively robust are limited. Recent retrospective analyses have not supported a beneficial effect of post-transplantation G-CSF use on major outcomes after Auto-HSCT leading to strategies to delay or eliminate the use of G-CSF altogether in this context. To test the hypothesis that the infusion of consistently higher doses of stem cells (defined as ≥4 × 106/kg) in Auto-HSCT will obviate the need for post-transplantation G-CSF. If so, the impact of withholding G-CSF will be noninferior to the use of G-CSF in terms of length of stay (LOS). The specific objectives were to conduct a prospective, randomized clinical trial primarily examining the impact of post-transplantation G-CSF on LOS, and secondarily on engraftment, infectious complications, antibiotic usage, and incidence of engraftment syndrome after Auto-HSCT in patients receiving versus not receiving G-CSF after Auto-HSCT. Patients with multiple myeloma or non-Hodgkin lymphoma (NHL) who underwent Pegfilgrastim plus Plerixafor-primed stem cell collection followed by Auto-HSCT were randomized to the G-CSF group (receive G-CSF starting at day 3 after Auto-HSCT) or the no G-CSF group (G-CSF withheld after Auto-HSCT). Seventy patients per arm were planned to demonstrate the primary endpoint of noninferiority in LOS between the G-CSF and the no G-CSF groups. Patient outcomes in the two groups were followed up and compared after Auto-HSCT, and an interim analysis for futility was planned when accrual reached 50%.The primary finding of this study was that despite only a 2-day longer median absolute neutrophil count (ANC) recovery in the no G-CSF arm (median 11 versus 13 days; P = .001), LOS was 4 days longer in patients not treated with G-CSF (median 11 days versus 15 days; P = .001). G-CSF use was associated with more robust incremental daily increases in ANC once recovered (P = .001), fewer days of febrile neutropenia (P = .001), and fewer days on antibiotics (P = .001), potentially contributing to this disproportionate finding. Inferiority in LOS in the no G-CSF group was demonstrated on the interim analysis, and the study was closed at the half-way point. There were no significant group differences in platelet recovery, documented infections, hospital readmissions, or overall survival at 1 year. Engraftment syndrome occurred in 54.3% of patients and was not related to G-CSF use. These results suggest that the increased LOS associated with the omission of G-CSF is largely due to concerns regarding the potential for infection in patients without a stable, recovered ANC in a hospital setting. Engraftment syndrome represented a significant source of febrile neutropenia further contributing to patient safety concerns and requires strategies to decrease its incidence. Infectious complications and death were not affected by the omission of G-CSF supporting a carefully monitored outpatient approach to Auto-HSCT in which white blood cell growth factor is eliminated or given as needed for documented infection. © 2023 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Outcomes of two-step haploidentical allogeneic stem cell transplantation in elderly patients with hematologic malignancies.

Allogeneic hematopoietic stem cell transplantation (allo-SCT) remains the best curative option for the majority of patients with hematologic malignancies (HM); however, many elderly patients are excluded from transplant and outcome data in this population is still limited. The novel two-step graft engineering approach has been the main platform for allo-SCT at Thomas Jefferson University since 2006. Following administration of the preparative regimen, we infuse donor lymphocytes, followed by cyclophosphamide to induce bidirectional tolerance, then infusion of CD34-selected cells. A total of 76 patients ≥ 65 years old with HM underwent haploidentical (haplo) allo-SCT on the two-step transplant platform between 2007 and 2021. The median time to neutrophil engraftment was 11 days and platelet engraftment was 18 days. With a median follow up of 44 months, the 3-year overall survival (OS) and progression-free survival (PFS) were 36.3% and 35.6%, respectively. The cumulative incidences of non-relapse mortality (NRM) and relapse at 3 years were 43.5% and 21.0% at 3 years, respectively. The cumulative incidence of grade III-IV acute graft-versus-host-disease (GVHD) was 11.1% at 6 months, and chronic GVHD requiring treatment was 15.1% at 2 years. The two-step haplo allo-SCT is a novel alternative platform for high-risk older HM patients, achieving fast engraftment, low relapse rates and promising survival.

The Two-Step Allogeneic Stem Cell Transplantation Approach Results in Rapid Engraftment and Excellent Outcomes in Patients with Lymphoid Malignancies.

