BACKGROUND:Neutrophils are increasingly recognised as immunosuppressive drivers of hepatocellular carcinoma (HCC), yet their persistence in the oxidative, lipid-rich tumour microenvironment remains poorly understood. OBJECTIVE:To elucidate the metabolic and molecular programmes that enable tumour-associated neutrophils (TANs) to resist ferroptosis and sustain immunosuppression in HCC. DESIGN:We employed human HCC samples, multiple murine HCC models, transcriptomic and lipidomic profiling, genetic loss-of-function systems and therapeutic interventions. Ferroptosis sensitivity, lipid metabolic rewiring and immunological consequences of TANs were systematically evaluated across models and validated in patient datasets and biospecimens. RESULTS:TANs in human HCC and mouse models exhibit pronounced lipid accumulation and oxidative stress compared with peripheral neutrophils. Multi-omic profiling revealed that TANs are enriched for lipid-binding gene programmes and undergo rewiring towards sphingolipid and unsaturated fatty acid metabolism. We identified triggering receptor expressed on myeloid cells 2 (TREM2) as a key lipid-sensing receptor selectively expressed in TANs. Functional deletion of TREM2 reprogrammed the tumour immune microenvironment, restoring CD8+ T cell activity and suppressing HCC progression. Mechanistically, tumour-derived sphingosine-1-phosphate (S1P) activates TREM2, triggering nuclear factor erythroid 2-related factor 2 (NRF2)-mediated transcription of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11), thereby promoting ferroptosis resistance. TREM2 expression is transcriptionally induced by granulocyte-macrophage colony-stimulating factor-signal transducer and activator of transcription 3 (GM-CSF-STAT3) signalling. Genetic deletion of TREM2, clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9)-mediated knockout of sphingosine kinase 1/2 (SPHK1/2) in tumour cells, or pharmacological inhibition of S1P synthesis disrupts this protective lipid-immune circuit, sensitises TANs to ferroptosis and restricts tumour growth. Therapeutically, a peptide-based TREM2 inhibitor reprogrammes TANs, restores CD8+ T cell function and enhances anti-programmed cell death protein 1 (PD-1) immunotherapy efficacy. Clinically, TREM2+ polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) are enriched in HCC tumours, correlate with SPHK1/2 expression and T cell dysfunction and associate with poor patient prognosis. CONCLUSION:Our study uncovers the S1P-TREM2-NRF2 axis as a critical metabolic-immune circuit that preserves neutrophil survival and immunosuppressive function in HCC. Targeting this lipid-dependent ferroptosis resistance pathway offers a promising therapeutic strategy to overcome immunotherapy resistance in liver cancer.
BACKGROUND:Alcohol-associated liver disease (ALD) is a major cause of morbidity, yet therapies for severe inflammation remain limited. OBJECTIVE:We examined whether circulating and hepatic immunoglobulin A (IgA) and hepatic myeloid-cell IgA binding are associated with interleukin-1 beta (IL-1β)-linked inflammation and hepatocyte injury in ALD. DESIGN:This single-centre cross-sectional study enrolled consecutive adults with ALD (n=276), chronic hepatitis B (CHB; n=177) and healthy controls (n=20). A clinically indicated liver-biopsy subcohort underwent flow cytometry, immunohistochemistry and real-time quantitative PCR. Mice received 16-day chronic-plus-binge ethanol feeding±fingolimod (FTY720; 1 mg/kg/day). CD14+ monocytes were stimulated on plate-bound secretory IgA (sIgA)±lipopolysaccharide (LPS) and conditioned media were applied to Huh7 cells. RESULTS:Serum IgA was higher in ALD (median 323-412 mg/dL) than in healthy/CHB (194/211 mg/dL; p<0.001) and correlated with hepatic IgA+area (ρ=0.680, p<0.001). Serum IgA correlated with CD68-normalised IL1B transcripts (ρ=0.383, p=0.008), while hepatic CD14+ cells from ALD samples showed greater IgA binding than those from CHB samples (p<0.05). In mice, serum IgA correlated with IgA-bound macrophage frequency (n=16, ρ=0.844, p<0.001). FTY720 reduced serum IgA (p<0.01), IgA-bound macrophages (p<0.001) and Cd68-normalised Il1b transcripts (p<0.01), and attenuated ethanol-induced liver injury (alanine aminotransferase/aspartate aminotransferase; p<0.05). Spatial transcriptomics suggested attenuation in monocyte-derived macrophage-enriched regions and IL-1-linked programmes with FTY720. sIgA+LPS monocyte supernatants contained higher tumour necrosis factor-α/IL-1β than LPS alone (Δ+280/+798 pg/mL, p<0.01) and increased Huh7-cell apoptosis (Δ+2.96% p; p<0.01). CONCLUSION:IgA binding to hepatic myeloid cells is associated with interleukin (IL)-1-linked inflammation in ALD, and in ethanol-fed mice pharmacologic modulation of immune-cell trafficking was accompanied by reduced IgA-bound hepatic myeloid cells and attenuated IL-1-related inflammation.
