Impact of patient characteristics on the clinical efficacy of mongersen (GED-0301), an oral Smad7 antisense oligonucleotide, in active Crohn's disease

BACKGROUND

In a phase 2 study, mongersen, an oral antisense oligonucleotide targeting Smad7, was effective in inducing clinical remission in approximately 60% of patients with active Crohn's disease (CD).

AIM

In a post hoc analysis to evaluate those patient disease characteristics that may have influenced the efficacy and safety of mongersen therapy.

METHODS

Patients with steroid-dependent/resistant, active CD were randomised to mongersen 10, 40 or 160 mg/day or placebo for 2 weeks; patients were followed for 10 weeks. Clinical remission [Crohn's Disease Activity Index (CDAI) score <150] and clinical response (CDAI score reduction ≥100 points) were assessed at weeks 2, 4 and 12 for these subgroups: disease duration <5/≥5 years, human serum C-reactive protein (hsCRP) <3/≥3 mg/L, and CDAI at baseline ≤260/>260. Additional patient baseline and disease characteristics were explored.

RESULTS

Clinical remission and response rates were significantly higher in patients receiving mongersen 40 and 160 mg/day but not 10 mg/day vs. placebo and independent of disease duration and hsCRP. Patients with baseline CDAI ≤260 had significantly higher remission rates with 40 and 160 mg/day. In patients with baseline CDAI >260, remission rates were statistically greater with 160 mg/day and numerically better with 40 mg/day vs. placebo. Adverse event rates were similar across treatment groups. Mongersen was safe and well tolerated.

CONCLUSIONS

Patients with higher CDAI scores achieved clinical remission most frequently with the highest mongersen dose. Disease duration and baseline human serum C-reactive protein did not appear to significantly impact efficacy of mongersen in this study (EudraCT Number: 2011-002640-27.).

Th17-type cytokines, IL-6 and TNF-α synergistically activate STAT3 and NF-kB to promote colorectal cancer cell growth

Colorectal cancers (CRCs) often show a dense infiltrate of cytokine-producing immune/inflammatory cells. The exact contribution of each immune cell subset and cytokine in the activation of the intracellular pathways sustaining CRC cell growth is not understood. Herein, we isolate tumor-infiltrating leukocytes (TILs) and lamina propria mononuclear cells (LPMCs) from the tumor area and the macroscopically unaffected, adjacent, colonic mucosa of patients who underwent resection for sporadic CRC and show that the culture supernatants of TILs, but not of LPMCs, potently enhance the growth of human CRC cell lines through the activation of the oncogenic transcription factors signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappa B (NF-kB). Characterization of immune cell complexity of TILs and LPMCs reveals no differences in the percentages of T cells, natural killer T cells, natural killer (NK) cells, macrophages and B cells. However, T cells from TILs show a functional switch compared with those from LPMCs to produce large amounts of T helper type 17 (Th17)-related cytokines (that is, interleukin-17A (IL-17A), IL-17F, IL-21 and IL-22), tumor necrosis factor-α (TNF-α) and IL-6. Individual neutralization of IL-17A, IL-17F, IL-21, IL-22, TNF-α or IL-6 does not change TIL-derived supernatant-driven STAT3 and NF-kB activation, as well as their proproliferative effect in CRC cells. In contrast, simultaneous neutralization of both IL-17A and TNF-α, which abrogates NF-kB signaling, and IL-22 and IL-6, which abrogates STAT3 signaling, reduces the mitogenic effect of supernatants in CRC cells. IL-17A, IL-21, IL-22, TNF-α and IL-6 are also produced in excess in the early colonic lesions in a mouse model of sporadic CRC, associated with enhanced STAT3/NF-kB activation. Mice therapeutically given BP-1-102, an orally bioavailable compound targeting STAT3/NF-kB activation and cross-talk, exhibit reduced colon tumorigenesis and diminished expression of STAT3/NF-kB-activating cytokines in the neoplastic areas. These data suggest that strategies aimed at the cotargeting of STAT3/NF-kB activation and interaction between them might represent an attractive and novel approach to combat CRC.

Defective expression of SIRT1 contributes to sustain inflammatory pathways in the gut

In inflammatory bowel disease (IBD), tissue damage is driven by an excessive immune response, poorly controlled by counter-regulatory mechanisms. SIRT1, a class III NAD+-dependent deacetylase, regulates negatively the expression of various proteins involved in the control of immune-inflammatory pathways, such as Stat3, Smad7, and NF-κB. Here we examined the expression, regulation, and function of SIRT1 in IBD. SIRT1 RNA and protein expression was less pronounced in whole biopsies and lamina propria mononuclear cells (LPMCs) of IBD patients in comparison with normal controls. SIRT1 expression was downregulated in control LPMC by tumor necrosis factor (TNF)-α and interleukin (IL)-21, and upregulated in IBD LPMC by neutralizing TNF-α and IL-21antibodies. Consistently, SIRT1 expression was increased in mucosal samples taken from IBD patients successfully treated with Infliximab. Treatment of IBD LPMC with Cay10591, a specific SIRT1 activator, reduced NF-κB activation and inhibited inflammatory cytokine synthesis, whereas Ex527, an inhibitor of SIRT1, increased interferon (IFN)-γ in control LPMC. SIRT1 was also reduced in mice with colitis induced by 2,4,6-trinitrobenzenesulphonic acid or oxazolone. Cay10591 prevented and cured experimental colitis whereas Ex527 exacerbated disease by modulating T cell-derived cytokine response. Data indicate that SIRT1 is downregulated in IBD patients and colitic mice and suggest that SIRT1 activation can help attenuate inflammatory signals in the gut.

Serum regenerating islet-derived 3-alpha is a biomarker of mucosal enteropathies

BACKGROUND

The clinical presentation of organic and functional intestinal disorders can overlap and clinicians often rely on invasive and time-consuming procedures to make a final diagnosis. Regenerating islet-derived 3-alpha (Reg3α) is detectable in the circulation of patients with intestinal graft-versus host disease and patients with inflammatory bowel disease (IBD).

AIM

To determine whether serum Reg3α testing is useful for discriminating mucosal enteropathies from functional intestinal disorders.

METHODS

We prospectively included 47 patients with active coeliac disease (ACD), 13 patients with refractory coeliac disease (RCD), seven patients with common variable immunodeficiency (CVID), 72 patients with active Crohn's disease, 22 patients with active ulcerative colitis (UC) and 28 patients with irritable bowel syndrome (IBS)-related diarrhoea. Sera were also taken from 10 CD patients before and after 6-12 months of a gluten-free diet (GFD) and from 14 patients with IBD before and after induction therapy with Infliximab (IFX). Sera of 119 healthy volunteers were used to determine the cut-off value. Reg3α levels were measured by a commercial ELISA kit.

RESULTS

Levels of Reg3α exceeded the cut-off value of the assay in 43/47(91%) ACD patients, 13/13(100%) RCD patients, 7/7(100%) CVID patients, 65/72(90%) Crohn's disease patients, 17/22(77%) UC patients and one patient with IBS(4%). Reg3α levels distinguished mucosal enteropathies from IBS with a sensitivity of 90% and a specificity of 96%. Reg3α levels significantly decreased in CD patients following a GFD and in IBD patients after treatment with IFX.

CONCLUSION

Reg3α is a serum biomarker of intestinal damage that, combined with clinical data, identifies patients who should undergo invasive tests for diagnosing enteropathies.

A functional role for Smad7 in sustaining colon cancer cell growth and survival

Initially identified as an inhibitor of transforming growth factor (TGF)-β mainly owing to its ability to bind TGF-β receptor type I and abrogate TGF-β-driven signaling, Smad7 can interact with additional intracellular proteins and regulate TGF-β-independent pathways, thus having a key role in the control of neoplastic processes in various organs. Genome-wide association studies have shown that common alleles of Smad7 influence the risk of colorectal cancer (CRC), even though the contribution of Smad7 in colon carcinogenesis is not fully understood. In this study, we assessed the expression and role of Smad7 in human and mouse models of sporadic CRC. We document a significant increase of Smad7 in human CRC relative to the surrounding nontumor tissues and show that silencing of Smad7 inhibits the growth of CRC cell lines both in vitro and in vivo after transplantation into immunodeficient mice. Knockdown of Smad7 results in enhanced phosphorylation of the cyclin-dependent kinase (CDK)2, accumulation of CRC cells in S phase and enhanced cell death. Smad7-deficient CRC cells have lower levels of CDC25A, a phosphatase that dephosphorylates CDK2, and hyperphosphorylated eukaryotic initiation factor 2 (eIF2)α, a negative regulator of CDC25 protein translation. Consistently, knockdown of Smad7 associates with inactivation of eIF2α, lower CDC25A expression and diminished fraction of proliferating cells in human CRC explants, and reduces the number of intestinal tumors in Apc^min/+ mice. Altogether, these data support a role for Smad7 in sustaining colon tumorigenesis.

