Superior bowel preparation quality for colonoscopy with 1L-PEG compared to 2L-PEG and picosulphate: Data from a large real-world retrospective outpatient cohort

BACKGROUND

Several randomized clinical trials comparing different bowel preparations (BP) have shown similar efficacy; however, there is a lack of real-world studies on this topic.

AIMS

This study aims to identify the most effective BP regimen in a real-world setting and any predictors of inadequate BP.

METHODS

A retrospective single-center study was conducted over 14 months at an academic hospital including outpatient colonoscopies in which adult patients did not teach on how to perform BP before colonoscopy. Colonoscopies with 1L-PEG, 2L-PEG and picosulphate mixtures were considered. A multivariable analysis for factors associated to poor BP was fitted.

RESULTS

Overall, 1779 patients (51 %F, 60±14) years were included. The 1L-PEG regimen provided a higher rate of BP adequacy at multivariate analysis (adjusted OR 2.30, 95 %CI 1.67-3.16,p < 0.001) and was associated with higher median Boston Bowel Preparation Scale score (p < 0.001), higher rate of right-colon cleansing (p < 0.001) and exam completion (p = 0.04). Furthermore, we identified male sex, history of constipation, active smoking, previous pelvic surgery, concomitant psychiatric/neurological or chronic kidney diseases as predictors of inadequate BP.

CONCLUSIONS

This is the largest real-world study comparing 1L-PEG to other BP regimens. Our results suggest 1L-PEG provides better BP in a non-controlled setting, improving clinical practice quality and minimizing the need for repeated colonoscopies and saving healthcare resources.

Gastric carcinoma in autoimmune gastritis: a histopathologic and molecular study

Patients with autoimmune gastritis (AIG) have a 13-fold risk of developing type-1 neuroendocrine tumors, whereas the risk for gastric adenocarcinoma is still uncertain. Here we describe the clinicopathological and molecular features of a series of gastric carcinomas (GC) arising in the context of AIG. A total of 26 AIG-associated GC specimens were collected from four Italian Institutions. Immunohistochemistry for MUC1, MUC2, MUC5AC, MUC6, CDX2, HER2, PD-L1, CLDN18, Mismatch Repair (MMR) proteins, and p53 and EBER in situ hybridization were performed. Histologic features and IHC were jointly reviewed by five expert gastrointestinal pathologists. Next-generation sequencing analysis (TrueSight Oncology 500, Illumina) of 523 cancer-related genes was performed on 19 cases. Most tumors were diagnosed as pT1 (52%), were located in the corpus/fundus (58%) and were associated with OLGA stage II gastritis (80.8%), absence of parietal cells, complete intestinal metaplasia and ECL-cell micronodular hyperplasia. Only 4 (15.4%) GCs were diagnosed during follow-up for AIG. The following histotypes were identified: 20 (77%) adenocarcinomas; 3 (11%) mixed neuroendocrine non-neuroendocrine neoplasms, and 2 (8%) high-grade solid adenocarcinomas with focal neuroendocrine component, 1 (4%) adenocarcinoma with an amphicrine component. Overall, 7 cases (27%) showed MMR deficiency, 3 (12%) were positive (score 3+) for HER2, 6 (23%) were CLDN18 positive, and 11 (42%) had PD-L1 Combined Positive Score ≥ 10. EBER was negative in all cases. Molecular analysis revealed 5/19 (26%) MSI cases and 7 (37%) TMB-high. The most frequently altered genes were: TP53 (8/19, 42%), RNF43 (7/19, 37%), ERBB2 (7/19, 37% [two amplified and five mutated cases]), ARID1A (6/19, 32%), and PIK3CA (4/19, 21%). In summary, AIG-associated GCs are often diagnosed at low stage in patients with long-standing misrecognized severe AIG; they often display a neuroendocrine component or differentiation, have relatively higher rates of MMR deficiency, and TMB-high.

