Posters

We present a rare case of millet allergy in a 13-year-old girl who experienced an allergic reaction, including urticaria and vomiting, after consuming a teff-based product. Teff is related to millet and common in Eritrean cuisine. Positive skin prick tests and elevated sIgE levels confirmed an allergy to both millet and teff. The sensitization in millet allergy seems to typically occur through the respiratory route via exposure to millet-containing birdseed in pet bird owners. Our patient had no history of contact with pet birds. The allergic reaction occurred a while after she prepared a dish using teff flour. This suggests that sensitization may have occurred either via the respiratory route from inhaling the flour or through the cutaneous route during food preparation in this patient with atopic dermatitis.

There are case reports about millet allergy and cross-reactivity with rice, corn and wheat. Our patient reported oral itching after consuming whole-grain wheat products. Oats, like millet, are a sweet grass, and our patient also reported oral itching when consuming oats. We could confirm a sensitization to wheat, rye, and oats. The patient was advised to avoid millet, teff, whole wheat products and oats and was equipped with emergency medication including EpiPen. This report highlights the need for the awareness of rare food allergies in clinical practice. With increasing immigration from Eritrea, the incidence of millet allergy may rise in the future. Potential cross-reactions with related grains should be considered in the diagnostic work-up and dietary management.

Case report: A 2-year-old boy was referred to the allergy department for recurrent eyelid and facial swelling over the past 2 years, each episode associated with febrile respiratory infections and resolving spontaneously within 2-3 days. The episodes were often temporally linked to non-steroidal anti-inflammatory drug (NSAID) use, raising suspicion of drug hypersensitivity. However, controlled oral challenges with NSAIDs were tolerated without allergic reactions. Given the atypical presentation and inconsistent NSAID exposure, further evaluation was pursued. Routine laboratory testing revealed nephrotic-range proteinuria without hematuria, leading to the diagnosis of nephrotic syndrome. Corticosteroid therapy was initiated, resulting in marked improvement and disease remission.

Discussion: NSAIDs are a common cause of drug-induced angioedema, particularly during infections. However, when the clinical presentation is atypical or the temporal relationship with drug exposure is inconsistent, alternative diagnoses must be considered. In this case, the swelling was secondary to nephrotic syndrome, a condition that can mimic allergic angioedema in its early stages. Recognizing nephrotic proteinuria is critical, as delayed diagnosis may result in serious complications.

Conclusion: This case highlights the importance of maintaining a broad differential diagnosis in patients presenting with recurrent edema. Early identification of nephrotic syndrome through simple urine testing enables prompt treatment and the prevention of long-term renal and systemic complications.

Aim: The development of biologic drugs for the treatment of CRSwNP generated growing interest in defining disease remission, for which there currently is no consensus on a precise definition and no validated criteria exist. The aim of our study is to develop and validate clinical remission criteria for CRSwNP.

Methods: We conducted a retrospective study on patients with severe refractory CRSwNP, under therapy with Dupilumab. Patients were evaluated at T0 (baseline) and at 1, 3, 6, 12 and 24 months (T1, T3, T6, T12 and T24, respectively) after initiating dupilumab. We hypothesized 3 definitions of clinical remission: Definition 1 (D1): NPS 0; SNOT-22 <20. Definition 2 (D2): NPS reduction >2 points; SNOT-22 <20. Definition 3 (D3): NPS reduction >2 points; SNOT-22 reduction ≥9points. All the definitions also include no use of systemic steroids nor adjuvant surgery.

Results: 64 patients were included in the analysis at T12 and 40 at T24. The NPS was 6.3±1.48, 4.02±2.52, 2.93±2.31, 2.48±2.42, 2.24 ±2.29, 1.36±2.03 at T0, T1, T3, T6, T12 and T24. The SNOT-22 was 64.24±19.72, 37.74±20.39, 28.71±19.00, 25.35±17.12, 21.91±15.46, 16.29±13.30 at T0, T1, T3, T6, T12 and T24.

Complete clinical remission (D1) is achieved by 15.6% of patients by T12. 39.1% of patients reach the more lenient clinical remission (D2) by T12. D3, resembling Dupilumab response criteria, was achieved by 70.7% by T3.

Conclusions: The introduction of biologic drugs in the treatment of CRSwNP has positively impacted the disease outcome, making remission achievable. Now clinical remission criteria need to be validated.

Aim: We present a case of a SDRIFE-like reaction 3 times after intake of paracetamol which could reproduced with oral provocation testing (OPT). The aim of this case report is to raise awareness for a rare but frequently prescribed elicitor of SDRIFE-like eruption. 

Case: Our patient had 3 episodes of skin rash in association with the intake of metamizole and paracetamol. The latency of the first 2 episodes was 3 to 4 days under continued use of both drugs with skin changes lasting 2 and 1 week, respectively. The latency of the 3rd episode was 8h after the 1st dose of paracetamol with skin changes lasting for 1 week. In the further course, the patient avoided both drugs, so that no statement on tolerance could be made. Later 1g acetylsalicylic acid was taken without complications.

Methods: 10 months after the last skin reaction, we performed a skin test with paracetamol (prick, patch) and metamizole (prick, intradermal, patch) which was negative. Later an OPT with 875mg paracetamol was administered. About 20h later, symmetrical erythema manifested on the flexural sides of the forearms, thighs extending to the popliteal fossa, the inguinal area and the flanks for a duration of approx. 24 hours. Unfortunately the patient did not present to our allergy clinic. 1 week later, an OPT with 875mg metamizole was carried out without complications. 3 months later, we repeated the OPT with paracetamol, whereby after 24h a similar erythema, as observed after the first provocation, developed again.

Conclusion: It is important to be aware that SDRIFE-like rashes can be caused by paracetamol.

Background: Drug Reaction with eosinophilia and Systemic Symptoms (DReSS) is a severe T-cell-mediated hypersensitivity reaction with delayed onset, eosinophilia, and multi-organ involvement. This study explores the role of pharmacological interaction with immune receptors (p-i) in pathogenesis and clinical course of DReSS.

Methods: The role of p-i stimulation in DReSS was previously shown by analysis of drug specific T cell clones, molecular modeling and HLA-binding studies. Data on drug dose and tissue concentration, therapy duration, and affinity of drug binding to HLA or TCR, as well as amount of cytokine secretion in vitro (IL-5, IL-13, IFNγ, granzyme B, granulysin) are combined to explain the clinical picture of DReSS and its clinical course.  

Results: DReSS progresses through four phases: (1) Silent phase (asymptomatic T-cell expansion via high-affinity p-i stimulation, often >14 days latency); (2) Acute phase (cytokine storm, cytotoxicity, eosinophilia); (3) Viraemia/autoimmunity phase with peptide reactivity; (4) Chronic phase (persistent T-cell hyperreactivity and multi-drug hypersensitivity).

p-i Drivers: High drug doses (>300 mg/day), prolonged therapy (>7 days), and strong HLA affinity (e.g., HLA-B*58:01) amplify T-cell activation. Low-affinity interactions (piperacillin, contrast media) can be compensated by excessive drug concentrations.

