Sequential Transplantation Research Articles

Single-Cell Multi-Omics Analysis Reveals the Role of CX3CR1+ GNLY+ CD8+ T Cells in Improving Survival of Patients with Relapse/Refractory Hematologic Malignancies after Haplo+Cord HSCT

Background Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment for hematological malignancies. Previous works have shown superior survival outcomes of sequential transplantation of haploidentical stem cell and unrelated cord blood (haplo+cord HSCT) among recipients with relapsed/refractory leukemia, compared with single cord HSCT. However, the underlying mechanisms of immune reconstitution remain largely unexplored. Methods we first performed scRNA-seq and scATAC-seq on bone marrow mononuclear cells (BMMCs) from nine patients with relapsed/refractory leukemia underwent haplo+cord or single cord HSCT to profile the immune landscapes at single cell resolution. Second, we compared the differences of gene expression and chromatin accessibility between the subsets of immune cells. Finally, by integrating multi-omics data, we explored the gene expression regulation mechanism behind the differences between two transplant group. Results We observed distinct composition and function of global immune landscapes (T, B, natural killer cells and monocytes) between two transplant strategies, where immune cells from haplo+cord HSCT involved in interferon signaling pathway and response to virus. Analysis on T cells revealed two cytotoxic CD8+ T cells populations, enriched in haplo+cord HSCT (expressing GNLY, GZMB and PRF1) and enriched in single cord HSCT (expressing CXCR4 and GZMK) respectively. Interestingly, the augmented expression of GNLY and CX3CR1 suggested a dual property of effector and memory of haplo+cord HSCT enriched CD8+ T cells that potentially offers long-term protection for patients post-transplantation. The transcription factor IRF7, IRF9 and TBX21 played the key role on regulating immune signal transduction of CD8+ T cell subsets after haplo+cord HSCT, which might be the mechanism of transcriptional regulation for cytotoxic CD8+T cell function. Finally, single cell multi-omics analysis delineate regulatory network controlling lineage-specific gene expression after HSCT, illustrated by the example of GNLY expression in CD8+ T cells regulated by an enhancer cluster within CTCF-mediated chromatin loop. Conclusions These data collectively constitute the transcriptomic and epigenetic landscape of bone marrow post-transplantation in hematopoietic malignancies at single-cell resolution, demonstrating that a CX3CR1+ GNLY+ CD8+ T cells characterized by effector and memory property served the improved survival of patients receiving haplo+cord HSCT. keywords Single cell multi-omics, CX3CR1+ GNLY+ CD8+T cells, haplo+cord HSCT, single cord HSCT, relapsed/refractory leukemia

In vivo generation of bone marrow from embryonic stem cells in interspecies chimeras.

Generation of bone marrow (BM) from embryonic stem cells (ESCs) promises to accelerate the development of future cell therapies for life-threatening disorders. However, such approach is limited by technical challenges to produce a mixture of functional BM progenitor cells able to replace all hematopoietic cell lineages. Herein, we used blastocyst complementation to simultaneously produce BM cell lineages from mouse ESCs in a rat. Based on fluorescence-activated cell sorting analysis and single-cell RNA sequencing, mouse ESCs differentiated into multiple hematopoietic and stromal cell types that were indistinguishable from normal mouse BM cells based on gene expression signatures and cell surface markers. Receptor-ligand interactions identified Cxcl12-Cxcr4, Lama2-Itga6, App-Itga6, Comp-Cd47, Col1a1-Cd44, and App-Il18rap as major signaling pathways between hematopoietic progenitors and stromal cells. Multiple hematopoietic progenitors, including hematopoietic stem cells (HSCs) in mouse-rat chimeras derived more efficiently from mouse ESCs, whereas chondrocytes predominantly derived from rat cells. In the dorsal aorta and fetal liver of mouse-rat chimeras, mouse HSCs emerged and expanded faster compared to endogenous rat cells. Sequential BM transplantation of ESC-derived cells from mouse-rat chimeras rescued lethally irradiated syngeneic mice and demonstrated long-term reconstitution potential of donor HSCs. Altogether, a fully functional BM was generated from mouse ESCs using rat embryos as 'bioreactors'.

Study on Application of RVD Regimen Sequential Auto-HSCT in the Treatment of Multiple Myeloma Evaluated by Propensity Score Matching

To investigate the application effect of sequential autologous hematopoietic stem cell transplantation (Auto-HSCT) with lenalidomide, bortezomib and dexamethasone (RVD) in the treatment of multiple myeloma (MM) evaluated by propensity score matching. The clinical data of 49 MM patients treated with RVD scheme and followed-up for 36 months in the hospital from January 2015 to January 2021 were retrospectively analyzed and included in the control group, the clinical data of 54 MM patients who received RVD scheme and sequential Auto-HSCT scheme and completed 36 months of follow-up in the hospital during the same period were collected and included in the observation group. PSM method (1∶1, caliper value=0.01) was used to match the control group with the observation group based on baseline data and laboratory indexes, covariate equilibrium samples were obtained between groups (40 cases in each group). The clinical efficacy of patients in the two groups after 18 weeks of treatment was compared; the incidence of toxic and side effects during treatment of patients in the two groups was compared; the survival of patients in the two groups was compared after 36 months of follow-up. The ORR and DCR in the observation group were higher than those in the control group, the difference was statistically significant (P<0.05). Compared the incidence of fatigue, rash, thrombocytopenia, anemia and nausea of patients in the two groups, there was no statistical significant difference (P>0.05). After 36 months of follow-up (no loss during follow-up), 4 cases died from illness in the observation group, with a survival rate of 90% and an average survival time of 35.61 (95% CI: 35541-35.685) months, 10 cases died from illness in the control group, with a survival rate of 75% and an average survival time of 34.70 (95% CI: 34.559-34.832) months, the survival rate of the observation group was higher than that of the control group, the difference was statistically significant (P<0.05). Sequential Auto-HSCT with RVD regimen in the treatment of MM can improve the short-term efficacy and increase the survival rate of patients, which will not increase toxic and side effects and has high safety.

