Search Results (560)

Intestinal microbiome dysbiosis has been associated with transplant-related mortality and graft-versus-host disease in allo-HSCT patients. We assessed how pre-transplant antibiotic and antineoplastic exposures, together with multidrug-resistant colonization, are associated with baseline gut microbiome diversity at allo-HSCT. We conducted a prospective, single-center cohort study at Fundeni Clinical Institute (Bucharest, Romania) between August 2024 and June 2025, enrolling 52 allo-HSCT recipients and 27 healthy controls. Fecal samples were collected before conditioning. Gut microbiome composition was assessed via 16S rRNA gene sequencing and analyzed using QIIME2 and R. Associations were evaluated using Wilcoxon test, multivariable linear regression, and PERMANOVA. Shannon diversity was significantly lower in patients (median 4.71, IQR 3.97–5.44) than in healthy controls (median 6.09, IQR 5.87–6.28; p < 0.001). In bivariate analyses, carbapenem (p adj = 0.02) and oxazolidinone exposure (p adj = 0.005) were associated with reduced diversity, while immunotherapy was associated with higher diversity (p adj = 0.042). Broad-spectrum penicillin (p adj = 0.062) and ESBL colonization (p adj = 0.066) did not reach significance. In the multivariable antibiotic model, although the overall model was statistically significant (model p = 0.039), no individual antibiotic class remained significantly associated with Shannon diversity after adjustment for co-exposures. Beta diversity differed modestly with carbapenem exposure (R² = 0.033, p = 0.019). Pre-transplant antibiotic exposures were associated with lower gut microbiome diversity at allo-HSCT admission, with patterns consistent with a cumulative rather than a class-specific association. These findings support antibiotic stewardship in pre-transplant care. Full article

Graft failure and graft-versus-host disease are the main limiting factors for the engraftment of not only xenogeneic but also allogeneic grafts. Long-term engraftment of human immune cells in mice with severe combined immunodeficiency and IL2rg deletion is key to the success of long-term studies in modeling human immunodeficiency virus (HIV) infection. Human peripheral blood mononuclear cells were injected intravenously into males of one strain and females of two other strains of immunodeficient mice. Before the injection of human cells, mice of each strain were irradiated with three different doses. Interleukin-2 was administered to 50% of mice within 5 days of human cell injection. Its effect was assessed by monitoring graft-versus-host disease, survival, complete blood count (CBC) indices, quantification of human cells in whole blood, pathological changes, and immunohistochemical detection of human cells in tissues. Furthermore, the applicability of correlating immune-inflammation indices with mouse body weight (BW) dynamics, graft-versus-host disease (GVHD) progression, degrees of chimerism and human T-helper cells was determined for the first time. As a result of this work, a panel of biomarkers was developed for predicting the long-term welfare of mice with elements of the human immune system (HIS) in long-term studies, including HIV testing. Full article

Autoimmune diseases arise from a breakdown of immune tolerance and complex interplay of genetic susceptibility, environmental triggers, tissue-specific immune responses, microbiota, and regulatory pathways. Mouse models remain essential for dissecting these mechanisms, but no single model fully reproduces the heterogeneity, chronicity, and immune complexity of autoimmune disease in humans. This review summarizes classical murine and humanized mouse models used to study inflammatory bowel disease (IBD), multiple sclerosis (MS), type-1 diabetes (T1D), and rheumatoid arthritis (RA). We also highlight disease-specific scoring systems, including clinical indices, histopathology, imaging, cytokine profiling, autoantibody assessment, and human immune-cell readouts, as essential tools for standardized interpretation. Conventional murine models provide experimental control and mechanistic clarity, whereas humanized models improve assessment of human immune responses, patient-specific biology, and therapeutic translation. However, humanized systems remain limited by incomplete immune reconstitution, graft-versus-host disease, donor variability, cost, and incomplete tissue architecture. By providing a comparative framework spanning both conventional and humanized models, this review aims to guide informed model selection tailored to specific research questions in autoimmune disease biology and translational therapeutic development. Full article

