Search Results (118)

The Bacillus Calmette-Guérin (BCG) vaccine confers broad, non-specific immunity that may bolster defenses against respiratory viruses. While NOD2 (nucleotide-binding oligomerization domain-containing protein 2)-driven pathways are central to innate immune responses, the contribution of surface receptor modulation on monocytes to shaping these responses remains underexplored. We analyzed whole-blood cultures from BCG-vaccinated Polish children, stratified by serostatus to SARS-CoV-2 and RSV, and stimulated for 48 h with live BCG, purified viral antigens, or both. RT-qPCR quantified mRNA levels of NOD2 and key cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, TNF), while flow cytometry assessed CD14, HLA-DR, CD11b, and CD206 expression. Co-stimulation with BCG + RSV elicited the strongest transcriptional response, notably a 2–4-fold upregulation of NOD2, IL-1β, and IL-6 versus RSV alone. In SARS-CoV-2(+) donors, RSV alone induced higher NOD2 expression than BCG or BCG + RSV, while IL-2 peaked following BCG + SARS-CoV-2. Across conditions, NOD2 positively correlated with IL-4 and IL-6 but negatively correlated with IL-1β in SARS-CoV-2 cultures. Viral antigens increased CD14 and HLA-DR on monocytes, suggesting activation; CD206 rose only in dual-seropositive children. Our findings indicate that BCG stimulation affects pediatric antiviral immunity through NOD2-related cytokine production and induction of a CD14⁺HLA-DR⁺ phenotype, supporting its potential role in boosting innate defenses against respiratory pathogens. Full article

Background: Kidney transplantation is the treatment of choice for pediatric patients with end-stage kidney disease. However, transplantation in children weighing < 15 kg remains challenging due to limited donor availability and higher surgical and medical risks. We report our 35-year single-center experience in this population, focusing on perioperative and long-term outcomes. Methods: We retrospectively analyzed kidney transplants performed from 1987 to 2023 in children weighing < 15 kg. Data on demographics, donor type, complications, immunosuppression, and outcomes at 2, 5, and 10 years (including survival, graft function, rejection, infections, and urological issues) were collected. Outcomes were compared between deceased and living donors and between recipients weighing < 10 kg and ≥10 kg. Results: Ninety-six transplants were included (mean age 3.3 years; mean weight 11.1 kg), 80 from deceased and 16 from living donors. Most patients (69.8%) had been treated with peritoneal dialysis. Median follow-up was 120 months. Patient survival was 95.8%; graft survival was 78.1%. Eight grafts (8.3%) were lost to renal vein thrombosis, all in deceased-donor recipients (p = 0.60). Preserved renal function (eGFR > 60 mL/min/1.73 m²) declined from 80.4% at 2 years to 66.0% at 5 years and 18.0% at 10 years. Graft survival at 10 years was significantly lower in children < 10 kg vs. ≥10 kg (49.6% vs. 80.3%, p = 0.003). CAKUT was associated with higher urological complication rates (p = 0.017). No significant differences emerged between living and deceased donor groups. Conclusions: Transplantation in children < 15 kg is feasible with good outcomes, but those <10 kg present lower graft survival at 10 years. Multidisciplinary assessment and center experience are key to optimizing results. Full article

Graft-versus-host disease (GVHD) remains a significant barrier to the success of allogeneic hematopoietic stem cell transplantation (allo-HSCT), contributing to long-term morbidity and non-relapse mortality in both pediatric and adult populations. Central to GVHD pathophysiology is the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway, where JAK2 mediates key pro-inflammatory cytokines, including IL-6, IFN-γ, and GM-CSF. These cytokines promote donor T cell activation, effector differentiation, and target organ damage. The introduction of ruxolitinib, a selective JAK1/2 inhibitor, has transformed the treatment landscape for steroid-refractory acute and chronic GVHD, leading to improved response rates and durable symptom control. However, its limitations—such as cytopenias, infectious complications, and incomplete responses—have catalyzed the development of next-generation agents. In 2024, the FDA approved axatilimab, a CSF-1R inhibitor that targets monocyte-derived macrophages in fibrotic chronic GVHD, and remestemcel-L, an allogeneic mesenchymal stromal cell therapy, for pediatric steroid-refractory acute GVHD. Both agents offer mechanistically distinct and clinically meaningful additions to the therapeutic armamentarium. In parallel, emerging combination strategies involving JAK2 inhibitors and novel biologics show promise in enhancing immune tolerance while preserving graft-versus-leukemia (GvL) effects. Recent advances in biomarker development, such as the MAGIC Algorithm Probability (MAP), are enabling early risk stratification and response prediction. The integration of these tools with organ-specific and personalized approaches marks a shift toward more precise, durable, and tolerable GVHD therapy. This review highlights the current state and future direction of JAK2 inhibition and complementary therapies in the evolving GVHD treatment paradigm. Full article

