A shared and unique epitope(s) on human colon, skin, and biliary epithelium detected by a monoclonal antibody

Gut microbiota does not play a mediating role in the causal association between inflammatory bowel disease and several its associated extraintestinal manifestations: a Mendelian randomization study

Background and objectives

Observational study has found inflammatory bowel disease to be associated with multiple extraintestinal manifestations. To this end, we characterized the causal association between inflammatory bowel disease and extraintestinal manifestations through a Mendelian randomization study and further explored the role of intestinal flora in inflammatory bowel disease and the extraintestinal manifestations associated with it.

Materials and methods

We genetically predicted the causal relationship between inflammatory bowel disease and twenty IBD-related extraintestinal manifestations (including sarcoidosis, iridocyclitis, interstitial lung disease, atopic dermatitis, ankylosing spondylitis, psoriatic arthropathies, primary sclerosing cholangitis, primary biliary cholangitis). We used the full genome-wide association study (GWAS) summary statistics on gut microbiota in 18,340 participants from 24 cohorts to explore its role in the casual relationships between IBD and IBD-related extraintestinal manifestations. Inverse variance weighting (IVW) was used as the main analytical method to assess the causal associations. We performed Cochran's Q test to examine the heterogeneity. To assess the robustness of the IVW results, we further performed sensitivity analyses including the weighted median method, MR-Egger regression, and Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test. The leave-one-out sensitivity analysis was further performed to monitor if significant associations were dominated by a single nucleotide polymorphism (SNP).

Result

A total of eight extraintestinal manifestations were found to be at elevated risk of development due to inflammatory bowel diseases. A total of 11 causal relationships were found between IBD and gut microbiota, four of which were stable. Between gut microbiota and these eight extraintestinal manifestations, a total of 67 nominal causal associations were identified, of which 13 associations were stable, and notably 4 associations were strongly correlated.

Conclusion

Through the two-sample MR analysis, we identified extraintestinal manifestations that were causally associated with inflammatory bowel disease and obtained multiple associations from inflammatory bowel disease and gut microbiota, and gut microbiota and extraintestinal manifestations in further analyses. These associations may provide useful biomarkers and potential targets for pathogenesis and treatment.

Association between inflammatory bowel disease, nephrolithiasis, tubulointerstitial nephritis, and chronic kidney disease: A propensity score-matched analysis of US nationwide inpatient sample 2016-2018

OBJECTIVES

The incidence and prevalence of inflammatory bowel disease (IBD), mainly including ulcerative colitis (UC) and Crohn's disease (CD), are increasing globally. We aimed to evaluate the potential association between IBD and nephrolithiasis, tubulointerstitial nephritis, and chronic kidney disease (CKD).

METHODS

Data of hospitalized adults ≥20 years of age were extracted from the U.S. National Inpatient Sample (NIS) during 2016-2018. Patients with UC, CD, or CKD were identified through the International Classification of Diseases, Tenth Revision (ICD-10) codes. Propensity score matching (PSM) analysis (1:1) was conducted to balance the characteristics between groups. Logistic regression analyses were performed to determine the relationships between UC or CD and kidney conditions.

RESULTS

Three cohorts were included for analysis after PSM analysis. Cohorts 1, 2 and 3 contained 235 262 subjects (117 631 with CD or without IBD), 140 856 subjects (70 428 with UC or without IBD), and 139 098 subjects (69 549 with CD or UC), respectively. Multivariate analysis revealed that compared to non-IBD individuals, CD patients were significantly associated with greater odds for nephrolithiasis (adjusted odds ratio [aOR] 2.25, 95% confidence interval [CI] 2.08-2.43), tubulointerstitial nephritis (aOR 1.31, 95% CI 1.24-1.38), CKD at any stage (aOR 1.28, 95% CI 1.24-1.32), and moderate-to-severe CKD (aOR 1.22, 95% CI 1.17-1.26), while UC was associated with a higher rate of nephrolithiasis. Compared to UC, CD was associated with higher odds for all such kidney conditions.

CONCLUSIONS

Patients with CD are more likely to have nephrolithiasis, tubulointerstitial nephritis, CKD at any stage, and moderate-to-severe CKD compared to non-IBD individuals.

Cutaneous manifestations of inflammatory bowel disease: basic characteristics, therapy, and potential pathophysiological associations

Inflammatory bowel disease (IBD) is a chronic inflammatory disease typically involving the gastrointestinal tract but not limited to it. IBD can be subdivided into Crohn's disease (CD) and ulcerative colitis (UC). Extraintestinal manifestations (EIMs) are observed in up to 47% of patients with IBD, with the most frequent reports of cutaneous manifestations. Among these, pyoderma gangrenosum (PG) and erythema nodosum (EN) are the two most common skin manifestations in IBD, and both are immune-related inflammatory skin diseases. The presence of cutaneous EIMs may either be concordant with intestinal disease activity or have an independent course. Despite some progress in research on EIMs, for instance, ectopic expression of gut-specific mucosal address cell adhesion molecule-1 (MAdCAM-1) and chemokine CCL25 on the vascular endothelium of the portal tract have been demonstrated in IBD-related primary sclerosing cholangitis (PSC), little is understood about the potential pathophysiological associations between IBD and cutaneous EIMs. Whether cutaneous EIMs are inflammatory events with a commonly shared genetic background or environmental risk factors with IBD but independent of IBD or are the result of an extraintestinal extension of intestinal inflammation, remains unclear. The review aims to provide an overview of the two most representative cutaneous manifestations of IBD, describe IBD's epidemiology, clinical characteristics, and histology, and discuss the immunopathophysiology and existing treatment strategies with biologic agents, with a focus on the potential pathophysiological associations between IBD and cutaneous EIMs.

