Search Results (297)

Introduction: Post-infectious bronchiolitis obliterans (PIBO) is a rare and severe chronic lung disease. Our goal was to characterize respiratory epithelium in children with PIBO, which remains unexplored, using an ex vivo model culture. Methods: Proximal bronchial biopsies from children with PIBO and reconstituted bronchial epithelium from PIBO patients (n = 3) and controls (n = 17) were analyzed using an air–liquid interface culture model. Epithelial cell composition, barrier integrity, and mediator production, including mucins, inflammatory and antiviral responses, were assessed in this pathological and functional approach. Results: Epithelial thickness was assessed in PIBO biopsies. Ex vivo reconstituted PIBO epithelia appeared to exhibit comparable cohesion and cell composition to controls. Mucin expression and secretion were likewise similar between groups. PIBO epithelial might have displayed reduced IL-33 transcript levels and decreased TSLP secretion, whereas IFN-λ1, IFN-λ2-3 and IFN-β secretion could have been elevated. No differences were detected in remodeling markers (MMP-9 and YKL-40). Conclusions: In summary, ex vivo model of PIBO epithelia suggested that the epithelium may preserve structural characteristics and mucin production, without evidence of remodeling. However, PIBO epithelial cells may have a distinct immune profile, with lower alarmin expression and higher interferon secretion. This could indicate a tendency toward enhanced antiviral response rather than structural changes. These preliminary results need to be confirmed in larger cohorts. Full article

Spontaneous regression of metastatic renal cell carcinoma is a rare and incompletely understood phenomenon. We report the case of a 61-year-old man with biopsy-proven pulmonary metastases from clear cell renal cell carcinoma who experienced durable tumor regression without receiving any systemic therapy. The patient underwent cryoablation of a symptomatic iliac bone metastasis and discontinued methotrexate, previously prescribed for inflammatory polyarthritis. Serial imaging demonstrated initial slow progression followed by significant shrinkage of pulmonary and mediastinal lesions, leading to a sustained partial response according to RECIST 1.1 criteria. No disease progression has been observed after extended follow-up. Two non-mutually exclusive mechanisms may explain this observation: restoration of antitumor immunity following withdrawal of immunosuppressive therapy, and a systemic immune response triggered by local tumor destruction (abscopal effect). Although such events are exceptional, this case highlights the potential interplay between immune modulation and local therapies in renal cell carcinoma. Further investigation is warranted to better understand these mechanisms and their potential therapeutic implications. Full article

Extramedullary relapse (EMR) of acute lymphoblastic leukemia (ALL) after allogeneic hematopoietic stem cell transplantation (Allo-HSCT) represents a clinically and biologically distinct entity compared with medullary relapse, characterized by marked heterogeneity, compartmental immune escape mechanisms, and generally poor prognosis. EMR arises at the intersection of clonal resistance, evolutionary disease adaptation, and heterogeneous distribution of the graft-versus-leukemia effect, resulting in evolutionary trajectories that are often dissociated between medullary and extramedullary compartments. In the absence of prospectively validated therapeutic algorithms, EMR management requires a structured and adaptive approach based on multidimensional assessment integrating leukemia biology, disease burden and anatomical distribution, bone marrow minimal residual disease (MRD) status, and immune reconstitution. Therapeutic strategies include local treatments, targeted agents, immunotherapies, and immunomodulatory interventions, applied within a dynamic sequence tailored to treatment response. Follow-up plays a central role as an active tool for prognostic stratification and clinical decision-making, enabling early detection of systemic progression and optimization of the timing of consolidative strategies, including second Allo-HSCT in selected patients. An integrated and biologically driven management of post-Allo-HSCT EMR is essential to improve outcomes in this high-risk clinical setting. Full article

