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1.
J Clin Med ; 13(17)2024 Aug 30.
Article in English | MEDLINE | ID: mdl-39274359

ABSTRACT

Objectives: The Wilms' tumor gene 1 (WT1) plays a critical role in cell development and the regulation of essential genes involved in cell growth and metabolism. In the context of hematopoietic tumors, including acute myeloid leukemia (AML), WT1 has been identified as a potential marker for measurable residual disease (MRD) assessment. Relapse after allogeneic hematopoietic stem cell transplantation (allo-SCT) remains a significant challenge in AML treatment, highlighting the importance of MRD monitoring for risk stratification and treatment decisions. This study aimed to investigate the clinical significance of WT1 as a molecular marker for MRD and its correlation with chimerism in AML patients post-allo-SCT setting. Methods: We have included 58 patients with WT1-expression-positive acute myeloid leukemia (AML) who received allo-SCT in our center between 2016-2022. The exclusion criteria are as follows: not having WT1 polymerase chain reaction (PCR) measurement at diagnosis, not receiving allo-SCT, and not having a serial measurement of WT1 post-transplant. Pre- and post-transplant assessments were made with flow cytometry, WT1 PCR, and bone marrow morphological evaluations. Statistical analyses were carried out to explore correlations between WT1 levels, MRD markers, and chimerism post-transplantation. Results: We found that WT1 had a significant correlation with flow cytometry and bone marrow morphological evaluation, but not with chimerism. Interestingly, high WT1 expressors exhibited a more robust correlation with chimerism compared to the general cohort. The negative predictive value for post-allo-SCT relapse was 91.8% for the whole WT1 cohort; for high WT1 expressors, it was similar, at 87.5%. The negative predictive value for post-allo-SCT relapse was high for the whole WT1 cohort; for high WT1 expressors, it was similar. The WT1 MRD assay showed a high negative predictive value for post-allo-SCT relapse, consistent across both the entire cohort (91.8%) and high WT1 expressors (87.5%). Conclusions: WT1 expression levels may serve as a valuable ancillary marker in MRD assessment and relapse prediction post-allo-SCT in AML patients, particularly for those lacking specific fusion genes or mutations. However, further large-scale, controlled studies are needed to standardize WT1 MRD assays and establish clear guidelines for their clinical application.

3.
Front Cell Dev Biol ; 12: 1390533, 2024.
Article in English | MEDLINE | ID: mdl-39206089

ABSTRACT

Multiple complex biological processes take place during pregnancy, including the migration of fetal cells to maternal circulation and their subsequent engraftment in maternal tissues, where they form microchimerisms. Fetal microchimerisms have been identified in several tissues; nevertheless, their functional role remains largely unknown. Different reports suggest these cells contribute to tissue repair and modulate the immune response, but they have also been associated with pre-eclampsia and tumor formation. In the maternal heart, cells of fetal origin can contribute to different cell lineages after myocardial infarction. However, the functional role of these cells and their effect on cardiac function and repair are unknown. In this work, we found that microchimerisms of fetal origin are present in the maternal circulation and graft in the heart. To determine their functional role, WT female mice were crossed with male mice expressing the diphtheria toxin (DT) receptor. Mothers were treated with DT to eliminate microchimerisms and the response to myocardial infarction was investigated. We found that removal of microchimerisms improved cardiac contraction in postpartum and post-infarction model females compared to untreated mice, where DT administration had no significant effects. These results suggest that microchimerisms play a detrimental role in the mother following myocardial infarction.

4.
Article in English | MEDLINE | ID: mdl-39181858

ABSTRACT

BACKGROUND: Regular monitoring of CD34 donor chimerism (DC) is a highly sensitive method of predicting relapse in allogeneic stem cell transplant (alloHSCT) recipients with AML/MDS. A fall of CD34 DC below 80% is an indicator of ensuing relapse. There are limited studies assessing the efficacy of donor lymphocyte infusion (DLI) triggered by mixed CD34 DC (MDC), in addressing falling chimerism. PATIENTS AND METHODS: We performed a retrospective analysis of consecutive alloHSCT patients between 2012 to 2023 who received DLI (with or without azacitidine) for CD34 MDC without morphologic relapse at the time of infusion. RESULTS: Of the 21 patients with follow up CD34 DC available, 14 (66.7%) achieved CD34 full donor chimerism (FDC) following DLI with or without azacitidine (dli-FDC), while 7 (33.3%) did not (dli-MDC). The 2-year cumulative incidence of relapse (CIR) was significantly lower in dli-FDC compared to dli-MDC (21.4% vs. 85.7%, P < 0.001), correlating with superior overall survival (OS; median years not reached vs. 0.67 years [95% CI, 0.58-ND], P < .001). Rates of grade II-IV acute GVHD post-DLI were 14.9%, and moderate-severe cGVHD was 42.8% in the dli-FDC group. The 5-year nonrelapse mortality (NRM) of the dli-FDC group was 7.1% following DLI. CONCLUSION: Our study shows the restoration of CD34 FDC post-DLI is associated with reduced relapse and improved overall survival, with low NRM.