A Comprehensive Review on Bariatric Endoscopy: Where We Are Now and Where We Are Going

Background: Obesity is a chronic disease that impairs quality of life and leads to several comorbidities. When conservative therapies fail, bariatric surgical options such as Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are the most effective therapies to induce persistent weight loss. Over the last two decades, bariatric endoscopy has become a valid alternative to surgery in specific settings. Primary bariatric endoscopic therapies: Restrictive gastric procedures, such as intragastric balloons (IGBs) and endoscopic gastroplasty, have been shown to be effective in inducing weight loss compared to diet modifications alone. Endoscopic gastroplasty is usually superior to IGBs in maintaining weight loss in the long-term period, whereas IGBs have an established role as a bridge-to-surgery approach in severely obese patients. IGBs in a minority of patients could be poorly tolerated and require early removal. More recently, novel endoscopic systems have been developed with the combined purpose of inducing weight loss and improving metabolic conditions. Duodenal mucosal resurfacing demonstrated efficacy in this field in its early trials: significant reduction from baseline of HbA1c values and a modest reduction of body weight were observed. Other endoscopic malabsorptive have been developed but need more evidence. For example, a pivotal trial on duodenojejunal bypasses was stopped due to the high rate of severe adverse events (hepatic abscesses). Optimization of these more recent malabsorptive endoscopic procedures could expand the plethora of bariatric patients that could be treated with the intention of improving their metabolic conditions. Revisional bariatric therapies: Weight regain may occur in up to one third of patients after bariatric surgery. Different endoscopic procedures are currently performed after both RYGB and SG in order to modulate post-surgical anatomy. The application of argon plasma coagulation associated with endoscopic full-thickness suturing systems (APC-TORe) and Re-EndoSleeve have shown to be the most effective endoscopic treatments after RYGB and SG, respectively. Both procedures are usually well tolerated and have a very low risk of stricture. However, APC-TORe may sometimes require more than one session to obtain adequate final results. The aim of this review is to explore all the currently available primary and revisional endoscopic bariatric therapies focusing on their efficacy and safety and their potential application in clinical practice.

Mucosal Overexpression of Thymic Stromal Lymphopoietin and Proinflammatory Cytokines in Patients With Autoimmune Atrophic Gastritis

INTRODUCTION

The immune mechanisms underlying human autoimmune atrophic gastritis (AAG) are poorly understood. We sought to assess immune mucosal alterations in patients with AAG.

METHODS

In 2017-2021, we collected gastric corpus biopsies from 24 patients with AAG (median age 62 years, interquartile range 56-67, 14 women), 26 age-matched and sex-matched healthy controls (HCs), and 14 patients with Helicobacter pylori infection (HP). We investigated the lamina propria mononuclear cell (LPMC) populations and the mucosal expression of thymic stromal lymphopoietin (TSLP) and nicotinamide phosphoribosyltransferase (NAMPT). Ex vivo cytokine production by organ culture biopsies, under different stimuli (short TSLP and zinc-l-carnosine), and the gastric vascular barrier through plasmalemma vesicle-associated protein-1 (PV1) were also assessed.

RESULTS

In the subset of CD19+ LPMC, CD38+ cells (plasma cells) were significantly higher in AAG compared with HC. Ex vivo production of tumor necrosis factor (TNF)-α, interleukin (IL)-15, and transforming growth factor β1 was significantly higher in AAG compared with HC. At immunofluorescence, both IL-7R and TSLP were more expressed in AAG compared with HC and HP, and short TSLP transcripts were significantly increased in AAG compared with HC. In the supernatants of AAG corpus mucosa, short TSLP significantly reduced TNF-α, while zinc-l-carnosine significantly reduced interferon-γ, TNF-α, IL-21, IL-6, and IL-15. NAMPT transcripts were significantly increased in AAG compared with HC. PV1 was almost absent in AAG, mildly expressed in HC, and overexpressed in HP.

DISCUSSION

Plasma cells, proinflammatory cytokines, and altered gastric vascular barrier may play a major role in AAG. TSLP and NAMPT may represent potential therapeutic targets, while zinc-l-carnosine may dampen mucosal inflammation.

Histologic heterogeneity and syndromic associations of non-ampullary duodenal polyps and superficial mucosal lesions

BACKGROUND

Duodenal polyps and superficial mucosal lesions (DP/SMLs) are poorly characterised.

AIMS

To describe a series of endoscopically-diagnosed extra-ampullary DPs/SMLs.

METHODS

This is a retrospective study conducted in a tertiary referral Endoscopy Unit, including patients who had DPs or SMLs that were biopsied or removed in 2010-2019. Age, gender, history of familial polyposis syndromes, DP/SML characteristics were recorded. Histopathological, immunohistochemical and molecular analyses were performed.