Background: Chimerism analysis is a key tool for monitoring donor-cell engraftment and the risk of relapse and graft-versus-host disease (GVHD) following allogeneic hematopoietic cell transplantation (allo-HCT). The advantage of lineage-specific chimerism assessment, and its dynamics in patients receiving post-transplant cyclophosphamide (PTCy)-based GVHD prophylaxis, remains unclear. Objective: This review summarizes the current state of the art on chimerism analysis in patients with myeloid neoplasms undergoing allo-HCT with PTCy, with emphasis on lineage-specific testing and modern methodologies. Methods: A structured literature review was conducted to assess chimerism dynamics in whole blood (WB), bone marrow, and peripheral blood (PB) subpopulations, including T-cells, CD34⁺, myeloid, B, and NK (natural killer) cells, and their association with clinical outcomes following PTCy. Results: Lineage-specific PB chimerism, particularly in T-cells, myeloid lineage and CD34⁺ cells, is more sensitive than WB chimerism for predicting relapse. Declining donor myeloid chimerism or persistent myeloid mixed donor chimerism (MDC) may precede hematologic relapse and provide an early signal of graft instability or ineffective graft-versus-leukemia activity. T-cell MDC has been associated with an increased risk of relapse and a lower risk of GVHD, although persistent T-cell MDC in some patients may instead indicate immune tolerance. Declining CD34⁺ donor chimerism correlates with a higher risk of relapse and inferior survival outcomes and may therefore complement measurable residual disease testing. Data regarding B-cell and NK-cell chimerism remain inconsistent, likely influenced by delayed immune reconstitution. Compared to anti-thymocyte globulin, PTCy may promote higher donor T-cell chimerism, though findings across studies are variable. Next-generation sequencing (NGS) enables more sensitive detection of microchimerism and relapse prediction. Conclusions: Chimerism analysis, particularly when lineage-specific and NGS-based, offers valuable prognostic insight in allo-HCT with PTCy. Further prospective studies are needed to standardize testing and guide personalized post-HCT strategies. Full article

A history of invasive mold disease (IMD) often delays or contraindicates allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children. Given the limited data on pediatric patients with pre-allo-HSCT IMD, we aimed to describe the management and clinical outcomes of a cohort of children with IMD prior to allo-HSCT through day +100 post-transplantation. Between 2021 and 2024, ten pediatric patients were identified with proven or probable IMD. Their median age was 8.5 years. The most common pathogens were Aspergillus (n = 5) and Fusarium (n = 4). Infections most frequently involved the lungs followed by paranasal sinuses, bloodstream, liver, and skin. All patients demonstrated clinical improvement before transplantation, and by day +100 post-HSCT, no IMD relapses or infection-related mortality were observed. These findings suggest that complete radiologic or clinical resolution is not a prerequisite for proceeding with transplantation. Recent IMD should not be considered an absolute contraindication to urgent allo-HSCT when clinical improvement is evident, as transplantation facilitates immune reconstitution necessary for definitive infection control. Full article

Acute myeloid leukemia (AML) remains a highly morbid malignancy in which outcomes are constrained not only by disease refractoriness and relapse, but also by therapy-related toxicity—particularly infections, mucosal injury, and delayed hematopoietic reconstitution. The gut microbiota has emerged as a potentially modifiable layer of host vulnerability and resilience during AML treatment. Microbiome disruption is detectable already at diagnosis, even in antibiotic-naïve patients, and is often characterized by reduced community diversity, depletion of anaerobic taxa linked to short-chain fatty acids (SCFAs) production, and enrichment of pathobiont-associated profiles. During induction, cytotoxic therapy and antimicrobials precipitates diversity loss, domination events, and persistent shifts beyond discharge. Clinically, the most consistent translational signal is the association between baseline or early-treatment microbiome features and infectious outcomes, while emerging data suggest that diagnosis-time microbiome structure may also relate to hematologic recovery kinetics. Mechanistic models converge on pathways linking barrier integrity, microbial metabolites (notably butyrate and other SCFAs), immune calibration, and inflammatory translocation of microbial products. These insights support hypotheses: antimicrobial stewardship may preserve microbiome function; ecosystem repair strategies such as autologous fecal microbiota transfer (A-FMT) are feasible and can restore community structure; and metabolite or nutritional interventions merit evaluation in immunocompromised hosts. Regimen-specific microbiome effects and microbiome–drug interactions suggest that treatment choice could have downstream microbiome-mediated consequences. We synthesize evidence, outline interventional concepts, and define methodological priorities for next-generation trials assessing causality and clinical benefit. Progress will require longitudinal sampling, multi-omic integration (metabolomics, resistomics, and barrier/inflammatory biomarkers), and interventional designs linking microbiome dynamics to clinically meaningful outcomes. Full article