Conclusion: DReSS exemplifies a strong p-i-mediated immune stimulation. Risk to develop DReSS may be mitigated by considering the presence of risk-alleles (HLA), avoidance of high drug doses and long drug therapy.

Aim: Anaphylaxis from ant stings are very rare in Europe. It is most often linked to stings from Myrmica rubra or Formica rufa. Other species, such as Manica rubida and Solenopsis invicta, an invasive species in the United States and recently detected in Sicily, are feared for their venom with anaphylactic potential.
We report two cases of anaphylaxis to M. rubida to highlight the problem of ant allergy, which has been little studied and for which diagnostic and therapeutic methods are limited.

Methods: Retrospective study of two documented cases based on: anamnesis, identification of the insect by an entomologist and detection of IgE against a hymenoptera venom allergen.

Results: A mother and her daughter repeatedly experienced H.L. Muller grade I-III anaphylactic reactions to stings from red ants near their home in eastern Switzerland. In both cases, the assessment showed IgE to paper ant venom antigen 5 (rPol d5), without other specificities, notably to allergens from S. invicta, the only ant venom available for assay. None of the patients recalled being stung by paper ants. Homologues of antigen 5 are found in the venom of other hymenoptera, including ants. An ant, killed at the time of the sting by one of the patients, was identified by an entomologist as M. rubida, a species endemic to the mountainous regions of central Europe.

Conclusions: As S. invicta reaches Europe, an increase in cases of anaphylaxis to ant venom is expected. We should not forget the possibility of anaphylaxis to ant venom from stings of endemic species, for which diagnostic methods remain limited.

Introduction
ENABLE (NCT04130191), a Phase IV, non-interventional, prospective study, assessed lanadelumab’s real-world effectiveness in preventing hereditary angioedema (HAE) attacks. This abstract reports on patient-reported attack rates.

Methods
Patients aged ≥12 years with HAE at 18 sites across 7 countries initiated lanadelumab per product labeling and recorded attacks via smartphone diaries. Disease control perception was measured via the Angioedema Control Test (AECT) at baseline and at follow-ups (months 1, 2, 3, 6, 12, and annually for up to 36 months).

Results
Of 139 enrolled, 138 received lanadelumab (mean±SD age: 41.0±14.4 years; 62.3% female). Most had HAE-C1INH-Type1 (n=127). Median treatment duration was 26.6 months. Mean monthly attack rates dropped by 83.9%, from 3.88±3.43 pre-lanadelumab to 0.30±0.53 on treatment; median attack rates reduced by 96.7%, from 3.0 to 0.1 attacks/month. Most attacks (85.9%) were mild/moderate; 82.6% of patients used on-demand treatments. AECT scores improved from poorly controlled at baseline (7.5±3.7) to well-controlled disease (≥10) within 1 month, further increasing to 14.4±2.9 by month 36. By month 1, AECT score changes exceeded the minimal clinically important difference (≥3 points). The proportion of patients achieving well-controlled disease rose from 51.9% at baseline to 88.3% and 89.7% at months 12 and 36.

Conclusions
Lanadelumab significantly reduced HAE attacks and improved disease control early, maintaining benefits through 36 months, supporting its use as first-line prophylaxis.

Aim. The Aim is to compare the differences between the 2005 and 2021 ERS/ATS criteria. The ERS/ATS 2021 guidelines redefined a positive bronchodilator response (BDR) in pulmonary function tests as an increase >10% of the predicted value of FEV1 or FVC, replacing the 2005 criteria of a 200 ml and 12% change from baseline. This change, which accounts for individual patient characteristics, increases specificity for detecting lung function changes and supports personalized treatment.

Methods. We conducted a bicenter retrospective study using BDR tests from the Allergology and Clinical Immunology Center in Monserrato (Cagliari, Italy) and the Asthma and Allergology Center at IRCCS Humanitas in Rozzano (Milan, Italy) between January 2020 and October 2024. BDR outcomes based on the 2005 and 2021 criteria were designated as 2005-BDR and 2021-BDR, respectively. We compared these outcomes and examined the trend of positive BDR (BDR+) in relation to the degree of airflow obstruction.

Results. Out of 1794 tests, 540 (23%) were BDR+ by one or both definitions (using FEV1 only). Specifically, 512 tests (52%) were positive by the 2005 criteria and 482 tests (48%) by the 2021 criteria. Among 81 discordant cases—positive by only one guideline—57 (70%) were positive solely according to the 2005 criteria, while 24 (30%) were positive only under the 2021 criteria.

Conclusions. The 2021 ERS/ATS criteria yield fewer positive BDRs than the 2005 criteria, suggesting a more specific and conservative definition that likely reflects clinically significant lung function changes.

Aim: Peanut allergy prevalence has increased over the last decade to reach 2% in the general population. As the leading cause of food allergy-related fatalities, it urgently needs improved therapies.

Methods: Mabylon has developed MY006, a trispecific anti-peanut antibody engineered from patient-derived monoclonal antibodies, for prophylactic treatment of peanut allergy.

Results: MY006 possesses excellent developability and manufacturability profiles and offers a novel mode of action via allergen neutralization, overcoming limitations of current approaches. Functionally, this trispecific molecule remarkably targets four allergenic epitopes across the three major peanut allergens. ex vivo, MY006 prevents the binding of patients’ IgE to peanut allergen and inhibits subsequent mast cell and basophil degranulation. Due to antibody half-life extension, its potency and its mode of action, MY006 is expected to provide continuous protection from allergic reactions caused by accidental peanut exposure with only two subcutaneous injections per year.

Conclusions: MY006 is predicted to offer safe, rapid, and continuous protection from peanut allergic reactions to a very broad patient population, including pediatrics and adults. Currently, MY006 is undergoing IND-enabling studies and first-in-human Phase 1 trials will be started by the end of 2025. Applying Mabylon’s advanced human antibody discovery, engineering and development platform, antibodies targeting a range of food allergies are currently developed, offering a preventive treatment for poly-allergic patients in the future.

Persistent antigen exposure in chronic infection and cancer drives CD8 T cells towards an exhausted state of differentiation. Exhausted CD8 T cells are characterized by an increased expression of coinhibitory molecules (e.g., PD-1, Tim3), dampened effector function and reduced proliferative capacity, hampering efficient solving of viral infection or cancerous cells clearance. Despite intense research on the topic, the full picture of exhaustion remains elusive.

Our laboratory focuses on understanding tumor-specific mechanisms driving CD8 T cells exhaustion. Several transcription factors have been found to enforce exhaustion (e.g., TOX, IRF4, NFAT5). We found that IRF8, an Interferon Regulatory Factor family member and homolog of IRF4, was overexpressed in exhausted tumor infiltrating lymphocytes (TILs) from murine and human tumors. Thus my project aims at investigating the role of IRF8 during tumor-induced CD8 T cell exhaustion.