Adenoma, advanced adenoma and colorectal cancer prevalence in asymptomatic 40- to 49-year-old subjects with a first-degree family history of colorectal cancer

AIM

First-degree relatives (FDRs) of patients with colorectal cancer (CRC) have an increased CRC risk. Few studies have addressed if adenoma and advanced adenoma risk is increased among individuals, 40-49 years of age, with a family history of CRC. Therefore, the aim of the study was to define the prevalence and location of adenoma, advanced adenoma and CRC, according to age, in asymptomatic individuals with a family history of CRC.

METHOD

Retrospective study of asymptomatic FDRs, 40 to ≥70 years of age undergoing first screening colonoscopy over a 3-year period, of CRC patients.

RESULTS

Among 464 individuals studied, the prevalence of adenoma and advanced adenoma was 18.1% and 6.4%, respectively. According to age intervals, the prevalences of adenoma and advanced adenoma were 14% and 3.5%, respectively, in subjects 40-49 years of age; 14.4% and 6.3%, respectively, in subjects 50-59 years of age; 27% and 8%, respectively, in subjects 60-69 years of age; and 25% and 14%, respectively, in subjects ≥70 years of age; no significant difference was found among the four groups. No difference in lesion location was found, with similar numbers of preneoplastic lesions being present in the right colon and the left colon. CRC was diagnosed in three (0.64%) subjects, one of whom was in the 40-49 years age group.

CONCLUSION

In our population of FDRs of CRC patients, 40-49 years of age, the prevalences of adenoma and advanced adenoma were similar to those observed in older subjects with the same CRC risk. Our data support the current indication to perform screening colonoscopy earlier than 45 years of age in subjects at high CRC risk.

A phase 1 open-label trial shows that smad7 antisense oligonucleotide (GED0301) does not increase the risk of small bowel strictures in Crohn’s disease

BACKGROUND

In Crohn's disease (CD), knockdown of Smad7, an inhibitor of Transforming Growth Factor (TGF)-β1 activity, with a specific antisense oligonucleotide (GED0301) seems to be safe and tolerable and associates with TGF-β1-mediated suppression of inflammatory pathways.

AIM

Since TGF-β1 has pro-fibrogenic effects in many organs, we evaluated whether GED0301 treatment associates with the formation of small bowel strictures.

METHODS

Fifteen patients with active, inflammatory CD, receiving oral GED0301 once daily for 7 days, were monitored for the formation of small bowel strictures by Small Intestine Contrast Ultrasonography (SICUS). Serum basic fibroblast growth factor (bFGF) and human chitinase 3-like 1 (also known as YKL-40), two markers of CD-related intestinal strictures, and matrix metalloproteinases (MMP) and tissue inhibitor 1 of MMPs (TIMP1) were analysed at day 0 and day 180 by ELISA. Crohn's disease activity index (CDAI) changes were also monitored.

RESULTS

Fourteen patients completed the 6-month study; the remaining underwent intestinal resection for a severe relapse not responsive to medical treatment. No patient developed small bowel stricture and none experienced obstructive symptoms during the study period. GED0301 treatment induced no significant change in the circulating levels of bFGF, YKL-40, MMPs and TIMP1. Seven of 12 patients who reached clinical remission following GED0301 treatment maintained a CDAI < 150 at day 180.

CONCLUSION

Short-term treatment of patients with Crohn's disease using GED0301 is not associated with the development of small bowel stricture, thus reinforcing the concept that this drug is safe at least at early time points.

Th17-related cytokines in inflammatory bowel diseases: friends or foes?

T helper (Th)17 cells and other interleukin (IL)-17-producing cells are supposed to play critical roles in several human immune-mediated diseases, including Crohn's disease (CD) and ulcerative colitis (UC), the main forms of inflammatory bowel diseases (IBD) in man. Th17 cells infiltrate massively the inflamed intestine of IBD patients and in vitro and in vivo studies have shown that Th17-type cytokines may trigger and amplify multiple inflammatory pathways. Nonetheless, some Th17-related cytokines, such as interleukin (IL)-17A and IL-22, may target gut epithelial cells and promote the activation of counter-regulatory mechanisms. This observation together with the demonstration that Th17 cells are not stable and can be converted into either regulatory T cells or Th1 cells if stimulated by immune-suppressive (e.g. TGF-β1) or inflammatory (e.g. IL-12, IL-23) cytokines have contributed to advance our understanding of mechanisms that regulate mucosal homeostasis and inflammation in the gut.

Efficacy and safety of infliximab and adalimumab in Crohn's disease: a single centre study

BACKGROUND

Infliximab and adalimumab are highly effective in Crohn's Disease (CD). This is supported by clinical trials and open-label studies using either infliximab or adalimumab, thus not allowing a proper comparison between these anti-TNFs in CD.

AIM

To evaluate the efficacy and safety of infliximab and adalimumab in active CD.

METHODS

In a longitudinal study, CD patients with indication for anti-TNFs were treated with infliximab or adalimumab.

RESULTS

Ninety-three patients were treated with infliximab (n = 44) or adalimumab (n = 49). In the infliximab group, the induction was completed by 77.3% of patients, due to no response (n = 2), delayed hypersensitivity reactions (DHR) or infusion reactions (n = 8). Maintenance with infliximab was completed by 60% of patients, due to clinical worsening or loss of efficacy (n = 5), DHR or infusion reactions (n = 5). In the adalimumab group, all patients completed the induction, while maintenance was completed by 67% of patients, due to clinical worsening or loss of efficacy (n = 8), DHR (n = 1), other causes (n = 7). In both groups, the CDAI significantly reduced at baseline vs. each visit (P < 0.04). The Kaplan-Meier survival analysis performed to evaluate the risk of steroid-free remission in patients treated with infliximab vs. adalimumab detected no differences (log-rank test P = 0.4). Cox proportional-hazards regression identified two predictors of steroid-free remission using anti-TNFs: no smokers [HR = 2.94 (1.52-5.70), P = 0.001] and non stricturing non penetrating behaviour [HR = 3.116 (1.06-9.13), P = 0.03826].

CONCLUSIONS

Infliximab and adalimumab showed a similar efficacy. No smoking and non-stricturing non-penetrating behaviour were predictors of steroid-free remission.

Epigenetically silenced miR-34b/c as a novel faecal-based screening marker for colorectal cancer

BACKGROUND

MicroRNAs are tiny non-coding small endogenous RNAs that regulate gene expression by translational repression, mRNA cleavage and mRNA inhibition. The aim of this study was to investigate the hypermethylation of miR-34b/c and miR-148a in colorectal cancer, and correlate this data to clinicopathological features. We also aimed to evaluate the hypermethylation of miR-34b/c in faeces specimens as a novel non-invasive faecal-DNA-based screening marker.

METHODS

The 5-aza-2'-deoxycytidine treatment and methylation-specific PCR were carried out to detect the hypermethylation of miR-34b/c and miR-148a.

RESULTS

The miR-34b/c hypermethylation was found in 97.5% (79 out of 82) of primary colorectal tumours, P=0.0110. In 75% (21 out of 28) of faecal specimens we found a hypermethylation of miR-34b/c while only in 16% (2 out of 12) of high-grade dysplasia. In addition, miR-148a was found to be hypermethylated in 65% (51 out of 78) of colorectal tumour tissues with no significant correlation to clinicopathological features. However, a trend with female gender and advanced age was found, P=0.083. We also observed a trend to lower survival rate in patients with miR-148a hypermethylation with 10-year survival probability: 48 vs 65%, P=0.561.

CONCLUSIONS

These findings show that aberrant hypermethylation of miR-34b/c could be an ideal class of early screening marker, whereas miR-148a could serve as a disease progression follow-up marker.