3'-sulfated LewisA/C: An oncofetal epitope associated with metaplastic and oncogenic plasticity of the gastrointestinal foregut

Metaplasia, dysplasia, and cancer arise from normal epithelia via a plastic cellular transformation, typically in the setting of chronic inflammation. Such transformations are the focus of numerous studies that strive to identify the changes in RNA/Protein expression that drive such plasticity along with the contributions from the mesenchyme and immune cells. However, despite being widely utilized clinically as biomarkers for such transitions, the role of glycosylation epitopes is understudied in this context. Here, we explore 3'-Sulfo-Lewis A/C, a clinically validated biomarker for high-risk metaplasia and cancer throughout the gastrointestinal foregut: esophagus, stomach, and pancreas. We discuss the clinical correlation of sulfomucin expression with metaplastic and oncogenic transformation, as well as its synthesis, intracellular and extracellular receptors and suggest potential roles for 3'-Sulfo-Lewis A/C in contributing to and maintaining these malignant cellular transformations.

Association of gallbladder diseases with risk of gastrointestinal polyps

BACKGROUND

It has not yet been determined whether gastroscopy and colonoscopy screening help patients with gallbladder diseases. We aim to retrospectively investigate the relationship between gallbladder diseases and gastrointestinal polyps in order to provide a theoretical basis for the early screening of gastrointestinal polyps in patients with gallbladder disease.

METHODS

This is a retrospective cross-sectional study involving 1662 patients who underwent gastroscopy, colonoscopy, and abdominal ultrasound as part of their health check-up from January 2015 to July 2020. We also compared the patients with and without gallbladder diseases to determine the prevalence of gastrointestinal polyps.

RESULTS

Patients with gallbladder polyps had greater odds of having colorectal polyps (adjusted odds ratio (OR)=1.77, 95% confidence interval [Cl]: 1.23 to 2.54, p=0.002) and gastric plus colorectal polyps (adjusted OR=2.94, 95%Cl: 1.62 to 5.32, p<0.001) than those without. Patients with multiple gallbladder polyps had greater odds of having colorectal polyps (adjusted OR=2.33, 95% CI: 1.33 to 4.07, p=0.003) and gastric plus colorectal polyps (adjusted OR=3.95, 95% CI: 1.72 to 9.11, p=0.001), and patients with gallbladder polyps had greater odds of having left-colon polyps (adjusted OR=1.90, 95% CI: 1.25 to 2.88, p=0.003) and colorectal adenoma (adjusted OR=1.78, 95% CI: 1.19 to 2.66, p=0.005). We also noted that women with gallbladder polyps had a higher prevalence of colorectal polyps (OR=2.13, 95% CI: 1.20 to 3.77, p=0.010) and gastric plus colorectal polyps (OR=3.69, 95% CI: 1.58 to 8.62, p=0.003). However, no positive correlation was observed between gallbladder stones and gastrointestinal polyps.

CONCLUSIONS

Gallbladder polyps are significant indicators of colorectal and gastric plus colorectal polyps. Hence, gastroscopy and colonoscopy screening should be performed for patients with gallbladder polyps, particularly female patients and those with multiple gallbladder polyps.

Risk of inflammatory bowel disease in uveitis patients: a population-based cohort study

OBJECTIVES

To investigate the potential association between uveitis and an increased risk of developing inflammatory bowel disease (IBD).

METHODS

We conducted a retrospective cohort study by interrogating data from the Taiwan National Health Insurance Research Database entered between January 1, 2001 and December 31, 2013 to identify uveitis patients and age- and gender-matched controls. The cumulative incidence rates of subsequent IBD in the two groups were compared. The adjusted hazard ratio (HR) of IBD related to uveitis was generated by a multivariate cox regression model after adjustment for hypertension, diabetes, hyperlipidaemia, obesity and smoking. Furthermore, the HRs of the Crohn's disease (CD) and ulcerative colitis (UC) IBD subtypes were calculated separately.

RESULTS

A total of 198,923 subjects with uveitis and 397,846 controls were enroled. The mean age of the cohort was 47.7 ± 18.9 years. A significantly higher cumulative incidence of IBD was found in the uveitis group than in controls (4.13% vs. 1.48%, p < 0.0001). Under univariate cox regression analysis, uveitis patients had a significantly higher risk of IBD (HR = 1.47; 95% confidence interval (CI): 1.43-1.52, p < 0.0001). The association remained significant in the multivariate regression model, with an adjusted HR of 1.44 (95% CI: 1.39-1.49, p < 0.0001). Moreover, in subgroup analysis, uveitis was significantly associated with an increased risk of Crohn's disease (adjusted HR = 1.49; 95% CI: 1.44-1.54), but not with ulcerative colitis (adjusted HR = 1.03; 95% CI: 0.92-1.15).