First, we demonstrated a TCR-dependent upregulation of IRF8 in tumor-specific CD8 T cells. Interestingly, IRF8 expression in CD8 T cells was maintained in TILs but not in virus-specific CD8 T cells during chronic infection. We showed that IRF8 overexpression in TILs aggravated their exhausted profile in a melanoma mouse model. Inversely, TILs with CRISPR/Cas9-mediated KO of IRF8 displayed a more functional and less exhausted phenotype compared to the WT counterpart. We also confirmed these findings at the transcriptomic level by scRNAseq.

Together, our data suggest that IRF8 plays a role in regulating CD8 T cell exhaustion in the context of cancer.

Most vaccines confer protection against infection by induction of specific antibodies. The effectiveness of vaccines depends on the sustained production of long-lasting, high-titre antibody responses. However, recent experiences with the COVID-19 pandemic have highlighted a lack of fundamental understanding of how these vaccine-induced antibody responses can be sustained over the long term, an essential goal in the field of vaccinology. Our experiments have shown an increased expression of Arginase 2 in MBC compared to GCB, while Arginase 1 was higher in GCB cells compared to MBC. Both arginases convert L-Arginine to Urea and L-ornithine and thus compete with inducible nitric oxide synthase (iNOS or NOS2) for the L-Arginine substrate and thus can regulate the nitric oxide (NO) pathway, a known regulator of immune function again via NF-κB. This led us to generate a CD19^creArg1^lox mouse line to study the role of Arginase 1 in B cells and GC versus plasma cell formation. We found levels of antigen-specific IgG antibody in these mice are initially similar to wild type mice after immunization with VLPs. After day 21, these mice fail to maintain high levels of antigen-specific IgG, indicating a failure to generate long-lived plasma cells as we have previously seen in complement-receptor deficient mice. In contrast, deletion of arginase 2 in B cells led to an early increase and earlier decline of antibody responses. These indicate a critical role for arginase metabolism in the antibody response and, surprisingly, a dual role of the two enzymes in the regulation antibody responses.

Introduction. Trained immunity reflects the capacity of the host to adapt to an initial challenge and mount an improved response to a secondary challenge. We reported that trained immunity protects mice from a wide range of bacterial infections. Neutrophils play a key role in host defences, but their role during training is poorly understood.

Aim. Determine whether neutrophils are reprogrammed during training and assess their role in protection against streptococcal pneumoniae.

Methods. Mice were challenged with PBS (control) or β-glucan (training) given intraperitoneally. After one week, mice were sacrificed to isolate bone marrow (BM) and BM neutrophils or challenged intranasally with Streptococcus pneumoniae.

Results. Training increased BM stem and progenitor cells as well as neutrophils in blood and lungs (P<0.001). RNAseq demonstrated that the transcriptome of trained BM neutrophils was altered with gene pathways related to effector functions significantly enriched. In agreement, trained BM neutrophils showed increased chemotaxis, phagocytosis and S. pneumoniae-induced IL-1β, IL-6 and G-CSF production (P<0.05). Training protected mice from lethal pneumococcal pneumonia. The protection was lost upon neutrophil depletion (0.0% versus 87.5% survival in neutrophil-depleted versus neutrophil-non-depleted trained mice, P<0.001). The adoptive transfer of trained neutrophils to naive mice increased their resistance to S. pneumoniae infection.

Conclusions. Neutrophils are substantially altered upon training and required in the protection against pneumococcal pneumonia.

Aim: Environmental exposures can impair epithelial barriers and contribute to disease. Here, we report the impact of monosodium glutamate (MSG), disodium guanylate (DSG), disodium inosinate (DSI) and their combined effects on intestinal epithelial cells.

Methods: Monolayer Caco-2 cells and organ-on-a-chip model were established, and cellular cytotoxicity, transepithelial electrical resistance (TEER), paracellular flux (PF), RNA-sequencing, and reactive oxygen species (ROS) detection were performed at consumer-relevant doses.

Results: MSG, DSG, DSI, and their combination caused cytotoxicity at 1%, 0.5%, 2%, and 0.5%, respectively. A one-day exposure to 1% MSG, 1% DSG or the 1% doses of combined compounds reduced TEER. After three days, 1% MSG and the combined treatment significantly increased PF, indicating compromised barrier integrity. RNA-sequencing transcriptome revealed significant differences in gene expression between the 1% MSG and the combined exposure groups compared to controls. Key pathways affected by 1% MSG included oxidative stress, unfolded protein response and mitochondrial dysfunction. Increased ROS levels after 24 hours of MSG exposure were significantly reduced with 4 mM N-acetyl-L-cysteine. Autophagy regulation and upregulation of Deptor and TORC1 signaling were also observed.

Conclusions: Food flavor enhancers induce cytotoxicity, cellular stress, and barrier damage in gut epithelial cells. These findings raise concerns about their potential role in microbial imbalance, immune dysfunction, and inflammation.

Persistent infections with human immunodeficiency virus (HIV), hepatitis B/C viruses, or cancer are characterized by chronic antigen exposure and/or inflammatory signals, a condition where specific CD8⁺ cytolytic T lymphocytes (CTLs) gradually become "exhausted" and unable to eliminate these pathogens. Recent therapies aim to reactivate these exhausted T cells by using immune checkpoint inhibitors (ICIs) that block inhibitory molecules specifically upregulated on these cells. While these treatments boost immunity, they often cause severe immune-related side effects. Identifying new molecular pathways involved in T cell exhaustion could therefore provide safer alternatives to current ICI-based approaches.

Exhausted T cells have recently been found to upregulate CD39, a purine metabolizing enzyme, on their surface. Yet it is currently unknown whether this molecule is simply a marker or whether it directly contributes to T cell functional impairment.

In this project, we used in vivo approaches based on a mouse model of chronic viral infection, together with in vitro methods, to investigate the differential roles of purinergic signaling and CD39 in acute versus chronic T cell activation. Our results suggest that CD39 modulates T cell function in a cell-autonomous manner.

Bladder cancer was ranked as the 4^th most frequent cancer in males in America and Europe in 2022. Among all the patients, 20% is diagnosed with muscle-invasive bladder cancer (MIBC), characterized by disruption of the urothelium and invasion of the muscle layer by tumor cells. The gold standard treatment is cisplatin-based chemotherapy followed by radical cystectomy, but it confers patients a median 5-years survival of 46-63%. The use of Abs targeting the PD-1/PD-L1 axis has been approved but the response rate is only 17-23%, which highlights the urgent need to develop new therapeutic options. Radiotherapy (RT) is used in BC for bladder-sparing protocol which include very few patients who will undergo high dose RT combined with chemotherapy. However, low-dose RT has been investigated for its capacity to stimulate the TME and could be used in combination with immunotherapy.

Our project aims to detail the effects of diverse doses of RT on the TME of MIBC. We used a mouse model of MIBC that recapitulates features of the human disease, presents a suppressed TME and resistance to anti-PD-1 treatment. MIBC-bearing mice were irradiated with different doses of X-rays and the immune compartment was characterized by flow cytometry 7 days post-RT. Data showed an increase of anti-tumor immune cells, especially CD8 and CD4 T cells, and decrease of Tregs and pro-tumoral macrophages with low dose of X-rays compared to untreated mice. The beneficial effect of RT can lead to the development of novel therapeutic solution for MIBC patients, especially combined with immunotherapy treatments.