Frataxin participates to the hypoxia-induced response in tumors

Defective expression of frataxin is responsible for the degenerative disease Friedreich's ataxia. Frataxin is a protein required for cell survival since complete knockout is lethal. Frataxin protects tumor cells against oxidative stress and apoptosis but also acts as a tumor suppressor. The molecular bases of this apparent paradox are missing. We therefore sought to investigate the pathways through which frataxin enhances stress resistance in tumor cells. We found that frataxin expression is upregulated in several tumor cell lines in response to hypoxic stress, a condition often associated with tumor progression. Moreover, frataxin upregulation in response to hypoxia is dependent on hypoxia-inducible factors expression and modulates the activation of the tumor-suppressor p53. Importantly, we show for the first time that frataxin is in fact increased in human tumors in vivo. These results show that frataxin participates to the hypoxia-induced stress response in tumors, thus implying that modulation of its expression could have a critical role in tumor cell survival and/or progression.

Endoscopic vs ultrasonographic findings related to Crohn's disease recurrence: a prospective longitudinal study at 3 years

BACKGROUND AND AIMS

Ileocolonoscopy (IC) is the gold standard for assessing Crohn's Disease (CD) recurrence after ileo-colonic resection. In a prospective longitudinal study we compared findings related to CD recurrence when using techniques visualizing either the luminal or the extraluminal surface (IC and small bowel follow through, SBFT vs Small Intestine Contrast Ultrasonography, SICUS).

METHODS

From 2003 to 2008, 25 CD patients undergoing ileo-colonic resection were enrolled. Clinical assessment (CDAI) was performed at 1, 2 and 3 years. IC was performed at 1 (n=25) and 3 years (n=15), SBFT at 2 years (n=21) and SICUS at 1 (n=25), 2 (n=21) and 3 years (n=15). Recurrence was assessed by SBFT and SICUS (bowel wall thickness, BWT) when using IC as gold standard.

RESULTS

At 1 year, all patients were inactive and recurrence was detected by IC in 24/25 (96%) and by SICUS in 25/25 patients. At 2 years, 6/21 patients (29%) were active and recurrence was detected by SBFT in 12/21 (57%) and by SICUS in 21/21 patients. At 3 years, 5/15 patients (33%) were active, IC showed recurrence in 14/15 (93%), and SICUS in 15/15 patients. The endoscopic score at 1 year was higher in patients developing relapse at 2 years (n=5) than in patients maintaining remission (n=10) (median: 4, range 3-4 vs 2, range 0-3; p=0.003). The same finding was not observed by using SICUS (median BWT at 1 year: 5, range 4-7 vs 3.7, range 3.5-6; p=0.19).

CONCLUSIONS

Although IC and SICUS provide a different view of the bowel wall, in experienced hands SICUS provides findings compatible with endoscopic recurrence after ileo-colonic resection for CD. Discrepant findings may be observed in a low proportion of patients with minor lesions related to CD recurrence.

Clinical trial: ulcerative colitis maintenance treatment with 5-ASA: a 1-year, randomized multicentre study comparing MMX with Asacol

BACKGROUND

5-ASA-MMX (1.2 g/tablet) is a 5-aminosalicylic acid formulation, designed for once-daily dosing in the treatment of ulcerative colitis.

AIM

To evaluate the efficacy and safety of 5-ASA-MMX (2.4 g/day, once daily), compared with Asacol (2.4 g/day, twice daily) in the maintenance of left-sided UC, through a double-blind, double-dummy, parallel-group, randomized, comparator study.

METHODS

In all, 331 patients with UC were randomized to receive either 5-ASA-MMX 2.4 g/day, once daily, or Asacol 2.4 g/day, twice daily, for 12 months. All patients were in remission for >or=1 month prior to the trial, with >or=1 documented relapse in the previous year. The co-primary endpoints of this study were the proportion of patients in clinical, and clinical and endoscopic remission following 12 months' treatment.

RESULTS

In the intent-to-treat population, excluding those with major protocol deviations, 68.0 and 65.9% patients in the 5-ASA-MMX and Asacol groups, respectively, were in clinical remission (P = 0.69), and 60.9 and 61.7% of patients, respectively, were in clinical and endoscopic remission (P = 0.89). Diary card data revealed statistically significant treatment differences favouring 5-ASA-MMX. Both treatments were similarly tolerated.

CONCLUSIONS

Once-daily 5-ASA-MMX is similarly effective with a comparable safety profile to Asacol administered twice daily, for the maintenance treatment of ulcerative colitis.

Transcriptional and post-translational regulation of Flip, an inhibitor of Fas-mediated apoptosis, in human gut inflammation

OBJECTIVE

Defects in Fas-mediated apoptosis are supposed to contribute to the accumulation of T lymphocytes in the gut of patients with Crohn's disease (CD). This phenomenon has been functionally linked with the elevated expression of Flip, an inhibitor of Fas-mediated apoptosis. In this study, the molecular mechanisms that control Flip in CD were examined.

METHODS

Paired colonic biopsies of patients with CD, patients with ulcerative colitis (UC) and normal controls were analysed for Flip by real-time PCR and western blotting. Flip was also evaluated in CD3(+) lamina propria lymphocytes (T-LPLs) cultured with tosyl phenylalanyl chloromethyl ketone (TPCK; a nuclear factor-kappaB (NF-kappaB) inhibitor), AG490 (a Janus kinase 2 (Jak2)/signal transducer and activator of transcription (Stat) inhibitor) or 17-desmethoxy-17-N,N-dimethylamino-geldanamycin (DMAG; an inhibitor of heat shock protein 90). The rate of apoptosis was examined by flow cytometry.

RESULTS

In CD, upregulation of Flip occurred at both the RNA and protein level. Treatment of CD CD3(+) T-LPLs with TPCK or AG490 markedly reduced Flip RNA, suggesting a role for NF-kappaB and Jak/Stat pathways in the transcriptional control of Flip in this condition. Consistently, both TPCK and AG490 sensitised CD T-LPLs to Fas-mediated apoptosis. Flip protein in cells from normal gut was rapidly degraded by the proteasome pathway. In contrast, in inflamed gut of both CD and UC patients, there was a reduced degradation of Flip via the ubiquitin-proteasome-dependent pathway, but Flip expression can be decreased by DMAG.

CONCLUSIONS

The data demonstrate that Flip is regulated at both the transcriptional and post-translational level in CD, and indicate that in the normal but not inflamed gut Flip is degraded via the ubiquitin-proteasome-dependent pathway.

Unsedated transnasal versus transoral sedated upper gastrointestinal endoscopy: a one-series prospective study on safety and patient acceptability

BACKGROUND

While conventional oesophagogastroduodenoscopy is frequently performed under sedation to improve acceptability, transnasal oesophagogastroduodenoscopy would appear to be less invasive.

STUDY AIMS

To compare diagnostic accuracy, feasibility, acceptability and safety of transnasal oesophagogastroduodenoscopy without sedation versus conventional oesophagogastroduodenoscopy under sedation.

PATIENTS

Following anxiety assessment, 30 dyspeptic patients underwent transnasal oesophagogastroduodenoscopy under local anaesthesia (lidocaine) and conventional oesophagogastroduodenoscopy under conscious sedation (i.v. midazolam) on two consecutive days. Transnasal oesophagogastroduodenoscopy was performed with an ultrathin and conventional oesophagogastroduodenoscopy with a standard endoscope.

METHODS

Safety, evaluated by monitoring cardio-respiratory functions. Acceptability, rated according to discomfort and preference between the two examinations. Diagnostic accuracy evaluated taking into account endoscopic patterns and adequacy of biopsy specimens for histology. Feasibility, defined according to endoscopic performance, quality of images and overall opinion of the endoscopist. Only gastric biopsies were evaluated.

RESULTS

All patients but one who refused conventional oesophagogastroduodenoscopy underwent both transnasal oesophagogastroduodenoscopy and conventional oesophagogastroduodenoscopy. No cardiorespiratory complications occurred during either technique. Majority of patients (87%) preferred transnasal oesophagogastroduodenoscopy. Examinations were completed in all cases, with comparable endoscopic patterns. All biopsy specimens were suitable for histology.

CONCLUSIONS

Transnasal oesophagogastroduodenoscopy without sedation provides good diagnostic accuracy, is safer and better accepted than conventional oesophagogastroduodenoscopy under sedation and, therefore, represents a valid alternative in routine diagnosis of upper digestive tract diseases.