Sequential Stem Cell–Kidney Transplantation in Schimke Immuno-osseous Dysplasia

SummaryLifelong immunosuppression is required for allograft survival after kidney transplantation but may not ultimately prevent allograft loss resulting from chronic rejection. We developed an approach that attempts to abrogate immune rejection and the need for post-transplantation immunosuppression in three patients with Schimke immuno-osseous dysplasia who had both T-cell immunodeficiency and renal failure. Each patient received sequential transplants of αβ T-cell–depleted and CD19 B-cell–depleted haploidentical hematopoietic stem cells and a kidney from the same donor. Full donor hematopoietic chimerism and functional ex vivo T-cell tolerance was achieved, and the patients continued to have normal renal function without immunosuppression at 22 to 34 months after kidney transplantation. (Funded by the Kruzn for a Kure Foundation.)

Lumasiran in the Management of Patients with Primary Hyperoxaluria Type 1: From Bench to Bedside.

Primary hyperoxaluria (PH) is a rare genetic disease caused by excessive hepatic production and elevated urinary excretion of oxalate that leads to recurrent nephrolithiasis, nephrocalcinosis and, eventually, kidney failure. As glomerular filtration rate declines, oxalate accumulates leading to systemic oxalosis, a debilitating condition with high morbidity and mortality. Although PH is usually diagnosed during infancy, it can present at any age with different phenotypes, ranging from mild symptoms to extremely debilitating manifestations. PH is an autosomal recessive disorder and, to date, three types have been identified: PH1, PH2 and PH3. PH1 is the most common and most aggressive type, accounting for almost 80% of primary hyperoxaluria diagnoses. Until 2020, general treatment for PH1 consisted mainly in high fluid intake, urine alkalization, surgical management of recurrent nephrolithiasis and eventually, if and when kidney failure occurred, intensive dialysis regimens and transplantation strategies (simultaneous or sequential liver-kidney transplant or isolated liver/kidney transplant in carefully selected patients). Specific treatment did and still consists in administration of pyridoxine hydrochloride, although it is only effective in a subset of PH1 patients. Lumasiran, a novel biological drug based on mRNA interference that has been recently approved in the US and European Union, showed promising results and is set to be a turning point in the management of PH1. This literature review aims to summarize the available evidence on PH1 treatment with lumasiran, in order to provide both pediatric and adult nephrologists and clinicians with the knowledge for the identification and management of PH1 patients suitable for treatment.

MO096: Chronic Liver Disease and Hepatic Calcium-Oxalate Deposition in Patients with Primary Hyperoxaluria Type I

Abstract BACKGROUND AND AIMS Patients with primary hyperoxaluria type I (PH I) are prone to develop early end-stage kidney failure (ESKF). Systemic deposition of calcium-oxalate (CaOx) crystals starts when renal function declines and plasma oxalate (Pox) increases &amp;gt;30 µmol/L. It is anticipated that all parenchymal organs, but also bone (marrow), retina and the central nervous system can be involved. However, liver involvement, either as CaOx deposition or as chronic hepatitis/fibrosis, was never reported. METHOD We now examined liver involvement in 19 patients with PH I aged 1.5–52 years. Liver specimen was obtained by biopsy for diagnostic purposes (1), at autopsy (1) or at the time of combined or sequential liver kidney transplantation (17). RESULTS With polarization microscopy, crystals with the typical star-like appearance of CaOx were found in 3/19 patients. The crystals were located in small arteries but not within hepatocytes. Cirrhosis was seen in one patient. Fibrosis was seen in 10/19 patients, with porto-portal and nodular fibrosis (n = 1), and a limitation of fibrosis to the portal field in eight and/or to central areas in five patients. Unspecific hepatitis features were observed in seven patients. Fiber proliferations were detectable in 10 cases, and in one sample, transformed Ito-cells (myofibroblasts) were found. Iron deposition but also megakaryocytes as a sign of extramedullary erythropoiesis were found in nine and three patients, respectively. CONCLUSION Overall, liver involvement in patients with PH I was more pronounced, as previously described. However, compared with CaOx deposition in other organs/tissue, such crystal accumulations were only minimal in the liver, although the oxalate concentration must be the highest.