5.
Br J Haematol ; 2024 Jul 07.
Article in English | MEDLINE | ID: mdl-38973155

ABSTRACT

Routine ABO blood group typing of apparently healthy individuals sporadically uncovers unexplained mixed-field reactions. Such blood group discrepancies can either result from a haematopoiesis-confined or body-wide dispersed chimerism or mosaicism. Taking the distinct clinical consequences of these four different possibilities into account, we explored the responsible cause in nine affected individuals. Genotype analyses revealed that more than three-quarters were chimaeras (two same-sex females, four same-sex males, one sex-mismatched male), while two were mosaics. Short tandem repeat analyses of buccal swab, hair root and nail DNA suggested a body-wide involvement in all instances. Moreover, genome-wide array analyses unveiled that in both mosaic cases the causative genetic defect was a unique copy-neutral loss of heterozygosity encompassing the entire long arm of chromosome 9. The practical transfusion- or transplantation-associated consequences of such incidental discoveries are well known and therefore easily manageable. Far less appreciated is the fact that such findings also call attention to potential problems that directly ensue from their specific genetic make-up. In case of chimerism, these are the appearance of seemingly implausible family relationships and pitfalls in forensic testing. In case of mosaicism, they concern with the necessity to delineate innocuous pre-existent or age-related from disease-predisposing and disease-indicating cell clones.

6.
Mitochondrial DNA B Resour ; 9(7): 861-864, 2024.
Article in English | MEDLINE | ID: mdl-38983844

ABSTRACT

The complete mitochondrial genome of Blue-fronted Redstart (Phoenicurus frontalis), GenBank accession number MT360379 (NC_053917), was published by Li and colleages in 2020. Here we show that this mitogenome is actually a chimera containing DNA fragments of both P. frontalis (15,518 bp, 92.5%) and Pink-rumped Rosefinch (Carpodacus waltoni eos, 1258 bp, 7.5%). This mitogenome has been re-used in at least three phylogenies. Our study confirms that mitogenomes are best verified with multiple gene trees, and that any anomalies should be investigated by direct comparison of sequences.

7.
Microbiome ; 12(1): 126, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39010229

ABSTRACT

BACKGROUND: Single amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) are the predominant sources of information about the coding potential of uncultured microbial lineages, but their strengths and limitations remain poorly understood. Here, we performed a direct comparison of two previously published collections of thousands of SAGs and MAGs obtained from the same, global environment. RESULTS: We found that SAGs were less prone to chimerism and more accurately reflected the relative abundance and the pangenome content of microbial lineages inhabiting the epipelagic of the tropical and subtropical ocean, as compared to MAGs. SAGs were also better suited to link genome information with taxa discovered through 16S rRNA amplicon analyses. Meanwhile, MAGs had the advantage of more readily recovering genomes of rare lineages. CONCLUSIONS: Our analyses revealed the relative strengths and weaknesses of the two most commonly used genome recovery approaches in environmental microbiology. These considerations, as well as the need for better tools for genome quality assessment, should be taken into account when designing studies and interpreting data that involve SAGs or MAGs. Video Abstract.