Background/Objectives: Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) has expanded donor availability for patients with acute myeloid leukemia; however, it is associated with a high risk of endothelial complications. Among them, sinusoidal obstruction syndrome (SOS) and transplant-associated thrombotic microangiopathy (TA-TMA) are life-threatening conditions with overlapping clinical features, making early diagnosis and management challenging. Case Presentation: We report the case of a 47-year-old woman with acute myeloid leukemia who underwent haploidentical HSCT and developed sequential endothelial complications. On day +11 post-transplant, she presented with weight gain (>5%), hyperbilirubinemia (44 μmol/L), elevated liver enzymes (ALT 2228 U/L and AST 3477 U/L), and multi-organ dysfunction, consistent with probable SOS according to EBMT criteria. Intensive supportive care, glucocorticosteroids, and hemodiafiltration resulted in partial clinical improvement. Subsequently, on day +22, the patient developed progressive thrombocytopenia, hemolytic anemia (hemoglobin 71 g/L), elevated lactate dehydrogenase (3129 U/L), undetectable haptoglobin, and schistocytosis (up to 3.9%), accompanied by neurological symptoms, leading to the diagnosis of TA-TMA. Results: Management included discontinuation of tacrolimus, initiation of plasma exchange, and complement inhibition with eculizumab, along with ruxolitinib for graft-versus-host disease prophylaxis. This approach resulted in rapid clinical and laboratory improvement, including resolution of hemolysis, reduction in schistocytes (to 1%), normalization of lactate dehydrogenase, and regression of neurological symptoms. The patient was discharged in stable condition, although requiring ongoing renal replacement therapy. Conclusions: This case highlights the complexity of diagnosing and managing sequential endothelial complications after haplo-HSCT. SOS and TA-TMA may reflect overlapping manifestations of endothelial injury rather than entirely isolated complications. Full article

Genetically modified hematopoietic stem cell therapy using gene-modified autologous hematopoietic stem cells has evolved over the last 30 years as an alternative approach to circumvent the limitations of donor availability, risks of excessive regimen related toxicity, prolonged immune suppression and graft-versus-host disease associated with allogeneic hematopoietic cell transplantation. Gene replacement therapy based on viral insertion of transgene into host genome was developed as one of the main methods for gene modification of autologous cells. Unfortunately, many cases of oncogenesis were directly caused by genetically modified hematopoietic stem cell therapy. The purpose of the present review is the description of cases of leukemogenesis in gene replacement therapy in hematopoietic stem cells, elucidation of the causes, and overview of the risk mitigation strategies. It aims to elucidate the main risk factors in gene replacement therapy in hematopoietic stem cells. The insertional mutagenesis leads to activation of proto-oncogenes, mostly LMO2 and MECOM-EVI1. γ-retroviral vectors are dangerous in this case, as they contain long terminal repeats with strong promotor activity and are prone to integration near transcription initiation sites. Therefore, safer self-inactivating lentiviral vectors were developed, with long terminal repeats modified to reduce their promoter activity and with safer integration pattern. Nevertheless, the risk of leukemogenesis remains because the promoter integrated into the transgene expression cassette may still influence nearby gene expression. Another risk factor is monosomy 7, either pre-existing or caused by MECOM-EVI1 activation, which may contribute directly to leukemogenesis. Thus, oncogenesis in HSPC gene replacement therapy does not have a single definitive cause; rather, multiple factors may contribute, and each may be sufficient under specific conditions. Full article

Membranous nephropathy (MN) and minimal change disease (MCD) are the most common causes of nephrotic syndrome following hematopoietic stem cell transplantation (HSCT), a complication conventionally attributed to chronic graft-versus-host disease (GVHD). Paraneoplastic MCD is well described in lymphoid malignancies but is rarely reported in myeloid neoplasms. We report two cases of biopsy-confirmed MCD presenting as the initial manifestation of acute myeloid leukemia (AML) relapse following allogeneic HSCT. Both patients were White men in their sixties with relapsed/refractory AML who developed nephrotic-range proteinuria and acute kidney injury after matched unrelated donor HSCT without histologic evidence of GVHD. Renal biopsies confirmed MCD in both cases. Corticosteroid therapy was ineffective in halting renal deterioration; renal function improved only after initiation of leukemia-directed therapy, with one patient achieving dialysis independence. These cases highlight a rare paraneoplastic presentation of AML relapse. Nephrotic syndrome due to MCD may signal post-HSCT leukemia recurrence, and evaluation for AML relapse warrants consideration in steroid-refractory cases or those without concurrent GVHD. In such cases, control of the underlying malignancy, rather than escalation of immunosuppression, may be central to renal recovery. Full article