In the era of big data and machine learning, knowledge databases are becoming invaluable resources of structured data that can be integrated in omics pipelines and neural networks to accelerate data interpretation, generate new hypotheses and research projects.

UniProtKB knowledgebase (www.uniprot.org) is a reference resource of protein sequences and functional annotations across species of all branches of the tree of life. It integrates expert-curated structured data using ontologies and bioinformatic tools to link protein sequences to molecular functions, processes and phenotypes. Such data encompass gene-centric curation of immune system collections of antigen presentation and recognition molecules together with antigenic peptide epitopes mapped to immunology-specialized databases IMGT and IEDB.

We are currently curating the biochemistry of immune metabolites and immunogenic molecular structures aiming to provide a reference dataset relevant to immune cell activation and migration in innate and memory immune responses. Structured data of metabolic processes and protein-ligand interactions are integrated in UniProtKB, where an immune metabolite is mapped to a biochemical reaction curated in Rhea (www.rhea-db.org) based on chemical ontology of ChEBI (www.ebi.ac.uk/chebi), to enzyme, transporter or receptor binding sites based on resolved protein structures in the Protein Data Bank (PDB/PDBe), and to biological processes based on Gene Ontology (www.geneontology.org). Such structured data can be used in neural networks to contextualize raw data and infer immunogenic molecular structures involved in interspecies interactions.

Introduction: Mucosal cancers, including human papillomavirus (HPV)-driven head and neck carcinomas (HNC), present unique challenges due to their anatomical and immunological complexity. While therapeutic vaccines often prioritize T cell activation, emerging evidence highlights B cells as critical mediators of antitumor immunity, though their role in mucosal tumors remains poorly understood. Method: Here, we evaluate a tetravalent virus-like particle (VLP) nanovaccine, Qβ-HPVag, delivering HPV16 E6/E7 antigens and a TLR-9 agonist, administered intranasally in an orthotopic HPV⁺ HNC model. Results: We show that mucosal immunization with Qβ-HPVag significantly reduces tumor growth and enhances cytotoxic CD8⁺ T cell infiltration and function. Crucially, B cell depletion abrogated vaccine efficacy, with vaccination promoting the expansion of tumor-infiltrating memory B cells, plasmablasts, and IgA⁺ B cells, alongside systemic antigen-specific IgG responses. Conclusion: These findings contrast with traditional T cell-centric paradigms, revealing that B cells coordinate localized humoral immunity and synergize with CD8⁺ T cells to mediate tumor control. By integrating mucosal-targeted delivery with coordinated B and T cell activation, this study advances therapeutic vaccine strategies against HPV⁺ cancers and B cells as essential targets for next-generation immunotherapies.

Introduction: Triple-negative breast cancer (TNBC) is highly aggressive, with poor prognosis and limited effective treatments. Virus-like particles (VLPs)-based personalized vaccines offer a promising way to induce lasting antitumor immunity. While γδ T cells play roles in cancer, their interaction with nanoparticles is unclear. Administration route impacts efficacy: subcutaneous (s.c.) delivery within lymphatic watersheds targeting draining lymph nodes (dLNs), enhance local and systemic immune responses. Method: We developed plant-derived VLPs carrying TLR ligands and validated them by cryo-EM and biochemical assays. Using imaging flow cytometry and in vivo studies in the 4T1 s.c. TNBC model, we examined γδ T cell–VLP interaction and their role in vaccine efficacy. We compared three s.c. routes: systemic, targeting tdLNs, and targeting non-tdLNs. Survival was assessed under different dosing and ICI co-treatment. CD4+, CD8+, and γδ T cells were depleted to determine their contributions. Results: γδ T cells were expanded in dLNs and internalized VLPs post-vaccination. γδ subsets showed distinct activation. tdLN-targeted delivery, especially with ICI, gave the best outcomes. Depletion of CD4+, CD8+, or γδ T cells impaired efficacy, showing all are essential. Despite their rarity, γδ T cells were key to early tumor control. Conclusion: Our study highlights a crucial early role for γδ T cells in VLP-based cancer vaccination. Efficacy improved with ICI co-treatment and tdLN-targeted delivery, supporting inclusion of rare immune subsets like γδ T cells in cancer immunotherapy.

Urinary tract infections (UTIs) are highly prevalent, and traditional antibiotic treatments do not completely clear a UTI. The immune response is critical to the resolution of a UTI. Although animal models have given insights into the immune response to UTI, the human system is understudied, highlighting the need for human in vitro approaches. We aim to develop an immunocompetent human urothelial microtissue model to study the interaction between human immune cells and uropathogens.

The urothelial microtissue model is based on an established in vitro Transwell model of UTI, which contains a functional urothelium but lacks immune components. The model is adapted to enable immune cell migration, while urothelial integrity is confirmed by microscopy and the Transepithelial Electrical Resistance (TEER). Monocyte-derived macrophages are integrated into the model and the response to infection is analyzed by cytokine and LDH release.

A collagen matrigel coating was successfully added to create a porous barrier below the urothelium, where immune cells can be integrated. Urothelial microtissues were successfully grown, differentiated and stratified on the new substrate. In response to infection, the urothelium secretes a multitude of pro-inflammatory cytokines. Preliminary results show that macrophages can be integrated into the model, their response to infection will be studied next.

The novel immunocompetent urothelial microtissue model will provide new insights into the interplay between human immune cells and uropathogens, enabling discovery of novel pathways to combat UTI.

In the context of chronic diseases, such as cancer, a small proportion of exhausted memory-like T progenitor cells (Tex^prog) is maintained, and co-localizes with in niches formed by conventional type 1 dendritic cell (cDC1) to support them. Moreover, cDC1 also assists exhausted CD8⁺ T (Tex) populations in the early stages of tumor development. The tumor microenvironment (TME) alters cDC1 functionality to favor a more immunoregulatory state. Another critical component is the accumulation of collagen and other ECM components, produced by cancer-associated fibroblasts (CAFs), leads to fibrosis, which is linked to poor prognosis, and treatments targeting fibrogenesis are limited. Studying the role of cDC1s in tumor fibrosis offers a new therapeutic approach.

We used the Yumm1.7-OVA melanoma model to explore cDC1 capacity to control fibrosis and improve the infiltration capacity of anti-tumor CD8⁺ T cells during the early stages of tumor development. In later stages, cDC1 functionality changes, leading to an increase in collagen deposition, a loss of motility of tumor-infiltrating lymphocytes (TILs), and an accumulation of Tex cells. Transferring functional cDC1s from splenocytes from naïve mice restores the motility of tumor-infiltrating lymphocytes and counteracts fibrogenesis.

These results demonstrate an anti-fibrotic role of cDC1s in the tumor microenvironment, a finding that has the potential to extend to chronic inflammatory diseases where disregulated fibrous contributes to the underlying pathology.