Subject(s)
Bacteria , Metagenome , Plankton , RNA, Ribosomal, 16S , RNA, Ribosomal, 16S/genetics , Bacteria/genetics , Bacteria/classification , Plankton/genetics , Plankton/classification , Plankton/microbiology , Phylogeny , Seawater/microbiology , Chimerism , Genome, Bacterial , Metagenomics/methods , Microbiota/genetics , Genomics
8.
Gastroenterol Clin North Am ; 53(3): 413-430, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39068003

ABSTRACT

In this review, the authors outlined concepts and strategies to achieve immune tolerance through inducing hematopoietic chimerism after solid organ transplantation and introduced challenges and opportunities in harnessing two-way alloresponses to improve outcomes after intestinal transplantation (ITx). Next, the authors discussed the dynamics and phenotypes of peripheral blood and intestinal graft T-cell subset chimerism and their association with outcomes. The authors also summarized studies on other types of immune cells after ITx and their potential participation in chimerism-mediated tolerance. The authors further discussed strategies and future directions to promote chimerism-associated tolerance after ITx to overcome rejection and minimize immunosuppression.


Subject(s)
Intestines , Transplantation Chimera , Humans , Intestines/transplantation , Intestines/immunology , Transplantation Chimera/immunology , Transplantation Tolerance/immunology , Chimerism , Organ Transplantation/methods , Graft Rejection/immunology , Graft Rejection/prevention & control , Immune Tolerance
9.
Front Immunol ; 15: 1397567, 2024.
Article in English | MEDLINE | ID: mdl-39044816

ABSTRACT

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for various hematological, immunological and metabolic diseases, replacing the patient's hematopoietic system with donor-derived healthy hematopoietic stem cells. HSCT can be complicated by early and late events related to impaired immunological recovery such as prolonged hypogammaglobulinemia post-HSCT. We present a 16-year-old female patient with sickle-cell disease who underwent HSCT with stem cells from a human leukocyte antigen (HLA) class-II mismatched family donor. While cellular recovery was good post-HSCT, the patient developed mixed chimerism and suffered from cervical lymphadenopathy, recurrent airway infections and cutaneous SLE. She presented with hypogammaglobulinemia and was started on immunoglobulin substitution therapy and antibiotic prophylaxis. B-cell phenotyping showed that she had increased transitional and naïve mature B cells, reduced memory B cells, and diminished marginal zone/natural effector cells. In-depth immunophenotyping and B-cell receptor repertoire sequencing ruled out an intrinsic B-cell defect by expression of activation-induced cytidine deaminase (AID), presence of somatic hypermutations and differentiation into IgG- and IgA-producing plasma cells in vitro. Immunohistochemistry and flow cytometry of lymph node tissue showed a clear block in terminal B-cell differentiation. Chimerism analysis of sorted lymph node populations showed that exclusively patient-derived B cells populated germinal centers, while only a minor fraction of follicular helper T cells was patient-derived. Given this discrepancy, we deduced that the HLA class-II disparity between patient and donor likely hinders terminal B-cell differentiation in the lymph node. This case highlights that studying disturbed cognate T-B interactions in the secondary lymphoid organs can provide unique insights when deciphering prolonged hypogammaglobulinemia post-HSCT.


Subject(s)
Agammaglobulinemia , Hematopoietic Stem Cell Transplantation , Humans , Hematopoietic Stem Cell Transplantation/adverse effects , Female , Agammaglobulinemia/immunology , Agammaglobulinemia/therapy , Adolescent , Anemia, Sickle Cell/therapy , Anemia, Sickle Cell/immunology , B-Lymphocytes/immunology , Transplantation Chimera , HLA Antigens/immunology , HLA Antigens/genetics
10.
Ann Hematol ; 103(9): 3775-3782, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39046509

ABSTRACT

Hemophagocytic Lymphohistiocytosis (HLH) is a rare disorder of immune dysregulation characterized by fever, cytopenias, and splenomegaly. Its primary form poses a therapeutic challenge due to its high fatality when left untreated. We retrospectively analyzed 28 patients who underwent related-donor allogeneic stem cell transplant for primary HLH from 2010 to 2021. Among them were 10 cases of familial HLH, 8 cases of Griscelli syndrome type 2, and 1 case each with PRF1 and STX11 mutations. All the patients underwent transplants with reduced-intensity or myeloablative conditioning and 26 of them achieved neutrophil engraftment at a median of day + 14. The donors were either fully matched (68%) or haploidentical (32%). With a median follow-up of 1 year, overall survival was 68% (n = 19) and disease-free survival was 64.4% (n = 18). OS was better in patients transplanted with a sibling donor (compared to parent donor), who achieved complete donor chimerism, and those transplanted early in the course of the disease (diagnosis to transplant duration less than 6 months).