RESULTS

399 non-ampullary DP/SMLs from 345 patients (60.6% males; median age 67 years) were identified. Gastric foveolar metaplasia represented the most frequent histotype (193 cases, 48.4%), followed by duodenal adenomas (DAs; 77 cases, 19.3%). Most DAs (median size 6 mm) were sessile (Paris Is; 48%), intestinal-type (96.1%) with low-grade dysplasia (93.5%). Among syndromic DAs (23%), 15 lesions occurred in familial adenomatous polyposis 1, two were in MUTYH-associated polyposis and one was in Peutz-Jeghers syndrome (foveolar-type, p53-positive, low-grade dysplasia). Only one (3.3%) tubular, low-grade DA showed mismatch repair deficiency (combined loss of MLH1 and PMS2, heterogeneous MSH6 expression), and it was associated with a MLH1 gene germline mutation (Lynch syndrome).

CONCLUSION

DPs/SMLs are heterogeneous lesions, most of which showing foveolar metaplasia, followed by low-grade, intestinal-type, non-syndromic DAs. MMR-d testing may identify cases associated with Lynch syndrome.

Incidence and risk factors for preneoplastic and neoplastic lesions of the colon and rectum in patients under 50 referred for colonoscopy

Colorectal cancer (CRC) diagnosed before the age of 50, known as early-onset CRC (eoCRC), is considered uncommon. We aimed at analysing the incidence of preneoplastic and neoplastic lesions of the colon and rectum in patients under 50 years old and to identify possible predictors Methods: We retrospectively collected data from 1778 patients under 50 years old (mean age 39.9±7.8) referred for colonoscopy between 2015-2018. Cumulative incidence of adenomas and eoCRC was assessed. Multivariable regression models were fitted Results: The cumulative incidence for adenomas was 11.0% (95% CI 9-12), while it was 1.5% (95% CI 1-2) for eoCRC (metastatic disease in 13/27 patients). Age as a continuous variable was associated with the presence of adenomas (incidence rate ratio 1.06; 95% CI 1.03-1.09; p<0.001). EoCRC arose in most cases in the rectum (13/27, 48.1%). Age ≥40 was the main risk factor (OR 2.25; 95% CI 1.35-3.73; p=0.002) for both adenomas (160/196 patients, 81.6%) and eoCRC (20/27 patients, 74.1%), while smoking seemed to have no role (p=0.772). The presence of alarm symptoms was statistically significant at bivariable analysis for eoCRC only (OR 3.70; 95% CI 1.49-9.22; p=0.005), as well as having multiple gastrointestinal symptoms (OR 19.85; 95% CI 2.64-149.42; p=0.004). Only 3/27 (11.1%) patients with eoCRC had a family history for CRC Conclusions: A high cumulative incidence rate of both adenomas and eoCRC was found, this latter occurring more common in patients aged 40-49, without apparent risk factors. The presence of alarm symptoms or multiple gastrointestinal symptoms led to a late diagnosis.

Epstein-Barr virus negative smooth muscle neoplasm of the stomach in a young woman

Gastric smooth muscle neoplasms are rare and poorly investigated malignancies. Their importance relies on differential diagnosis with more frequent neoplasms(e.g. GIST), on their often mild and deceitful clinical presentation and on their heterogeneous outcome. Moreover, the pathogenesis of gastric leiomyosarcoma seems to point to some acknowledged oncogenic factors such as radiations or oncogenic viral infections. Herein, we describe a case of metastatic gastric leiomyosarcoma in a young woman, previously diagnosed with acute lymphoblastic leukemia treated with chemoradiotherapy.

Safety and durability of PEG-J: a single-centre experience

INTRODUCTION

Although percutaneous endoscopic gastrostomy with jejunal extension (PEG-J) is currently indicated in a variety of conditions, limited data are available regarding its safety and the best timing for its replacement. We herein describe a single-centre cohort of patients who underwent PEG-J placement or replacement to assess the short- and long-term safety of the procedure.

METHODS

Demographic and procedure-related data regarding all patients undergoing a PEG-J procedure between March 2010 and 2020, either first placement or any replacement, at the Endoscopy Unit of a University Hospital in Northern Italy (IRCCS Policlinico San Matteo, Pavia, Italy), were retrospectively collected. Data were collected until last available follow-up.