The 2-step graft engineering approach has been the main platform for allogeneic hematopoietic cell transplantation (allo-HCT) at Thomas Jefferson University since 2005. We have previously described separating donor lymphocyte infusion followed by cyclophosphamide for bidirectional tolerization from CD34-selected hematopoietic grafts in haploidentical and matched related donors. Here we analyzed 60 patients with high-risk lymphoid malignancies who underwent a 2-step allo-HCT between 2008 and 2020. The majority of patients received haploidentical stem cell grafts (82%), and 20% of patients received matched related donor stem cell grafts. The patients underwent allo-HCT for diffuse large C cell lymphoma (n = 17; 28%), chronic lymphoblastic leukemia (n = 10; 17%), follicular lymphoma (n = 8; 13%), and Hodgkin lymphoma (n = 7; 12%). Eight patients (13%) had received prior high-dose chemotherapy. Thirty patients (50%) had a Hematopoietic Cell Transplantation Comorbidity Index ≥3, and 20 patients (33%) had a Center for International Blood & Marrow Transplant Research Revised Disease Risk Index of high risk or very high risk. The median patient age was 56 years (range, 24 to 75 years). Neutrophils engrafted at a median of 11 days (range, 9 to 16 days), and platelets engrafted at a median of 16 days (range, 13 to 37 days). With a median follow-up of 6 years, the 3-year probability of overall survival was 62.9% (95% confidence interval [CI], 49.3% to 73.8%), and that of disease-free survival was 60.2% (95% CI, 46.4% to 71.6%). The cumulative incidence of relapse at 3 years was 11.9% (95% CI, 5.2% to 21.6%). The cumulative incidence of nonrelapse mortality at 3 years was 30.1% (95% CI, 1.91% to 42.0%). The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) at 1 year was 45% (95% CI, 32.2% to 57.0%), and that of grade III-IV acute GVHD at 1 year was 5% (95% CI, 1.3% to 12.6%). The cumulative incidence of cGVHD at 3 years was 15.2% (95% CI, 7.5% to 25.4%). The 2-step approach achieved excellent outcomes in high-risk lymphoid malignancies, with rapid neutrophil and platelet recovery.

An Examination of Cytomegalovirus, Socioeconomic Status, Race, and Ethnicity on Outcomes after Haploidentical Hematopoietic Transplantation.

Previous analyses of the effects of race and socioeconomic status (SES) on outcomes after hematopoietic stem cell transplantation (HSCT) have suggested that minority populations and those in disadvantaged groups have inferior outcomes. However, the results of these studies have been inconsistent, potentially due to a multitude of factors, both medical and nonmedical, that have confounded results. In haploidentical (HI) HSCT, an expanding approach with the potential to enfranchise more minority patients, data on the effect of race and SES on outcomes are very limited. To identify and potentially correct factors that negatively impact outcomes after HI HSCT in disadvantaged groups at our institution, we performed a retrospective, multivariable analysis of the impact of race and SES as single and combined variables on HI HSCT outcomes of relapse, transplantation-related mortality, acute and chronic graft-versus-host disease (GVHD), and overall survival (OS). In addition to controlling for race and SES, all patients had HI donors and were treated with the same 2-step approach, with consistent T cell dosing and GVHD prophylaxis to further reduce the impact of confounders in this complex area. The study cohort of 239 patients was 71% Caucasian, 19.7% African American, 4.6% Hispanic, and 4.2% Asian. The majority of minority patients were in areas of higher deprivation (P = .001) and had the highest incidence of cytomegalovirus (CMV) seropositivity (P = .001) and the lowest likelihood of possessing a CMV immunodominant (IMD) allele (P = .001), which was previously associated with an OS benefit. Positive CMV serostatus was highly linked to post-transplantation CMV reactivation (P = .001) which was associated with higher relapse rates (hazard ratio [HR], 1.56; 95% confidence interval [CI], 1.06 to 2.30; P = .026), higher TRM (HR, 2.10; 95% CI, 1.09 to 4.05; P = .027), and lower OS (HR, 1.77; 95% CI, 1.18 to 2.65; P = .006). The lack of a CMV IMD allele largely replicated the results of CMV reactivation on HSCT results. Although race and SES did not directly correlate with either OS or relapse incidence, non-Caucasians in a more disadvantaged group had a higher incidence of chronic GVHD (HR, 2.55; 95% CI, 1.08 to 6.01; P = .033) compared with Caucasians and minorities in less disadvantaged groups. Regardless of SES, minorities had a lower incidence of acute GVHD than Caucasians in a more advantaged SES group (HR, 0.52; 95% CI, 0.30 to 0.90; P = .020). The primary finding of this study is that CMV reactivation was the major driver of mortality after HI HSCT. CMV reactivation may have be associated with poor HSCT outcomes in HI HSCT recipients in disadvantaged areas, most of whom were minorities. The data suggest that the prevention of post-transplantation CMV reactivation possibly could have a major impact on HI HSCT outcomes, especially in minority recipients. The finding of different GVHD manifestations between races are intriguing and merits further study.