Subject(s)
Hematopoietic Stem Cell Transplantation , Lymphohistiocytosis, Hemophagocytic , Humans , Lymphohistiocytosis, Hemophagocytic/therapy , Lymphohistiocytosis, Hemophagocytic/mortality , Male , Female , Retrospective Studies , Adolescent , Child , Child, Preschool , Adult , Infant , Transplantation Conditioning/methods , Transplantation, Homologous , Allografts , Young Adult , Piebaldism/therapy , Middle Aged , Survival Rate , Disease-Free Survival , Follow-Up Studies , Primary Immunodeficiency Diseases , Perforin
11.
Cells ; 13(11)2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38891125

ABSTRACT

Chimerism analysis after allogeneic hematopoietic stem cell transplantation serves to confirm engraftment, indicate relapse of hematologic malignancy, and attribute graft failure to either immune rejection or poor graft function. Short tandem repeat PCR (STR-PCR) is the prevailing method, followed by quantitative real-time PCR (qPCR), with detection limits of 1-5% and 0.1%, respectively. Chimerism assays using digital PCR or next-generation sequencing, both of which are more sensitive than STR-PCR, are increasingly used. Stable mixed chimerism is usually not associated with poor outcomes in non-malignant diseases, but recipient chimerism may foretell relapse of hematologic malignancies, so higher detection sensitivity may be beneficial in such cases. Thus, the need for and the type of intervention, e.g., immunosuppression regimen, donor lymphocyte infusion, and/or salvage second transplantation, should be guided by donor chimerism in the context of the feature and/or residual malignant cells of the disease to be treated.


Subject(s)
Chimerism , Hematopoietic Stem Cell Transplantation , Transplantation, Homologous , Humans , Hematopoietic Stem Cell Transplantation/methods , Transplantation Chimera , Hematologic Neoplasms/therapy , Hematologic Neoplasms/genetics , Hematologic Neoplasms/immunology
12.
J Surg Res ; 300: 389-401, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38851085

ABSTRACT

INTRODUCTION: Vascularized composite allotransplantation (VCA) is the transplantation of multiple tissue types as a solution for devastating injuries. Despite the highly encouraging functional outcomes of VCA, the consequences of long-term immunosuppression remain the main obstacle in its application. In this review, we provide researchers and surgeons with a summary of the latest advances in the field of cell-based therapies for VCA tolerance. METHODS: Four electronic databases were searched: PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature , and Web of Science. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis as the basis of our organization. RESULTS: Hematopoietic stem cells prolonged VCA survival. A combination of immature dendritic cells and tacrolimus was superior to tacrolimus alone. T cell Ig domain and mucin domain modified mature dendritic cells increased VCA tolerance. Bone marrow-derived mesenchymal stem cells prolonged survival of VCAs. A combination of adipose-derived mesenchymal stem cells, cytotoxic T-lymphocyte antigen 4 immunoglobulin, and antilymphocyte serum significantly improved VCA tolerance. Ex-vivo allotransplant perfusion with recipient's bone marrow-derived mesenchymal stem cells increased VCA survival. Recipient's adipose-derived mesenchymal stem cells and systemic immunosuppression prolonged VCA survival more than any of those agents alone. Additionally, a combination of peripheral blood mononuclear cells shortly incubated in mitomycin and cyclosporine significantly improved VCA survival. Finally, a combination of donor recipient chimeric cells, anti-αß-T cell receptor (TCR), and cyclosporine significantly prolonged VCA tolerance. CONCLUSIONS: Evidence from animal studies shows that cell-based therapies can prolong survival of VCAs. However, there remain many obstacles for these therapies, and they require rigorous clinical research given the rarity of the subjects and the complexity of the therapies. The major limitations of cell-based therapies include the need for conditioning with immunosuppressive drugs and radiation, causing significant toxicity. Safety concerns also persist as most research is on animal models. While completely replacing traditional immunosuppression with cell-based methods is unlikely soon, these therapies could reduce the need for high doses of immunosuppressants and improve VCA tolerance.


