Introduction

Celiac disease (CD) is an autoimmune disorder triggered by gluten ingestion in genetically predisposed individuals, leading to chronic intestinal inflammation. It affects about 1% of the global population and is often undiagnosed in childhood due to the absence of symptoms, with around 65% of cases in Italy going unnoticed. Early screening is a key tool for timely diagnosis and preventing long-term complications. In this perspective, the D1Ce Screen pilot study follows Italian Republic Law 130/2023, which mandates screening for pre-symptomatic CD and type 1 diabetes (T1D) in the general paediatric population through autoantibody measurements in capillary blood. Paediatric screening is a key tool for early detection and the prevention of long-term complications, associated with late or missed diagnosis. Individuals who tested positive for CD and T1D -specific autoantibodies will undergo further clinical evaluation at the regional specialized center to confirm the diagnosis

Aims & Methods

Primary objective of D1Ce Screen study is to assess, feasibility, acceptability and sustainability of a nationwide screening program, for the evaluation of undiagnosed CD cases and presymptomatic T1D. To assess operational aspects D1Ce Screen evaluates the involvement of primary care pediatricians (PCPs), blood sample collection accuracy and acceptability for families measuring anxiety, depression and quality of life through 3 validated questionnaires.
This is an observational multicenter study to screen 5,363 children in four Italian regions (Lombardy, Marche, Campania, Sardinia), distributed into three classes of age (2-2.9, 6-6.9, and 10-10.9 years), corresponding to peaks of seroconversion for these diseases. For eligibility, the inclusion criterion is age. T1D is the exclusion criterion. Voluntary PCPs were responsible for recruitment of participants, administration of informed consents and questionnaires, execution of blood drawing by finger prick, capillary blood collection and sample shipment. Specific T1D and CD autoantibodies are measured by ELISA in capillary samples. In addition, HLA DQ2 and DQ8 HLA typing is performed on dried blood spot (DBS).

Results

PCPs initially accepting to participate were 565, with 428 (75,7%) completing the study. Enrolled children were 5534, with 91,1% within the target age. The gender distribution was 49.4% females, 50.6% males. Samples suitable for analysis (adequacy for at least one assay) were 89% of the total collected. Most of DBS samples were suitable for HLA typing. The target of families undergoing questionnaire evaluation of 2% has been exceeded.

Conclusion

The D1Ce Screen pilot study provides evidence supporting the feasibility of a nationwide screening initiative. The active collaboration of PCPs, the high level of participation from families, and the efficient implementation of capillary blood sampling procedures were key contributors to its success. These findings confirm the potential for scalability of a paediatric screening program for T1D and CD within the framework of the Italian National Health Service. Early detection and timely initiation of a gluten-free diet in children diagnosed with CD are essential to preventing long-term complications and improving health outcomes.

References

Bosi E, Catassi C. Screening type 1 diabetes and celiac disease by law. Lancet Diabetes Endocrinol. 2024 Jan;12(1):12-14. doi: 10.1016/S2213-8587(23)00354-6

Introduction

TPM502 is a mixture of three distinct nanoparticles, each coupled with one celiac disease (CeD)-relevant gluten peptide, representing immunodominant and deamidated CD4⁺ T cell epitopes. TPM502 targets liver sinusoidal endothelial cells, which are unconventional antigen-presenting cells capable of inducing antigen-specific tolerance.

Aims & Methods

TCeD21 (NCT00565136) was a phase 2a double-blind, randomized, placebo-controlled study in HLA-DQ2.5-positive adults with confirmed CeD on a gluten-free diet. Patients achieving a predefined IL-2 response to a single dose (6 g) gluten challenge (GC1) were randomized into four cohorts to receive two intravenous infusions with escalating doses of TPM502 or placebo on day (D) 1 and D15. The GC was repeated 7 days after the second TPM502 dose (GC2). Peripheral blood mononuclear cells collected from each patient at predefined timepoints were analyzed by high-dimensional (30-color) flow cytometry, before and after HLA-DQ2.5-gliadin-specific tetramer (tet) enrichment, using surface staining for various phenotypic markers. The study aimed to characterize the phenotypes of gluten-specific T cells in CeD patients before and after TPM502 treatment to assess its immunomodulatory effects.