Interleukin 21 contributes to the mucosal T helper cell type 1 response in coeliac disease

BACKGROUND

In coeliac disease (CD), the upper bowel lesion is associated with a marked infiltration of the mucosa with Th1 cells secreting interferon gamma (IFNgamma) and expressing the Th1-associated transcription factor, T-bet. However, the molecular mechanisms which regulate T-bet and promote the Th1 cell response are unknown.

OBJECTIVE

To examine whether interleukin 21 (IL21), a cytokine that regulates T cell activation, has a role in CD.

METHODS

Duodenal mucosal samples were taken from CD patients and normal controls. IL21 and T-bet were examined by real-time PCR and western blotting, and IFNgamma was assessed by real-time PCR and ELISA. The effect of blockade of endogenous IL21 on the expression of T-bet was examined in an ex vivo culture of biopsies taken from untreated CD patients. Finally, the role of IL21 in controlling T-bet and IFNgamma was also evaluated in cultures of biopsies taken from treated CD patients and cultured with a peptic-tryptic digest of gliadin (PT) in the presence or absence of a neutralising IL21 antibody.

RESULTS

Enhanced IL21 RNA and protein expression was seen in duodenal samples from untreated CD patients. Blockade of IL21 activity in biopsies of untreated CD patients reduced T-bet and IFNgamma secretion. Stimulation of treated CD biopsies with PT enhanced IL21 expression, and neutralisation of IL21 largely prevented PT-driven T-bet and IFNgamma induction.

CONCLUSIONS

IL21 is overproduced in the mucosa of CD patients, where it helps sustain T-bet expression and IFNgamma production.

Non-invasive techniques for assessing postoperative recurrence in Crohn's disease

Postoperative recurrence after ileo-colonic resection is a feature of Crohn's Disease (CD), almost 73% of patients show endoscopic recurrence at 1 year and 90% at 3 years. After surgical resection for CD, symptoms may be related to the surgical resection itself. Moreover, the development of an early severe endoscopic recurrence within 1 year represents a risk factor for early clinical recurrence. On the basis of these observations, the early detection and assessment of asymptomatic endoscopic recurrence may allow a timely and appropriate treatment of CD patients after ileo-colonic resection. At this purpose, conventional colonoscopy with ileoscopy currently represents the gold standard for assessing CD recurrence, graded according to the Rutgeerts' score. Lesions compatible with CD recurrence can be also detected by conventional radiology, including small bowel follow through and enema, both associated with a high radiation exposure. Due to the ineluctable course of CD after resection, and to the need of a proper follow up for assessing CD recurrence, several alternative, non invasive techniques have been searched in order to assess the post-operative recurrence, including: faecal alpha 1-antitrypsin clearance, faecal calprotectin, 99Tc-HMPAO scintigraphy, virtual colonoscopy, ultrasonography and, more recently, wireless capsule endoscopy (WCE) and Small Intestine Contrast Ultrasonography (SICUS). Among these, current evidences suggest that in experienced hands, ultrasound examination by SICUS represents a non-invasive technique useful for assessing recurrence in CD patients under regular follow up after surgery. The same findings are suggested for WCE, although the impact risk related to the recurrence or to the surgical anastomosis itself limits the use of this non-invasive technique for assessing CD recurrence after surgery.

Beclomethasone dipropionate versus mesalazine in distal ulcerative colitis: a multicenter, randomized, double-blind study

BACKGROUND

Topical beclomethasone diproprionate has shown efficacy in ulcerative colitis.

AIM

To assess, in a multicenter, randomized, double-blind study, the tolerability and safety of topical beclomethasone diproprionate (3mg) enema and foam versus mesalazine (2g) enema and foam in mild-moderate distal ulcerative colitis.

PATIENTS

In 15 referral gastrointestinal units, 99 patients with distal ulcerative colitis were enrolled. This number was lower than planned according to the statistical analysis, due to a low recruitment rate.

METHODS

Patients were randomly assigned to random preparations (beclomethasone diproprionate enema, beclomethasone diproprionate foam, mesalazine enema, mesalazine foam) once nightly for 8 weeks, with clinical and endoscopical assessment (Disease Activity Index score) at baseline (T0), 4 (T4) and 8 weeks (T8). Results were expressed as median and range (95% confidence interval). The efficacy was assessed by comparing the Disease Activity Index value at T4 and T8 by using the Student's t-test or the Wilcoxon-Mann-Whitney test.

RESULTS

Efficacy was comparable in the beclomethasone diproprionate or mesalazine groups at both T4 and T8 (response at T4: beclomethasone diproprionate 78% [95% confidence interval 0.6-0.8] versus mesalazine 79% [95% confidence interval 0.6-0.8]; T8: beclomethasone diproprionate 84% [95% confidence interval 0.7-0.9] versus mesalazine 90% [95% confidence interval 0.7-1.0]; p=n.s.; remission at T4: beclomethasone diproprionate 24% [95% confidence interval 0.1-0.3] versus mesalazine 28% [95% confidence interval 0.1-0.3]; remission at T8: beclomethasone diproprionate 36% [95% confidence interval 0.2-0.5] versus mesalazine 52% [95% confidence interval 0.3-0.6]; p=n.s.). The Disease Activity Index lowered at T4 and T8 versus T0 in the four groups (T4 versus T0: beclomethasone diproprionate foam Disease Activity Index 2 versus 6 p<0.0001; beclomethasone diproprionate enema 4 versus 6, mesalazine enema 3 versus 6, mesalazine foam 3.5 versus 7, p<0.001 for all three groups; T8 versus T0: p<0.01). The Disease Activity Index lowered at T8 versus T4 in the beclomethasone diproprionate enema and foam (Disease Activity Index: 2 versus 4 and 1 versus 4, respectively; p<0.05) and in the mesalazine enema (Disease Activity Index: 1.5, range 0-4 versus 3, range 0-12; p<0.01), but not in the mesalazine foam group (Disease Activity Index: 1, range 0-9 versus 3.5, range 0-8; p=n.s.). The safety profile was favourable for all groups.

CONCLUSIONS

Beclomethasone diproprionate and mesalazine enema and foam show a comparable tolerability and efficacy in mild active distal ulcerative colitis.

Control of matrix metalloproteinase production in human intestinal fibroblasts by interleukin 21

BACKGROUND

T cell-mediated immunity plays a central part in the pathogenesis of tissue damage in inflammatory bowel disease (IBD). The mechanism by which T cells mediate tissue damage during IBD remains unclear, but evidence indicates that T cell-derived cytokines stimulate fibroblasts to synthesise matrix metalloproteinases (MMPs), which then mediate mucosal degradation. We have previously shown that, in IBD, there is high production of interleukin (IL) 21, a T cell-derived cytokine, which enhances Th1 activity.

AIM

To investigate whether IL21 controls MMP production by intestinal fibroblasts.

METHODS

IL21 receptor (IL21R) was evaluated in intestinal fibroblasts by reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting. Fibroblasts were stimulated with IL21 and MMPs were evaluated by RT-PCR and western blotting. The effect of a neutralising IL21R fusion protein (IL21R/Fc) on the induction of MMPs in fibroblasts stimulated with IBD lamina propria mononuclear cell (LPMC) supernatants was also evaluated.

RESULTS

Intestinal fibroblasts constitutively express both IL21R and the common gamma chain receptor, which are necessary for IL21-driven signalling. IL21 enhances fibroblast production of MMP-1, MMP-2, MMP-3 and MMP-9, but not tissue inhibitors of MMP-1 and MMP-2. Moreover, IL21 synergises with tumour necrosis factor alpha to increase synthesis of MMP synthesis. IL21 enhances MMP secretion without affecting gene transcription and protein synthesis. IBD LPMC supernatants stimulate MMP secretion by intestinal fibroblasts, and this effect is partly inhibited by IL21R/Fc.

CONCLUSIONS

These results suggest that fibroblasts are a potential target of IL21 in the gut and that IL21 controls MMP secretion by fibroblasts.