Subject(s)
Vascularized Composite Allotransplantation , Humans , Vascularized Composite Allotransplantation/methods , Animals , Graft Survival/immunology , Graft Survival/drug effects , Transplantation Tolerance , Immunosuppressive Agents/therapeutic use , Cell- and Tissue-Based Therapy/methods , Graft Rejection/immunology , Graft Rejection/prevention & control , Mesenchymal Stem Cell Transplantation/methods
13.
Biomedicines ; 12(5)2024 May 11.
Article in English | MEDLINE | ID: mdl-38791026

ABSTRACT

Cell-based therapies hold promise for novel therapeutic strategies in regenerative medicine. We previously characterized in vitro human umbilical di-chimeric cells (HUDCs) created via the ex vivo fusion of human umbilical cord blood (UCB) cells derived from two unrelated donors. In this in vivo study, we assessed HUDC safety and biodistribution in the NOD SCID mouse model at 90 days following the systemic intraosseous administration of HUDCs. Twelve NOD SCID mice (n = 6/group) received intraosseous injection of donor UCB cells (3.0 × 106) in Group 1, or HUDCs (3.0 × 106) in Group 2, without immunosuppression. Flow cytometry assessed hematopoietic cell surface markers in peripheral blood and the presence of HLA-ABC class I antigens in lymphoid and non-lymphoid organs. HUDC safety was assessed by weekly evaluations, magnetic resonance imaging (MRI), and at autopsy for tumorigenicity. At 90 days after intraosseous cell administration, the comparable expression of HLA-ABC class I antigens in selected organs was found in UCB control and HUDC therapy groups. MRI and autopsy confirmed safety by no signs of tumor growth. This study confirmed HUDC biodistribution to selected lymphoid organs following intraosseous administration, without immunosuppression. These data introduce HUDCs as a novel promising approach for immunomodulation in transplantation.

14.
Front Genet ; 15: 1268728, 2024.
Article in English | MEDLINE | ID: mdl-38746054

ABSTRACT

Background: For many years, transplantation outcomes were uncertain and not hopeful, until histocompatibility testing spread. Common criteria for histocompatibility assays and communications' improvement allowed an efficient organ sharing system. The possibility of organ exchanges is closely linked to the importance of interlaboratory comparisons for histocompatibility and immunogenetics methods. The external proficiency testing (EPT) systems are the most powerful quality assurance tools. They help achieve harmonization of analyses, set a standard of performance, and a common interpretation. Methods: The external quality assurance program for diagnostic immunology laboratories (Garantía Externa de Calidad para Laboratorios de Inmunología Diagnóstica, GECLID) program nowadays runs 13 external quality assurance (EQA) histocompatibility and immunogenetics schemes, with the first of them from 2011 to date: serological and molecular: low- and high-resolution human leukocyte antigen (HLA), human platelet antigen (HPA), and killer inhibitory receptor (KIR) typing(HLA-B*27, HLA-B*57:01, and coeliac disease-related HLA), cell-dependent cytotoxicity (CDC) and flow cytometry (FC) crossmatches, anti-HLA and anti-HPA antibodies, and chimerism. Results: A total of 85 laboratories participated in this subprogram in the last 12 years reporting over 1.69 M results: 1.46 M for anti-HLA and anti-HPA antibodies, 203.810 molecular typing data (HLA, HPA, and KIR genes), 2.372 for chimerism analyses, and 39.352 for crossmatches. Based on the European Federation for Immunogenetics (EFI) standards for EPT providers, the mean success rates ranged from 99.2% for molecular typing schemes and antibodies and 94.8% for chimerism, was 96.7% regarding crossmatches, and was 98.9% in serological typing. In 2022, 61.3% of the participating laboratories successfully passed every HLA EQA scheme, although 87.9% annual reports were satisfactory. Most penalties were due to nomenclature errors or misreporting of the risk associated to HLA and disease. Conclusion: This EQA confirms the reliability of HLA and immunogenetics assays in routine care. There is little heterogeneity of results of different assays used by participating laboratories, even when in-house assays are used. Reliability of test results is reasonably granted.