RESULTS

We included 73 patients (mean age 70 ± 9.7, 60.3% female) who underwent a PEG-J procedure. Data on a total of 215 procedures were gathered with a median follow up time of 21 months (IQR 9.3-39.5). No immediate adverse events (AEs) were reported. Short-term (within 30 days) AEs, including jejunal extension dislocations, accidental removal, obstruction and kinking occurred in 12 patients (5.6% of the total procedures), whilst long-term AEs (obstruction, tube malfunctions, inner tube dislocation, pyloric ulcer, hypergranulation tissue, wear, buried bumper syndrome and accidental removal) were reported in 40 patients. The risk of developing an AE was not reduced if tube replacement was performed electively. The median duration of the PEG-J before replacement was 12 months (IQR 6-16 months).

CONCLUSION

PEG-J placement and replacement are safe procedures. Although PEG-J durability is variable an elective procedure might be indicated to reduce urgent replacements.

Proteolytic cleavage and loss of function of biologic agents that neutralize tumor necrosis factor in the mucosa of patients with inflammatory bowel disease

BACKGROUND & AIMS

Many patients with inflammatory bowel disease (IBD) fail to respond to anti-tumor necrosis factor (TNF) agents such as infliximab and adalimumab, and etanercept is not effective for treatment of Crohn's disease. Activated matrix metalloproteinase 3 (MMP3) and MMP12, which are increased in inflamed mucosa of patients with IBD, have a wide range of substrates, including IgG1. TNF-neutralizing agents act in inflamed tissues; we investigated the effects of MMP3, MMP12, and mucosal proteins from IBD patients on these drugs.

METHODS

Biopsy specimens from inflamed colon of 8 patients with Crohn's disease and 8 patients with ulcerative colitis, and from normal colon of 8 healthy individuals (controls), were analyzed histologically, or homogenized and proteins were extracted. We also analyzed sera from 29 patients with active Crohn's disease and 33 patients with active ulcerative colitis who were candidates to receive infliximab treatment. Infliximab, adalimumab, and etanercept were incubated with mucosal homogenates from patients with IBD or activated recombinant human MMP3 or MMP12 and analyzed on immunoblots or in luciferase reporter assays designed to measure TNF activity. IgG cleaved by MMP3 or MMP12 and antihinge autoantibodies against neo-epitopes on cleaved IgG were measured in sera from IBD patients who subsequently responded (clinical remission and complete mucosal healing) or did not respond to infliximab.

RESULTS

MMP3 and MMP12 cleaved infliximab, adalimumab, and etanercept, releasing a 32-kilodalton Fc monomer. After MMP degradation, infliximab and adalimumab functioned as F(ab')2 fragments, whereas cleaved etanercept lost its ability to neutralize TNF. Proteins from the mucosa of patients with IBD reduced the integrity and function of infliximab, adalimumab, and etanercept. TNF-neutralizing function was restored after incubation of the drugs with MMP inhibitors. Serum levels of endogenous IgG cleaved by MMP3 and MMP12, and antihinge autoantibodies against neo-epitopes of cleaved IgG, were higher in patients who did not respond to treatment vs responders.

CONCLUSIONS

Proteolytic degradation may contribute to the nonresponsiveness of patients with IBD to anti-TNF agents.

Recent advances in understanding Crohn's disease

Crohn's disease is a chronic inflammatory bowel disorder resulting from an inappropriate innate and acquired immune response to commensal microorganisms in genetically susceptible individuals. This disease has a fluctuating course, with alternating periods of remission and relapses, and it is characterized by a remarkable clinical heterogeneity; it may be complicated by perianal fistulas, abscesses, and intestinal strictures leading to obstructions, besides several systemic manifestations. However, a complete resolution of the disease is currently not possible, yet Crohn's disease can be managed with established and novel therapies, which achieve long-term remission and acceptable quality of life. This review is focused on novel advances in basic and clinical aspects of Crohn's disease, although it also deals with new trends in diagnosis and treatment.

Recent advances in understanding ulcerative colitis

Ulcerative colitis, one of the two main forms of inflammatory bowel disease, is characterized by inflammation of the large bowel with constant involvement of the rectum, and a possible continuous retrograde distribution up to the cecum. Typical macroscopic lesions are mucosal ulcerations, with immune cell infiltration and cryptic abscesses at histology. Ulcerative colitis usually manifests with bloody diarrhea, is associated with a number of extra-intestinal manifestations, and may be acutely complicated by toxic megacolon. Longstanding disease may predispose to the development of colorectal cancer. Therapeutic options include mesalazine, corticosteroids, immunomodulators and biologic agents; however, if these treatments fail, the only available therapeutic choice remaining is the surgical removal of the colon. This review emphasizes novel concepts in the basic aspects of ulcerative colitis, and, in addition to the current clinical and diagnostic knowledge, it also describes new treatment options for this condition.