The autophagy regulator ATG7 helps maintain cellular homeostasis and has been suggested to modulate aspects of antiviral immune responses. In Drosophila, ATG7-dependent autophagy contributes to host resistance to vesicular stomatitis virus (VSV), a negative-strand RNA virus of family Rhabdoviridae that is widely used for studying viral biology and developing vaccines and virotherapy. However, the role of ATG7 in mammalian cells, especially non-immune cell types, remains unclear. Herein, we systematically examined the impact of ATG7 on VSV infection using CRISPR-edited cell lines derived from murine embryonic fibroblast (MEF), HeLa, and Huh7.5 cells, in relation to its effect on the expression of antiviral interferon-stimulated genes (ISGs). We found that ATG7 deficiency blocked basal as well as VSV-induced LC3B lipidation, concomitant with moderate reductions in progeny virus yields, while the reconstitution of ATG7 reversed the phenotypes. Mechanistically, ATG7 did not affect viral entry but rather was associated with moderate upregulation of VSV RNA replication. Intriguingly, ATG7 inhibited baseline ISG expression, and this correlated with its pro-VSV effect in all three cell types, while its suppression of innate immune responses elicited post-VSV infection did not. Altogether, these data provide new insights into the role of ATG7 in regulating VSV replication and innate immunity and have implications for developing VSV-based prophylaxis/therapeutics. Full article

Background: This case report presents a 12-year-old male with vertically transmitted chronic hepatitis B virus (HBV) infection, exhibiting a rare pan-reactive serological profile (concurrent HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb positivity) alongside fluctuating low-level viremia (HBV DNA: 1.06 × 10² IU/mL to undetectable). Rigorous exclusion of technical artifacts confirmed the authenticity of this atypical serologic pattern, observed in <0.001% of the general population. Methods: Liver biopsy and immunohistochemical staining were performed to evaluate hepatic inflammation and fibrosis. HBV serological markers and viral load were quantified using commercial diagnostic kits, with longitudinal monitoring for 18 months. Results: Liver biopsy revealed Grade 2 inflammation with focal HBsAg/HBcAg expression, supporting immune-active chronic hepatitis B (CHB) despite partial seroconversion. The patient’s clinical course highlights key challenges in pediatric HBV management: (1) delayed immune reconstitution (18-month longitudinal HBeAg/HBeAb dynamics), (2) non-linear virologic-ALT correlation, and (3) diagnostic ambiguity in pan-positive serology—potentially reflecting S-gene escape mutants or transitional immune responses. Initiation of tenofovir disoproxil fumarate (TDF) achieved sustained virologic suppression, underscoring the importance of early antiviral therapy in pediatric CHB with atypical markers. Conclusions: This case provides preliminary insights into the complex interplay between viral evolution and immature host immunity, advocating for refined monitoring protocols integrating high-sensitivity HBV DNA, quantitative serology, and non-invasive fibrosis assessment in pediatric HBV care. Full article

Vitamin D is a pleiotropic secosteroid with endocrine and intracrine actions that influence key phases of allogeneic hematopoietic stem cell transplantation. Epithelial barriers, antigen-presenting cells and effector lymphocytes express the vitamin D receptor and enzymes required for local activation, allowing circulating 25-hydroxyvitamin D to be converted into its active form and modulate immune interactions. During the peri-transplant period, sunlight deprivation, reduced intake, mucosal injury, cholestasis and corticosteroid exposure markedly reduce vitamin D levels at a time when antigen presentation and immune reconstitution occur. This review integrates mechanistic immunology with clinical observations and interventional data to outline strategies that prevent severe deficiency. It summarizes epidemiology before and after transplantation, associations with acute and chronic graft-versus-host disease, relapse, engraftment, infections, bone health and survival, and evaluates dosing approaches including pre-conditioning loading and reassessment at day thirty with escalation if needed. Absorption-savvy formulations such as oral thin-film and intramuscular cholecalciferol are considered when gastrointestinal function is compromised. Given the high prevalence of deficiency, biological plausibility, safety and low cost, a structured approach that includes screening, repletion and monitoring to achieve concentrations of at least thirty nanograms per milliliter by day thirty represents a pragmatic and low-risk component of supportive care pending definitive evidence. Full article