15.
Biomolecules ; 14(5)2024 May 13.
Article in English | MEDLINE | ID: mdl-38785982

ABSTRACT

Chimerism-based strategies represent a pioneering concept which has led to groundbreaking advancements in regenerative medicine and transplantation. This new approach offers therapeutic potential for the treatment of various diseases, including inherited disorders. The ongoing studies on chimeric cells prompted the development of Dystrophin-Expressing Chimeric (DEC) cells which were introduced as a potential therapy for Duchenne Muscular Dystrophy (DMD). DMD is a genetic condition that leads to premature death in adolescent boys and remains incurable with current methods. DEC therapy, created via the fusion of human myoblasts derived from normal and DMD-affected donors, has proven to be safe and efficacious when tested in experimental models of DMD after systemic-intraosseous administration. These studies confirmed increased dystrophin expression, which correlated with functional and morphological improvements in DMD-affected muscles, including cardiac, respiratory, and skeletal muscles. Furthermore, the application of DEC therapy in a clinical study confirmed its long-term safety and efficacy in DMD patients. This review summarizes the development of chimeric cell technology tested in preclinical models and clinical studies, highlighting the potential of DEC therapy in muscle regeneration and repair, and introduces chimeric cell-based therapies as a promising, novel approach for muscle regeneration and the treatment of DMD and other neuromuscular disorders.


Subject(s)
Cell- and Tissue-Based Therapy , Dystrophin , Muscle, Skeletal , Muscular Dystrophy, Duchenne , Regeneration , Muscular Dystrophy, Duchenne/therapy , Muscular Dystrophy, Duchenne/genetics , Humans , Animals , Cell- and Tissue-Based Therapy/methods , Dystrophin/genetics , Dystrophin/metabolism , Myoblasts/metabolism
16.
Hum Immunol ; 85(4): 110808, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38762429

ABSTRACT

Since the first published case study of human intestinal transplantation in 1967, there have been significant studies of intestinal transplant immunology in both animal models and humans. An improved understanding of the profiles of different immune cell subsets is critical for understanding their contributions to graft outcomes. While different studies have focused on the contribution of one or a few subsets to intestinal transplant, no study has integrated these data for a comprehensive overview of immune dynamics after intestinal transplant. Here, we provide a systematic review of the literature on different immune subsets and discuss their roles in intestinal transplant outcomes on multiple levels, focusing on chimerism and graft immune reconstitution, clonal alloreactivity, and cell phenotype. In Sections 1, 2 and 3, we lay out a shared framework for understanding intestinal transplant, focusing on the mechanisms of rejection or tolerance in the context of mucosal immunology and illustrate the unique role of the bidirectional graft-versus-host (GvH) and host-versus-graft (HvG) alloresponse. In Sections 4, 5 and 6, we further expand upon these concepts as we discuss the contribution of different cell subsets to intestinal transplant. An improved understanding of intestinal transplantation immunology will bring us closer to maximizing the potential of this important treatment.


Subject(s)
Graft Rejection , Intestines , Humans , Intestines/immunology , Intestines/transplantation , Animals , Graft Rejection/immunology , Organ Transplantation , Host vs Graft Reaction/immunology , Transplantation Tolerance/immunology , Graft vs Host Reaction/immunology , Transplantation Immunology , Intestinal Mucosa/immunology
17.
Hum Immunol ; 85(4): 110827, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38805779

ABSTRACT

Tolerance is the Holy Grail of solid organ transplantation (SOT) and remains its primary challenge since its inception. In this topic, the seminal contributions of Thomas Starzl at Pittsburgh University outlined foundational principles of graft acceptance and tolerance, with chimerism emerging as a pivotal factor. Immunologically, intestinal transplantation (ITx) poses a unique hurdle due to the inherent characteristics and functions of the small bowel, resulting in increased immunogenicity. This necessitates heavy immunosuppression (IS) while IS drugs side effects cause significant morbidity. In addition, current IS therapies fall short of inducing clinical tolerance and their discontinuation has been proven unattainable in most cases. This underscores the unfulfilled need for immunological modulation to safely reduce IS-related burdens. To address this challenge, the Leuven Immunomodulatory Protocol (LIP), introduced in 2000, incorporates various pro-tolerogenic interventions in both the donor to the recipient, with the aim of facilitating graft acceptance and improving outcome. This review seeks to provide an overview of the current understanding of tolerance in ITx and outline recent advances in this domain.