Immune cells display diverse metabolic activities closely tied to their differentiation and function. CD8 T cells, in particular, exhibit distinct metabolic profiles across cell states during acute/chronic infections and in tumors. Advances in single-cell omics have enabled detailed transcriptomic and metabolomic analyses, yet integrating metabolic activity with transcriptomics at single-cell resolution remains a challenge, especially considering metabolism-driven epigenetic effects.

We introduce PrEMIuM-seq (Projectable Epitope and Metabolic Index Coupled Multi-Omics by Sequencing), a sequencing-based method extending the 10X Genomics single-cell platform. It uses DNA-barcoded monoclonal antibodies to capture surface epitopes, metabolic enzymes, and transcription factors. A correctable barcode library and in silico analysis improve unbiased protein detection. This allows simultaneous profiling of metabolic activity and transcriptomes at single-cell resolution.

To complement PrEMIuM-seq, we collected paired samples from same batch for traditional metabolomic/lipidomic analyses and SCENITH, a flow cytometry-based metabolic assay. Integrating these with machine learning enhances interpretation of cellular metabolism. This multi-omics framework offers a comprehensive view of how metabolic processes intersect with immune cell function.

Type-2 cytokine-driven macrophage polarization plays a pivotal role in both tissue repair and protective immunity against helminth infections. Although several characteristic features of alternatively activated, or M2, macrophages are well established, the mechanisms by which these cells mediate anti-helminth functions remain incompletely understood. In this study, we examined the role of arachidonate 15-lipoxygenase (Alox15), a key enzyme implicated in macrophage function during metabolic disease and a defining marker of human M2 macrophages. We found that Alox15 is essential for M2 macrophages to effectively immobilize and kill helminths. Surprisingly, M2 surface marker expression remained intact in Alox15-KO cells, despite a marked impairment in their function. This dysfunction was accompanied by heightened pro-inflammatory signaling linked to dysregulated activation of glycolysis. Further investigation revealed that lipid-mediated activation of Peroxisome proliferator-activated receptor-delta (PPAR-δ), specifically via downstream products of Docosapentaenoic acid (DPA), could re-establish proper glycolytic control. These findings uncover a previously unrecognized lipid-mediated regulatory axis that is critical for the metabolic programming underpinning effective M2 macrophage polarization, and underscore the importance of assessing both functional and phenotypic markers of polarization.

Aim:

Ferroptosis is a form of regulated cell death characterized by iron-dependent lipid peroxidation. Alternatively activated macrophages (AAM) play key roles in type 2 immunity against helminth parasites, despite being highly susceptible to lipid peroxidation and ferroptotic cell death. Thus, we investigate the role of ferroptosis in type 2 immune responses against the helminth H. polygyrus bakeri (Hpb).

Methods:

We utilize murine in vivo infection models, ex vivo cell cultures, immunostainings, transcriptomics, western blotting, live cell imaging and lipidomics to characterize the presence and consequences of ferroptosis during Hpb infection.

Results:

Hpb infection induces ferroptotic cell death in the small intestine (SI), while administration of the ferroptosis inhibitior liproxstatin-1 attenuates cell death, lipid peroxidation and anti-helminth immunity. The increase of lipid peroxidation and cell death in the SI was abrogated in mice lacking hematopoietic transglutaminase-2 (TG2). In line, TG2 deficient AAM show reduced arachidonic acid oxidation (eicosanoids) and an increased PUFA/ MUFA ratio in membrane phospholipids. Genetic deficiency, siRNA-mediated knock-down or pharmacological inhibition of TG2 consistently suppressed ferroptosis of human or mouse macrophages. Hpb-secreted glutamate dehydrogenase (heGDH), in turn, suppressed AAM ferroptosis.

Conclusions:

Ferroptosis contributes to parasite control, with host-derived TG2 orchestrating ferroptosis susceptibility in AAM, while heGDH impedes ferroptosis as a helminthic immune evasion strategy during type 2 immunity.

The heterotrimeric translocon Sec61 plays a crucial role in the endoplasmic reticulum (ER) by facilitating the transport of newly synthesized proteins into the ER and the export of misfolded proteins for proteasomal degradation, a process known as ER-associated degradation (ERAD). Peptides presented on MHC-I molecules originate from proteasomal degradation, suggesting that inhibiting Sec61 could impact MHC-I peptide presentation. Consequently, this may influence communication with other immune cells and potentially alter immune responses. Kezar Life Sciences has developed two chemically-related Sec61 inhibitors, KZR-834 and KZR-261, which have demonstrated broad anti-tumor activity in vitro and in vivo at well-tolerated doses. KZR-834 was examined here for its impact on bulk MHC-I presentation at non-toxic levels and on certain MHC-I epitopes. Flow cytometry analysis revealed a concentration-dependent decrease in MHC-I surface expression across various cancer cell lines and primary cells. The effect of KZR-834 extends to other unrelated surface proteins, indicating a broad impact on protein surface expression. Additionally, antigen presentation assays demonstrated a reduced presentation of specific MHC-I epitopes. Further experiments investigated whether KZR-834 affects antigen transport from endosomes to the cytosol. Indeed, Sec61 inhibition in cross-presentation experiments with ovalbumin showed a reduction in this process. Taken together, Sec61 inhibition can reduce MHC-I direct- and cross-presentation and is an attractive tool in modulating MHC-I surface expression.

Neutrophils are the most abundant immune cells in human blood and are essential in microbial defense. Recent studies show that they are transcriptionally active, responsive to external stimuli, and represent a heterogeneous population. Atopic dermatitis (AD) is a chronic inflammatory skin disease involving genetic predisposition, barrier dysfunction, microbial dysbiosis, and type-2-T-helper-cells (Th2)-predominant inflammation. While AD skin lesions are often colonized by pathogenic bacteria, neutrophils tend to be relatively limited compared to other inflammatory conditions. In mice, IL-4 has been shown to suppress neutrophil function, promote aging features, and increase susceptibility to infection.
Here, we investigated how human neutrophils adapt to opposing signals using in vitro stimulation with IL-4, IL-13, IFN-γ, and their combinations. IL-4 and IL-13 induced STAT6 phosphorylation, with IL-4 showing faster kinetics, while IFN-γ triggered STAT1 phosphorylation. Co-stimulation led to simultaneous STAT6 and STAT1 activation, although IFN-γ attenuated STAT6 signaling in IL-4-treated neutrophils. Functionally, NETosis was reduced by IL-4Rα signaling and enhanced by IFN-γ. Transcriptomic analyses further revealed that IFN-γ addition to IL-4 and IL-13 promotes expression of genes linked to neutrophil migration and chemotaxis. These findings highlight the plasticity of neutrophils and the immune-regulatory interplay between opposing cytokine signals in vitro.

