Introduction

Corticosteroids are a common treatment for patients with moderate to severe active ulcerative colitis (UC), but their effects can vary among individuals, including resistance, response, and dependence. While patient responses to corticosteroid therapy are generally swift, clinical remission may not be immediate for some. This suggests that corticosteroid treatment should be continued for a period of time to differentiate between corticosteroid-resistant and corticosteroid-sensitive patients with moderate to severe disease activity. Consequently, identifying factors that can predict whether steroid use should be maintained or if a switch to a different treatment is necessary is an important consideration.

Aims & Methods

We compared the clinical characteristics of steroid responders and non-responders in patients with UC and retrospectively evaluated for biomarkers that could predict the efficacy of corticosteroid therapy prior to treatment in patients with moderate to severe active UC. Additionally, we compared the changes in various parameters before and after corticosteroid administration between steroid responders and non-responders. We enrolled 102 UC patients from Nippon Medical School Hospital who had a history of corticosteroid treatment prior to June 2024. The patients were divided into two groups: steroid responders and steroid non-responders. Their clinical characteristics were determined based on medical records.

Results

A total 102 UC patients with moderate to severe disease activity were included in this study. The clinical characteristics at baseline were as follows: the median age, 43 years (average 44.76± 17.79); with 61 males and 41 females. The most common distribution of disease type was total colitis (65%), followed by left-sided colitis (32%), and proctitis (2%). 42.6% of patients had severe disease activity. After remission induction therapy, 16% of patients were steroid non-responders, while 84% were steroid responders. The average Mayo Endoscopic Score was significantly lower, and eosinophil counts were higher in the steroid responder group compared to the steroid non-responder group (P=0.023, 0.016). We also compared changes in various parameters at baseline and 4 weeks after steroid treatment between the two groups. After 4 weeks, inflammation markers including CRP and platelet counts decreased significantly in both groups. Hemoglobin and albumin levels increased significantly, and eosinophil counts decreased in the steroid responder group, but these changes were not observed in the steroid non-responder group.
Histological examination revealed no significant difference in the number of eosinophils infiltrating the colorectal mucosa on biopsy before steroid therapy between the two groups. However, 4 weeks after treatment, the number of infiltrating eosinophils was significantly decreased in the steroid responder group (P<0.001, Wilcoxon signed-rank test), while no change was observed in the steroid non-responder group.

Conclusion

Eosinophil count in the blood could serve as a potential biomarker for steroid responsiveness prior to administration. Additionally, steroid use decreases inflammatory markers such as CRP and platelet count, regardless of patient response. However, eosinophil counts were reduced only in the responder group, suggesting that changes in eosinophil count may also be a predictor of efficacy in the long term.

Introduction

PD-1 downregulates activated T cells and dysregulation of its signaling impacts critical T cell responses in inflammatory and autoimmune diseases, including ulcerative colitis (UC). In UC lamina propria, multiple T cell subtypes express PD-1, including peripheral helper T cells (Tph) and effector memory T cells, and the reduction of PD-1+ Tph cells is correlated with remission.¹ While PD-1 is being evaluated in UC, it has been clinically validated as a target in two Ph2 studies in RA.^2,3 Rosnilimab, an investigational antibody, aims to leverage immune homeostatic mechanisms to regulate T cell activity by depleting PD-1^high T cells and reducing the activity of remaining PD-1+ T cells.⁴ Rosnilimab, when compared to isotype control, reduced inflammation of the colon, reduced infiltration of CD4 T cells and maintained body weight of mice in a murine model of colitis induced by the transfer of CD4+CD45Rb+ T cells from human PD-1 transgenic mice.⁵ Additionally, pathway genes indicative of fibrosis and impaired barrier function in human UC were normalized in rosnilimab-treated animals while dysregulated in the control group.⁶ Myeloid cells also contribute to inflammation in human UC, and reduction of their elevated numbers are associated with disease remission.⁷ An inflammatory myeloid cell gene signature was derived from human UC and used to assess inflammatory myeloid cells and the therapeutic impact of rosnilimab in this murine model of colitis.

