Introduction

Infiltration of neutrophils into the intestinal tissue is a crucial component of the inflammatory response in Crohn‘s disease (CD). CPa9-HNE, a calprotectin fragment released by human neutrophil elastase during NETosis, has been shown to strongly correlate with endoscopic disease activity in inflammatory bowel disease (IBD) and serves as an indicator for pharmacodynamic response. Furthermore, emerging data suggests that neutrophil extracellular traps (NETs) significantly contribute to the pathogenesis of fibrosis.

Aims & Methods

For the first time, we investigated the association of CPa9-HNE with histological grading of both inflammation and fibrosis. The cohort included 62 patients with stenotic Crohn‘s disease. Inclusion criterion was the presence of stenotic disease requiring bowel resection, as confirmed by radiographic assessment. Upon surgery, the resected specimens were collected and histologically graded according to transmural fibrosis burden, and inflammation (D'Haens score). Serum was drawn at baseline (before resection). CPa9-HNE was measured, reflecting a human neutrophil elastase-derived fragment of calprotectin. Spearman’s rank correlation was applied.

Results

CPa9-HNE showed an overall positive correlation to the D'Haens score (ρ=0.279, p<0.005). Significant positive correlation was observed between CPa9-HNE and the presence of neutrophils, both in the epithelium and the lamina propria (ρ=0.309, ρ=0.349, p<0.005 both), as well as with epithelial damage (ρ=0.262, p<0.005). We also observed a positive correlation between CPa9-HNE and transmural fibrosis burden, specifically fibrosis in the submucosa (ρ=0.294, p<0.005)

Conclusion

This study showed that CPa9-HNE, a biomarker of neutrophil activity, correlated with the presence of neutrophils in the intestinal tissue, as well as epithelial damage. Interestingly, CPa9-HNE also showed association to submucosal fibrosis, emphasizing the importance of considering neutrophil activity when targeting the fibro-inflammatory axis. These findings highlight the potential use of CPa9-HNE as a complementary tool for histological grading of inflammation and fibrosis burden, and could be used to further explore the role of neutrophil extracellular traps in intestinal fibrosis.

Disclosure

MSA, TKA, MP, MAK, ACBJ and JHM are employees of Nordic Bioscience. MAK, ACBJ and JHM are shareholders of Nordic Bioscience.

Introduction

While ileocecal resection (ICR) is the most common surgical procedure in Crohn's disease (CD), non-ICR surgeries account for only 20% of cases and remain underrepresented in the literature. This study aimed to identify specific clinical risk factors for surgical recurrence in CD patients undergoing small bowel or colonic resections without involving the ileocecal valve.

Aims & Methods

This multicenter retrospective cohort study included 257 patients with CD (124 small bowel resections, 133 colonic resections) across 13 Italian centers from 1978 to 2023. Univariate and multivariate logistic regression and Cox proportional hazards analyses were performed to identify clinical risk factors associated with surgical recurrence.

Results

The cohort comprised two distinct groups: small bowel resections (n=124), characterized by male predominance (63.71%), a high prevalence of stricturing disease (60.48%), and a median follow-up of 75.5 months; and colonic resections (n=133), featuring a more balanced gender distribution (47.37% male), higher rates of penetrating disease (47.37%), and a median follow-up of 88.0 months. Penetrating disease behaviour emerged as the only significant predictor of recurrence in logistic regression analysis (OR 2.16, 95% CI 1.03-4.52, p=0.041), while factors typically predictive in ICR, such as smoking (OR 0.90, p=0.843) and prior resections (OR 0.96, p=0.913), were non-significant. Cox regression identified prior biologic exposure as a significant predictor of earlier recurrence (HR 2.52, 95% CI 1.22-5.18, p=0.012), with TNF experience specifically associated with increased risk (HR 2.28, 95% CI 1.12-4.67, p=0.024). The cumulative number of risk factors (HR 1.35, 95% CI 1.01-1.82, p=0.046) and postoperative intra-abdominal septic complications (HR 2.75, 95% CI 1.18-6.44, p=0.020) also contributed to recurrence risk. Disease phenotypes significantly differed between resection types (p<0.001), with stricturing disease most prevalent in small bowel resections (60.48% vs. 36.09% in colonic) and penetrating disease more common in colonic resections (47.37% vs. 36.29% in small bowel). Results are summarized in Table 1.

Table 1: Univariate logistic regression analysis of predictors for postoperative surgical recurrence in patients undergoing small bowel or colonic resections. Abbreviations: CI: Confidence Interval; CD: Crohn’s Disease; IBD: Inflammatory Bowel Disease; POR: Postoperative recurrence; TNF: Tumour Necrosis Factors.

Conclusion

This study reveals distinct risk factors for surgical recurrence after non-ICR surgeries in CD. Unlike ICR where smoking, perianal disease, and prior resections predominate, non-ICR recurrence is primarily associated with penetrating disease phenotype and prior biologic exposure. These findings demonstrate that risk stratification models developed for ICR are not applicable to non-ICR surgeries, highlighting the need for procedure-specific approaches to postoperative management. Tailored prophylactic strategies should address the unique recurrence dynamics of small bowel and colonic resection surgeries.