New pathogenic paradigms in inflammatory bowel disease

Recent progresses in basic science have opened new pathogenic scenarios in inflammatory bowel disease. The T helper cell type (Th)1/Th2 paradigm has been outdated thanks to the advances in understanding the function of Th17 cells. Innate immunity, nonimmune cells, and defective tolerogenic mechanisms play a no less crucial role than do adaptive immunity, immune cells, and hyperactivation of effector mechanisms. These new paradigms, together with the no longer "static" but "dynamic" vision of intestinal inflammation, highlight new possible therapeutic targets in inflammatory bowel disease.

Involvement of CD40-CD40 ligand in uncomplicated and refractory celiac disease

OBJECTIVES

Cognate interaction between CD40 on antigen-presenting cells and CD40 ligand (CD40L) on T cells is a crucial costimulatory signal in T-cell activation. In this study, we investigated CD40-CD40L expression in the duodenum of uncomplicated and refractory celiac disease patients, and explored the ex vivo effects of CD40L blockade on cytokine production and the T-helper cell type 1-specific transcription factor T-bet.

METHODS

CD40L and colocalization of CD40 with the dendritic cell markers CD11c and CD123 were investigated by confocal microscopy on tissue sections of duodenal biopsy samples obtained from 14 uncomplicated celiac patients before and after 12 months of gluten-free diet, 5 refractory celiac patients, and 12 controls. CD40 was also analyzed by flow cytometry on single cell suspension of mucosal biopsies. Treated celiac biopsies were stimulated with peptic-tryptic digest of gliadin (PT-gliadin) with or without an anti-CD40L-neutralizing antibody. Interferon (IFN)-γ and interleukin (IL)-17 were measured by ELISA (enzyme-linked immunosorbent assay). T-bet, CD40, and CD40L were determined by immunoblotting.

RESULTS

CD40 and CD40L expression was higher in uncomplicated untreated and refractory celiac patients than in controls; the expression returned to normal after gluten-free diet in uncomplicated patients. Flow cytometric analysis confirmed that most CD40(+) cells were dendritic cells. The addition of the anti-CD40L antibody to treated celiac biopsies significantly inhibited the PT-gliadin-induced production of IFN-γ and IL-17, and mucosal T-bet.

CONCLUSIONS

Our results indicate that the CD40-CD40L pathway has a key role in celiac disease. Disruption of CD40-CD40L interaction may offer a therapeutic alternative in refractory celiac disease.

Peripheral regulatory T cells and serum transforming growth factor-β: relationship with clinical response to infliximab in Crohn's disease

BACKGROUND

CD4(+)Foxp3(+) regulatory T cells (Treg) inhibit T-cell proliferation in vitro and are effective in suppressing colitis in mouse models. Tumor necrosis factor (TNF)-α, which is centrally involved in Crohn's disease (CD) pathogenesis, also impairs Treg function. Here we investigated the influence of anti-TNF therapy on Treg frequency and function in CD.

METHODS

Twenty CD patients were treated with infliximab administered at weeks 0, 2, and 6. Blood was collected immediately before the first infusion and after 10 weeks. Treg frequency was quantified by flow cytometry. Treg function was measured using a standard coculture assay. Serum levels of transforming growth factor (TGF)-β1 and interleukin (IL)-10 were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Pretreatment Treg frequency and serum TGF-β1 levels were significantly higher in nonresponder than responder patients. Clinical improvement in 12 CD patients was associated with a significant increase of Treg frequency after 10 weeks. Treg were functionally active before and after treatment with infliximab, both in responder and nonresponder CD patients. In responder patients the restoration of Treg pool was accompanied by a parallel significant increase of serum TGF-β1 and IL-10. No significant change in the elevated Treg or serum TGF-β1 was seen in nonresponder patients.

CONCLUSIONS

This study suggests that there may be a relationship between numbers of Treg in the blood, serum TGF-β1, and response to infliximab; however, further prospective studies are needed.