Modeling of multiple primary malignant tumors in experiment

Purpose of the study. Creation and study of models of primary multiple malignant tumors (MMPT model) under experimental conditions.Materials and methods. The study was carried out involving male and female BALB/c Nude mice (n = 42). Experimental groups of mice: with melanoma B16/F10 (B16/F10), males (control 1) and females (control 3) by n = 7; control 2 – with sarcoma 45 (C45), males n = 7; control 4 – with Guerin carcinoma (KG), females n = 7; basic: MMPT model No. 1 – B16/F10 and S45, males n = 7, and MMPT model No. 2 – B16/F10 and GC, females n = 7. 0.5 ml suspension of murine B16/F10 melanoma tumor cells diluted in the saline proportions 1:20 was injected under the skin of the left dorsal side to all animals with MMPT model, as well as 0.5 ml of a suspension containing 0.50 × 106 S45 or GC tumor cells in the saline under the skin on the right dorsum. Control groups received the same amount of tumors as the MMPT model.Results. Tumors in male mice in MMPT model No. 1 appeared simultaneously and significantly earlier than in controls: В16/ F10 melanoma by 3 times, S45 by 2 times. Tumor zises in MMPT model No. 1 were larger than in the corresponding controls: by 8.5 times at the area of В16/F10 melanoma inoculation and by 2.2 times at the area of S45 inoculation. Melanoma metastasized under the S45 capsule. Tumor at the area of GC transplantation in MMPT model No. 2 grew 5 times faster than at the area of В16/F10 melanoma injection; both tumors appeared on average 3 times earlier than in control groups 3 and 4. Tumor volumes in MMPT model No. 2 were larger than in the corresponding controls: by 7.5 times at the area of В16/F10 melanoma inoculation and by 2.2 times at the area of GC inoculation. However, almost the entire volume of the tumor node in the area of B16/F10 melanoma transplantation was represented by GC tumor tissue due to metastasis from the primary GC tumor. Melanoma remained as a small black spot with a diameter of 5–6 mm at the area of its inoculation under the skin. The average survival of mice in MMPT models No. 1 and No. 2 was 1.5–2 times (p &lt; 0.05) lower than in the corresponding controls.Conclusions. Sequential subcutaneous transplantation of mouse B16/F10 melanoma and rat sarcoma 45 to BALB/c Nude mice increased the malignant potential of each tumor: the time of their onset was shorter, and the growth rate of tumors increased which decreased the survival of animals. Sequential subcutaneous transplantation of mouse B16/F10 melanoma and Guerin's rat carcinoma to female BALB/c Nude mice suppressed tumor growth of B16/F10 melanoma and increased the malignant potential of rat GC.

Sequential Double-Lung Transplantation in Kartagener Syndrome: A Case Report

<h3>Introduction</h3> Kartagener syndrome (KS) is a rare congenital disorder, characterized by sinusitis, bronchiectasis and situs inversus. Lung transplantation is an effective treatment for end-stage lung failure. Main surgical difficulties found in these patients are due to dextrocardia and differences between left and right hilar structures and pulmonary lobes, which may cause the need to adapt the usual surgical technique. Only few technical reports were made for lung transplantation in situs inversus. <h3>Case Report</h3> We present a 48-year-old male patient with KS. He was 1,69m and had a TLC of 7,32L. When first evaluated for transplantation in 2019, he had a FEV1 and DLCO of 32% (1.1L) and 38% (3.7L), respectively, with a need of supplemental O2 (2L-rest; 4L-effort). He remained clinical and functionally stable for 2 years and was transplanted in 2021 (donor: 1,75cm, TLC 6,9L). Patient ventilation was performed with left sided double lumen tube that made selective ventilation quite difficult, therefore, an endobronchial blocker was used. A Clamshell incision was made with identification of left-right structure rotation. Without extracorporeal circulation, sequential double-lung transplantation was performed. Despite the evident anatomical changes, donor and recipient ipsilateral lungs had a good morphometric matching. Different anatomic relationships were taken into consideration. Since left recipient hilus had a right anatomy and right recipient hilus had a left anatomy, to provide an end-to-end arterial and bronchial anastomosis, we had to preserve a longer donor PA in both sides, and a longer donor right main bronchus. No technical alterations were made in the auricular cuff. There was no need to perform wedge resection of the right inferior lobe and left residual cardiac chamber wasn't verified. Left and right lung ischemic time were 4h12min and 6h22min, respectively. Patient was extubated 14h post-op and discharged 32 days after surgery with no complications. <h3>Summary</h3> We performed sequential double-lung transplantation in a patient with KS. Due to anatomic relations, longer donor pulmonary arteries and main right bronchus were necessary. There was no need for plastic maneuvers and the surgery was performed in the usual operative time.

457 - Functional Immune Tolerance Induced By Sequential Hematopoietic Stem Cell-Solid Organ Transplantation

457 - Functional Immune Tolerance Induced By Sequential Hematopoietic Stem Cell-Solid Organ Transplantation

Sequential transplantation of exosomes and mesenchymal stem cells pretreated with a combination of hypoxia and Tongxinluo efficiently facilitates cardiac repair