Background Supragastric belching (SGB) can trigger reflux episodes, but the contribution of SGB to pathological reflux burden is incompletely understood. Objective To characterise and identify clinical predictors for excessive SGB-related gastro-oesophageal reflux disease (GERD) phenotype. Design This was a multicentre cross-sectional study of patients with acid exposure time (AET) >6% on pH-impedance monitoring off therapy across 11 international tertiary centres. SGB episodes were manually identified. Excessive SGB was defined by ≥13 episodes/24 hours. SGB-related AET was determined by duration of pH <4 following an SGB episode. Univariate and multivariable analyses assessed relationships between excessive SGB and conclusive GERD. Results Of 580 patients (age 56.1±0.6 year, 62% women) from four world regions (Europe/North America/Latin America/Asia), 107 (18.5%) had excessive SGB (p=0.97 across regions). Excessive SGB-related GERD phenotype had lower total AET (p=0.01) with 24.6±2.2% total AET attributable to SGB, higher total reflux episodes (TRE, p=0.0006) and higher number of SGB-related symptom episodes (p<0.0001). On logistic regression, higher TRE (OR 1.01, 95% CI 1.004 to 1.014, p=0.0004) independently predicted excessive SGB, while predominant perceptive symptoms (heartburn/chest pain, OR 0.36, 95% CI 0.155 to 0.854, p=0.002) and higher distal AET (OR 0.96, 95% CI 0.920 to 0.998, p=0.042) were negative predictors. On receiver-operating characteristics curve analysis, >115 TRE and >56 proximal reflux episodes achieved >90% specificity for excessive SGB. Conclusions Excessive SGB is found in up to 20% of patients with conclusive GERD, with 25% of AET attributable to SGB. Higher TRE (>115 TRE, >56 proximal episodes) and more SGB-associated symptoms are predictors of excessive SGB-related GERD phenotype.
BACKGROUND:The recently published Rome V adult diagnostic criteria facilitated an updated epidemiological survey of disorders of gut-brain interaction (DGBI). OBJECTIVE:We aimed to describe the global epidemiology of DGBI using the Rome V criteria and compare it with the Rome IV Rome Foundation Global Epidemiology Study. METHODS:A population-based Internet survey of 28,771 adults was conducted in 15 countries using the Rome V diagnostic questionnaire. DGBI prevalence was determined and compared with the Rome IV data. Multivariable logistic regression models were used to examine associations of demographic factors to Rome V DGBI status in the global population and to assess potentially associated clinical factors. RESULTS:The surveys yielded similar results. The prevalence of at least one DGBI using the Rome V criteria was 40.9%, compared with 40.5% for Rome IV. In both, the prevalence was higher among females and decreased with increasing age. In the Rome V sample (25 DGBI), the most prevalent oesophageal disorder was functional dysphagia at 4.1%, the most prevalent gastroduodenal disorder was functional dyspepsia at 8.1%, unclassified bowel disorder was the most prevalent bowel disorder (9.6%), followed by chronic constipation (8.9%) and IBS (8.5%) and proctalgia fugax was the most prevalent anorectal disorder (7.3%). The prevalence rates for two new DGBI were 5.1% for abdominal migraine and 1.4% for inability to belch syndrome. CONCLUSION:The Rome V global prevalence of DGBI is consistent with Rome IV. This bolsters confidence in the validity of prevalence rates for DGBI and reaffirms their high global burden.