Down-regulation of p38 mitogen-activated protein kinase activation and proinflammatory cytokine production by mitogen-activated protein kinase inhibitors in inflammatory bowel disease

Crohn's disease and ulcerative colitis are inflammatory bowel diseases (IBD) characterized by chronic relapsing mucosal inflammation. Tumour necrosis factor (TNF)-α, a known agonist of the mitogen-activated protein kinase (MAPK) pathway, is a key cytokine in this process. We aimed first to determine whether p38 MAPK is activated in IBD inflamed mucosa, and then studied the effect of four different p38α inhibitory compounds on MAPK phosphorylation and secretion of proinflammatory cytokines by IBD lamina propria mononuclear cells (LPMCs) and organ culture biopsies. In vivo phospho-p38α and p38α expression was evaluated by immunoblotting on intestinal biopsies from inflamed areas of patients affected by Crohn's disease and ulcerative colitis, and from normal mucosa of sex- and age-matched control subjects. Both mucosal biopsies and isolated LPMCs were incubated with four different p38α selective inhibitory drugs. TNF-α, interleukin (IL)-1β and IL-6 were measured in the organ and cell culture supernatants by enzyme-linked immunosorbent assay. We found higher levels of phospho-p38α in the inflamed mucosa of IBD patients in comparison to controls. All the p38α inhibitory drugs inhibited p38α phosphorylation and secretion of TNF-α, IL-1β and IL-6 from IBD LPMCs and biopsies. Activated p38α MAPK is up-regulated in the inflamed mucosa of patients with IBD. Additionally, all the p38α selective inhibitory drugs significantly down-regulated the activation of the MAPK pathway and the secretion of proinflammatory cytokines.

Differential regulation of interleukin 17 and interferon gamma production in inflammatory bowel disease

BACKGROUND AND AIMS

Interleukin 17 (IL17) is now known to be involved in a number of chronic inflammatory disorders. However, the mechanisms regulating its production in inflammatory bowel disease (IBD) are still unclear.

METHODS

Endoscopic biopsies or surgical specimens were taken from inflamed and uninflamed colonic mucosa of 72 patients with IBD (38 with Crohn's disease and 34 with ulcerative colitis), and normal colon of 38 control subjects. IL17 and interferon gamma (IFNgamma) were detected by ELISA in the supernatants of biopsies cultured ex vivo, and anti-CD3/CD28-stimulated lamina propria mononuclear cells (LPMCs) incubated with IL12, IL23, IL1beta plus IL6, transforming growth factor beta1 (TGFbeta1), or anti-IL21 neutralising antibody. Intracellular flow cytometry was performed to analyse mucosal Th17 and Th1/Th17 cells.

RESULTS

IL17 production by organ culture biopsies was higher in IBD inflamed mucosa than IBD uninflamed mucosa and controls, and was equivalent in amount to IFNgamma. Anti-CD3/CD28-stimulated IBD LPMCs produced higher IL17 amounts compared to controls. The percentages of Th17 and Th1/Th17 cells were increased in patients with IBD. IL23 and IL1beta plus IL6 had no effect on IBD LPMC production of IL17; however, IL12 markedly increased IFNgamma production and decreased IL17 production. TGFbeta1 dose-dependently decreased IFNgamma, but had no significant inhibitory effect on IL17 production. Blocking IL21 significantly downregulated IL17 production.

CONCLUSIONS

Our findings support a role for IL12, TGFbeta and IL21 in modulating IL17/IFNgamma production in IBD. The abundant IL17 in inflamed IBD mucosa may help explain the relative lack of efficacy of anti-IFNgamma antibodies in clinical trials of Crohn's disease.

Transforming growth factor beta signalling and matrix metalloproteinases in the mucosa overlying Crohn's disease strictures

BACKGROUND AND AIMS

In addition to its crucial role in dampening tissue-damaging immune responses in the gut, transforming growth factor beta (TGFbeta) is a potent profibrogenic agent inducing collagen synthesis and regulating the balance between matrix-degrading matrix metalloproteinases (MMPs) and their inhibitors (TIMPs). TGFbeta signalling was investigated by analysis of Smad proteins and MMPs/TIMPs in the mucosa overlying strictures in patients with Crohn's disease (CD).

METHODS

Specimens were collected from macroscopically normal mucosa overlying strictured and non-strictured gut of patients with fibrostenosing CD. Isolated myofibroblasts were cultured with anti-TGFbeta blocking antibody or TGF beta 1. TGFbeta transcripts were analysed by quantitative reverse transcription-PCR (RT-PCR). Smad proteins and MMPs were determined by immunoblotting. MMP-12 activity was measured by a real-time MMP-12 activity assay. An in vitro wound-healing scratch assay was used to assess myofibroblast migration.