BackgroundBone marrow-derived mesenchymal stem cells (MSCs), which possess immunomodulatory characteristic, are promising candidates for the treatment of acute myocardial infarction (AMI). However, the low retention and survival rate of MSCs in the ischemic heart limit their therapeutic efficacy. Strategies either modifying MSCs or alleviating the inflammatory environment, which facilitates the recruitment and survival of the engrafted MSCs, may solve the problem. Thus, we aimed to explore the therapeutic efficacy of sequential transplantation of exosomes and combinatorial pretreated MSCs in the treatment of AMI.MethodsExosomes derived from MSCs were delivered to infarcted hearts through intramyocardial injection followed by the intravenous infusion of differentially pretreated MSCs on Day 3 post-AMI. Enzyme linked immunosorbent assay (ELISA) was performed to evaluate the inflammation level as well as the SDF-1 levels in the infarcted border zone of the heart. Echocardiography and histological analysis were performed to assess cardiac function, infarct size, collagen area and angiogenesis.ResultsSequential transplantation of exosomes and the combinatorial pretreated MSCs significantly facilitated cardiac repair compared to AMI rats treated with exosomes alone. Notably, compared to the other three methods of cotransplantation, combinatorial pretreatment with hypoxia and Tongxinluo (TXL) markedly enhanced the CXCR4 level of MSCs and promoted recruitment, which resulted in better cardiac function, smaller infarct size and enhanced angiogenesis. We further demonstrated that exosomes effectively reduced apoptosis in MSCs in vitro.ConclusionSequential delivery of exosomes and pretreated MSCs facilitated cardiac repair post-AMI, and combined pretreatment with hypoxia and TXL better enhanced the cardioprotective effects. This method provides new insight into the clinical translation of stem cell-based therapy for AMI.

Resident stroma-secreted chemokine CCL2 governs myeloid-derived suppressor cells in the tumor microenvironment.

Accumulating evidence has shown that cancer stroma and BM-derived cells (BMDCs) in the tumor microenvironment (TME) play vital roles in tumor progression. However, the mechanism by which oral cancer stroma recruits any particular subset of BMDCs remains largely unknown. Here, we sought to identify the subset of BMDCs that is recruited by cancer stroma. We established a sequential transplantation model in BALB/c nude mice, including (a) BM transplantation of GFP-expressing cells and (b) coxenografting of patient-derived stroma (PDS; 2 cases, designated PDS1 and PDS2) with oral cancer cells (HSC-2). As controls, xenografting was performed with HSC-2 alone or in combination with normal human dermal fibroblasts (HDF). PDS1, PDS2, and HDF all promoted BMDC migration in vitro and recruitment in vivo. Multicolor immunofluorescence revealed that the PDS coxenografts recruited Arginase-1+CD11b+GR1+GFP+ cells, which are myeloid-derived suppressor cells (MDSCs), to the TME, whereas the HDF coxenograft did not. Screening using microarrays revealed that PDS1 and PDS2 expressed CCL2 mRNA (encoding C-C motif chemokine ligand 2) at higher levels than did HDF. Indeed, PDS xenografts contained significantly higher proportions of CCL2+ stromal cells and CCR2+Arginase-1+CD11b+GR1+ MDSCs (as receiver cells) than the HDF coxenograft. Consistently, a CCL2 synthesis inhibitor and a CCR2 antagonist significantly inhibited the PDS-driven migration of BM cells in vitro. Furthermore, i.p. injection of the CCR2 antagonist to the PDS xenograft models significantly reduced the CCR2+Arginase-1+CD11b+GR1+ MDSC infiltration to the TME. In conclusion, oral cancer stroma–secreted CCL2 is a key signal for recruiting CCR2+ MDSCs from BM to the TME.

En-Bloc Transplantation of Dual Adult Kidneys with Multiple Vessels

Background. To provide optimal nephron mass, two adult kidneys with suboptimal function can be transplanted into one single recipient. All techniques described to date are based on the lengthy sequential transplantation of one allograft after the other, in each iliac fossa, or through one long incision in the right iliac quadrant. Material and Methods. We report on a novel shorter and simpler operative technique allowing the en-bloc transplantation of seven dual adult kidneys with multiple vessels into a single iliac fossa, with revascularization through the donor aorta and vena cava. A proposal for the identification, allocation, procurement, and placement of the dual adult kidneys is presented. Results. There was no primary non-function, no thrombosis, and no urinary leakage. No urosepsis and hydronephrosis were noted during the follow-up. The operative time was 180 min. At 36 months, serum creatinine levels averaged 1.8 mg/dL (range 1.4–1.9 mg/dL). Conclusions. The procedure described permits converting two complex vascular kidneys into one en-bloc graft, which then can be transplanted into a single iliac incision, using only one arterial and one venous anastomoses. It avoids extensive dissection, shortens the operative time, and reduces the complications rate for the elderly recipients. It is applicable to the transplantation of dual kidneys with single or multiple arteries.

A Multi-Factorial Observational Study on Sequential Fecal Microbiota Transplant in Patients with Medically Refractory Clostridioides difficile Infection.

Fecal microbiota transplantation (FMT) is highly effective in recurrent Clostridioides difficile infection (CDI); increasing evidence supports FMT in severe or fulminant Clostridioides difficile infection (SFCDI). However, the multifactorial mechanisms that underpin the efficacy of FMT are not fully understood. Systems biology approaches using high-throughput technologies may help with mechanistic dissection of host-microbial interactions. Here, we have undertaken a deep phenomics study on four adults receiving sequential FMT for SFCDI, in which we performed a longitudinal, integrative analysis of multiple host factors and intestinal microbiome changes. Stool samples were profiled for changes in gut microbiota and metabolites and blood samples for alterations in targeted epigenomic, metabonomic, glycomic, immune proteomic, immunophenotyping, immune functional assays, and T-cell receptor (TCR) repertoires, respectively. We characterised temporal trajectories in gut microbial and host immunometabolic data sets in three responders and one non-responder to sequential FMT. A total of 562 features were used for analysis, of which 78 features were identified, which differed between the responders and the non-responder. The observed dynamic phenotypic changes may potentially suggest immunosenescent signals in the non-responder and may help to underpin the mechanisms accompanying successful FMT, although our study is limited by a small sample size and significant heterogeneity in patient baseline characteristics. Our multi-omics integrative longitudinal analytical approach extends the knowledge regarding mechanisms of efficacy of FMT and highlights preliminary novel signatures, which should be validated in larger studies.