Myeloproliferative neoplasms (MPN) are a group of chronic and life-threatening blood cancers characterized by the aberrant expression and activity of inflammatory cytokines, yet their precise contribution to disease pathogenesis is unclear. MPN patients may develop bone marrow (BM) fibrosis (BMF), which is usually associated with impaired hematopoiesis. BMF strongly correlates with increased morbidity and mortality of MPN patients. However, the mechanisms underlying BMF remain poorly understood, and current MPN treatments offer only limited improvement in BMF.

MPN patients exhibit elevated levels of IL-33 in their BM, suggesting that IL-33/ST2 signaling may play a role in MPN pathogenesis. Using a mouse model of MPN with transgenic expression of the JAK2-V617F mutated allele, we found that stromal cell-derived IL-33 is important for MPN development. Sinusoidal endothelial cells show increased IL-33 expression during MPN progression. In the BM niche, IL-33 binds to its receptor ST2 on stromal cells but not JAK2-V617F+ hematopoietic stem and progenitor cells. While megakaryocytes are known to play a critical role in bone marrow fibrosis, ST2 is present on wild-type, yet not on JAK2-V617F+ megakaryocytes. Further studies are ongoing to investigate whether and how IL-33/ST2 signaling contributes to BMF in mouse and human MPN.

Introduction. Trained immunity describes challenge-induced long-term functional reprogramming of hematopoietic progenitor cells and immune cells, resulting in an altered response to a secondary challenge. We have shown that training increases central granulopoiesis and neutrophilia, but whether training stimulates extramedullary granulopoiesis is unknown.

Aim. Determine whether trained immunity induces splenic granulopoiesis generating neutrophils with altered functions.

Methods. Mice challenged intraperitoneally with PBS (control) or β-glucan (training) were sacrificed after 7 days to collect spleens used in clonogenic assays and to isolate neutrophils characterized by flow cytometry and functional assays.

Results. Training induced splenomegaly and increased 4.8-fold clonogenic progenitors of granulocytes (CFU-G, p<0.0001) and 12.1-fold splenic neutrophils (p<0.001). In trained mice, splenic neutrophils expressed increased levels of Ly6G and CXCR2 that are associated with neutrophil maturation. Trained neutrophils secreted higher levels of granule molecules (MPO, MMP9, S100A8/A9) upon stimulation with microbial products and migrated more in response to CXCL1 and CXCL2 than control neutrophils (p<0.05).

Conclusions. Training induced in the spleen (i) extramedullary granulopoiesis, and (ii) phenotypically and functionally altered neutrophils. The molecular mechanisms underlying neutrophil reprogramming and the consequences of splenic neutrophilia on host defenses are under investigation.

Asthma is a chronic airway inflammatory disease marked by dysregulated innate immune responses. Recent evidence implicates innate immune memory, or trained immunity, in asthma pathogenesis. Yet, the underlying mechanisms remains poorly understood. Here, we explore the role of central trained immunity in a murine model of severe, steroid-resistant house dust mite (HDM)-allergic asthma induced by co-administration of HDM and the β-glucan Curdlan.

Flow cytometry and histological analyses revealed that HDM/Curdlan induces eosinophilic and Th2 responses, followed by sustained neutrophilic, Th17 inflammation in the lung, with persistent monocyte-derived alveolar macrophage (AlvM) infiltration and enhanced bone marrow myelopoiesis.

Single-cell RNA- and ATAC-seq analyses of hematopoietic stem and progenitor cells (HSPCs) demonstrated transcriptional, epigenetic, and metabolic reprogramming of myeloid HSPCs toward a pro-inflammatory state.

In parallel, SeaHorse assays and RNA-seq analysis of BMDMs showed reduced mitochondrial respiration and upregulation of pro-inflammatory genes.

Lastly, RNA-seq and ELISA analyses of AlvMs revealed a sustained pro-inflammatory phenotype characterized by increased eicosanoid production and transcriptional reprogramming similar to BMDMs.

Taken together, these results suggests that central trained immunity, characterized by myelopoiesis and HSPC reprogramming, contributes to persistent airway inflammation through the replacement of lung-resident AlvMs by “trained” bone marrow-derived cells, revealing a novel mechanism driving severe asthma.

Therapeutic immunoglobulin G (IVIG) production is constrained by the limited supply of human plasma. As an alternative, recombinant hexamers (HEX) derived from IgG1-Fc fused with the IgM μ-tailpiece have been developed. One key mechanism of IVIG involves targeting Fcγ receptors (FcγRs) to inhibit NK cell-mediated antibody-dependent cell-mediated cytotoxicity (ADCC). This study aimed to compare the effects of IVIG, HEX variants and Fc monomers on NK cell viability, metabolism, and function.

NK cell viability was tested by trypan blue exclusion; metabolic activity by resazurin-based assay; apoptosis (Annexin-V staining), activating/inhibitory NK receptors, and activation markers were analyzed by flow cytometry; cytokines release was quantified by cytometric-bead array. Direct cytotoxicity and ADCC were assessed by non-radioactive release assays using K562 or anti-CD20-coated Daudi cells as targets.

After 16h of incubation, HEX-variants masked CD16 detection by flow cytometry, whereas CD16 was still detectable following incubation with IVIG and the Fc monomer. Both IVIG and HEX induced minimal NK cell death compared to medium (<20%), with no alterations in metabolic activity. HEX was the most potent inhibitor of ADCC (90% inhibition). Furthermore, IVIG and HEX inhibited direct cytotoxicity (55% and 45% reduction, respectively). All IgG molecules, except Fc monomer, triggered the release of TNF and IFNγ by NK cells.

In conclusion, HEX inhibited NK cell effector functions indicating the potential to substitute IVIG in the treatment of auto-antibody-mediated diseases.

The fate of CD8⁺ T cells is crucial for immunity against chronic infection, cancer, and autoimmunity. Promoting stem-like properties and reversing exhaustion are pivotal strategies to enhance adoptive cell therapy (ACT) and immune checkpoint blockade, yet the mechanisms underlying memory formation remain poorly understood. Here, in vivo CRISPR–Cas9 screening during acute LCMV infection identifies a noncanonical PI3Kγ signaling axis as a central regulator of CD8⁺ T cell fate. We show that while both PI3Kδ and PI3Kγ deficiency enhance memory formation, only PI3Kγ deficiency improves cytokine production and strengthens T cell recall responses. Using kinase-dead knock-in models, we demonstrate that PI3Kγ kinase activity is essential for T cell fate decisions. Single-cell RNA sequencing and epigenomic profiling reveal that PI3Kγ deficiency promotes memory formation through upregulation of TCF1 and Bcl-2, bypassing canonical PI3K–mTOR signaling and engaging NFAT pathways. In chronic infection, PI3Kγ-deficient T cells sustain proliferation, resist exhaustion, and enhance cytotoxicity, driving superior responses to ACT and checkpoint blockade. These findings establish the CXCR4–PI3Kγ axis as a critical switch for CD8⁺ T cell fate, offering new strategies for optimizing T cell–based immunotherapies.