BACKGROUND:Global prevalence estimates of paediatric disorders of gut-brain interaction (DGBI) are largely unknown and published studies are hindered by heterogeneous methodology. OBJECTIVE:To determine the multinational prevalence and burden of paediatric DGBI as defined by Rome V. DESIGN:Caregivers of 8000 children aged 0-17 years from China, Italy, Mexico and the USA completed an online Rome V survey assessing gastrointestinal symptoms, illness burden and comorbid health conditions. Prevalence was calculated by DGBI category, country, sex and age. RESULTS:Paediatric DGBI were highly prevalent, affecting 28.0% (95% CI 27.0% to 29.0%) of children. Upper DGBI were present in 8.7% (95% CI 8.2% to 9.5%) and lower DGBI in 23.7% (95% CI 22.8% to 24.7%). The most common lower DGBI were defecation and anorectal disorders (20.2%) followed by abdominal pain disorders (4.4%) and discomfort disorders (1.8%). The most common upper DGBI were gastroduodenal disorders (6.6%), followed by functional feeding disorders (3.4%) and oesophageal disorders (0.6%). Significant geographic differences were observed with the highest prevalence in Mexico and the lowest in China. There was a female predominance in gastroduodenal and discomfort disorders. Overall prevalence declined with age, from approximately 41% in children aged 0-3 years to 22% in adolescents. DGBI were associated with significant anxiety, depression, functional disability and healthcare utilisation, as well as parental time spent in care and coordination particularly when upper and lower DGBI overlapped. CONCLUSIONS:This global Rome V study demonstrates the high multi-national prevalence, burden and heterogeneity of paediatric DGBI, supporting improved recognition, classification, research and clinical care.
Background While pancreatic cysts have been described in syndromic ciliopathies, the pancreas is not commonly recognised as a target organ. However, several ciliary gene knockout mouse models develop a pancreatic phenotype combining acinar atrophy and adipocyte accumulation, here called adipopancreatosis, suggesting a link between ciliary dysfunction and pancreatic disease. Objective We investigated whether mutations in ciliopathy-associated genes are linked to pancreatic dysfunction in humans. Design We analysed a cohort of 341 patients with paediatric-onset pancreatic anomalies and characterised the pancreatic phenotype of new mouse models with conditional Nphp3 inactivation or bearing Nphp3 mutations recapitulating human mutations. In patients, pancreatic fat content was quantified using Dixon-MRI. Results Mutations in the cilium-related HNF1B and NPHP3 were identified in patients presenting with both renal and pancreatic dysfunction. Nphp3 mutant mice developed acinar atrophy, adipopancreatosis and moderate inflammation. Adipocytes in the pancreas exhibited a white adipocyte-like profile and may originate from mesothelial-derived fibroblasts. Reduced numbers and altered length of ductal cilia were monitored. Interestingly, secretory canaliculi, typically unnoticed structures found within and between acinar cells and connected to the acinar lumen, exhibited a microcystic morphology. Consistent with the mouse phenotype, Dixon-MRI revealed significantly increased pancreatic fat content in patients with HNF1B and NPHP3 mutations. Conclusion We describe a previously unrecognised pancreatic manifestation of ciliopathies, which we name ciliogenic pancreatopathy. Patients with known ciliopathy-causing mutations should be evaluated for this pancreatic condition, particularly those with kidney disease, as concomitant exocrine pancreatic insufficiency may further compromise renal function or the outcome of kidney graft.