Aims & Methods

A UC myeloid gene signature was derived via secondary analyses of single-cell RNA sequencing data from a published atlas of human UC tissue⁷ to identify 1,652 genes that were upregulated in inflamed myeloid cells compared to non-inflamed cells. These genes were then compared with 3,859 genes upregulated in a murine model of colitis. The resultant overlap of 625 genes was used to define the mouse colitis myeloid gene signature. Overlapping genes were analyzed for regulation in the murine model of colitis following rosnilimab treatment. Myeloid cell gene transcription in colonic tissue from mice treated with rosnilimab or isotype control was assessed via spatial transcriptomics.

Results

In a murine model of colitis, rosnilimab treatment resulted in the downregulation of 399 (64%) of the mouse colitis myeloid signature genes, suggesting an ability to impact a large proportion of the overlapping genes that are similarly dysregulated in human UC. These included mediators of immune cell recruitment (Ccl3, Ccr1) and detection of bacterial components (Cd14, Tlr2 and Tlr4). Additionally, genes involved in immune activation and amplification mediated by myeloid cells were reduced by rosnilimab (Il6, Cd80, Cd86, Myd88, Trem1, and Stat4). Spatial transcriptomic analyses of colonic tissue showed that rosnilimab reduced myeloid cell numbers, including M1 and M2 macrophage subtypes, compared to isotype control treated mice.

Conclusion

In addition to reducing pathogenic T cell numbers in this murine model of colitis, rosnilimab treatment also reduced pathogenic macrophages and the inflammatory myeloid gene signature in the colon. These data support previous preclinical findings demonstrating the potential therapeutic benefits of selectively targeting activated PD-1+ T cells and depleting PD-1^high T cells in reducing inflammation and improving UC outcomes in a murine model of colitis. These results, together with existing rosnilimab safety data in humans, support the scientific rationale for evaluating rosnilimab in an ongoing Phase 2 study in UC (NCT06127043).

References

1. Long Y, et al. Immunol Letters 2021;233:2-10.
2. AnaptysBio press release February 12, 2025. Ir.anaptsbio.com/news-release-details.
3. Tuttle J, et al. N Engl J Med 2023;388:1853-62.
4. Luu K, et al. J Crohn’s Colitis 2024;18(S1):i225 (Abstract DOP81).
5. Parmley S, et al. United Eur Gastroenterol J 2024;12:482 (Abstract MP448).
6. Linggi B, et al. J Crohn’s Colitis 2025;19(S1):i475 (Abstract P0101).
7. Thomas T, et al. Nature Immunol 2024;25:2152-65.

Disclosure

All authors are employees and shareholders of AnaptysBio

Introduction

Inflammatory Bowel Diseases (IBD) are chronic immune-mediated disorders of the gastrointestinal tract. Fibrosis is a frequent manifestation in IBD driven by inflammatory cytokines. During fibrosis, extracellular matrix proteins accumulate in the tissue, causing the disruption of the epithelial barrier and stenosis, ultimately causing malabsorption and intestinal motility issues. This can eventually lead to further serious complications, strictures, fistulas, or ileus. No drugs are available targeting fibrosis, in these cases, only surgical intervention can be used. A defined primary in vitro cell culture model is not available for intestinal fibrosis modeling.

Aims & Methods

Therefore, we aimed to establish and characterize human primary fibroblast cell culture from intestinal biopsies of control and IBD patients.
Human primary fibroblast cell cultures were generated from colonic biopsy of patients with IBD (N=4) and control (N=4). All downstream analyses were applied in passage number 3. For the phenotype observation, immunofluorescent staining was used. Targeted proteins were COL1A1, TGF-ß1, PAI-1, α-SMA, and PHH3. Proteome Profiler Human Cytokine Array Kit was used for the secreted cytokine pattern observation. For the gene expression analysis, RNA was isolated, and the qRT-PCR technique was utilized for the following target genes: COL1A1, ACTA2, TGF-ß1, FN1, PAI-1, H3C4. Scratch assay was used to examine wound closure, we monitored the closing for 48 hours taking photographs throughout. We evaluated the collected data and performed statistical analysis.