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

Acetaminophen (APAP) overdose is a primary cause of drug-induced liver injury (DILI). Although the inflammatory microenvironment plays a critical role in APAP-induced liver injury (AILI), its cellular interaction network and molecular regulatory mechanisms remain incompletely elucidated. Krüppel-like factor 4 (KLF4), a zinc finger transcription factor, is known to regulate monocyte differentiation, but its functional role in the AILI inflammatory microenvironment remains unclear. This study aims to investigate the regulatory effects of myeloid KLF4 deletion on the AILI microenvironment.

Aims & Methods

By integrating multidimensional omics analysis and a myeloid-specific Klf4 knockout mouse model, we dynamically dissected microenvironmental remodeling during AILI progression. Liver samples were collected for RNA sequencing, combined with single-cell transcriptomics, flow cytometry, and molecular interaction validation to clarify the KLF4-dependent cellular subpopulation interaction network. In vivo liver imaging, histology, biochemical assays, and molecular experiments were performed to validate KLF4-dependent intercellular interactions. Primary hepatocytes and hepatocyte cell lines were used for in vitro verification.

Results

Myeloid-specific KLF4 deletion led to an increase in CXCL2⁺CXCL3⁺CD24⁺ monocytes, which activated the NF-κB signaling pathway to secrete CXCL2/CXCL3 chemokines. These chemokines bound to the CXCR2 receptor on neutrophils, driving neutrophil infiltration and neutrophil extracellular traps (NETs) formation, while amplifying the TNF-α signaling pathway. Concurrently, myeloid KLF4 knockout induced enrichment of CXCL1⁺IL17RA⁺ endothelial cells. Neutrophil-derived NETs promoted endothelial phenotypic switching toward pro-inflammatory polarization, while endothelial-derived CXCL1 further recruited neutrophils, establishing a "monocyte-neutrophil-endothelial" cellular subpopulation interaction that perpetuated microenvironmental inflammation.

Conclusion

This study reveals the molecular mechanism by which KLF4 drives inflammatory cascades in the AILI microenvironment through regulation of the myeloid-endothelial interaction network. We propose therapeutic strategies targeting NETs formation or the CXCL2/CXCL3-CXCR2 axis, providing novel targets for precise intervention in AILI.

Introduction

Chemotherapy-induced diarrhea (CID), a dose-limiting toxicity impairing treatment adherence and anticancer efficacy, lacks targeted prophylaxis. While short-acting glucagon-like peptide-2 (GLP-2) analog was approved for short bowel syndrome (SBS), the mucosal regenerative properties of GLP-2 suggest therapeutic potential for CID prevention. GLP-2 can also enhance the intestinal mucosal barrier and may provide a new treatment option for inflammatory bowel disease (IBD). In this study, we developed FT1, a long-acting GLP-2 analog engineered for sustained exposure, and reported first-in-human phase I trial data of FT1 in Chinese healthy adults.

Aims & Methods

This randomized, double-blind, placebo-controlled, single-center phase I study (NCT06610487) evaluated the safety, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of FT1 to establish dosing rationale for the future CID trials. Single ascending dose (SAD: 0.05-0.4 mg/kg) and multiple ascending dose (MAD: 0.1-0.2 mg/kg, once weekly for 3 weeks) were administered subcutaneously. Participants were randomized 3:1 (SAD; except for 0.05 mg/kg: 2:1) or 4:1 (MAD) to receive FT1 or placebo. Plasma citrulline, a validated biomarker of enterocyte mass, served as the primary PD endpoint. Safety, PK, PD, and immunogenicity were assessed up to 28 days post-dose.

Results

Currently available analyzed data (n=50) revealed:
1. PK: FT1 exhibited dose-proportional exposure (C_max/ AUC_0-inf) across SAD doses (0.05-0.4 mg/kg). Median T_max was 24 h with prolonged t_1/2 = 67.6-69.1 h. MAD regimens showed moderate accumulation (1.42- 1.73-fold post-3rd dose).
2. PD: Citrulline elevation was dose- and regimen-dependent. SAD 0.4 mg/kg achieved maximal change in plasma citrulline (ΔE_max) = 3,340 ng/mL (baseline: 5,125 ng/mL) at 8.5 days post-dose. After weekly administration of FT1, the citrulline level was further enhanced. MAD 0.2 mg/kg induced 33% greater ΔE_max vs MAD 0.1 mg/kg (4,512 vs 3,390 ng/mL; both post-3rd dose), exceeding SAD 0.4 mg/kg response.
3. Safety: All adverse events were Grade 1-2 (CTCAE v5.0) with no dose-limiting toxicities or immunogenicity signals.

Conclusion

FT1 demonstrated favorable safety and linear PK up to 0.4 mg/kg (SAD) and 0.2 mg/kg weekly×3 (MAD) in healthy participants. The 0.2 mg/kg MAD regimen achieved superior enterotrophic effects (citrulline ΔE_max) versus lower doses while maintaining tolerability, supporting it as a priority candidate for further clinical evaluation in patients with once-weekly dosing.

References

1. McQuade RM, et al. Chemotherapy-induced constipation and diarrhea: pathophysiology, current and emerging treatments. Front. Pharmacol. 2016, 7:414.
2. Barzał J, et al. Plasma citrulline level as a biomarker for cancer therapy-induced small bowel mucosal damage. Acta Biochim Pol. 2014; 61(4):615-31

Disclosure

Chengyong Tang, Mingxue Zhu, and Lei Wan have no conflicts of interest that are directly relevant to the content of this article. Kai Fan, Qing Chen, and Yanmin Bai are Chongqing Peg-Bio Biopharm Co., Ltd employees.