Low Nonrelapse Mortality after HLA-Matched Related 2-Step Hematopoietic Stem Cell Transplantation Using Cyclophosphamide for Graft-versus-Host Disease Prophylaxis and the Potential Impact of Non- Cyclophosphamide-Exposed T Cells on Outcomes.

The use of cyclophosphamide (CY) for bidirectional tolerization of recipient and donor T cells is associated with reduced rates of graft-versus-host disease (GVHD) and nonrelapse mortality (NRM) after HLA-matched hematopoietic stem cell transplantation (HSCT). However, recurrent disease remains the primary barrier to long-term survival. We extended our 2-step approach to HLA-matched related HSCT using a radiation-based myeloablative conditioning regimen combined with a high dose of T cells in an attempt to reduce relapse rates while maintaining the beneficial effects of CY tolerization. After conditioning, patients received their grafts in 2 components: (1) a fixed dose of 2 × 108/kg T cells, followed 2 days later by CY, and (2) a CD34-selected graft containing a small residual amount of non-CY-exposed T cells, at a median dose of 2.98 × 103/kg. Forty-six patients with hematologic malignancies were treated. Despite the myeloablative conditioning regimen and use of high T cell doses, the cumulative incidences of grade II-IV acute GVHD, chronic GVHD, and NRM at 1 year and 5 years were very low, at 13%, 9%, and 4.3%, respectively. This contributed to a high overall survival of 89.1% at 1 year and 65.8% at 5 years. Relapse was the primary cause of mortality, with a cumulative incidence of 23.9% at 1 year and 45.7% at 5 years. In a post hoc analysis, relapse rates were significantly lower in patients receiving greater than versus those receiving less than the group median of non-CY-exposed residual T cells in the CD34 product (19.3% versus 58.1%; P = .009), without a concomitant increase in NRM. In its current form, this 2-step regimen was highly tolerable, but strategies to reduce relapse, potentially the addition of T cells not exposed to CY, are needed.

The Presence of a CMV Immunodominant Allele in the Recipient Is Associated With Increased Survival in CMV Positive Patients Undergoing Haploidentical Hematopoietic Stem Cell Transplantation.

Specific major histocompatibility (MHC) class I alleles dominate anti-CMV responses in a hierarchal manner. These CMV immunodominant (IMD) alleles are associated with a higher magnitude and frequency of cytotoxic lymphocyte responses as compared to other human leukocyte antigen (HLA) alleles. CMV reactivation has been associated with an increased incidence of graft-vs.-host disease and non-relapse mortality, as well as protection from relapse in HLA-matched HSCT settings. Less is known about the impact of CMV reactivation on these major outcomes after haploidentical (HI) HSCT, an increasingly applied therapeutic option. In HI HSCT, the efficiency of the immune response is decreased due to the immune suppression required to cross the MHC barrier as well as MHC mismatch between presenting and responding cells. We hypothesized that the presence of a CMV IMD allele would increase the efficiency of CMV responses after HI HSCT potentially impacting CMV-related outcomes. In this retrospective, multivariable review of 216 HI HSCT patients, we found that CMV+ recipients possessing at least 1 of 5 identified CMV IMD alleles had a lower hazard of death (HR = 0.40, p = 0.003) compared to CMV+ recipients not possessing a CMV IMD allele, and an overall survival rate similar to their CMV- counterparts. The analysis delineated subgroups within the CMV+ population at greater risk for death due to CMV reactivation.

Autologous Stem Cell Transplantation for Multiple Myeloma: Growth Factor Matters.