Results

We can successfully generate and maintain human colon primary fibroblast cell cultures from colonic biopsies of healthy and Crohn’s disease (CD) origins. Morphological differences were observed between control and diseased patient samples. In the protein examinations, the fluorescent intensity of fibrotic markers (COL1A1, TGF-ß1, PAI-1) and the mitosis marker PHH3 were significantly higher in the CD samples, indicating that the cells maintained fibrotic phenotype and the diseased fibroblasts had a higher proliferation rate. The myofibroblast marker, α-SMA, didn’t show a significant difference. In the cytokine pattern analysis, 22 cytokines showed a twofold increase or decreased by half between the two groups. HGF and DPPIV showed higher quantities in the CD-originated fibroblast. These cytokines are connected to the induction of fibrosis. However, the ANG, BDNF, PTX-3, VEGF, and VCAM-1 were higher in the control samples. Interestingly, no significant differences were noted between the two groups in the targeted genes examined by qRT-PCR measurements. We observed the closure of the artificial wound was faster and more effective in the Crohn’s disease culture compared to the control.

Conclusion

In conclusion, we can generate primary human intestinal fibroblast cell cultures and maintain them to passage number 3, approximately a month long. Fibrotic markers, secreted cytokines and morphological differences distinguish the diseased cultures from the healthy subjects; therefore, it could be useful for in vitro fibrosis modeling in the future. On the other hand, the gene expression analysis doesn’t discriminate between the two groups at passage number 3. To continue with our work, we will observe the fibrotic properties in earlier passage numbers.

Introduction

The Mayo Endoscopic Subscore (MES) is widely used in clinical trials and daily practice to assess disease activity and response to treatment in UC.

Aims & Methods

The objective of this study was to identify any nuances in patients with MES > 1 treated with non-TNF biologics and targeted oral therapies. The Ipsos UC Therapy Monitor, a multi-centre online medical chart review study of patients with UC, was conducted between July and September 2024 among gastroenterologists practicing across hospital and private practices in the UK, France, Germany, Italy, and Spain. Physicians were screened for practice duration and patient volume. Charts of patients prescribed advanced therapy were included in the analysis.

Results

205 sampled physicians collectively reported 820 UC patients. Of the reported patients with MES > 1, 62 were treated with non-TNF biologics and 62 were treated with novel oral therapies. Among the patients treated with non-TNF biologics, a higher proportion were female vs those receiving oral therapy (48% vs 31%); they were also older in age (mean years: 43 vs 38).
The patients treated with non-TNF biologics had a higher prevalence of comorbidities, including depression/anxiety (24% vs 19%), cardiovascular disease (8% vs 0%), and dyslipidemia/hyperlipidemia/hypercholesterolemia (11% vs 7%), compared to those treated with novel oral therapy.
Mean CRP levels were higher in the oral therapy group (10.2 mg/L vs 9.1 mg/L), while mean Mayo scores were slightly lower (4.7 vs 5.2). Fecal calprotectin levels were elevated in patients treated with non-TNF biologics vs oral therapy group (441 µg/g vs 503 µg/g).
When analysing reasons for prescribing selected advanced therapy between the two patient groups, a greater proportion of patients treated with non-TNF biologics had safety reasons specified more frequently by the sampled physicians.

Table 1: % of reported UC patients receiving advanced therapy for specific cited reasons

Conclusion

This study highlights key differences in patient characteristics and treatment considerations among UC patients with MES > 1 treated with non-TNF biologics compared to those treated with targeted oral therapies. Patients on non-TNF biologics tend to be older, more often female, and have a higher prevalence of comorbidities. Physicians prescribing non-TNF biologics prioritize safety, while those prescribing oral therapies focus on rapid symptom control. These findings highlight the importance of considering patient characteristics and treatment goals when selecting advanced therapies for UC patients with MES > 1. Further investigation using comparator cohort is warranted.

Introduction

The Mayo Endoscopic Subscore (MES) is the most widely used endoscopic index for assessing disease activity in ulcerative colitis (UC). Although artificial-intelligence　(AI)–assisted colonoscopy is expected to reduce inter-observer variability, the MES 4-point scale (0–3) lacks sufficient sensitivity to detect subtle changes in mucosal activity, limiting its ability to capture incremental improvement or deterioration. Moreover, because MES focuses on qualitative features—such as bleeding and erosions—without considering the extent or surface area of inflammation, it provides an incomplete estimate of a patient’s overall inflammatory burden.