Silencing of SH-PTP2 defines a crucial role in the inactivation of epidermal growth factor receptor by 5-aminosalicylic acid in colon cancer cells

Recent studies have suggested that 5-aminosalicylic acid (5-ASA) inhibits colorectal cancer (CRC) development. However, the mechanism underlying the antineoplastic effect of 5-ASA remains unknown. We here examined the effect of 5-ASA on epidermal growth factor receptor (EGFR) activation, a pathway that triggers mitogenic signals in CRC cells. We show that 5-ASA inhibits EGFR activation, through a mechanism that does not rely on CRC cell death induction. 5-ASA enhances the activity, but not expression, of phosphorylated (p)-EGFR-targeting phosphatases (PTPs), and treatment of cells with PTP inhibitors abrogates the 5-ASA-mediated EGFR dephosphorylation. Both SH-PTP1 and SH-PTP2 interact with EGFR upon 5-ASA treatment. However, knockdown of SH-PTP2 but not SH-PTP1 by small interference RNAs prevents the 5-ASA-induced EGFR dephosphorylation. Finally, we show that 5-ASA attenuates p-EGFR in ex vivo organ cultures of CRC explants. Data indicate that 5-ASA disrupts EGFR signalling by enhancing SH-PTP2 activity, and suggest a mechanism by which 5-ASA interferes with CRC growth.

Infliximab and newly diagnosed neoplasia in Crohn's disease: a multicentre matched pair study

BACKGROUND AND AIMS

The widespread use of anti-tumour necrosis factor alpha antibody (Infliximab) in Crohn's disease (CD) raises concerns about a possible cancer risk in the long term. In a matched pair study, we assessed whether Infliximab is associated with an increased risk of neoplasia.

METHODS

In a multicentre matched pair study, 404 CD patients treated with Infliximab (CD-IFX) were matched with 404 CD patients who had never received Infliximab (CD-C). Cases and controls were matched for sex, age (+/-5 years), site of CD, age at diagnosis (+/-5 years), immunosuppressant use, and follow up. New diagnoses of neoplasia from April 1999 to October 2004 were recorded.

RESULTS

Among the 404 CD-IFX, neoplasia was diagnosed in nine patients (2.22%) while among the 404 CD-C, seven patients developed neoplasia (1.73%) (odds ratio 1.33 (95% confidence interval 0.46-3.84); p=0.40). The survival curve adjusted for patient year of follow up showed no differences between CD-IFX and CD-C (p=0.90; log rank test). In the CD-IFX group, there was one cholangiocarcinoma, three breast cancers, one skin cancer, one leukaemia, one laryngeal cancer, and two anal carcinomas. Among the 7/404 (1.73%) CD-C, there were three intestinal adenocarcinomas (two caecum, one rectum), one basalioma, one spinalioma, one non-Hodgkin's lymphoma, and one breast cancer. Age at diagnosis of neoplasia did not differ between groups (CD-IFX v CD-C: median 50 (range 40-70 years) v 45 (27-72); p=0.50).

CONCLUSION

In our multicentre matched pair study, the frequency of a new diagnosis of neoplasia in CD patients treated with Infliximab was comparable with CD patients who had never received Infliximab.

A novel diagnostic tool for detecting functional patency of the small bowel: the Given patency capsule

BACKGROUND AND STUDY AIMS

The current visualization of small-bowel strictures using traditional radiological methods is associated with high radiation doses and false-negative results. These methods do not always reveal small-bowel patency for solids. The aim is to assess the safety of the Given patency system and its ability to detect intestinal strictures in patients with strictures that are known or suspected radiologically.

MATERIALS AND METHODS

The Given patency capsule is composed of lactose, remains intact in the gastrointestinal tract for 40-100 hours post ingestion, and disintegrates thereafter. A total of 34 patients with small-bowel stricture were prospectively enrolled; 30 had a previous diagnosis of Crohn's disease, three had adhesion syndrome and in one ischemic enteritis was suspected. Of the patients, 15 (44.1 %) had previously undergone surgery. Following ingestion, the capsule was monitored for integrity and transit time, using a specially designed Given scanner and also radiologically. Seventeen patients had been enrolled with the intent of using the patency capsule as a preliminary test in patients with small-bowel strictures before undergoing video capsule endoscopy.

RESULTS

30 patients (88.2 %) retrieved the capsule in the stool; it was intact in 20 (median transit time 22 hours), and disintegrated in 10 patients (median transit time 53 hours). Six patients complained of abdominal pain which disappeared within 24 hours. The scanner successfully indicated the presence of the capsule in 94 % of cases. Ten patients underwent video capsule endoscopy following the patency capsule examination; in all of these the video capsule passed through the small-bowel stricture.

CONCLUSIONS

This feasibility study has shown that the Given patency capsule is a safe, effective, and convenient tool for assessment of functional patency of the small bowel. It can indicate functional patency even in cases where traditional radiology indicates stricture.

Technetium-99m-HMPAO labeled leukocyte single photon emission computerized tomography (SPECT) for assessing Crohn's disease extent and intestinal infiltration

OBJECTIVES

Scintigraphy using radiolabeled leukocytes is a useful technique for assessing intestinal infiltration in Crohn's disease (CD). However, limits of planar images include overlapping activity in other organs and low specificity. To investigate the usefulness of (99m)Tc-HMPAO (hexametyl propylene amine oxime) labeled leukocyte single photon emission computerized tomography (SPECT) for assessing CD lesions, in comparison with planar images.

METHODS

Twenty-two inflammatory bowel disease patients (19 CD; 2 ulcerative colitis, UC; 1 ileal pouch) assessed by conventional endoscopy or radiology were enrolled. Leukocytes were labeled with (99m)Tc-HMPAO. SPECT images were acquired at 2 h and planar images at 30 min and 2 h. Bowel uptake was quantitated in nine regions (score 0-3).

RESULTS

Both SPECT and planar images detected a negative scintigraphy (score 0) in the UC patient with no pouchitis and a positive scintigraphy (score 1-3) in the 21 patients showing active inflammation by conventional techniques. SPECT showed a higher global score than planar images (0.71 +/- 0.09 vs 0.30 +/- 0.05; p < 0.001), and in particular in the right iliac fossa (p= 0.003), right and left flank (p < 0.001; p= 0.02), hypogastrium (p= 0.002), and mesogastrium (p < 0.001). SPECT provided a better visualization and a higher uptake than planar images in patients with ileal and ileocolonic CD (6.45 +/- 0.82 vs 2.8 +/- 0.55, p < 0.001; 5.5 +/- 1.6 vs 2.6 +/- 0.7, p= 0.03), and with perianal CD (6.6 +/- 1.6 vs 3.4 +/- 1.2; p= 0.03).

CONCLUSIONS

(99m)Tc-HMPAO labeled leukocyte SPECT provides a more detailed visualization of CD lesions than planar images. This technique may better discriminate between intestinal and bone marrow uptake, thus being useful for assessing CD lesions within the pelvis, including perianal disease.

Regulation of the T helper cell type 1 transcription factor T-bet in coeliac disease mucosa

BACKGROUND

In coeliac disease (CD) mucosa, the histological lesion is associated with marked infiltration of T helper cell type 1 (Th1) cells. However, the molecular mechanisms which regulate Th1 cell differentiation in CD mucosa are unknown.

AIMS

To analyse expression of transcription factors which control the Th1 cell commitment in CD.

PATIENTS

Duodenal mucosal samples were taken from untreated CD patients and normal controls.

METHODS

Interferon gamma (IFN-gamma) and interleukin (IL)-4 RNA expression was examined in T lamina propria lymphocytes by quantitative reverse transcription-polymerase chain reaction. T-bet and STAT-4, two Th1 promoting transcription factors, and STAT-6 and GATA-3, transcription factors which govern T helper cell type 2 (Th2) cell polarisation, were examined in duodenal biopsies by western blotting. The effect of gliadin and IFN-gamma on expression of T-bet was examined in an ex vivo culture of biopsies taken from normal and treated CD patients.

RESULTS

As expected, IFN-gamma but not IL-4 RNA transcripts were increased in the mucosa of CD patients in comparison with controls. CD mucosal samples consistently exhibited higher levels of T-bet than controls. However, no difference in active STAT-4 expression was seen between CD patients and controls, suggesting that Th1 polarisation was not induced by local IL-12. GATA-3 and STAT-6 were also low in both CD and control mucosa. In normal duodenal biopsies, IFN-gamma stimulated T-bet through a STAT-1 dependent mechanism. Challenge of treated CD but not control biopsies with gliadin enhanced T-bet and this effect was also inhibited by STAT-1 inhibition.

CONCLUSIONS

This study shows that activation of STAT-1 by IFN-gamma promotes T-bet in CD mucosa.