Medulloblastoma is one of the most prevalent pediatric brain tumors. Currently, existing therapies for this devastating type of cancer can only prolong survival time with severe side-effects and relapse. These therapies are not curative for almost a third of treated patients, while most survivors are condemned to a poor quality of life. The addition of immune checkpoint inhibitors (ICIs) to immune therapy has given some hope to those suffering from this type of cancer. Although ICIs provide a valuable contribution to immunotherapy, the exploitation of immune checkpoint inhibition within existing therapeutic strategies to cure Medulloblastoma remains understudied. However, the identification of the main molecular subgroups of medulloblastoma is considered one of the success stories of oncology. This advancement in molecular profiling of MB paved the way to subgroup-directed clinical trials, which may lead to efficacious immune-targeted therapy. However, this relatively new development is still hampered by a substantial biological heterogeneity of the disease and the absence of a full understanding of the various mechanisms behind its resistance to existing therapeutic modalities. The inclusion of chimeric antigen receptor (CAR) T and CAR NK cell therapy within various therapeutic strategies and ongoing clinical trials has given fresh hope those suffering from this fatal disease. However, ongoing clinical trials suggest that this highly promising therapy can be impaired by a number of serious limitations, including cytokine release syndrome, Graft-versus-host disease, the scarcity of target antigens, and severe adverse events. Some of the ongoing clinical trials also suggest that CAR NK is less prone to some of these limitations. This review also highlights the contribution of mass spectrometry-based proteomics, and the increasing role of liquid biopsy rather than tissue biopsy. Full article

Background: Toxic epidermal necrolysis (TEN) is a rare but life-threatening complication that may occur in patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT), particularly in the context of extensive drug exposure. In this population, TEN can closely resemble severe acute graft-versus-host disease (GVHD), making diagnosis and management challenging. Case presentation: We report the clinical course of an allo-HSCT recipient who developed a rapidly progressive skin rash early after transplantation, and we analyzed the clinical features, histopathology, treatment and outcome. Results: The patient developed rapidly progressive epidermal detachment with severe oral, ocular, and genital mucosal involvement shortly after exposure to trimethoprim/sulfamethoxazole (TMP-SMX). Disease severity was reflected by a SCORTEN score of 5, corresponding to a very high predicted mortality risk. The clinical picture raised concern for both TEN and severe acute GVHD, while histopathological findings favored TEN but were not definitive. Management included systemic corticosteroids, intravenous immunoglobulin, ruxolitinib, and intensive supportive care. The patient gradually re-epithelialized and recovered without long-term sequelae. Conclusions: This case underscores the diagnostic difficulty of distinguishing TEN from severe acute GVHD in the early post-transplant period. Careful assessment of drug exposure, clinical evolution, and multidisciplinary evaluation are essential to guide timely and appropriate management. Full article

Sickle Cell Disease (SCD) is a pervasive monogenic disorder characterized by chronic hemolytic anemia, unpredictable vaso-occlusive crises, and progressive multi-organ damage, representing a significant global health burden. Driven by a point mutation in the β-globin gene, the resulting abnormal Hemoglobin S (HbS) polymerizes under deoxygenated conditions, leading to erythrocyte sickling and systemic endothelial dysfunction. While supportive therapies such as hydroxyurea and transfusions manage symptoms, the mandate for definitive curative therapies is urgent. Historically, allogeneic hematopoietic stem cell transplantation (HSCT) utilizing matched sibling donors (MSD) has been the sole curative option, offering high survival rates but constrained by limited donor availability and the risk of graft-versus-host disease (GVHD). Consequently, alternative donor sources, including matched unrelated donors, umbilical cord blood, and haploidentical donors, have expanded patient access, particularly with the integration of post-transplant cyclophosphamide (PTCy) to mitigate alloreactivity. Concurrently, the advent of autologous gene therapy, encompassing lentiviral gene addition (Lyfgenia) and CRISPR-Cas9 gene editing (Casgevy) offers a revolutionary donor-independent approach that eliminates GVHD risk. Lyfgenia employs a lentiviral vector to introduce an anti-sickling βT87Q hemoglobin variant into autologous hematopoietic stem cells, while Casgevy employs CRISPR-Cas9 to disrupt the erythroid-specific enhancer of the BCL11A transcription factor, derepressing γ-globin expression and elevating fetal hemoglobin. This review synthesizes the pathophysiological mechanisms of SCD, evaluates the clinical outcomes and limitations of both allogeneic HSCT and autologous gene therapies, and outlines the clinical decision-making paradigms and future innovations required to achieve equitable global access to these transformative treatments. Full article