While the pathogenic role of donor-specific anti-HLA antibodies (DSAs) in long-term immune-mediated injury after kidney transplantation is well established, the clinical relevance of non-donor-specific antibodies (nDSAs), also detected in transplant recipients, remains a subject of debate. This retrospective study evaluated the prognostic value of nDSAs in 92 pediatric kidney transplant recipients (89.1%, 9.8%, and 1.1% for first, second, and third transplants, respectively) at the University Hospital of Padua between January 2015 and December 2022, investigating the association between antibody development and clinical outcomes, including graft function, rejection episodes, and viral infections. Clinical, immunological, virological, and histopathological data were collected at 6, 12, and 24 months post-transplant. Antibody prevalence increased over time, with nDSAs being more frequent than DSAs at all timepoints. The combined presence of DSAs and nDSAs significantly increased the risk of ABMR (HR = 45.10; p < 0.001). Isolated nDSAs and DSAs were also associated with an increased risk of ABMR (HR = 6.43 and 12.10, respectively), suggesting a synergistic alloimmune effect. Viral infections also emerged as relevant cofactors in humoral alloimmunity. EBV viremia and intrarenal Parvovirus B19 (PVB19) infection were significantly associated with ABMR, with PVB19 also correlating with nDSA formation. In conclusion, integrated immunological and virological monitoring may support risk stratification and guide individualized post-transplant management. Larger multicenter studies are warranted to define the long-term impact of nDSAs in pediatric kidney transplantation. Full article

Background and Clinical Significance: Progressive familial intrahepatic cholestasis (PFIC) refers to a heterogeneous group of autosomal recessive disorders consisting of mutations of hepatocyte transporting-system genes involved in bile formation. The exact prevalence remains unknown but is estimated at 1 in 500.000 for PFIC 3, caused by mutations in the ABCB4 gene. We report three cases of PFIC 3 from the patient’s sister, brother, and cousin, diagnosed in our Pediatric Department in 2022–2023. Case Presentation: Case 1: A 10-year-old girl was admitted for jaundice and abdominal pain. She was diagnosed with severely advanced hepatic cirrhosis and massive cholestasis. Genetic testing showed ABCB4 homozygous mutation. She rapidly developed fulminant liver failure, and a living donor liver transplant was performed. Case 2: A 6-year-old brother was previously diagnosed with cholestatic hepatitis of unknown cause back in 2018 and presented with similar features (generalized jaundice, severe pruritus with generalized scratching lesions); symptoms had progressively developed from the first year of life. He also exhibited particular facial features (big forehead, twisted ear lobe, straight nose). He received cadaveric liver transplantation. Case 3: Nephew of first two children, a 3-year-5-month-old boy, was admitted for failure to thrive and a one-year history of jaundice, pruritus, and splenomegaly. He was tested positive for homozygous ABCB4 mutation. He is currently under medical treatment with stable liver function. Conclusions: The clinical significance of this particular homozygous variant identified in ABCB4 in our series of cases (c.2534G>T (p.Gly845Val)) was uncertain up to this case report. The present data provide convincing evidence as to the correlation between this mutation and the clinical phenotype of PFIC 3. Full article