BACKGROUND:Interleukin-10 (IL-10) is an essential regulator of intestinal immune homeostasis. Neutralising autoantibodies against IL-10 (anti-IL-10) have been identified in children and also adult patients with IBD. Positivity for anti-IL-10 autoantibodies was associated with carriage of HLA-DRB1*01:03 allele. OBJECTIVE:To determine the prevalence of anti-IL-10 in paediatric IBD and assess the associated clinical phenotype. DESIGN:We conducted a cross-sectional multicentre study across paediatric IBD cohorts from four countries. Anti-IL-10 antibodies were investigated in serum and plasma from paediatric patients with IBD (mean age of IBD onset 11.2±3.8 years). IL-10-neutralisation capacity was confirmed by functional IL-10 reporter assay, competitive ELISA and cytokine release assay. Clinical data were analysed to evaluate disease phenotype and treatment outcomes, with comparison with matched controls. HLA-DRB1*01:03 analysis was performed. RESULTS:Anti-IL-10 positivity was identified in 26/1045 paediatric patients with IBD (2.5%) (Crohn's disease n=6, UC n=19, IBD unclassified n=1; IBD diagnosis age of 13±3 years). Anti-IL-10 autoantibodies were of the IgG class and amplified pro-inflammatory cytokine responses in vitro. Anti-IL-10-positive patients exhibited more severe disease compared with matched controls, including an increased prevalence of difficult-to-treat disease (23% vs 6%, p=0.03), higher rate of acute severe UC (26% vs 6%; p=0.038) and higher rates of colectomy (27% vs 6%, p=0.01). Eighty percent (16/20) of anti-IL-10-positive patients with available HLA data carried the HLA-DRB1*01:03 allele, compared with 1.5% in the anti-IL-10-negative group. CONCLUSION:Anti-IL-10 autoantibodies are present in a subgroup of paediatric patients with IBD and are associated with difficult-to-treat disease.
BACKGROUND:Luminal proteases have been implicated in epithelial barrier dysfunction and visceral hypersensitivity in irritable bowel syndrome (IBS), yet their impact on the enteric nervous system (ENS), the principal regulator of gastrointestinal function, remains unknown. OBJECTIVE:To investigate whether faecal mediators differentially activate enteric neurons across IBS subtypes and whether proteolytic and proteomic profiles explain neuronal phenotypes. DESIGN:The effects of faecal supernatants (FSN) from 21 IBS-D (diarrhoea-predominant), 9 IBS-C (constipation-predominant) and 18 healthy control (HC) patients recruited across centres in three countries on guinea pig distal colon submucous plexus neurons were assessed using a neuroimaging technique. Faecal proteolytic activities and proteomic profiles were analysed. RESULTS:IBS-D and IBS-C supernatants evoked significantly stronger neuronal activation than HC, demonstrating that FSN directly modulate ENS. In IBS-D, but not IBS-C, effects were mediated by serine and cysteine proteases and PAR-1. Proteome analysis revealed a significant difference in 47 proteins between IBS-D and HC, including several immunoglobulin components, underlying the role of microinflammation in IBS-D. A combination of amylases, trypsin-2 and an immunoglobulin protein demonstrated high diagnostic performance to distinguish IBS-D from HC. CONCLUSION:These findings uncover a previously unrecognised luminal-ENS axis in IBS and reveal fundamentally different pathological mechanisms between IBS-D and IBS-C. IBS-D is characterised by proteases and PAR-1-dependent neuronal activation and a distinct immune-enriched faecal proteome, whereas mediators in IBS-C act independently of these factors. These findings establish a functional link between faecal protease activity, ENS signalling and molecular biomarkers, highlighting new therapeutic and diagnostic avenues for subtype-specific management of IBS.