Relapse remains the leading cause of treatment failure following hematopoietic cell transplantation (HCT) for hematologic malignancies. Circulating tumor DNA (ctDNA) has emerged as a promising minimally invasive biomarker for measurable residual disease (MRD) assessment and early relapse detection; however, the prognostic significance of ctDNA in the post-transplant setting has not been comprehensively synthesized. We conducted a systematic review and meta-analysis in accordance with PRISMA guidelines and registered the protocol in PROSPERO (CRD420261392100). PubMed, Embase, Web of Science, EBSCO, Cochrane CENTRAL, and supplementary sources were searched through November 2025. Eligible studies evaluated tumor-specific ctDNA or tumor-informed/tumor-associated cfDNA in patients undergoing allogeneic or autologous HCT for hematologic malignancies. Random-effects meta-analyses were performed for relapse/progression, overall survival (OS), and relapse-free/progression-free survival (RFS/PFS). Studies evaluating total cfDNA quantity, methylation-based cfDNA profiling, cfRNA, or chimerism-only monitoring were synthesized narratively. Ten observational cohort studies comprising 883 patients met inclusion criteria. Across acute leukemias, lymphomas, multiple myeloma, and myelodysplastic syndromes, ctDNA/cfDNA positivity was consistently associated with adverse outcomes. The pooled hazard ratio (HR) for relapse or disease progression was 12.57 (95% CI: 4.59–34.46; p < 0.001), while pooled HRs were 7.45 (95% CI: 4.11–13.48; p < 0.001) for OS and 4.46 (95% CI: 2.22–8.97; p < 0.001) for RFS/PFS. Although statistical heterogeneity was low, interpretation was limited by the relatively small number of studies contributing to each pooled endpoint. Narrative evidence additionally suggested that broader circulating nucleic acid approaches may provide complementary information regarding graft-versus-host disease, infection, and other post-transplant complications. Tumor-specific ctDNA positivity is consistently associated with increased relapse risk and inferior survival outcomes following HCT. These findings support further investigation of ctDNA-based MRD monitoring as a promising non-invasive biomarker for post-transplant molecular surveillance and risk stratification. However, prospective multicenter validation studies, assay standardization, and ctDNA-guided interventional trials remain necessary before routine clinical implementation can be recommended. Full article

Adoptive cell therapies, and more specifically, regulatory T cell (Treg) therapies, have shown significant therapeutic promise across multiple immune-mediated diseases including graft-versus-host disease (GvHD), solid organ transplant (SOT) rejection, and autoimmune diseases. One key challenge is the lack of insight into the biodistribution and fate of adoptively transferred T cells and Tregs in living organisms. These uncertainties delay progress on establishing optimal dosage(s), infusion timing and route, as well as investigations into off-target effects. Magnetic resonance imaging (MRI) cell tracking is particularly beneficial in this setting because it enables real-time, deep-tissue coverage without ionizing radiation. In this review, we compare existing MRI T cell tracking strategies using iron oxide particles and fluorinated agents. We describe preclinical and clinical applications of MRI for cell therapy tracking and provide a perspective on the potential impact on the field. Full article

Background: Acute graft-versus-host disease (aGVHD) is a leading cause of morbidity and mortality following pediatric hematopoietic stem cell transplantation (HSCT). Approximately half of children achieve complete response (CR) to corticosteroids, whereas steroid-refractory (SR) disease carries a 1–2-year mortality of 41–44%. Mortality risk is 2.6-fold higher in children > 13.9 years, and respiratory failure accounts for 26% of deaths. Existing second-line agents—ruxolitinib, tocilizumab, or extracorporeal photopheresis—have delayed onset or high toxicity. Begelomab (BEGESAND^®), a monoclonal antibody targeting CD26/dipeptidyl peptidase-4 (DPP4), inhibits CD26-mediated T-cell activation and has demonstrated 75% response in adults with minimal toxicity. However, pediatric data are lacking. Methods: We retrospectively reviewed five consecutive pediatric patients (ages 3–20 years) treated with Begelomab (BEGESAND^®) for SR (n = 4) or steroid-dependent (SD; n = 1) aGVHD between 2017–2021 under emergency IND authorization. Begelomab (BEGESAND^®) was administered intravenously at 2.7 mg/m²/day on days 1–5, 10, 14, 17, 21, 24, and 28. GVHD was graded by MAGIC criteria; flow cytometry and immunohistochemistry (IHC) assessed CD26 expression and immune effects. Results: All patients had grade IV disease after ≥2 prior agents. Two with pre-existing sepsis died early, before treatment response could be assessed. Of three evaluable patients, two (67%) achieved CR within 21 days and one achieved durable control by 6 months. All three remain alive; no Begelomab (BEGESAND^®)-related toxicity, cytopenia, or new infections occurred. Flow cytometry showed preserved T-cell subsets, and IHC demonstrated CD26 localization at sites of epithelial injury. Conclusions: Begelomab (BEGESAND^®) showed promising timely and durable responses with excellent safety in pediatric SR/SD-aGVHD, supporting further evaluation in multicenter pediatric trials. Full article