Engraftment syndrome (ES) is a known complication of autologous hematopoietic stem cell transplant during neutrophil recovery. There is a limited amount of data available comparing the incidence of ES with post-transplant granulocyte colony-stimulating factor versus granulocyte macrophage colony-stimulating factor (GM-CSF), specifically in patients with multiple myeloma. Our retrospective review of 156 patients at a single center showed that GM-CSF was associated with a higher incidence of ES compared with G-CSF (32% versus 8% of patients, P < .001) and that development of ES was associated with a 32.9% (P < .001) longer hospital stay. This suggests that the choice of growth factor could possibly contribute to the development of ES and the associated costs of increased medical care.

A Two-Step Haploidentical Versus a Two-Step Matched Related Allogeneic Myeloablative Peripheral Blood Stem Cell Transplantation.

Haploidentical stem cell transplantation (SCT) offers a transplantation option to patients who lack an HLA-matched donor. We developed a 2-step approach to myeloablative allogeneic hematopoietic stem cell transplantation for patients with haploidentical or matched related (MR) donors. In this approach, the lymphoid and myeloid portions of the graft are administered in 2 separate steps to allow fixed T cell dosing. Cyclophosphamide is used for T cell tolerization. Given a uniform conditioning regimen, graft T cell dose, and graft-versus-host disease (GVHD) prophylaxis strategy, we compared immune reconstitution and clinical outcomes in patients undergoing 2-step haploidentical versus 2-step MR SCT. We retrospectively compared data on patients undergoing a 2-step haploidentical (n = 50) or MR (n = 27) peripheral blood SCT for high-risk hematological malignancies and aplastic anemia. Both groups received myeloablative total body irradiation conditioning. Immune reconstitution data included flow cytometric assessment of T cell subsets at day 28 and 90 after SCT. Both groups showed comparable early immune recovery in all assessed T cell subsets except for the median CD3/CD8 cell count, which was higher in the MR group at day 28 compared with that in the haploidentical group. The 3-year probability of overall survival was 70% in the haploidentical group and 71% in the MR group (P = .81), while the 3-year progression-free survival was 68% in the haploidentical group and 70% in the MR group (P = .97). The 3-year cumulative incidence of nonrelapse mortality was 10% in the haploidentical group and 4% in the MR group (P = .34). The 3-year cumulative incidence of relapse was 21% in the haploidentical group and 27% in the MR group (P = .93). The 100-day cumulative incidence of overall grades II to IV acute GVHD was higher in the haploidentical group compared with that in the MR group (40% versus 8%, P < .001), whereas the grades III and IV acute GVHD was not statistically different between both groups (haploidentical, 6%; MR, 4%; P = .49). The cumulative incidence of cytomegalovirus reactivation was also higher in the haploidentical group compared to the MR group (haploidentical, 68%; MR, 19%; P < .001). There were no deaths from GVHD in either group. Using an identical conditioning regimen, graft T cell dose, and GVHD prophylaxis strategy, comparable early immune recovery and clinical outcomes were observed in the 2-step haploidentical and MR SCT recipients.

A two-step approach to myeloablative haploidentical transplantation: low nonrelapse mortality and high survival confirmed in patients with earlier stage disease.

Haploidentical hematopoietic stem cell transplantation (HSCT) is an attractive alternative donor option based on the rapid availability of an acceptable donor for most patients and decreased cost compared with costs of other alternative donor strategies. The safety of haploidentical HSCT has increased in recent years, making it ethically feasible to offer to patients with earlier stage disease. We developed a 2-step approach to haploidentical HSCT that separates the lymphoid and myeloid portions of the graft, allowing fixed T cell dosing to improve consistency in outcome comparisons. In the initial 2-step trial, the subset of patients without morphologic disease at HSCT had high rates of disease-free survival. To confirm these results, 28 additional patients without evidence of their disease were treated and are now 15 to 45 (median, 31) months past HSCT. To date, the 2-year cumulative incidence of nonrelapse mortality is 3.6%, with only 1 patient dying of nonrelapse causes, confirming the safety of this approach. Based on low regimen toxicity, the probabilities of disease-free and overall survival at 2 years are 74% and 77%, respectively, consistent with the findings in the initial trial and supporting the use of this approach in earlier stage patients lacking a matched related donor.

Desert hedgehog is a mammal-specific gene expressed during testicular and ovarian development in a marsupial.