Results

Samples from 36 patients completing the study (12 placebo, 24 TPM502) were analyzed across five timepoints. In the placebo group, tet⁺ CD45RA^-CD62L^-CD4⁺ T (Ttet) cells increased after both GCs. By contrast, the TPM502 cohorts exhibited elevated Ttet cell numbers before GC2 (D22) but showed limited expansion afterward (D29), suggesting that TPM502 treatment may prevent further activation-induced expansion. Moreover, the frequency of activated Ttetcells—indicated by activation markers CD38, ICOS, and OX40—significantly decreased across all TPM502 dose levels after GC2 compared to the placebo group (fold change D22 vs D29, all p < 0.0001 by Kruskal-Wallis test). Notably, the diminished gluten response of Ttet cells post-treatment was accompanied by enhanced expression of co-inhibitory receptors TIGIT and PD-1 (D-21 vs D29, p < 0.0001), along with reduced CD127 expression (p < 0.01), indicative of decreased cell survival. These phenotypic changes, consistent with T cell exhaustion or anergy, persisted until study end and were visibly distinct from those in the placebo group, as illustrated by the heatmap of delta log-transformed flow cytometry data of Ttet cells across timepoints, clustered hierarchically. Gliadin-specific CD4⁺ regulatory T cells (CD25⁺CD127^- Ttet) and CD39⁺ Ttet cells increased post-treatment at the highest TPM502 dose, suggesting the induction of regulatory states in these T cells. Moreover, pre-enriched samples showed reduced activation of αEβ7⁺ γδ⁺ and CD8⁺ Tcells after GC2 at the highest TPM502 dose, suggesting potential bystander effects.

Conclusion

Data from the first longitudinal tetramer-based flow cytometry analysis in CeD patients provide evidence that TPM502 induces antigen-specific tolerance through T-cell immunomodulation. These results corroborate other pharmacodynamic outcomes generated in this study, including a significant and dose-dependent reduction in ex vivo IL-2 and IFN-γ secretion by gluten-specific T cells after treatment. In addition to a good safety and tolerability profile of TPM502, this nanoparticle-mediated induction of antigen-specific tolerance may provide a novel therapeutic avenue to treat celiac disease.

Introduction

Obesity, characterized by low-grade systemic inflammation, is associated with numerous chronic inflammatory conditions including inflammatory bowel diseases (IBD). While accumulating body fat has direct influence on IBD progression, creeping fat (CF) in Crohn’s disease (CD) manifests independently of body weight. As a response of mesenteric adipose tissue (AT) to intestinal inflammation, preadipocytes migrate towards affected intestinal segments to form a distinct immunophenotypic AT comprising hyperplastic adipocytes, preadipocytes and immune cells which exert complex immunologic and metabolic interactions with the adjacent intestine. However, associations between the cellular architecture of CF and CD progression remain unclear.

Aims & Methods

We aim to study gut-AT interactions in the context of IBD, focusing on the role of preadipocytes in CF as well as relevance of metabolic integrity of mesenteric adipocytes for intestinal homeostasis. Ex vivo co-cultures of wild-type murine intestinal organoids and mesenteric mature adipocytes or preadipocytes using a novel 3D culture system allowed us to study direct effects on transcriptional profiles and growth capacity, distinguishably between adipogenic cells of distinct differentiation states. Furthermore, we generated a mouse model of adipocyte-specific mitochondrial dysfunction by genetic deletion of heat shock protein 60 (Hsp60) to investigate mechanisms of metabolic and inflammatory phenotype transmission between mesenteric AT and intestinal epithelium. In addition, we used human mesenteric and CF explants from CD patients undergoing surgical resection to isolate preadipocytes and perform ex vivo proliferation and differentiation studies.

Results

In intestinal organoids from mice, the presence of both, mature adipocytes and preadipocytes induces downregulation of Hsp60 accompanied by induction of mitochondrial stress markers (Trb3, Chop). However, solely preadipocytes were sufficient to induce intestinal epithelial gene signatures involved in oxidative stress (Ido1, Nos2, Duox2) and reduced stemness (Lgr5) as attributable to metabolic impairment and injury phenotypes. Conversely, in response to presence of intestinal organoids, mesenteric adipocytes show upregulated expression of browning markers (Ucp1, Cidea, Cox7a1) accompanied by reduced inflammatory and mitochondrial stress signaling. In mice, genetically induced mitochondrial dysfunction in adipocytes leads to phenotypic AT remodeling of specifically the mesenteric depot, resulting in extensive immune cell infiltration and crown-like structure formation in anatomic relation to the intestinal epithelium. Human CF-derived preadipocytes in comparison to equivalent cells from healthy mesentery of the same patient exhibit distinct morphological features and diminished lipid incorporation after adipogenic differentiation ex vivo.