Background: Allogeneic hematopoietic stem cell transplantation (allo-HCT) is the only curative therapy for myelofibrosis (MF), but its use is limited by substantial transplant related morbidity and mortality, particularly in older or comorbid patients. Treosulfan has emerged as a less toxic alternative to busulfan, with potential advantages in myeloablative and reduced intensity conditioning. Methods: We conducted a comprehensive, multi-database literature search (PubMed, Scopus/EMBASE, Cochrane Library, Web of Science, and grey literature) for studies published between 2000 and 2025 evaluating treosulfan-based conditioning in MF patients undergoing allo-HCT. Data on patient characteristics, conditioning regimens, engraftment, graft-versus-host disease (GVHD), and survival outcomes were synthesized. Results: Eight studies including more than 800 patients were analyzed. Treosulfan was most commonly combined with fludarabine, with or without additional agents. Engraftment rates were consistently high at 94 to 100%, with low non-relapse mortality (NRM) and favorable progression-free survival (PFS). An EBMT registry study demonstrated superior survival and significantly lower NRM compared with busulfan based regimens. Benefits were observed across older patients, alternative donors, and second transplants. Higher treosulfan doses were associated with increased toxicity in some cohorts. Conclusions: Treosulfan based conditioning offers an effective and better tolerated option for MF transplantation. Prospective trials are needed to refine dosing and patient selection. Full article

The role of zonulin as a biomarker of intestinal permeability in the allogeneic hematopoietic stem cell transplantation (allo-HSCT) setting remains poorly understood. In this study, we aimed to evaluate serum zonulin dynamics, identify its predictors, and assess its prognostic significance in patients undergoing allo-HSCT. This multicenter, prospective cohort study was conducted across four Brazilian hospitals. Eligible participants were patients aged ≥12 years who provided at least one blood sample during the allo-HSCT course. A control group of 15 healthy adult individuals was also included. Serum zonulin levels were quantified using enzyme-linked immunosorbent assay multiple times over the allo-HSCT course. Outcomes included acute graft-versus-host disease, overall survival, and bloodstream infections. A total of 477 blood samples were collected from 140 patients. Compared with the control group, zonulin levels were persistently elevated at all evaluated time points throughout the allo-HSCT course. However, no significant differences were observed among the different time points assessed during transplantation. No clinical or transplantation-related characteristics were identified as significant predictors of elevated zonulin levels. Finally, zonulin did not demonstrate prognostic value for allo-HSCT-related outcomes. Future studies should investigate whether other intestinal permeability biomarkers have prognostic relevance in the allo-HSCT setting. Full article

Fanconi anemia (FA) is a rare inherited disorder associated with impaired DNA repair, characterized by congenital anomalies, bone marrow failure, and a significantly increased risk of developing malignancies, particularly squamous cell carcinoma (SCC) of the head and neck. Treatment options for advanced SCC in FA are limited due to hypersensitivity to DNA-damaging agents. This article presents a unique case of SCC that developed in a 17-year-old patient with FA caused by a homozygous mutation in the FANCA gene. At the age of 10, he received a bone marrow transplant from a compatible related donor. Conditioning therapy included busulfan, thymoglobulin, and fludarabine, while graft-versus-host disease (GvHD) prophylaxis was administered with rituximab, methotrexate, and cyclosporine A. Nevertheless, he developed chronic cutaneous GVHD, which was treated for four years with ruxolitinib and tacrolimus, achieving only partial control. During this period, locally advanced cutaneous SCC (T3N0M0, stage III) manifested on the face. Surgery, radiation therapy, and immunotherapy with pembrolizumab led only to an initial partial response. This first pediatric case of immunotherapy for SCC in FA highlights the challenges of treating this rare patient group. Nevertheless, combining radiation therapy with immunotherapy may represent a possible option for disease control. Full article