Aims & Methods

We sought to develop and validate a quantitative, AI–driven colonoscopic score—Quantitative Ulcerative Colitis Assessment using Deep-learning (QUAD)—and to determine whether it predicts clinical relapse in patients with UC. The QUAD system was trained on 84 743 colonoscopic images from 998 UC patients at three centers and comprises three main functions: i) Image filtering: Automatic exclusion of low-quality images that are unsuitable for analysis owing to light saturation (halation), inadequate insufflation, excessive proximity to the mucosa, chromoendoscopy, or virtual chromoendoscopy. ii) Frame-level scoring: Each frame is divided into four quadrants; inflammation in each quadrant is graded from 0 to 3, and the quadrant scores are summed to yield a QUAD score of 0–12. iii) Video-level aggregation: Full-length withdrawal videos are processed to generate (i) an Entire QUAD score (0–60), representing pan-colonic inflammation, and (ii) a Distal QUAD score (0–12) for the rectosigmoid segment (final 20 % of the video).
The QUAD system contains mainly three function: i) automatically exclude low quality images that is ineligible for analysis in cases of halation, inadequate air de­livery, proximity to mucosa, chromoendoscopy, and virtual chromoendoscopy; ii) fully auto­mated twelve-class score output based on frame analysis: Each frame was divided into four quadrants; inflammation in each quadrant was graded 0–3 and summed to yield a QUAD score of 0–12; and iii) full-length withdrawal videos were processed to generate (I) an Entire QUAD (0–60) for considering whole-colon inflammation status and (II) a Distal QUAD (0–12) for the distal rectum–sigmoid segment (final 20 % of the video). An open-label cohort of adults with quiescent UC (partial Mayo score ≤ 2 for ≥6 months) was prospectively enrolled at a single center (August 2022–February 2023), and followed for 24 months after baseline colonoscopy; clinical relapse was defined as partial Mayo score > 2. The predictive value of QUAD scores for relapse was evaluated.

Results

Frame-level QUAD scores correlated strongly with expert-assigned MES values (Spearman r = 0.68, p < 0.01). Among 156 participants (median age, 51 years; 49 % male), 22 experienced relapse during follow-up. Relapse occurred in 19.4 % (19/98) of patients with a QUAD score > 3 versus 5.2 % (3/58) with a score ≤ 3 (log-rank p = 0.01).
In video analysis, an Entire QUAD > 6 did not significantly stratify relapse risk (16.8 % [17/101] vs 9.1 % [5/55]; log-rank p = 0.17). In contrast, a Distal QUAD > 3 was strongly associated with relapse (43.8 % [7/16] vs 10.7 % [15/140]; log-rank p < 0.01).

Conclusion

AI-generated QUAD provides a sensitive, fully quantitative measure of mucosal inflammation and stratifies relapse risk in clinically quiescent UC. In particular, the automatically derived Distal QUAD—focused on the distal colon and independent of operator image selection—offers a practical, objective tool for longitudinal monitoring and treatment tailoring in UC.

Introduction

Prevalence of MASLD in patients with Inflammatory Bowel Disease (IBD) has been and 21.6% in a previous cross-sectional study from our center. However, data on the progression of MASLD in IBD patients are scanty. reported 24.4% in a recent metaanalysis

Aims & Methods

We aimed to investigate the prevalence and the progression of MASLD, diagnosed by non-invasive tools, in a homogeneous cohort of patients with IBD followed in our referral center.
Consecutive IBD patients without known chronic liver disease were retrospectively enrolled and prospectively followed between 2020 and 2024. MASLD was defined as Controlled Attenuation Parameter (CAP) ≥275 dB/m. Significant fibrosis was defined as Liver Stiffness (LSM) ≥8 kPa by FibroScan. Demographic, metabolic and biochemical data were collected at baseline and at the last follow-up visit. All patients were genotyped for PNPLA3 rs738409 C>G by Taqman assay. Appropriated statistical analysis were performed to identify risk factors associated with the prevalence of MASLD and its progression.