Functional Immune Tolerance Induced By Sequential Hematopoietic Stem Cell-Solid Organ Transplantation

Solid organ transplantation (SOT) treats over 1500 children/year in the US. While short-term outcomes have improved, long-term outcomes still remain poor. With the rare exception of monozygotic twins as donors, recipients require lifelong immunosuppression with its accompanying toxicities, the risk of nonadherence, and chronic rejection. Further, up to half of recipients require a second transplant.We have pioneered translational approaches that abrogate rejection and the need for post-transplant immunosuppression. Previous attempts in adult patients utilizing allogeneic hematopoietic stem cell transplantation (HSCT) to eliminate the need for post-SOT immunosuppression in non-histocompatible kidney transplant (KT) recipients have failed(Lowsky R, BMT 2019). The establishment of mixed lymphoid chimerism has permitted a reduction in the number of immunosuppressive drugs needed, but not their discontinuation, whereas complete donor engraftment after HSCT has resulted in fatal graft-versus-host disease in some patients (Leventhal JR, Eur J Pediatr 2000). The use of HSCT to eliminate the need for immunosuppression following pediatric KT has not been evaluated. We have pioneered sequential haploidentical HSCT followed by KT in three patients with Schimke immuno-osseous dysplasia (SIOD) to abrogate kidney rejection and the need for post-transplant immunosuppression.SIOD is a monogenic disorder with progressive nephropathy correctable by KT and a T-cell immunodeficiency curable by HSCT. All three patients received αβT-cell/CD19 B-cell depleted HSCT (αβhaplo-HSCT) from a parent prior to a KT from the same parental donor. The pre-HSCT reduced intensity preparative regimen consisted of fludarabine (a starting dose of 1 mg/kg x 4 days, which was adjusted based on AUC), total body irradiation (TBI) 200 cGy, cyclophosphamide 1200 mg/m 2, anti-thymocyte globulin (ATG) thymoglobulin® 7.5 mg/kg, and rituximab 200 mg/m 2. Immunosuppressive drugs were not prophylactically administered after HSCT. After confirmation of full donor lymphoid chimerism post-HSCT, the patients received a living donor KT from their parental HSCT donor. Post-KT immunosuppression included intraoperative methylprednisolone and post-operative low-dose oral prednisone (0.5 mg/kg/day with taper) and tacrolimus (target serum level of 3-5 ng/ml) to reduce potential reperfusion inflammation. All immunosuppressive drugs were tapered off by Day +30 post-KT. To demonstrate functional tolerance after KT, Mixed Lymphocyte Cultures (MLC) were performed between peripheral blood mononuclear cells (PBMC) and patient/parent-derived irradiated EBV transformed lymphoblastoid cells lines (EBV-LCL) as stimulators (Figure 1). PBMC were isolated from SIOD patients (n=3) by Ficoll Hypaque separation and were labelled with Invitrogen™ CellTrace Violet Proliferation Kit (CTV). EBV-LCL were established from SIOD patients, parents and healthy donors. The assay was performed in round bottom microtiter plates with 100,000 labelled PBMC as responder cells (R) and 50,000 irradiated (30gy) EBV-LCL in RPMI medium with 10% fetal calf serum. Cells were harvested on Day 6, and T-cell proliferation determined by CTV expression of CD3+ T cells using a Novocyte Penteon flow cytometer (Agilent).Donor-derived T cells isolated from the peripheral blood of all three recipients > 1-year post-HSCT/KT, did not respond to the donor cells, while they did proliferate to the non-donor parental and control cells (Fig. 1). These results demonstrate that post-HSCT/KT the circulating donor-derived T cells are functionally tolerant to the transplanted kidney and, therefore, are unable to mediate graft rejection even in the absence of immune suppression. We have achieved two goals: first, ablating the recipient immune system before HSCT we safely established a new donor-derived immune system - that could also, if required, cure a patient's underlying disease- and, second, functional tolerance to the transplanted kidney.At 12 to 24 months after KT, all patients have full donor lymphoid and myeloid chimerism, normal renal function without immunosuppression, MLC demonstrated tolerance towards donor cells, and normal proliferative responses to non-donor parental cells. These findings suggest that the combination of αβhaplo-HSCT and SOT could be extended to other solid transplantation like liver and small intestine. [Display omitted] DisclosuresBertaina: Cellevolve Bio: Membership on an entity's Board of Directors or advisory committees; Neovii: Membership on an entity's Board of Directors or advisory committees; AdicetBio: Membership on an entity's Board of Directors or advisory committees. Shah: OrchardTherapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Dr. Shah currently serves on the medical advisory board for Orchard Therapeutics . Parkman: Jasper Biotech: Consultancy.