RESULTS

TGFbeta transcripts, phosphorylated Smad2-Smad3 (pSmad2-3) and TIMP-1 proteins were higher in mucosa overlying strictures than in mucosa overlying non-strictured areas. In contrast, mucosa overlying strictured gut had lower expression of Smad7, MMP-12 and MMP-3. Myofibroblasts from mucosa overlying strictured gut showed higher TGFbeta transcripts, a greater pSmad2-3 response to TGFbeta, increased TIMP-1, lower Smad7, increased collagen production and reduced migration ability compared with myofibroblasts from mucosa overlying non-strictured gut. TGFbeta blockade increased myofibroblast MMP-12 production and migration, more obviously in myofibroblasts isolated from mucosa overlying non-strictured compared with strictured gut.

CONCLUSIONS

Changes in TGF-beta signalling and MMP production were identified in the mucosa overlying strictures in CD which may give a window into the process of fibrosis.

Increased expression of mucosal addressin cell adhesion molecule 1 in the duodenum of patients with active celiac disease is associated with depletion of integrin alpha4beta7-positive T cells in blood

Mucosal addressin cell adhesion molecule 1, expressed on gut endothelial cells, in conjunction with integrin alpha(4)beta(7), expressed on lymphocytes, is critical in lymphocyte homing to the gut. The mucosal addressin cell adhesion molecule 1/integrin alpha(4)beta(7) pathway is involved in the pathogenesis of chronic intestinal inflammation by recruiting lymphocytes into inflamed gut. We explored the duodenal expression of mucosal addressin cell adhesion molecule 1 and the peripheral T-cell expression of integrin alpha(4)beta(7) in patients with celiac disease. Duodenal biopsies and a peripheral blood sample were collected from 15 celiac patients, before and after 12 months of gluten-free diet, and from 12 control subjects. Treated celiac biopsies were cultured with peptic-tryptic digest of gliadin and/or an anti-interferon alpha neutralizing antibody. Mucosal addressin cell adhesion molecule 1 was determined by confocal immunofluorescence microscopy and immunoblotting. Integrin beta(7)-positive T cells were analyzed by flow cytometry. Mucosal addressin cell adhesion molecule 1 expression was significantly higher in active celiac disease than in normal mucosa. After gluten-free diet, a dramatic reduction of mucosal addressin cell adhesion molecule 1 was also observed. No difference was seen between patients with celiac disease after treatment and controls. Ex vivo peptic-tryptic digest of gliadin challenge induced a marked increase of mucosal addressin cell adhesion molecule 1 expression. Blocking interferon alpha inhibited the peptic-tryptic digest of gliadin-induced mucosal addressin cell adhesion molecule 1 overexpression. The percentage of circulating beta(7)-positive T cells was significantly lower in untreated celiac disease in comparison to controls but normalized after gluten-free diet. Mucosal addressin cell adhesion molecule 1 is strongly up-regulated in active celiac disease dependent on interferon alpha and is associated with peripheral depletion of integrin alpha(4)beta(7)-expressing T cells. We conclude that mucosal addressin cell adhesion molecule 1 may represent an important determinant for the generation of mucosal damage in celiac disease.

Blockade of transforming growth factor beta upregulates T-box transcription factor T-bet, and increases T helper cell type 1 cytokine and matrix metalloproteinase-3 production in the human gut mucosa

BACKGROUND AND AIMS

The role of transforming growth factor beta (TGFbeta) in inhibiting T cell function in the normal gut has been studied in animal models. However, the impact of TGFbeta inhibition on T cells in the normal human gut remains poorly understood. The effect of TGFbeta blockade in normal intestinal biopsies grown ex vivo and lamina propria mononuclear cells (LPMCs) on T-bet, a T-box transcription factor required for T helper cell type (Th)1 differentiation, interferon gamma (IFN gamma) production, T cell apoptosis and matrix metalloproteinase (MMP)-3 production has therefore been tested.

METHODS

TGFbeta transcripts were determined by quantitative reverse transcription-PCR in laser-captured gut epithelium and lamina propria. Biopsies and LPMCs were cultured with anti-TGFbeta neutralising antibody. After 24 h culture, T-bet was determined by immunoblotting, and T cell apoptosis was assessed by flow cytometry. IFN gamma, tumour necrosis factor alpha (TNFalpha), interleukin (IL) 2, IL6, IL8, IL10, IL12p70 and IL17 were measured by ELISA. MMP-3 and tissue inhibitor of matrix metalloproteinase (TIMP)-1 were assessed by immunoblotting.