BACKGROUND: Desert hedgehog (DHH) belongs to the hedgehog gene family that act as secreted intercellular signal transducers. DHH is an essential morphogen for normal testicular development and function in both mice and humans but is not present in the avian lineage. Like other hedgehog proteins, DHH signals through the patched (PTCH) receptors 1 and 2. Here we examine the expression and protein distribution of DHH, PTCH1 and PTCH2 in the developing testes of a marsupial mammal (the tammar wallaby) to determine whether DHH signalling is a conserved factor in gonadal development in all therian mammals. RESULTS: DHH, PTCH1 and PTCH2 were present in the marsupial genome and highly conserved with their eutherian orthologues. Phylogenetic analyses indicate that DHH has recently evolved and is a mammal-specific hedgehog orthologue. The marsupial PTCH2 receptor had an additional exon (exon 21a) not annotated in eutherian PTCH2 proteins. Interestingly we found evidence of this exon in humans and show that its translation would result in a truncated protein with functions similar to PTCH1. We also show that DHH expression was not restricted to the testes during gonadal development (as in mice), but was also expressed in the developing ovary. Expression of DHH, PTCH1 and PTCH2 in the adult tammar testis and ovary was consistent with findings in the adult mouse. CONCLUSIONS: These data suggest that there is a highly conserved role for DHH signalling in the differentiation and function of the mammalian testis and that DHH may be necessary for marsupial ovarian development. The receptors PTCH1 and PTCH2 are highly conserved mediators of hedgehog signalling in both the developing and adult marsupial gonads. Together these findings indicate DHH is an essential therian mammal-specific morphogen in gonadal development and gametogenesis.

A 2-step approach to myeloablative haploidentical stem cell transplantation: a phase 1/2 trial performed with optimized T-cell dosing.

Studies of haploidentical hematopoietic stem cell transplantation (HSCT) have identified threshold doses of T cells below which severe GVHD is usually absent. However, little is known regarding optimal T-cell dosing as it relates to engraftment, immune reconstitution, and relapse. To begin to address this question, we developed a 2-step myeloablative approach to haploidentical HSCT in which 27 patients conditioned with total body irradiation (TBI) were given a fixed dose of donor T cells (HSCT step 1), followed by cyclophosphamide (CY) for T-cell tolerization. A CD34-selected HSC product (HSCT step 2) was infused after CY. A dose of 2 × 10(8)/kg of T cells resulted in consistent engraftment, immune reconstitution, and acceptable rates of GVHD. Cumulative incidences of grade III-IV GVHD, nonrelapse mortality (NRM), and relapse-related mortality were 7.4%, 22.2%, and 29.6%, respectively. With a follow-up of 28-56 months, the 3-year probability of overall survival for the whole cohort is 48% and 75% in patients without disease at HSCT. In the context of CY tolerization, a high, fixed dose of haploidentical T cells was associated with encouraging outcomes, especially in good-risk patients, and can serve as the basis for further exploration and optimization of this 2-step approach. This study is registered at www.clinicaltrials.gov as NCT00429143.

Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development.

BACKGROUND: We present the genome sequence of the tammar wallaby, Macropus eugenii, which is a member of the kangaroo family and the first representative of the iconic hopping mammals that symbolize Australia to be sequenced. The tammar has many unusual biological characteristics, including the longest period of embryonic diapause of any mammal, extremely synchronized seasonal breeding and prolonged and sophisticated lactation within a well-defined pouch. Like other marsupials, it gives birth to highly altricial young, and has a small number of very large chromosomes, making it a valuable model for genomics, reproduction and development. RESULTS: The genome has been sequenced to 2 × coverage using Sanger sequencing, enhanced with additional next generation sequencing and the integration of extensive physical and linkage maps to build the genome assembly. We also sequenced the tammar transcriptome across many tissues and developmental time points. Our analyses of these data shed light on mammalian reproduction, development and genome evolution: there is innovation in reproductive and lactational genes, rapid evolution of germ cell genes, and incomplete, locus-specific X inactivation. We also observe novel retrotransposons and a highly rearranged major histocompatibility complex, with many class I genes located outside the complex. Novel microRNAs in the tammar HOX clusters uncover new potential mammalian HOX regulatory elements. CONCLUSIONS: Analyses of these resources enhance our understanding of marsupial gene evolution, identify marsupial-specific conserved non-coding elements and critical genes across a range of biological systems, including reproduction, development and immunity, and provide new insight into marsupial and mammalian biology and genome evolution.