High seroprevalence of Helicobacter pylori infection in non-institutionalised children with mental retardation

Eighty-four children with mental retardation (34 boys, 50 girls; age range 2-18 years, median 6 years) and 84 age- and gender-matched outpatient controls were studied. All children were living at home, had never stayed in an institution, and came from the same urban area. Seropositivity for Helicobacter pylori was found in 42 (50%) of 84 mentally retarded children and 16 (19%) of 84 controls (p < 0.01). Socio-economic factors did not differ between the two groups. The findings indicated that a higher prevalence of H. pylori infection occurs in children with mental retardation, regardless of whether they are institutionalised.

Rofecoxib and early relapse of inflammatory bowel disease: an open-label trial

BACKGROUND

The safety and efficacy of selective cyclo-oxygenase-2 inhibitors in inflammatory bowel disease are under investigation.

AIM

To assess, in a prospective, open-label trial, the efficacy and safety of rofecoxib (12.5 mg/day) in inflammatory bowel disease patients and controls.

METHODS

The inflammatory bowel disease group included 45 inactive patients (25 Crohn's disease; 20 ulcerative colitis) with associated arthralgia. The control group included 30 dyspeptic patients. The efficacy and safety of rofecoxib were assessed in inflammatory bowel disease patients and controls before and after treatment (range, 3 days to 3 months).

RESULTS

In inflammatory bowel disease, nine of the 45 patients (20%) required rofecoxib withdrawal due to gastrointestinal symptoms inducing clinical relapse, which subsided on drug discontinuation. The percentage of patients requiring rofecoxib discontinuation was comparable in patients with Crohn's disease and ulcerative colitis (20% vs. 20%), but was higher in inflammatory bowel disease patients than in controls (20% vs. 3%; P < 0.001). In inflammatory bowel disease, arthralgia relief was reported by 32 patients (71%): complete relief by eight patients (18%) and partial relief by 24 (53%). Thirteen patients (29%) reported no benefit. A comparable percentage of inflammatory bowel disease patients and controls reported arthralgia relief (71% vs. 70%).

CONCLUSIONS

Rofecoxib appears to control arthralgia in almost two-thirds of inflammatory bowel disease patients. Side-effects requiring drug discontinuation are observed, however, in almost one-quarter of patients.

Intra-oesophageal distribution and perception of acid reflux in patients with non-erosive gastro-oesophageal reflux disease

BACKGROUND

The majority of patients with gastro-oesophageal reflux disease do not present with erosive oesophagitis and make up a heterogeneous group. Patients with non-erosive gastro-oesophageal reflux disease are less responsive than patients with oesophagitis to acid-suppressive therapy.

AIM

To assess the role of acid reflux in gastro-oesophageal reflux disease symptoms.

METHODS

The spatio-temporal characteristics of reflux events were analysed and related to reflux perception in 45 patients with non-erosive gastro-oesophageal reflux disease and 20 patients with erosive oesophagitis.

RESULTS

Compared with healthy controls, all patients showed a higher intra-oesophageal proximal spread of acid, which was prominent in patients with non-erosive gastro-oesophageal reflux disease (> 50% of events lasting for 1-2 min). Irrespective of mucosal injury, the risk of reflux perception was very high when acid reached proximal sensors (odds ratio, 7.6; 95% confidence interval, 4.6-12.5), being maximal in patients with non-erosive gastro-oesophageal reflux disease with normal acid exposure time (odds ratio, 11; 95% confidence interval, 5.2-22.3).

CONCLUSIONS

Patients with non-erosive gastro-oesophageal reflux disease are characterized by a significantly higher proportion of proximal acid refluxes and a higher sensitivity to short-lasting refluxes when compared with patients with oesophagitis. The highest proximal acid exposure and highest perception occurred in patients with non-erosive gastro-oesophageal reflux disease presenting with a normal pH-metric profile. The assessment of acid distribution and its perception in the oesophageal body can better identify reflux patients who should benefit from acid-suppressive treatment.

Intra-oesophageal distribution and perception of acid reflux in patients with non-erosive gastro-oesophageal reflux disease

BACKGROUND

The majority of patients with gastro-oesophageal reflux disease do not present with erosive oesophagitis and make up a heterogeneous group. Patients with non-erosive gastro-oesophageal reflux disease are less responsive than patients with oesophagitis to acid-suppressive therapy.

AIM

To assess the role of acid reflux in gastro-oesophageal reflux disease symptoms.

METHODS

The spatio-temporal characteristics of reflux events were analysed and related to reflux perception in 45 patients with non-erosive gastro-oesophageal reflux disease and 20 patients with erosive oesophagitis.

RESULTS

Compared with healthy controls, all patients showed a higher intra-oesophageal proximal spread of acid, which was prominent in patients with non-erosive gastro-oesophageal reflux disease (> 50% of events lasting for 1-2 min). Irrespective of mucosal injury, the risk of reflux perception was very high when acid reached proximal sensors (odds ratio, 7.6; 95% confidence interval, 4.6-12.5), being maximal in patients with non-erosive gastro-oesophageal reflux disease with normal acid exposure time (odds ratio, 11; 95% confidence interval, 5.2-22.3).

CONCLUSIONS

Patients with non-erosive gastro-oesophageal reflux disease are characterized by a significantly higher proportion of proximal acid refluxes and a higher sensitivity to short-lasting refluxes when compared with patients with oesophagitis. The highest proximal acid exposure and highest perception occurred in patients with non-erosive gastro-oesophageal reflux disease presenting with a normal pH-metric profile. The assessment of acid distribution and its perception in the oesophageal body can better identify reflux patients who should benefit from acid-suppressive treatment.

Review article: maintenance treatment of Crohn's disease

The aetiology of Crohn's disease is unknown and therefore no curative treatments are available for the disease. The natural history of Crohn's disease is characterized by recurrent flare-ups of symptoms. Several drug treatments are effective in inducing clinical remission. However, no drug treatments are available in order to prevent clinical relapses, although several drug regimens may delay clinical flare-ups. Crohn's disease treatment for maintaining clinical remission needs to be tailored in relation to specific characteristics of each patient. The frequency of clinical relapse indeed shows marked variations in subgroups of patients, as the likelyhood of relapse is higher in patients in clinical remission for less than 6 months. Treatment strategies for maintaining remission may therefore differ among inactive patients. In chronically active, steroid-dependent or steroid-refractory Crohn's disease patients immunomodulatory drugs (azathioprine 2-2.5 mg/kg by mouth, 6-mercaptopurine 1-1.5 mg/kg by mouth, or methotrexate 15-25 mg/i.m./week) should be added to oral mesalazine (2.4 g/day), while in long-term inactive Crohn's disease patients mesalazine alone may be effective in delaying relapse. Recently, treatment with anti-tumour necrosis factor-alpha monoclonal antibodies (Infliximab or CDP571) has shown efficacy in delaying relapse in responsive patients. One other issue which needs to be considered before selecting drug treatments for maintaining remission in Crohn's disease, is that Crohn's disease activity is currently assessed on the basis of standard clinical scores which may not appropriately reflect the biological activity of the disease. Clinical remission as defined by standardized scores may include heterogeneous subgroups of patients showing different endoscopic and histological activity or persistence of activated immunocompetent cells within the gut. Several sub-clinical markers of relapse have indeed been reported in quiescent Crohn's disease, although their usefulness in clinical practice in currently uncertain.

Resident bacterial flora and immune system

The "controlled inflammation" of the normal human gut is a closely controlled phenomenon and any change in the cell type number and/or functions, including the release of soluble mediators can lead to an "uncontrolled" inflammation. The physiological inflammation in the human gut plays a crucial role in maintaining a local immune response that is appropriate, efficiently protective and which respects the gut structure and function. The intestinal mucosa represents a considerable proportion of the human immune system. Disregulation of the mucosal immune response can switch a "controlled" toward an "uncontrolled" intestinal inflammation. A key role in the maintenance of an adequate balance between antigenic stimulation and host immune response is played by the immunoregulatory molecules released by activated immunocytes in the human gut. The role of the host immune system in the maintenance of an adequate balance between luminal antigens, including the resident bacterial flora and host immune response, is strongly supported by animal models of uncontrolled intestinal inflammation. Besides the aetiology of inflammatory bowel disease, luminal antigens (including food, viral and bacterial antigens) contribute to the maintenance of the inflammatory process in inflammatory bowel disease, by stimulating the immunocompetent cells in the intestinal mucosa. Of the luminal antigens, the resident bacterial flora seems to play a major role in the development of animal models of "uncontrolled" intestinal inflammation. Recent evidence also suggest that bacterial flora can modulate the function of the intestinal mucosal cells. These observations support the role of the intestinal bacterial flora in the induction of an uncontrolled inflammation in the human gut, leading to tissue damage. Probiotics, defined as living micro-organisms which, when taken in appropriate amounts, improve the health status, have been proposed in the treatment of inflammatory bowel disease, but their mechanisms of action still remain to be fully elucidated.