Background/Objectives: The oncofetal membrane protein Claudin 6 (CLDN6) is an attractive target for T cell-based therapies. There is a lack of detailed analyses on the age-dependent expression of CLDN6 in normal tissues is lacking, which limits the expansion of CLDN6 CAR-T cell clinical trials to pediatric populations. Methods: We analyzed CLDN6 expression in extracranial solid tumors and normal tissues of children using RNA-sequencing data from over 500 pediatric solid tumor samples, qRT-PCR and immunohistochemistry (IHC) in more than 100 fresh-frozen tumor samples and, approximately, 250 formalin-fixed paraffin-embedded (FFPE) samples. We examined normal tissue expression via qRT-PCR in 32 different infant tissues and via IHC in roughly 290 tissues from donors across four age groups, as well as in fetal autopsy samples. Results: In fetal tissues, we detected CLDN6 expression primarily in the epithelial cells of several organs, including the skin, lungs, kidneys, intestinal tract, and pancreas, but not in undifferentiated blastemal cells. Postnatally, we found CLDN6-positive epithelial progenitors only during the first few weeks of life. In older-age groups, isolated clusters of CLDN6-positive progenitors were present, but in scarce quantities. In tumor tissues, we found strong and homogeneous CLDN6 expression in desmoplastic small round cell tumors and germ cell tumors. Wilms tumors demonstrated heterogeneous CLDN6 expression, notably absent in the blastemal component. Conclusions: These findings highlight an organ-specific presence of CLDN6-positive epithelial precursors that largely disappear in terminally differentiated epithelia within weeks after birth. Therefore, our data support CLDN6 as a viable therapeutic target in pediatric patients and justify their inclusion in basket studies for anti-CLDN6-based therapies. Full article

Genetic profiling and molecular biology methods have made it possible to study the etiology of the end-stage organ disease that led to transplantation, the genetic factors of compatibility and tolerance of the transplant, and the pharmacogenetics of immunosuppressive drugs and allowed for the development of monitoring methods for the early assessment of allograft rejection. This study aims to report the design and baseline characteristics of an integrated personalized genetic approach in solid organ transplantation, including whole-exome sequencing (WES) and the monitoring of dd-cfDNA by dPCR. Preliminary results reported female recipients with male donors undergoing two pediatric and five adult kidney and three heart transplantations. WES revealed a pathogenic mutation in RBM20 and VUS in TTN and PKP2 in heart recipients, while kidney donors presented mutations in UMOD and APOL1 associated with autosomal-dominant kidney diseases, highlighting the risks requiring the long-term monitoring of recipients, donors, and their family members. %dd-cfDNA levels were generally stable but elevated in cadaveric kidney recipient and one pediatric patient with infectious complications and genetic variants in the ABCB1 and ABCC2 genes. These findings highlight the potential of combining genetic and molecular biomarker-based approaches to improve donor–recipient matching, predict complications, and personalize post-transplant care, paving the way for precision medicine in transplantation. Full article

Background/Objectives: While there are several debates on en bloc renal transplants and pediatric donors regarding the efficacy and concern for renal mass, multiple studies have supported the notion that transplanting pediatric en bloc kidneys produces comparable results in contrast to single kidneys from living or deceased donors. Methods: This case series included a retrospective analysis of a university medical center, primarily focused on comparing the post-operative outcomes between recipients of pediatric and adult en bloc kidneys, which are horseshoe kidneys, from deceased donors and recipients of single adult kidneys from living or deceased donors. Results: This study demonstrated that the post-operative results in recipients of pediatric en bloc kidneys consisting of serum creatinine and estimated glomerular filtration rate (eGFR) values were lower and higher, respectively, and had a comparable improvement in kidney function at post-transplant, 1-week, 1-month, 3-months, and 1-year post-op marks. Conclusions: Our center data and outcomes indicate that en bloc kidney transplantation from pediatric donors yields comparable results to that of single kidney transplantations from living and deceased donors. Full article