Kupffer cells (KCs) make up the predominant population of resident innate immune cells in the liver, serving as key immune sentinels that maintain local immune surveillance and immunoregulatory homeostasis. However, their functional involvement and phenotypic dynamics during radiation-induced liver damage (RILD) remain insufficiently explored. Therefore, we established a mouse model of RILD and, through systematic single-cell-level profiling of hepatic immune cell populations, found that KCs play a critical role in hepatic immune responses and undergo a pronounced radiation-induced shift toward a pro-inflammatory M1 phenotype. Further KC depletion/reconstitution, molecular assays, and coculture experiments consistently demonstrated that M1-polarized KCs exacerbate liver damage, with secretory leukocyte protease inhibitor (SLPI) being identified as a key molecular mediator driving this polarization and its pathogenic effects. To further substantiate these findings, we designed a liposome-based delivery strategy to selectively inhibit SLPI in KCs, which effectively suppressed M1 polarization and alleviated radiation-induced liver damage, underscoring the therapeutic relevance and translational potential of this approach in RILD. Overall, these findings demonstrate that radiation drives KCs toward an SLPI-dependent pro-inflammatory M1 state, thereby exacerbating liver injury. Moreover, targeted liposomal suppression of SLPI effectively reverses this polarization and protects against RILD, highlighting SLPI-modulated KC reprogramming as a promising therapeutic approach. Full article

Background: Acquired epidermodysplasia verruciformis (AEV) is a rare cutaneous disorder arising in immunocompromised individuals. AEV is characterized by flat-topped, wart-like, or hypopigmented lesions predominantly on sun-exposed areas. Unlike classic genetic EV, AEV develops in the absence of germline mutations or family history. AEV most commonly arises in patients receiving iatrogenic immunosuppressive therapy for organ transplantation, autoimmune disease, or hematologic disorders. Methods: A comprehensive literature review was conducted via the PubMed database. Case reports and case series studies describing AEV in transplant and non-transplant iatrogenic immunosuppression were identified through a literature search. There were no restrictions on language or publication year. The last search was conducted in July 2025. Reports were analyzed for patient demographics, immunosuppressive agents, HPV subtypes, clinical and histopathologic features, and treatment outcomes. Results: AEV occurs across a broad spectrum of immunosuppressive therapies, including calcineurin inhibitors, antimetabolites, biologics, tyrosine kinase inhibitors, and cytotoxic chemotherapy. β-HPV subtypes, most commonly HPV 5 and 8, drive lesion formation in the context of impaired cell-mediated immunity. Histopathology demonstrates keratinocyte vacuolization, acanthosis, and perinuclear halos. Lesions may persist despite immunosuppressive adjustment, due to viral latency and incomplete immune reconstitution. Treatment strategies are varied and include topical retinoids, immune response modifiers, systemic retinoids, and HPV vaccination, and have variable efficacy. AEV carries an elevated risk of cutaneous squamous cell carcinoma, particularly in transplant recipients, and highlights the need for proactive dermatologic management. Conclusions: AEV represents a clinically significant consequence of immunosuppression mediated by β-HPV. Early recognition, monitoring for malignant transformation, and individualized multimodal therapy are critical. Future studies should evaluate targeted interventions to enhance antiviral immunity and establish standardized treatment guidelines. Full article

The persistent emergence of infectious diseases has underscored the critical demand for next-generation vaccine technologies that are safe, effective, and scalable. This review explores virus biomimetic delivery systems, focusing on virus-like particles (VLPs) and virosomes as promising platforms for vaccine and therapeutic development. VLPs are self-assembled nanostructures composed of viral structural proteins that mimic native virions without carrying genetic material, while virosomes are reconstituted viral envelopes that retain functional glycoproteins but lack a nucleocapsid. Both systems provide strong immunogenicity and safety by mimicking viral architecture while eliminating the risk of replication. The paper examines various expression platforms for VLP production, including bacterial, yeast, insect, mammalian, and plant-based systems, highlighting their respective advantages, challenges, and optimization strategies. Mechanistic insights into antigen presentation, immune activation, and cellular uptake pathways are discussed to explain their superior performance in eliciting humoral and cellular immune responses. Furthermore, current applications of VLPs and virosomes in vaccines against major pathogens such as SARS-CoV-2, influenza, Newcastle disease virus, malaria, hepatitis, and respiratory syncytial virus are reviewed, demonstrating their versatility and clinical potential. By integrating molecular engineering, nanotechnology, and biofabrication strategies, virus biomimetic systems represent a transformative frontier in vaccinology, immunotherapy, and targeted drug delivery. Full article