Cytoskeletal proteins and resident flora

Recent observations demonstrate that enteropathogenetic and enterohaemorrhagic bacteria, as well as other non enteropathogenetic bacteria (Listeria, Coxiella Burnetii), may subvert the host cell cytoskeleton. Models from enteropathogenic bacteria demonstrate that cytoskeletal proteins are required for bacteria binding to the enterocytes and that they play a role in the immune response of the host to intestinal bacteria. The cytoskeletal protein family Tropomyosins is present in all eukaryotic cells, with multiple isoforms regulated by multiple genes. Of the different Tropomyosin isoforms, TM5 has been shown to be expressed in colonic and jejunal epithelial cells, while TM1 in colonic and jejunal smooth muscle. In vitro studies have shown the presence of serum and mucosal IgG against TM5 in almost two thirds of patients with ulcerative colitis, suggesting: a. a possible autoimmune response to Tropomyosin in these patients; b. the hypothesis that the development of pouchitis may be related to the expression of TM5 in the ileal pouch; c. the use of probiotics in the treatment of pouchitis. Overall, the new expression of cytoskeletal proteins on the cell surface appears to be possibly induced by several mechanisms, including intestinal bacteria and apoptosis. The expression of cytoskeletal proteins on the cell surface may induce tolerance or autoimmune response on target cells. Further investigations are, however needed on the possible role of cytoskeletal proteins in human diseases.

Review article: monitoring the activity of Crohn's disease

Crohn's disease is characterized by a chronic inflammation of the intestine of unknown aetiology. One of the main problems when treating patients with Crohn's disease, is the identification of patients undergoing early clinical relapse, for timely treatment and the possible prevention of complications. No sub-clinical markers are currently available that predict relapse during remission. Several parameters have been proposed for this purpose. Although none have proven useful, growing evidence suggests a possible benefit in the clinical management of Crohn's disease. Among these, we may identify: clinical behaviour, the characteristics of the host, clinical activity, markers of intestinal inflammation and markers of immune activation. In particular, the possible relationship between cytokine pattern and the clinical behaviour of Crohn's disease has been addressed. Overall, these observations suggest that mucosal immune activation is a feature of Crohn's disease, and may persist in the form of activated immunocompetent cells during remission. On the basis of this evidence, studies are currently investigating whether the down-regulation of immune activation markers is associated with clinical remission in Crohn's disease. It has been shown that higher mucosal levels of TNF-alpha and an increased state of activation of lamina propria mononuclear cells in patients with inactive Crohn's disease, are significantly associated with an earlier clinical relapse of the disease. These observations suggest that a persistent local immune activation during remission may represent a marker of early clinical relapse of Crohn's disease.

Immunoregulation in the gut: success and failures in human disease

In normal conditions, human gut mucosa is infiltrated with a large number of mononuclear cells. This is a reflection of the fact that human intestine is continuously subjected to a massive stimulation by luminal antigens. This state of "physiological" inflammation is a tightly controlled phenomenon, as several mucosal cells interact to generate and maintain an appropriate local immune response. Changes in cell type number and/or function, including the release of soluble mediators, have been associated with the development of chronic inflammatory diseases, such as Crohn's disease (CD) and ulcerative colitis (UC), the two major forms of inflammatory bowel disease. Evidence also indicates that the type of inflammatory response occurring in the intestine of patients with CD differs from that in UC, and this probably reflects distinct pathways of immune activation. In CD mucosa, a Th1 response with high IL-12 and IFNgamma production prevails, while in UC a humoral immunity appears to be predominant. Despite this, CD and UC share downstream inflammatory events, characterised by high levels of inflammatory cytokines, free radicals, matrix-degrading enzymes and growth factors.

Hepatitis B and C virus infection in Crohn's disease

Patients with Crohn's disease (CD) are at higher risk of hepatitis C (HCV) and B virus (HBV) infection, because of surgical and/or endoscopic procedures. However, the prevalence of HCV and HBV infection in CD is unknown. This issue may be relevant because of the growing use of immunomodulatory drugs in CD. The purpose of this study was to assess, in a multicenter study, the prevalence and risk factors of HCV and HBV infection in CD. The effect of immunomodulatory drugs for CD on the clinical course of hepatitis virus infections and of interferon-alpha (IFN-alpha) on the course of CD was examined in a small number of patients. Sera from 332 patients with CD and 374 control subjects (C) were tested for the following: hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb), HBcAb, HBeAg, HBeAb, anti-HCV, and HCV-RNA. An additional 162 patients with ulcerative colitis (UC) were tested as a disease control group. Risk factors were assessed by multivariate statistical analysis. Infection by either HCV or HBV was detected in 24.7% of patients with CD. In the age groups younger than 50 years, HCV prevalence was higher in CD than in C (p = 0.01). HCV infection in CD was associated with surgery (OR 1.71; 95% CI 1.00-2.93; p = 0.04), blood transfusions (OR 3.39; 95% CI 1.04-11.04; p = 0.04), and age (OR 2.3; 95% CI 1.61-3.56; p < 0.001). The event CD-related surgery appeared to be the main risk factor for HCV infection in CD. HCV prevalence was higher in CD (7.4%) than in UC (0.6%) (p = 0.001). HBcAb positivity was higher in CD (10.9%) and UC (11.5%) than in C (5.1%) (CD vs. C: p = 0.016; UC vs. C: p = 0.02), associated with age (OR 2.08; 95% CI 1.37-3.17; p = 0.001) and female gender (OR 2.68; 95% CI 1.37-3.17; p = 0.001) in CD and to UC duration (OR 1.20; 95% CI 1.06-1.36; p = 0.002). Immunomodulatory drugs did not influence the course of HBV or HCV infection in seven patients with CD, and IFN-alpha for chronic hepatitis C did not affect CD activity in six patients with CD. It is concluded that HBV prevalence is higher in CD than in C at all ages, whereas HCV prevalence is increased in young patients with CD, because of a greater need for surgery. The higher HCV (but not HBV) prevalence in CD than in UC suggests that the host immune response may influence the risk of HCV infection. Although a relatively high proportion of patients with CD showed HBV and/or HCV infections, this should not influence treatment strategies for CD.

Ultrasonographic assessment of gallbladder bile exchanges in healthy subjects and in gallstone patients

Impaired gallbladder motility may contribute to gallstone pathogenesis by providing time for nucleation and aggregation of cholesterol crystals. Simultaneous scintigraphic-ultrasonographic techniques have been proposed to assess alternating phases of gallbladder emptying and filling. To evaluate patterns of gallbladder motility and of postprandial bile flow by means of a single ultrasonographic technique, 12 healthy volunteers and 20 gallstone patients underwent minute-by-minute gallbladder ultrasonography for 3 h postprandially. Mathematical analysis of volume measurements was used to estimate hepatic and cholecystic bile flux through the gallbladder. Compared to controls, gallstone patients showed greater amounts of unexchanged cholecystic-to-hepatic bile (11% vs. 1%, p <.001) and most of them showed impaired gallbladder washout efficacy. Utrasonographic values of bile exchanges were similar to those derived from scintigraphic-sonographic studies in comparable groups of subjects. This study provides new ultrasonographic variables, which better express gallbladder bile retention in gallstone patients and strongly discriminate gallstone patients from controls.

Mechanisms of tissue damage in inflammatory bowel disease

Crohn disease and ulcerative colitis are caused by an excessive immune-inflammatory reaction in the intestinal wall. Analysis of the types of immune response ongoing in the inflamed intestine has revealed that in Crohn disease there is predominantly a T helper cell type 1 response, with exaggerated production of interleukin (IL)-12 and interferon-gamma, whereas in ulcerative colitis the lesion seems to be more of an antibody-mediated hypersensitivity reaction. Despite these differences, downstream inflammatory events are probably similar in both conditions. In both Crohn disease and ulcerative colitis there is an increased synthesis of proinflammatory cytokines, including IL-1beta, IL-6, IL-8, IL-16, and tumor necrosis factor-alpha accompanying the influx of nonspecific inflammatory cells into the mucosa. These cytokines contribute to the tissue damage either directly or indirectly by enhancing the production of matrix metalloproteinases and growth factors, which produce ulceration as well as mucosal repair.