Several etiologic factors for the development of acute leukemias have been suggested; however, none is applicable to all cases. We isolated a certain mycovirus-containing Aspergillus flavus (MCAF) from the home of a patient with acute lymphoblastic leukemia. Repeated electron microscopic evaluations proved the existence of mycovirus in this organism. According to chemical analysis, this organism does not produce any aflatoxin, possibly due to its infestation with mycoviruses. We reported that using the ELISA technique, forty pediatric patients with acute lymphoblastic leukemia (ALL) uniformly had antibodies to the products of MCAF. In contrast, three separate groups of controls, consisting of normal blood donors, individuals with solid tumors, and patients with sickle cell disease, were negative. In vitro exposure of mononuclear blood cells from patients with ALL, in full remission, to the products of MCAF induced redevelopment of cell surface phenotypes and genetic markers characteristic of ALL. The controls were negative. The incubation of normal and ALL cell lines with the products of MCAF resulted in significant cellular apoptosis, changes in the cell cycle, and the downregulation of transcription factors, including PAX-5 and Ikaros (75 and 55 kDa). Fungi are widespread in nature, and many contain mycoviruses. Normally, an individual inhales 1 to 10 fungal spores per minute, while farmers can inhale up to 75,000 spores per minute. It is known that farmers and foresters, who are more exposed to fungi, have a higher rate of acute leukemia. In contrast, asthmatics, most of whom are allergic to fungal agents, and individuals working in office settings have a lower rate. One of the theories for the development of acute leukemia suggests a genetic predisposition followed by exposure to an infectious agent. With the above findings, we propose that mycovirus-containing Aspergillus flavus may have an etiological role in leukemogenesis in immune-depressed and genetically susceptible individuals. Full article

Umbilical cord blood (UCB) is an alternative therapeutic resource for treating both hematological and non-hematological diseases, especially for pediatric patients. However, UCB transplantation faces challenges, including delayed engraftment, increased risk of graft failure, and slower immune recovery. To maximize its clinical potential, it is essential to understand the variability and functionality of its nucleated cells. This study focused on characterizing UCB cellular populations, viability, and functionality at three key processing stages: freshly collected, post-volume reduction, and post-thawing. Using EuroFlow-based flow cytometry, significant changes were observed in granulocyte and T-cell populations during processing. Additionally, integrating EuroFlow data with hematology counts revealed variability that could affect the yield of specific cell populations, potentially influencing therapeutic decisions. An in vitro migration assay, designed to mimic the vascular niche, was employed to study donor variability in cellular migratory patterns. Notably, thawed UCB cells displayed two distinct migration profiles, distinguishing lymphocyte-like cells from monocyte-like cells. These findings underscore the importance of reproducible cellular quality control measures, such as immunophenotypic and functional donor characterization, to ensure the integrity of UCB composition. A better understanding of these parameters could improve the consistency and reliability of UCB as a starting material for the development of advanced therapies. Full article

Despite the excellent survival rate, relapse occurs in 20% of children with ALL. Deep analyses of cell signaling pathways allow us to identify new markers and/or targets promising more effective and less toxic therapy. We analyzed 61 diagnostic samples collected from 35 patients with B- and 26 with T-ALL, respectively. The expression of CK2, MYC and ERG genes using Sybr-Green assay and the comparative 2-ΔΔCt method using 20 healthy donors (HDs) was evaluated. We observed a statistically significant difference in CK2 expression in non-HR (p = 0.010) and in HR (p = 0.0003) T-ALL cases compared to HDs. T-ALL patients with PTEN-Exon7 mutation, IKZF1 and CDKN2A deletions showed high CK2 expression. MYC expression was higher in pediatric T-ALL patients than HDs (p = 0.019). Surprisingly, we found MYC expression to be higher in non-HR than in HR T-ALL patients. TLX3 (HOX11L2)-rearranged T-ALLs (27%) in association with CRLF2 overexpression (23%) showed very high MYC expression. In B-ALLs, we detected CK2 expression higher than HDs and MYC overexpression in HR compared to non-HR patients, particularly in MLL-rearranged B-ALLs. We observed a strong difference in ERG expression between pediatric T- and B-ALL cases. In conclusion, we confirmed CK2 as a prognostic marker and a therapeutic target. Full article

Acute lymphoblastic leukemia (ALL) is a malignant condition of lymphoid progenitor cells that primarily affects the pediatric population, but also adults. The 5-year survival rate is 90% in children and approximately 40% in adults, with survival increasing through the use of peripheral stem cell allotransplantation (SCT). The relapse rate after stem cell transplantation (SCT) in adult acute lymphoblastic leukemia (ALL) patients ranges from 35% to 45%, making relapse a major cause of death in this population. Background: We present an atypical case of late testicular involvement in ALL in a 50-year-old man diagnosed with ALL pro-T in remission post-chemotherapy (GMALL 2003 protocol) and allogeneic stem cell transplantation (alloSCT) from a related donor. Methods: This case describes a 50-year-old male with ALL pro-T who experienced three rare extramedullary relapses post-chemotherapy and alloSCT. Five years after remission, he had a unilateral testicular relapse confirmed by immunophenotyping of spermatic fluid. Results: Despite no bone marrow involvement, he was treated with chemotherapy, intrathecal therapy, and bilateral testicular radiotherapy. He later relapsed in the orbit, controlled by radiotherapy, followed by a third relapse in the heart and colon. Conclusions: This case highlights the unusual sites and consecutive nature of extramedullary relapses in adult ALL. Full article