CARD11 is a scaffold protein essential for NF-κB, mTORC, and JNK activation following BCR/TCR engagement. Gain-of-function (GOF) mutations in CARD11 lead to constitutive NF-κB activity, B cell expansion, and T cell anergy in patients (BENTA syndrome), whereas loss-of-function (LOF) mutations result in immunodeficiency. We identified a novel CARD11 variant (K356T) by whole exome sequencing in a patient presenting fever of unknown origin and lacking typical BENTA clinical features. Our aim is to characterize the impact of this novel mutation variant on intracellular signaling.

Plasmids encoding wild-type (WT), K356T (novel), and C49Y (GOF control) CARD11 were generated. A CARD11-deficient Jurkat T-cell line expressing an NF-κB-driven GFP reporter (JPM50.6) was electroporated with WT or mutant plasmids and stimulated with anti-CD3/CD28 antibodies or phorbol 12-myristate 13-acetate plus Ionomycin. NF-κB reporter activity was assessed by flow cytometry. In parallel, phosphorylation kinetic of S6, p65, and JNK were analyzed by phospho-flow following stimulation of PBMC.

Transient expression of CARD11 novel K356T mutant in JPM50.6 induced modest constitutive NF-κB reporter activity, in contrast to the lack of activity of WT. This activity  was further enhanced  upon stimulation. Phospho-flow of healthy donor PBMC identified optimal stimulation times. In conclusion, we describe a novel CARD11 mutation associated with atypical clinical manifestations and mild GOF activity in vitro. Further characterization using phospho-flow in the patient’s PBMC is ongoing.

Nephrotic syndrome (NS) is a glomerular disease characterized by increased permeability of the filtration barrier. In order to understand the underlying immune mechanism, the aim of this study is to characterize different subsets of DCs in the urine of patients with NS.

Urine and blood samples were collected from children with NS (n=7) and compared with controls (n=10). Cells were analyzed by FACS with markers identifying DC subsets, as well as T cells, NK, neutrophils and macrophages.

Flow cytometry data, analysed by PCA, allowed the discrimination of NS patients from controls in both urine and blood samples, suggesting that the FACS panel used was relevant in identifying a cellular signature of NS in this study.

Preliminary data show that, although the frequencies of CD3T-cell populations in urine are very low (<0.05% total cells), the HLA-DR population may reach up to 5% of total cells. Among the DC subtypes, the DC3 (CD1c⁺CD14⁺) population was significantly increased in the urine of NS patients compared to controls. Screening the composition of DC3 population, a higher frequency of DC3 not expressing the FceRI-receptor accumulates in the urine of patients with complete remission compared to patients in remission but still on treatment or in relapse. These results suggest that the FceRI^negDC3 population may develop during patients' recovery and open the question of whether it is involved in the resolution of NS.

These findings demonstrate for the first time that a DC subset can be found in urine in pediatric patients with NS and may be related to the remission status.

Aim:

To review current evidence regarding the modulation of immunological biomarkers in atopic dermatitis (AD) following targeted therapeutic interventions.

Methods:

A narrative review was conducted, focusing on clinical trials investigating the impact of biologic therapies (dupilumab, tralokinumab, lebrikizumab) and JAK inhibitors (baricitinib, upadacitinib) on type 2 cytokines, chemokines (such as TARC/CCL17), eosinophil levels, and markers of skin barrier integrity including filaggrin.

Results:

Clinical data show that targeted therapies consistently lower serum concentrations of TARC/CCL17 and eosinophils [1,2], alongside reduced expression of IL-4 and IL-13 [1], which correlate with clinical improvement. In addition, IL-31 modulation has been associated with significant relief of pruritus [3]. Restoration of skin barrier function has been reported in responders, evidenced by increased filaggrin expression [4]. These findings reinforce current recommendations that highlight the relevance of biomarker monitoring in AD management [5].

Conclusions:

Targeted therapies in AD not only alleviate clinical symptoms but also address underlying immune dysregulation and epithelial barrier dysfunction. Biomarkers such as TARC/CCL17 and filaggrin may support clinicians in monitoring disease activity, evaluating therapeutic response, and informing treatment selection according to individual immune profiles. Nevertheless, additional clinical trials are needed to validate these biomarkers for routine use and to better define their role within future personalized treatment strategies.

Aim

Multicentric Castleman’s disease (MCD) is a rare lymphoproliferative disorder driven by human herpesvirus-8 (HHV-8) with cytokine overproduction. We report a case of MCD with agranulocytosis due to anti-proteinase 3 (PR3) antibodies in an HHV-8 positive, HIV-negative patient.

Methods
Retrospective study documenting agranulocytosis, anti-PR3 antibodies, and histologically confirmed MCD in the context of HHV-8 positivity and HIV negativity.

Results

A 59-year-old man with hepatitis C, cirrhosis, and substance abuse presented with fever, diarrhea, and weight loss. Labs showed agranulocytosis, elevated CRP (98 mg/l), and positive ANCA with anti-PR3 antibodies (70 UI/ml). CT revealed lymphadenopathy. Biopsy confirmed HHV-8 positive MCD. PCR for HHV-8 was positive in serum, bone marrow, bronchoalveolar lavage, and lymph node. HIV testing was negative. Skin lesions were diagnosed as Kaposi’s sarcoma (KS).

Despite G-CSF, agranulocytosis persisted. Bone marrow biopsy showed granulocytic maturation block. Rituximab (RTX) and low-dose prednisone were given, leading to fever reduction, CRP normalization, and KS regression. Agranulocytosis persisted for 11 months, improving with the disappearance of anti-PR3 antibodies.

Conclusion
This case demonstrates a rare presentation of agranulocytosis with MCD and HHV-8 positivity. In such MCD cases, RTX with or without liposomal doxorubicin is the preferred treatment. In our case, KS regressed with RTX alone. We suggest a link between anti-PR3 antibodies and agranulocytosis, as their disappearance coincided with the resolution of the condition.

SLE causes diverse clinical symptoms, leading to significant physical and psychological strain. Active disease and flares increase fatigue, pain and organ damage. Patient-reported tools such as SLAQ are vital to capture patient experiences. Here, we evaluate self-reported disease activity and its influencing factors in Swiss SLE patients. 

Patients were invited to survey via digital ads, patient organization newsletter and a letter from Swiss SLE Cohort Study. Inclusion criteria were SLE diagnosis, age 18+ and living in Switzerland. Disease activity was assessed with SLAQ total score (ranging from 0 to 47). SLAQ also covers the flares and global assessment of overall activity (ranging from 0-10).  

146 mostly female and Caucasians patients with a median age of 48.5 were studied. Mostly used SLE medications were antimalarials and immunosuppressants. The mean SLAQ score was 19.35 and disease overall activity was 3.86. Moderate/severe flares were reported by 28.7% of patients. 6.7% of those without or with mild flares were not on medication. Regression analysis showed SLAQ scores significantly correlated with having flares and daily pill intake. Higher NSAID and antidepressant use and lower average treatment satisfaction across all SLAQ dimensions were noted in patients with high disease activity. 

Persisting disease burden in SLE patients in Switzerland underscored by substantial disease activity, existence of flares and high usage of glucocorticoids. The study reveals an association between increased disease activity, treatment patterns and overall treatment satisfaction. 