The long-lasting, varied, and complicated nature of immune system issues in autoimmune disorders continues to make treatment difficult. Although standard immunosuppressive and biologic therapies have enhanced disease management, they infrequently provide enduring remission and often result in cumulative damage. Due to this, stem cell treatment has emerged as a potential alternative that aims to restore immunological homeostasis rather than maintain long-term immune suppression. This editorial review provides a comprehensive overview of the current evidence, unmet requirements, and future directions in the field, summarizing the primary contributions of the Special Issue “Stem Cell Therapy for Autoimmune Diseases”. We examine the conceptual distinction between immune reset, as demonstrated by hematopoietic stem cell transplantation, and immune modulation, which is facilitated by mesenchymal stromal cells and their secretome. Systemic sclerosis, neuroimmunological disorders, inflammatory bowel disease, and type 1 diabetes exhibit disease-specific clinical experiences that underscore both context-dependent limitations and therapeutic potential. Meanwhile, an urgent need to address persistent issues such as incomplete immune reconstitution, autoreactive memory cell-driven relapse, a lack of predictive biomarkers, safety concerns, and complex ethical and regulatory problems is addressed. This review concludes by offering perspectives on the future development of this approach, highlighting standardization, biomarker-driven patient selection, and next-generation techniques, including extracellular vesicles and genetically modified cells. This overview marks stem cell therapy as a crucial area of research for the treatment of autoimmune disorders. Full article

Torque Teno Virus (TTV), a common and genetically diverse component of the human virome, is not linked to any known disease but reflects immune status. Its plasma viral load has shown clinical relevance in solid organ transplant recipients, correlating it with immunosuppression when present at high levels. However, the clinical significance of TTV viral load in hematopoietic stem cell transplantation (HSCT) recipients is less understood. This systematic review aims to evaluate whether plasma TTV DNA load directly correlates with the degree of T-cell immune reconstitution after HSCT, supporting its potential role as a biomarker for immune competence. The study protocol was registered in the PROSPERO International Prospective Register of Systematic Reviews (CRD420251116208) and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Twenty-one studies were included. The results showed concordant data about TTV kinetics with peak levels reaching approximately between +90 to +120 days after transplantation. Contradictory results have instead been found for the association of TTV load with immune parameters (lymphocyte counts, viral opportunistic infection, and development of acute graft versus host diseases). Even if a low-risk bias assessment was classified in most studies (67%), it was possible to identify important clinical and methodological differences between them, which might account for the different findings observed. Therefore, future larger studies with standardized protocols are needed to assess whether TTV viral load can serve as a reliable tool for guiding clinical decisions in the context of HSCT. Full article

Background/Objectives: This systematic review aimed to evaluate the clinical and immunological outcomes of non-surgical periodontal therapy (NSPT) in HIV-positive patients with periodontitis. Methods: Systematic search on four databases (PubMed, Scopus, Web of Science, Cochrane Library) and the gray literature was completed through December 2025. A comprehensive set of clinical parameters and immunological markers were assessed. Three studies met the inclusion criteria and were included in the final synthesis and qualitative analysis. Extracted outcomes included clinical periodontal parameters (PPD, CAL, BoP, PI, GBI, BI) and immunological markers (viral load, CD4+ lymphocyte count, CD4/CD8 ratio, salivary LF, salivary HST, GCF LF, GCF HST). Results: With a very low level of certainty, NSPT was generally associated with significant improvements in clinical periodontal parameters compared to before treatment measurements and HIV-negative individuals. Improvements in immunological status were also reported. Heterogeneity of study designs and reporting standards limited this study’s quantitative analysis. Conclusions: NSPT demonstrates beneficial clinical and immunological outcomes in people living with HIV. However, the very low level of certainty in the available data limits confidence in changes in periodontal status and immune system reconstitution following NSPT in this population; therefore, the findings remain inconclusive and should be interpreted with caution. Full article