Polyomavirus BK (BKPyV)-associated nephropathy (BKPyV-nephropathy) remains a significant cause of premature kidney allograft failure. In the absence of effective antiviral treatments, current therapeutic approaches rely on immunosuppression (IS) reduction, possibly at the risk of inducing alloimmunity. Therefore, we sought to explore the long-term effects of a tailored viro-immunologic surveillance and treatment program for BKPyV on the development of alloimmunity and kidney graft outcome. Forty-five pediatric kidney transplant recipients were longitudinally monitored for BKPyV replication, virus-specific immunity, and donor-specific HLA antibodies (DSAs). DNAemia developed in 15 patients who were treated with stepwise IS reduction. Among the other 30 patients, 17 developed DNAuria without DNAemia and 13 always resulted as BKPyV-negative. All patients with DNAemia cleared BKPyV after having mounted a virus-specific cellular immune response, and no biopsy-proven BKPyV-nephropathy was observed. The presence of cytotoxic populations directed to the BKPyV Large-T (LT) antigen early after transplantation protected kidney recipients from developing BKPyV replication, and the appearance of LT-specific T cells in viruric patients prevented the development of BKPyV-DNAemia. In our cohort, no significant correlation was observed between BKPyV-DNAemia and the development of DSA and antibody-mediated rejection. However, patients who experienced and cleared BKPyV-DNAemia had a worse allograft survival at a median follow-up of 18.9 years (p = 0.048). These data need to be confirmed in larger cohorts. Full article

Currently, risk stratification for pediatric Hodgkin lymphoma is based on clinical factors such as stage, bulk, and systemic symptoms. Novel minimally invasive biomarkers could enhance both prognosis and treatment strategies. Therefore, the plasma extracellular vesicles’ microRNA profile was characterized by small RNA sequencing in 36 classical Hodgkin lymphoma cases and these findings were confirmed in an extended cohort of 86 patients by RT-qPCR. It was found that the levels of miR-122-5p at diagnosis were significantly higher (p-value: 0.0002) in patients who relapsed compared to patients in remission. The 5-year event-free survival of cases with high and low levels of miR-122-5p was 65 ± 7% and 93 ± 4%, respectively. MiR-122-5p levels were significantly associated with clinical events in both univariate (p-value: 0.0009) and multivariate (p-value: 0.0037) analysis (hazard ratio 5.8). Target prediction analysis suggests an involvement in the polarization of immune cells. The phenotypic characterization of peripheral blood mononuclear cells in 12 patients showed significantly increased levels of CD4+ T-cells in cases with high miR-122-5p levels as compared to low levels (p-value: 0.048). Moreover, CCL17 (TARC) and IL-6 plasma levels at diagnosis were significantly higher as compared to healthy donors (p-value: ≤0.0001). MiR-122-5p could complement current prognostic assays to identify patients at high risk of relapse. Full article

Background and Objectives: There is an increasing use of fecal matter transplantation (FMT) worldwide as research into the impact of the gut microbiome in various disease states is growing. FMT is the transfer of stool from a healthy human donor to a patient for the purpose of restoring intestinal dysbiosis. This review will assess the efficacy and safety of FMT in the treatment of pediatric inflammatory bowel diseases (IBDs) and explore the future directions of the use of FMT in children. Materials and Methods: A systematic review was performed where a literature search of publications published prior to 15 September 2023 was performed. Efficacy outcomes and safety data as well as microbiome analysis were reviewed from the studies where applicable. Results: Nine studies on UC and two studies on CD satisfied eligibility criteria and individually analysed. Most of the studies provided microbiome analyses. Conclusions: FMT is a safe treatment for paediatric IBD, and is shown to be effective in inducing clinical response by some studies. However the lack of randomized controlled trials limited the results of our study. Full article