A Single-Center Retrospective Clinical Study of Chidamide in the Treatment of Adult Peripheral T-Cell Lymphoma

Background: Peripheral T-cell lymphoma (PTCL) is a group of aggressive non-Hodgkin's lymphomas (NHL) with high heterogeneity. The first-line treatment commonly used for firstly-diagnosed PTCL is the CHOP-like regimen. However, in addition to ALK+ALCL, these regimens present poor long-term survival rate in other subtypes, mostly less than 30-40%. Even with the consolidation of autologous hematopoietic stem cell transplantation, studies have reported that the 5-year overall survival rate is barely about 50%. Therefore, for PTCL patients who have achieved remission and undergone autologous hematopoietic stem cell transplantation, there is an urgent need to explore a maintenance treatment strategy. Chidamide is an oral type of selective HDAC inhibitor with subtype specificity for HDAC 1, 2, 3, and 10. It has a regulatory effect on abnormal epigenetic functions of tumors and a novel induction and activation of cellular immune function. In China, it has been approved for relapsed or refractory PTCL at a dose of 30 mg/time, twice a week. The study of chidamide has proved its satisfactory efficacy and safety characteristics for PTCL again. This study preliminarily evaluates the near term effects of chidamide combined with chemotherapy in the first-line treatment and maintenance value of PTCL through retrospective analysis.Methods: We collect adult peripheral T-cell lymphomas inducing by CHOP-like regimen with chidamide or not. The complete response rate (CR), objective response rate (ORR), progression-free survival time (PFS) and overall survival time (OS) of patients in the combined chidamide group and non-combined group were separately analyzed and evaluated. Meanwhile, the OS in the chidamide-maintenance and non-chidamide maintenance of the PTCLs were also brought to study.Results: A total of 82 patients recruited, with a median age of 60 years (14-79 years), including 45 peripheral T-cell lymphoma (PTCL-NOS), 23 angioimmunoblastic lymphoma (AITL), 14 anaplastic large cell lymphoma (ALCL), and the follow-up time cutoff was April 30, 2021. Among 82 patients, 39 patients were treated with chidamide+CHOP-like as the first-line treatment, and 43 patients were treated with CHOP-like as the first-line treatment. The CR rate of the first-line combined chidamide group was 62%, and the ORR was 87%. The CR rate of the first-line non-combined chidamide group was 42% and the ORR was 74%. There was no significant difference in CR rate and ORR between the two groups, but the CR rate has potential clinical benefits. The median PFS of the combined chidamide group was longer than that of the non-combined group by 8 months (18.9m VS 10.9m), but there was no significant statistical difference (p=0.255). Among 82 patients, regardless of first-line treatment or salvage treatment, 42 patients in the maintenance treatment group of chidamide did not reach the median OS, and the median OS of 40 patients in the non-maintenance group was 18.9 months. The difference between the groups was statistically significant (p <0.001). There were totally 66 patients responding to the first-line treatment (CR+PR). 8 patients with sequential autologous stem cell transplantation (ASCT), 34 patients with chidamide maintenance treatment, and both groups didn't reach the median OS. The third group including 24 patients who did not undergo ASCT or chidamine maintenance presenting a median OS of 45.5 months. However, due to the limitation of follow-up time, the difference between the groups was not statistically significant, but the first two groups showed a trend of clinical benefit, which requires further follow-up. During the follow-up period, 48 patients had disease progression with first-line treatment, 23 patients had disease progression using combined chidamide as salvage treatment, and 25 patients in the non-combined chidamide group suffered disease progression. There was a statistically significant difference in OS between the groups (mOS: less than 11.8 months of VS, p =0.03). Subgroup analysis showed that chidamide maintenance treatment in the PTCL-NOS group provided a significant improvement in the prognosis (mOS: 21m VS 5.6m).Conclusion: It preliminarily suggested that chidamide maintenance therapy for PTCL provided an ideal survival benefit, especially In patients with PTCL-NOS subtypes. First-line treatment combined with chidamide and chidamide maintenance therapy may improve the poor survival prognosis. DisclosuresNo relevant conflicts of interest to declare.

The Clinical Characteristics and Outcomes of the Patients with POEMS Syndrome

To analyze the clinical characteristics of patients with POEMS syndrome and explore its effective treatment strategies. The clinical data of 75 patients with POEMS syndrome treated in The First Affiliated Hospital of Zhengzhou University from June 2012 to June 2018 were collected and retrospectively analyzed. The clinical characteristics, treatment regimes and outcomes of the patients were summarized. The median age of 75 diagnosed patients was 50 (30-81) years old and 100% (75/75) of the patients were accompanied with peripheral neuropathy, 77.3% (58/75) with organ enlargement, 82.7% (62/75) with endocrine abnormality, 93.3% (70/75) with monoclonal plasma cell diseases and 64.0% (48/75) with skin changes. Among the 75 patients, 5 cases gave up treatment, while the others showed varying degrees of improvement after treatment. The hematological complete remission (CRH) rate of the 70 patients was 28.6% and the rate of neurological remission (RN) was 85.7%. BD and RD regimens showed better efficacy in CRH and RN than old schemes, such as VAD and COP (P<0.05). Two patients underwent sequential autologous hematopoietic stem cell transplantation (HSCT) after BD chemotherapy and achieved ideal therapeutic effects, including the significant improvement of peripheral neurological symptoms and the M protein turned negative. The median follow-up time of the 70 patients was 42 (4-103) months, while the 2-year overall survival rate (OS) was 86.7%, and the 5-year OS was 81.0%. The clinical manifestations of POEMS syndrome are complex and diverse, the clinicians therefore should be vigilant to reduce the misdiagnosis and missed diagnosis. Bortezomib or Lenalidomide can be recommended as the first-line medicines and autologous HSCT should be considered for appropriate patients.