Conclusion

We demonstrate that exclusively preadipocytes condition the intestinal epithelium to injury-related phenotypic features, suggesting a novel and crucial relevance for IBD research and management. Vice versa, intestinal epithelial cells can stimulate mesenteric adipocytes to recruit thermogenic capacity, which is associated with anti-inflammatory effects, suggesting a protective role of mesenteric AT browning capacity. Disturbing adipocyte mitochondrial function is sufficient to remodel mesenteric AT architecture and induce propagating inflammation. Consequent effects on the adjacent intestine we address in our ongoing studies considering adipocyte mitochondria as target for therapeutic interventions in CD.

Introduction

The achievement of histological remission (HR) is a key treatment goal in ulcerative colitis (UC), as it is suggestive of better disease management and predicts response to therapy.
The absence of neutrophils in epithelium and lamina is crucial to define HR. However, the role of neutrophil number and localisation remains unclear. We aimed to develop a novel artificial intelligence (AI)-driven system to automate neutrophil detection, localisation, and quantification, supporting assessment of HR and enable the prediction of response to therapy.

Aims & Methods

We developed an AI-driven system by integrating two deep learning models to (1) segment whole slide images (WSIs) into epithelium, crypts and lamina propria and to (2) detect and quantify neutrophils. Outputs from these models were combined to compute neutrophil densities in the lamina propria, epithelium, and overall tissue. The optimal neutrophil density cut-offs to assess disease activity (Geboes score >2B.0) in UC patients were identified in the AMAC phase 2 Mirikizumab trial, and subsequently validated in the multicentre prospective PICaSSO cohort study. Cut-offs to determine treatment response at weeks 12 and 52 (histological improvement [HI; Geboes score ≤3.1] and histological remission [HR; Geboes score ≤2B.0]), were also evaluated.

Results

Table 1 shows the system diagnostic performance in assessing disease activity and predicting response to therapy at W12 and W52 in the Mirikizumab cohort.
303 WSIs from active UC patients from the multicentre, randomised, double-blind, parallel-arm, placebo-controlled phase 2 clinical trial of Mirikizumab were analysed. The model yielded a DICE SØrensen of 0.57 for segmentation, precision of 82.3% and recall of 77.0% for neutrophil detection. The system identified an overall optimal neutrophil density cut-off (cells/mm²) predictive of disease activity of >21.7.0 (>10.1 and >30.4 for epithelium and lamina propria, respectively), with an accuracy of 86% (85% and 85%, respectively). Further validation in the multicenter PICaSSO cohort yielded to similar results.
Moreover, the overall optimal cut-off to predict histological remission at W52 was <20.8 (<10.4 and <27.9 for epithelium and lamina propria, respectively), with an accuracy of 82.0% (81% and 80%, respectively).

Conclusion

Our novel AI-based system demonstrates strong potential as an automated tool to detect, localise, and quantify neutrophils to assess histological activity and predict response to therapy in a clinical trial UC cohort and real-world settings. This framework could be applied in clinical trials and routine clinical practice, offering objective guidance for personalised management in UC patients.

References

[1] Santacroce G, Meseguer P, Zammarchi I, et al. P406 A novel active learning-based digital pathology protocol annotation for histologic assessment in Ulcerative Colitis using PICaSSO Histologic Remission Index (PHRI). Journal of Crohn's and Colitis, Volume 18, Issue Supplement_1, January 2024, Pages i843–i844
[2] Graham S, Vu QD, Jahanifar M, et al. CoNIC Challenge: Pushing the frontiers of nuclear detection, segmentation, classification and counting. Med Image Anal. 2024;92:103047.

Disclosure

MI received research grants and consultant fees from Olympus, Pentax, Eli Lilly, and Janssen. All other authors declare no competing interests.