Results

230 patients (mean age was 46.1±13.4 years, 49.2% were males, 50.8% had Crohn’s disease, mean disease duration was 9.4±7.5 years) were recruited. 14.8% of them were obese (BMI > 30 kg/m2), 9.8% diabetic. 49.2% were PNPLA3 rs738409 CG/GG. 116 out of 230 patients had complete metabolic and biochemical assessment at follow-up. Mean follow-up time was 4 years. At baseline, 25% (29/116) had MASLD. 18% (16/87) of patients without steatosis at baseline, developed steatosis at follow-up; while 44 % of those having steatosis at baseline, did not show steatosis at follow-up. 13.5% developed obesity. Obesity was significantly associated with the prevalence of MASLD both at baseline (p=0.040) and on follow-up (p<0.001) and was a predictor of steatosis progression (p<0.001); no association was found in relation to sex, PNPLA3 polymorphism, disease characteristics and the use of biologics. Diabetes was not significantly associated with MASLD in our cohort, but the number of patients was low. The Biologics use was significantly associated with the steatosis regression (p=0.038).

Conclusion

One third of IBD patients had MASLD and obesity was the main predictor of its prevalence and progression, highlighting the relevance of active surveillance of MASLD and appropriate nutritional and lifestyle counselling especially in obese IBD patients. Further studies needed to confirm our results and to identify other risk factors for MASLD in larger populations

Introduction

Crohn ‘s disease (CD) is characterized by chronic inflammation in the gut, where severe complications such as fibrotic strictures require surgical resection. Stricture development involves excessive extracellular matrix (ECM) deposition due to continuous activation of intestinal myofibroblasts, that further contribute to intestinal fibrogenesis. Emerging data suggests that stricture-related intestinal myofibroblasts overexpress a serine protease called fibroblast activation protein (FAP). Furthermore, type III collagen deposition is increased during fibrosis in all layers of the intestinal tract, and studies have shown elevated collagen degradation in serum from patients with CD. The present study aimed at evaluating the potential of FAP-cleaved type III collagen [C3F] as a serum marker for intestinal fibrosis in CD.

Aims & Methods

The cohort consisted of 49 patients with luminal CD and 62 patients with stenotic CD. Clinical assessment was conducted for all patients at baseline and 12 months post study initiation. For the luminal phenotype, endoscopy was performed at both time points. For the stenotic group, radiographical assessment was done prior to surgery and endoscopy was performed at 12 months. C3F was measured in serum at all timepoints for baseline, post-operative day (POD), 1, 3, 6 and 12 months. To compare C3F levels at baseline for luminal vs stenotic phenotype, Mann-Whitney U-test was conducted. For the stenotic group, mixed-effect analysis, with a Dunnett’s multiple comparison applying Bonferroni Correction, was conducted to compare C3F levels for baseline vs POD and Spearman’s rank correlation was applied.

Results

C3F baseline levels were significantly higher in patients with stenotic CD compared to luminal CD (Table 1). In the stenotic group, C3F was significantly increased in patients at POD compared to baseline (Table 1). In the luminal group, C3F was significantly elevated in patients at 12 months compared to baseline. Furthermore, C3F showed a positive correlation with C-reactive protein (CRP) (ρ=0.350, p=0.006) and a significant negative correlation with disease duration (ρ= -0.257, p=0.048) for patients with the stenotic CD phenotype (Table 1).


Table 1. C3F levels are elevated in the stenotic CD vs the luminal CD group, with increased levels at POD compared to baseline for the stenotic phenotype. Spearman’s rank correlation, depicting the relationship between C3F and routine blood demographics, as well as demographics. Significant findings (p<0.05) are highlighted in bold.

Conclusion

C3F was elevated in patients with stenotic CD, with even higher levels after the surgical resection. The data suggests that C3F reflects fibroblast activity during fibrostenosis and tissue remodeling following surgery. The positive correlation with CRP supports the association with inflammation leading to collagen deposition and fibrosis. Interestingly, C3F shows negative correlation with disease duration suggesting that C3F could reflect fibrosis at early stages of stenotic CD. These findings highlight the potential use of C3F as a novel biomarker for intestinal fibrosis in CD.

Disclosure

TTK, MSA, MP are employed at Nordic Bioscience. ACBJ, JHM and MAK are employees and stock owners at Nordic Bioscience.