Lansoprazole-based triple therapy versus ranitidine bismuth citrate-based dual therapy in the eradication of Helicobacter pylori in patients with duodenal ulcer: a multicenter, randomized, double-dummy study

BACKGROUND

The optimal treatment regimen for eradication of Helicobacter pylori in patients with duodenal ulcer has yet to be determined. Based on a search of MEDLINE, no studies have been performed comparing a proton pump inhibitor-based triple therapy regimen with a ranitidine bismuth citrate (RBC)-based dual therapy regimen, both containing clarithromycin.

OBJECTIVE

This study was undertaken to compare the efficacy of lansoprazole (LAN)-based triple therapy with that of RBC-based dual therapy in H pylori-infected patients with duodenal ulcer.

METHODS

Patients were randomized to receive either 1 week of triple therapy with LAN 30 mg BID, clarithromycin 500 mg BID, and tinidazole 500 mg BID, followed by 3 weeks of LAN 30 mg BID, or 2 weeks of dual therapy with RBC 400 mg BID plus clarithromycin 500 mg BID, followed by 2 weeks of RBC 400 mg BID. Eradication of H pylori was defined as negative results on both the urease quick test and histologic examination > or =4 weeks after the end of treatment. Duodenal healing and recurrence rates were assessed endoscopically at 8 weeks and 6 months. A per-protocol (PP) analysis was conducted for each efficacy end point. Also conducted were an intent-to-treat (ITT) analysis in which patients with missing data were considered failures, and an observed analysis (OBS), which included patients with an evaluable result after treatment, regardless of compliance.

RESULTS

One hundred eighty-five patients (126 men, 59 women; age range, 18-76 years; mean age, 43 years) were enrolled and randomized to treatment. In the LAN and RBC groups, respectively, H. pylori eradication rates were 92.6%, 93.1%, and 72.8% versus 78.6%, 77.9%, and 64.5% in the PP (P = 0.02), OBS (P = 0.01), and ITT analyses. The corresponding duodenal ulcer healing rates were 98.6%, 98.7%, and 83.7% versus 90.8%, 91.5%, and 81.7%; these differences were not statistically significant. Side effects were mild, occurring in 20.7% of LAN patients and 17.2% of RBC patients. Ulcer recurred in 2 RBC patients. No difference was observed between treatments in terms of the occurrence of gastritis or improvement of symptoms.

CONCLUSION

Based on the results of the PP and OBS analyses, LAN-based triple therapy was superior to RBC-based dual therapy for the eradication of H. pylori in patients with duodenal ulcer.

Use of anti-tumour necrosis factor agents in inflammatory bowel disease. European guidelines for 2001-2003

The introduction of novel anti-tumor necrosis factor (TNF) agents has not only led to impressive new therapeutic opportunities but also resulted in uncertainty regarding their optimal use and possible side effects. Guidelines are presented here for the use of anti-TNF agents in gastrointestinal disorders. Experts were chosen from different European countries by an algorithm to avoid bias. An expert consensus on guidelines was established using a two-stage procedure of systematic Medline and abstract search for evidence and a qualifying meeting to derive recommendations. Detailed guidelines were developed for the use and the future clinical development of anti-TNF agents in inflammatory bowel disease. Grading of available evidence and grading of recommendations were performed according to AHCPR guidelines. At present infliximab is the only registered agent for Crohn's disease. Infliximab should be always used at a dose of 5 mg/kg. The guidelines define the indications both in refractory and in fistulating disease for the readministration and before surgery. Guidelines for safety and for concomitant treatments are given. Prospects, potential clinical use, and future directions for the clinical development of other anti-TNF agents are detailed. Clinical use of anti-TNF agents will be influenced by a large number of clinical trials being concluded in 2001 and 2002. It is likely that anti-TNF therapies will become an important long-term therapy for a proportion of patients with Crohn's disease. Biological agents will be followed by smaller and more stable, orally available compounds. These guidelines will be succeeded by a formal public consensus in 2002/2003.

Expression of proinflammatory and Th1 but not Th2 cytokines is enhanced in gastric mucosa of Helicobacter pylori infected children

BACKGROUND

Helicobacter pylori-induced gastric inflammation is thought to be largely regulated by cytokines.

PATIENTS AND METHODS

The expression of interferon-gamma, interleukin-12, interleukin-4, interleukin-10, interleukin-8, and interleukin-17 mRNA was examined on gastric mucosal samples from 24 children by semiquantitative reverse transcription polymerase chain reaction and southern blotting. Biopsy-based tests, serology, and urea 13C breath test were used to assess Helicobacter pylori status. Gastric biopsies were also evaluated for bacterial density, chronic inflammation, and acute inflammatory activity.

RESULTS

Interferon-gamma, interleukin-12, interleukin-8 and interleukin-17 expression was higher in Helicobacter pylori-infected (n=13) than uninfected (n=11) children. Conversely, interleukin-4 and interleukin-10 expression did not differ between Helicobacter pylori-infected and uninfected children. In Helicobacter pylori-infected children, interferon-gamma, interleukin-12, interleukin-8 and interleukin-17 expression correlated with bacterial density, and Interferon-gamma and interleukin-12 expression with chronic inflammation score.

CONCLUSIONS

The findings of this study indicate that, in children, Helicobacter pylori-induced inflammatory response would favour production of proinflammatory cytokines and development of cell-mediated immunity, namely Th1 response.

Antral nodularity identifies children infected with Helicobacter pylori with higher grades of gastric inflammation

BACKGROUND

The endoscopic pattern of antral nodularity is a peculiar finding in children with Helicobacter pylori infection. The aim of this study was to determine whether this finding is related to more severe gastritis.

METHODS

One hundred seventy-four consecutive children (median age 8.7 years) referred for gastroscopy were studied. Biopsy specimens from the antrum and body of the stomach were taken to assess H pylori status, gastritis score, and lymphoid follicles. Clinical diagnosis, major symptoms and endoscopic findings were recorded.

RESULTS

Eighty-four (48%) children (median age 10.5 years) had evidence of H pylori infection. The endoscopic pattern of antral nodularity was found only in children infected with H pylori (34/84, 40.5% vs. 0/90, 0%, p < 0.0001% 100% specificity, 40.5% sensitivity). Among all children infected with H pylori, the gastritis score was higher (p < 0.0001) in those with antral nodularity (n = 34) than in those without (n = 50). Completely normal gastric mucosal histology was never found in children infected with H pylori with antral nodularity. The presence and number of lymphoid follicles was strongly related to the finding of antral nodularity (p < 0.01).

CONCLUSIONS

The endoscopic pattern of antral nodularity identifies children with H pylori infection, severe gastritis, and increased lymphoid follicles.

Up-regulation of the IL-12 receptor beta 2 chain in Crohn's disease

Crohn' s disease (CD) is a chronic intestinal inflammatory disorder characterized by aberrant mucosal Th1 cell activation and production of IL-12, the major Th1-driving factor. The T cell response to IL-12 is dependent on the expression of a specific receptor composed of two subunits, termed IL-12Rbeta1 and IL-12Rbeta2. The content of IL-12Rbeta2, as measured at the mRNA level, is crucial in regulating Th1 differentiation. In this study we therefore investigated IL-12Rbeta2 RNA transcripts in CD. IL-12Rbeta2 expression was increased in active CD as well as Helicobacter pylori (HP)-associated gastritis and Salmonella colitis compared with that in inactive CD, ulcerative colitis, noninflammatory controls, and celiac disease. In contrast, IL-12Rbeta1 transcripts were expressed at comparable levels in all samples. In CD, IL-12Rbeta2 expression strictly correlated with tyrosine phosphorylation of STAT4, a key component of the IL-12-dependent Th1 polarization. This was associated with a pronounced expression of IFN-gamma. Transcripts for IL-12/p40 were detected in CD, HP-positive, and Salmonella colitis patients, but not in celiac disease, indicating that IL-12Rbeta2 up-regulation occurs only in IL-12-associated Th1 gastrointestinal diseases. Finally, we showed that stimulation of lamina propria mononuclear cells with IL-12 enhanced IL-12Rbeta2, suggesting that IL-12 regulates IL-12Rbeta2 expression in human gastrointestinal mucosa. The data show that the signaling pathway used by IL-12 to induce Th1 differentiation is increased at the site of disease in CD, further supporting the view that IL-12/IL-12R signals contribute to the inflammatory response in this condition.