Pediatric Liver Transplantation as Enzyme Replacement Therapy for Rare Metabolic Diseases with No Structural Liver Damage

Objective: Very rare monogenic metabolic diseases without structural liver damage can be cured by liver transplantation. This process is a surgical enzyme replacement therapy, and defective enzymes may or may not be confined to the liver. The aims of this single center study of children with metabolic diseases showing structurally normal liver parenchyma were to analyze the indications and post-operative outcomes of liver transplantation, identification of developmental and metabolic benefits of the procedure with recognition of peri-operative difficulties to improve the success rate.&#x0D; Materials and Methods: Patients under the age of 19-year-old who underwent liver transplantation for metabolic disorders with no structural liver injury between January 2015 and June 2021 analyzed retrospectively. Patient and graft survivals, indications for transplantation, presence of extra-hepatic enzyme deficiency causing other organ damage, inclusion of simultaneous or sequential kidney transplantation, immunosuppressive protocols, post-transplant complications, and metabolic outcomes were identified.&#x0D; Results: Eight children with primary hyperoxaluria type 1 (n = 4), Maple syrup urine disease (n = 1), Crigler-Najjar syndrome type 1 (n=1), familial hypercholesterolemia (n=1) and propionic acidemia (n = 1) received left lobe (n=6) and left lateral segment (2) allografts from living donors. The median age of 4 girls and 4 boys at time of transplantation was 6.8 years (range 2.2-12.7 years). The median follow-up time was 3.3 years (range 1.5-5.7 years). The most common post-transplant complications were biliary system complications and infections and, two patients died because of sepsis. Six patients are alive with normal functioning allografts and metabolically stable on unrestricted diet.&#x0D; Conclusion: Liver transplantation is a lifesaving treatment and improves patient’s and parent’s life quality for metabolic disorders with no parenchymal injury despite strict dietary restrictions and medical therapies. Especially, living donor liver transplantation is very important for populations with very low organ donation rates.

Combined Heart-Lung-Liver Transplantation for Patients With Cystic Fibrosis: The Australian Experience

Combined multivisceral transplantation has emerged as a therapeutic option for a select patient cohort; however, clinical decision-making remains complex and controversial. The aim of this study was to examine patient characteristics, operative complications, and long-term outcomes of all patients who have undergone combined heart-lung-liver transplantation (HLLTx) in Australia. In this study, we performed a retrospective analysis of all adult patients who have undergone combined HLLTx in Australia to date. Recipient clinical characteristics, waitlist, and transplant outcomes are described. Eight adult patients have received HLLTx at a single Australian transplant center. Recipients of HLLTx have typically been young (median age, 30.1 years; range, 24-37), underweight (median body mass index, 19.8 kg/m2; range, 16.2-30.4) patients with cystic fibrosis (n=8, 100%) with severe airflow obstruction (median forced expiratory volume in the first second of expiration, 24% predicted; range, 17%-48%) accompanied by liver cirrhosis confirmed on histopathology (n=8, 100%). Despite relative preservation of synthetic function and low model for end-stage liver disease scores (median, 8; range, 6-17), all recipients had complications of portal hypertension prior to transplantation, with many patients having suffered life-threatening variceal hemorrhage. In this cohort, HLLTx was associated with overall posttransplant survival of 87.5% at 30 days, 71.4% at 1 year, and 42.9% at 5 years. Listing for combined HLLTx was associated with prolonged waitlist times relative to bilateral sequential single-lung transplantation (median 556 vs 56 days, respectively), however waitlist mortality and/or delisting was comparable between groups. Taken together, these findings highlight the opportunities and challenges facing combined (heart-) lung and liver transplantation in patients with multiorgan failure.

Assessment of a Multi-Cytokine Profile By a Novel Biochip-Based Assay Reveals Unique Correlation Patterns with Immune Reconstitution after Cord Blood Transplantation in Adults