Subject(s)
Graft Rejection , Graft Survival , Immunomodulation , Organ Transplantation , Transplantation Tolerance , Humans , Transplantation Tolerance/immunology , Graft Rejection/immunology , Graft Rejection/prevention & control , Graft Survival/immunology , Intestines/immunology , Intestines/transplantation , Animals , Immunosuppression Therapy/methods , Immunosuppressive Agents/therapeutic use
18.
Leuk Res ; 142: 107504, 2024 07.
Article in English | MEDLINE | ID: mdl-38703634

ABSTRACT

INTRODUCTION: This longitudinal study was based on the outcomes of Donor Lymphocyte Infusion (DLI) for falling peripheral blood (PB) CD34+ and CD3+ donor chimerism (DC). METHODS: From 2012 to 2018, data was collected from the BMT database and electronic medical records (EMR). The primary objective was to compare the indication for DLI based on falling PB CD34+ or CD3+ DC in patients post allo-SCT for AML and MDS and their overall survival (OS). RESULTS: 18/70 patients met the inclusion criteria. Indications for DLI were i) falling PB CD34+ DC ≤ 80 % with morphological relapse, ii) falling PB CD34+ DC ≤ 80 % without morphological relapse and iii) falling PB CD3+ DC ≤ 80 % without falling PB CD34+ DC. Log rank analysis showed falling PB CD34+ DC and morphological relapse had significantly lower OS. Linear regression demonstrated better OS post DLI if there was PB CD34+ and CD3+ chimerism response at 30 days (p = 0.029), GVHD (p = 0.032) and tapering immunosuppression at the time of falling DC (p = 0.042). CONCLUSION: DLI for PB CD34+ DC values ≤ 80 % and morphological relapse had the lowest OS. In this study, full DC was achieved after DLI even with a PB CD3+DC value as low as 13 %, provided the PB CD34+ DC remained > 80 %. Further research is vital in CD34+ DC as a biomarker for disease relapse and loss of engraftment.


Subject(s)
Antigens, CD34 , Leukemia, Myeloid, Acute , Lymphocyte Transfusion , Myelodysplastic Syndromes , Transplantation, Homologous , Humans , Myelodysplastic Syndromes/therapy , Myelodysplastic Syndromes/pathology , Myelodysplastic Syndromes/mortality , Male , Female , Leukemia, Myeloid, Acute/therapy , Leukemia, Myeloid, Acute/mortality , Leukemia, Myeloid, Acute/pathology , Leukemia, Myeloid, Acute/immunology , Middle Aged , Retrospective Studies , Adult , Longitudinal Studies , Antigens, CD34/analysis , Aged , Hematopoietic Stem Cell Transplantation/methods , CD3 Complex/analysis , Transplantation Chimera , Young Adult , Tissue Donors , Graft vs Host Disease/etiology , Graft vs Host Disease/diagnosis
19.
Elife ; 132024 Apr 25.
Article in English | MEDLINE | ID: mdl-38661001

ABSTRACT

Single-cell RNA sequencing reveals the extent to which marmosets carry genetically distinct cells from their siblings.


Subject(s)
Callithrix , Single-Cell Analysis , Animals , Sequence Analysis, RNA
20.
Curr Oncol ; 31(4): 2067-2075, 2024 04 05.
Article in English | MEDLINE | ID: mdl-38668056

ABSTRACT

Donor cell leukemia (DCL) is a rare complication after allogeneic hematopoietic stem cell transplantation (HSCT) accounting for 0.1% of relapses and presenting as secondary leukemia of donor origin. Distinct in phenotype and cytogenetics from the original leukemia, DCL's clinical challenge lies in its late onset. Its origin is affected by donor cell anomalies, transplant environment, and additional mutations. A 43-year-old woman, treated for early stage triple-negative breast cancer, developed mixed-phenotype acute leukemia (MPAL), 12 years later. Following induction chemotherapy, myeloablative conditioning, and allo-HSCT from her fully HLA-matched brother, she exhibited multiple cutaneous relapses of the original leukemia, subsequently evolving into DCL of the bone marrow. Cytogenetic analysis revealed a complex male karyotype in 20 out of 21 metaphases, however, still showing the MPAL phenotype. DCL diagnosis was confirmed by 90.5% XY in FISH analysis and the male karyotype. Declining further intensive chemotherapy including a second allo-HSCT, she was subsequently treated with repeated radiotherapy, palliative systemic therapies, and finally venetoclax and navitoclax but died seven months post-DCL diagnosis. This case underlines DCL's complexity, characterized by unique genetics, further complicating diagnosis. It highlights the need for advanced diagnostic techniques for DCL identification and underscores the urgency for early detection and better prevention and treatment strategies.


Subject(s)
Hematopoietic Stem Cell Transplantation , Transplantation, Homologous , Hematopoietic Stem Cell Transplantation/adverse effects , Humans , Adult , Female , Leukemia/therapy , Tissue Donors , Male
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