RESULTS

A higher number of TGFbeta transcripts was found in the lamina propria than in the epithelium in normal gut. T-bet expression was significantly higher in biopsies and LPMCs cultured with anti-TGFbeta antibody than in those cultured with control antibody. TGFbeta blockade downregulated T cell apoptosis, and induced a significant increase in IFN gamma, TNFalpha, IL2, IL6, IL8 and IL17 production. A higher expression of MMP-3, but not TIMP-1, was observed in the tissue and supernatant of biopsies treated with anti-TGFbeta antibody.

CONCLUSIONS

The findings support a crucial role for TGFbeta in dampening T cell-mediated tissue-damaging responses in the human gut.

Evidence for the role of interferon-alfa production by dendritic cells in the Th1 response in celiac disease

BACKGROUND & AIMS

Dendritic cells (DCs) play a crucial role in immune responses by controlling the extent and type of T-cell response to antigen. Celiac disease is a condition in which T-cell immunity to gluten plays an important pathogenic role, yet information on DCs is scant. We examined mucosal DCs in celiac disease in terms of phenotype, activation/maturation state, cytokine production, and function.

METHODS

Mucosal DCs from 48 celiacs and 30 controls were investigated by flow cytometry. In situ distribution of DCs was analyzed by confocal microscopy. Interferon (IFN)-alfa, interleukin (IL)-4, IL-5, IL-12p35, IL-12p40, IL-18, IL-23p19, IL-27, and transforming growth factor-beta transcripts were measured by real-time reverse-transcription polymerase chain reaction in sorted DCs. DC expression of IL-6, IL-12p40, and IL-10 was assessed by intracellular cytokine staining. The effect of IFN-alfa and IL-18 blockade on the gluten-induced IFN-gamma response in celiac biopsy specimens grown ex vivo also was investigated.

RESULTS

Mucosal DCs were increased in untreated, but not treated, celiacs. The majority of them were plasmacytoid with higher levels of maturation (CD83) and activation (CD80/CD86) markers. Higher transcripts of Th1 relevant cytokines, such as IFN-alfa, IL-18, and IL-23p19, were produced by celiac DCs, but because IL-12p40 was undetectable, a role for IL-23 is unlikely. Intracellular cytokine staining of celiac DCs showed higher IL-6, but lower IL-10 expression, and confirmed the lack of IL-12p40. Blocking IFN-alfa inhibited IFN-gamma transcripts in ex vivo organ culture of celiac biopsy specimens challenged with gluten.

CONCLUSIONS

These data suggest that IFN-alfa-producing DCs contribute to the Th1 response in celiac disease.

Functional modulation of Crohn's disease myofibroblasts by anti-tumor necrosis factor antibodies

BACKGROUND & AIMS

Infliximab induces immune cell apoptosis by outside-to-inside signaling through transmembrane tumor necrosis factor-alpha (mTNF). However, in inflamed gut, myofibroblasts also produce TNF-alpha, and the affects of anti-TNF antibodies on these structural cells are unknown. We investigated the action of infliximab on apoptosis, the production of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMP)-1, and migration of Crohn's disease (CD) myofibroblasts.

METHODS

Colonic myofibroblasts were isolated from patients with active CD and controls. mTNF was evaluated by Western blotting and flow cytometry. Infliximab-treated myofibroblasts were analyzed for apoptosis by Annexin V staining and caspase-3. TIMP-1 and MMPs were measured by Western blotting, and fibroblast migration was assessed by using an in vitro wound-healing scratch assay.

RESULTS

CD myofibroblasts showed higher mTNF expression than control myofibroblasts. Infliximab had no effect on CD myofibroblast apoptosis, caspase-3 activation, and production of MMP-3 and MMP-12. However, infliximab induced a significant dose-dependent increase in TIMP-1 production, which was inhibited by the p38 mitogen-activated protein kinase inhibitor SB 203580. The anti-TNF agents adalimumab, etanercept, and p55 TNF-receptor-human IgG fusion protein also increased TIMP-1 production. The migration of CD myofibroblasts was enhanced significantly by infliximab and recombinant human TIMP-1, and infliximab-induced migration was inhibited by anti-TIMP-1 neutralizing antibody. Infliximab also decreased CD myofibroblast collagen production.

CONCLUSIONS

Our findings show a novel therapeutic pathway for anti-TNF therapies in enhancing TIMP-1 production and myofibroblast migration, which may reduce MMP activity and facilitate the wound healing.