Umbilical cord blood transplantation (UCBT) is an alternative stem cell source for allogeneic hematopoietic stem cell transplantation. The frequency of acute graft-versus-host-disease (aGvHD) in UCBT recipients is less than expected in recipients of adult donor allografts but delayed aGvHD can develop. Moreover, UCBT results in delayed and insufficient immune reconstitution leading to infection-related morbidity and mortality. We reasoned that an approach that would allow risk assessment for development of GvHD and/or for impaired immune reconstitution would be highly beneficial in adult UCBT recipients because it would guide therapeutic decisions for the prevention of these complications. Because reconstitution of hematopoietic lineages is delayed in UCB recipients, we focused on cytokines that can be assessed in patients' plasma at any time point before or after UCBT. Increase of proinflammatory cytokines IL-1b and TNF-α after BMT has been associated previously with the pathogenesis of GvHD. We previously determined that levels of IL-7 were inversely correlated with reconstitution of T cell subsets but were also associated with non-relapse mortality, development of GvHD and worse overall survival. In the present study, we employed a novel approach, which allows simultaneous assessment of multiple cytokines in a very small volume of patient's serum or plasma, to assess the prognostic value of this multi-cytokine profile in adult UCBT recipients. 32 patients with a median age of 50 years with hematopoietic malignancies were treated with reduced intensity conditioning (Flu/Mel/rATG) followed by two sequential UCB graft transplantation (dUCBT) and GvHD prophylaxis with tacrolimus and sirolimus. Results are based on 27 evaluable patients. Assessments were done prior to transplantation and at 1, 2, 3, 6, 12 and 24 months after dUCBT. Quantification of cytokines IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IFN-γ, TNF-α and GM-CSF in serum samples was conducted using the LUNARISTM Human 11-Plex Cytokine Biochip384 from AYOXXA Biosystems. Briefly, after diluting as 1:2 using the respective assay diluent, 5µl of samples or assay standards were loaded in duplicates on the AYOXXA Biochip and the assay was performed according to the manufacturers' instructions. Readout was performed using the AYOXXA Reader AR01 (Cat. No. LRS-001, AYOXXA Biosystems) and data were analyzed using the LUNARISTM Analysis Suite Software (Cat. No. LAS-001, AYOXXA Biosystems). Based on their median levels, cytokines could be categorized in four patterns of kinetics in comparison to pre-transplant baseline values: 1) Without significant changes (IL-2); 2) decrease over time (IL-1b, IL-17); 3) increase at 1-month after dUCBT and subsequent decline (IL-4, IL-5, IL-6, IL-8, IL-10, TNF-α, GM-CSF); 4) increase at 2 months after UCBT and subsequent decline (IFN-γ). At baseline, most cytokines correlated with total lymphocytes, CD4+, CD8+ subsets, CD4+CD25+ Treg, CD56+CD16+ NK cells, CD20+ B cells and CD14+ monocytes. At 1-month after dUCBT, the correlations with immune cell types disappeared for most cytokines and only CD14+ monocytes correlated with IFN-γ. At 2-months after dUCBT, most cytokines were positively correlated with T cell subsets. IL-8 displayed a unique pattern of correlation with CD14+ monocytes and B cells, both of which have potent antigen presenting function. Specifically, at 2-months after dUCBT IL-8 inversely correlated with CD14+ cells (r=-0.71, p=0.0007) and this pattern persisted until day 100, when CD20+ cells also showed a significant inverse correlation with IL-8 (r=-0.56, p=0.006). These inverse correlations declined by 6 months after dUCBT. IL-8 levels after BMT were previously associated with infectious complications, which subsequently drive elevation of IL-6 and development of GvHD. Our findings pose the intriguing possibility that multicytokine profile analysis might serve as a biomarker to guide patient management such as work-up for infectious complications that might prevent GVHD development in dUCBT recipients. Analysis of correlations between multicytokine profile and such clinical outcomes is currently ongoing. Our results provide evidence for the feasibility of a novel method for multicytokine assessment in patients' plasma, which might guide patient management, to diminish complications after dUCBT. [Display omitted] DisclosuresAntin:Gentium SpA/Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.

Immunity to childhood vaccines following high dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT) for germ cell tumors (GCT) with comparison to Hodgkin lymphoma (HL).

5017 Background: HDCT/ASCT represents a curative salvage treatment for patients with GCT but is rarely used for other solid tumors. Patients undergoing HDCT/ASCT for hematologic neoplasms require revaccination for their childhood immunizations. Whether this is necessary in patients with GCT is unknown. Methods: In this prospective longitudinal study, patients with GCT undergoing HDCT-ASCT from 11/2010 to 5/2018 had serologies for Measles, Mumps, Rubella, Diphtheria, Tetanus, Polio, and Varicella Zoster measured before HDCT and at 3, 6, and in a subset, 12+ months after the last HDCT with results at these timepoints compared using descriptive statistics. In addition, titer levels at ≥6 months post-transplant were matched 1:1 for age and gender with HL patients who underwent HDCT/ASCT during the same time period. Immunity was compared between cohorts using the Cochran-Mantel-Haenszel test. Results: Of 80 patients with GCT (median age 30, 84% nonseminoma), 91% received 3 sequential transplants and 68 had repeat titers at ≥6 months. Immunity at baseline was &gt;95% for Diphtheria, Tetanus and Polio and 89% for Varicella Zoster but lower for Measles (74%), Mumps (85%), and Rubella (83%) (Table). Compared to baseline, proportional immunity for all infections was similar at 3, 6, and 12 months post-transplant in the GCT population (≥6 months shown in Table). Matching resulted in 58 GCT-HL pairs. One-year immunity was numerically lower for most infections in the HL vs. GCT patients and significantly decreased for Measles and Rubella (Table). Conclusions: To our knowledge, this is the first study to assess vaccine titers following HDCT/ASCT for GCT. We demonstrate that HDCT/ASCT does not result in loss of immunity to childhood vaccines and that GCT patients retain protective titers more frequently than those with HL. However, 15-31% of GCT patients lack MMR immunity at baseline and at 1-year post-ASCT. Therefore, we recommend checking MMR titers at 1-year post-ASCT with revaccination of those lacking immunity. Titer evaluation and revaccination is not necessary for other childhood immunizations.[Table: see text]