Background: Common variable immunodeficiency (CVID) is a heterogenous antibody deficiency syndrome characterized by increased susceptibility to infection, autoimmune manifestations, and increased risk of malignancy. CVID patients can be divided according to the presence of immune dysregulation into complicated (c) versus infection only (io)CVID. Although CVID is the most prevalent symptomatic inborn error of immunity early detection of immune dysregulation can be challenging, and delayed detection can cause irreversible organ damage.

Methods: We conducted a single-center retrospective chart review of the role of routine biomarkers in CVID patients presenting with or without immune dysregulation prior to and upon immunosuppressive treatment.

Results: 45 CVID patients were assessed including 16 ioCVID and 29 cCVID patients on (20/29) or off immunosuppressive treatment. Routine inflammatory biomarkers (CRP, WBC, CD21low, Neopterin and sIL-2R) were compared among individual patients in respect to immune dysregulation and upon immunosuppressive treatment.

Conclusion: Our study affirms the role of biomarkers as effective method in the screening of manifestation of immune dysregulation and in monitoring treatment responses in cCVID.

Introduction

Anti-cytokine autoantibodies (ACAAb) are increasingly recognized for their impact on disease phenotypes in infections, inflammatory disorders, and autoimmune conditions. By specifically blocking cytokine signaling pathways, ACAAb can phenocopy inborn errors in the related signaling pathways.

Case report

Here we report a case of adult-onset Legionella pneumonia followed by disseminated Mycobacterium abscessus and Salmonella enterica subsp. enterica infection associated with neutralizing anti-IFN-γ antibodies. The results corroborate the disease-causing role of neutralizing anti-interferon-gamma ACCAb in disseminated non-tuberculous mycobacterial infections.

To assess the neutralizing capacity of the interferon-γ-specific ACAAb, we performed flow-cytometry based STAT1 phosphorylation experiments using Jurkat T cells in the presence or absence of recombinant IFN-gamma. Reduced IFN-gamma induced STAT1 phosphorylation was measured in the presence of the serum of the patient vs. sera from control patients from a prospective cohort of patient with primary immunodeficiency.

Discussion

IFN-gamma-specific ACAAb have been described as likely molecular cause of disease for non-tuberculous mycobacteria, Varicella-Zoster virus, Talaromyces marneffei, Salmonella spp., Cryptococcus spp., Mycobacterium tuberculosis, Burkholderia spp., and Histoplasma capsulatum. It is crucial to consider the possibility of anti-interferon gamma antibody disease. A targeted laboratory analysis should be conducted to investigate this condition. The therapeutic landscape of this disease is evolving.

Erasmus syndrome is a rare, occupationally related condition characterized by the development of systemic sclerosis (SSc) in a background of silica exposure or silicosis, a preventable fibrosing lung disease caused by the inhalation of crystalline silica. Silica particles trigger inflammation such as macrophage activation, cytokine release and upregulation of cell-signaling pathways, leading to fibrosis. The main manifestations are respiratory, including dyspnea, chronic cough, and fatigue, reflecting the underlying pulmonary and systemic fibrotic processes. We report on a 37-years-old male diagnosed in 2020 with nonspecific interstitial pneumonia (NSIP) in the context of systemic sclerosis (SSc) with diffuse cutaneous involvement. The patient is seropositive for anti-topoisomerase I and anti-Ku antibodies, although the clinical significance of the latter remains unclear. He was treated with Mycophenolate mofetil, resulting in stable pulmonary function and favorable cutaneous responses. A routine chest HRCT in early 2024 revealed mediastinal and hilar lymphadenopathies with intraparenchymal calcifications and micronodular changes in the upper lobes, unrelated to the autoimmune condition. NSIP-like alterations in the lower lobes indicated ongoing autoimmune involvement. Imaging deterioration with new findings prompted a review of the clinical history, revealing prolonged exposure to stone dust between the ages of 15 and 19, as well as ongoing exposure to ceramic dust since 2021. A lung biopsy subsequently confirmed the presence of silicotic nodules, establishing the diagnosis of Erasmus syndrome.

Most biological agents contain polyethylene glycol (PEG) derivatives, which are very stable and generally considered to be non-immunogenic. However, an explosion in hypersensitivity reactions to such products have been seen recently.

Here, we evaluated 13 patients who experienced severe anaphylaxis to SonoVue®, a contrast medium for ultrasound which contains lipid particles that are stabilised with PEG-4000. A control group of 13 tolerating individuals was also analysed. Sensitization to SonoVue® was confirmed using the basophil activation test (BAT), which yielded positive results in 6 of the 13 patients, but none in the tolerant group. Notably, all patients who suffered anaphylaxis also tested positive for BATs to COVID-19 vaccines, while none in the tolerant group did. Additionally, polysorbate 80 reactivity was observed in 8 of the 13 patients, but none in the tolerant group.

For mechanistic investigation, the inhibition of the FcεRI signalling pathway significantly reduced basophil activation. Furthermore, linear PEGs were shown to reduce basophil activation by spherical PEGs in vitro, suggesting that linear PEGs can occupy binding sites without cross-linking FcεRI and thus do not induce basophil degranulation.

PEG sensitization may have been boosted by mRNA COVID-19 vaccines, which contain PEG. Given its presence in numerous pharmaceuticals, PEG sensitization could pose a public health concern. Further research is crucial to understand the immune response to PEG, a molecule that is neither a protein nor a carbohydrate.

«Aim» As a first step evaluating a novel fully automated IFA analyzer (LumiQ^TM, AliveDx, Switzerland) combined with the HEp-2 substrate Diagnostic Kit for antinuclear antibodies (ANA) (investigational device, TEST), we assessed the analytical performance of the TEST, used manually by the same operator, compared with historical IFA results of samples from individuals under suspicion of autoimmune connective tissue diseases.

«Methods» Banked, de-identified sera, previously manually characterized by a routine HEp-2 IFA were included (50 non-reactive, 57 reactive, various titers and a broad range of IFA patterns) and assessed with the TEST at a 1:80 screening dilution. Manual testing followed the manufacturer's instructions, and 1 operator performed all readings using a fluorescent microscope. Results were interpreted as reactive/non-reactive, patterns identified, and reactivity graded (1+ to 4+) at 1:80 dilution. Positive (PPA), negative (NPA) and overall percent agreement (OPA) were calculated. Pattern agreement for reactive samples was also determined.

«Results» 5 samples were excluded due to operator error. PPA was 100% (52 of 52 reactive samples, 95% CI: 93.2, 100). 46/50 samples remained non-reactive, for a NPA of 92% (95% CI: 80.8, 97.8). OPA was 96.1% (95% CI: 92.3, 99.8). Pattern agreement was 96.3% (95% CI: 87.3, 99.5), with only 2 discordant results, graded 1+.

«Conclusions» Manual preparation and reading using the TEST showed high concordance with historical results. Future studies will assess the fully automated performance to further validate the device and platform.