CONCLUSIONS

Patients with uveitis are at significantly greater risk of developing IBD than individuals without uveitis.

Cutaneous Manifestations of Inflammatory Bowel Disease: A Basic Overview

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal (GI) tract that is subdivided into Crohn's disease (CD) and ulcerative colitis (UC). CD is characterized by involvement of the entire GI tract, while UC mainly affects the distal GI tract. Moreover, both CD and UC can present with extraintestinal manifestations (EIMs) of the disease affecting multiple organ systems including the hepatobiliary tract, kidney, bones, eyes, joints, and skin. These complications can cause significant morbidity and negatively impact the quality of life for IBD patients. Although the pathogenesis of EIMs is not clearly elucidated, it is postulated that the diseased GI mucosa similarly stimulates excess immune responses at the extraintestinal sites. Cutaneous EIMs occur in up to 15% of patients with IBD, often predating their IBD diagnosis. They are categorized into (1) specific, (2) reactive, (3) associated, and (4) treatment-induced. Here, we review the epidemiological, clinical, diagnostic, and histologic features of the most commonly described cutaneous EIMs of IBD along with their respective treatment options.

mAb Das-1 recognizes 3'-Sulfated Lewis A/C, which is aberrantly expressed during metaplastic and oncogenic transformation of several gastrointestinal Epithelia

INTRODUCTION

Multiple previous studies have shown the monoclonal antibody Das-1 (formerly called 7E12H12) is specifically reactive towards metaplastic and carcinomatous lesions in multiple organs of the gastrointestinal system (e.g. Barrett's esophagus, intestinal-type metaplasia of the stomach, gastric adenocarcinoma, high-grade pancreatic intraepithelial neoplasm, and pancreatic ductal adenocarcinoma) as well as in other organs (bladder and lung carcinomas). Beyond being a useful biomarker in tissue, mAb Das-1 has recently proven to be more accurate than current paradigms for identifying cysts harboring advanced neoplasia. Though this antibody has been used extensively for clinical, basic science, and translational applications for decades, its epitope has remained elusive.

METHODS

In this study, we chemically deglycosylated a standard source of antigen, which resulted in near complete loss of the signal as measured by western blot analysis. The epitope recognized by mAb Das-1 was determined by affinity to a comprehensive glycan array and validated by inhibition of a direct ELISA.

RESULTS

The epitope recognized by mAb Das-1 is 3'-Sulfo-Lewis A/C (3'-Sulfo-LeA/C). 3'-Sulfo-LeA/C is broadly reexpressed across numerous GI epithelia and elsewhere during metaplastic and carcinomatous transformation.

DISCUSSION

3'-Sulfo-LeA/C is a clinically important antigen that can be detected both intracellularly in tissue using immunohistochemistry and extracellularly in cyst fluid and serum by ELISA. The results open new avenues for tumorigenic risk stratification of various gastrointestinal lesions.

Ocular Manifestations of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is characterized by intestinal inflammation; however, it is also known to have extraintestinal manifestations. Ocular manifestations of IBD include keratopathy, episcleritis, scleritis, and uveitis and are among the most common extraintestinal manifestations. These diseases can lead to significant ocular morbidity if unrecognized and left untreated. A review of the literature was performed on PubMed and is summarized and critically appraised in this article with the aim being to describe the varying ocular manifestations of IBD and outlining their treatments. Ultimately, a framework is provided to investigate ocular symptoms in patients with IBD. An ocular review of systems is also provided as a tool to equip gastroenterologists and internal medicine physicians to be able to recognize and triage ocular complaints appropriately.

Case of nivolumab-induced sclerosing cholangitis: lessons from long-term follow-up

Nivolumab is an immune checkpoint inhibitor used to treat multiple solid-organ malignancies. While many of its immune-related adverse events are well established, nivolumab-induced sclerosing cholangitis remains poorly characterised, with no defined diagnostic criteria. Moreover, data regarding long-term outcomes are particularly lacking. We present a biopsy-proven case of nivolumab-induced sclerosing cholangitis, which uniquely captures 18 months of follow-up post-treatment. Our case highlights key features of intrahepatic subtype sclerosing cholangitis and suggests durable response to corticosteroid therapy.

Vedolizumab and Extraintestinal Manifestations in Inflammatory Bowel Disease

In Crohn's disease and ulcerative colitis, inflammation is not limited to the digestive tract. Extraintestinal manifestations (EIMs), which affect up to 50% of patients, can substantially impair quality of life. EIMs may parallel luminal disease activity or have an independent course. They most commonly involve the musculoskeletal system (e.g., peripheral or axial arthritis) and skin (e.g., erythema nodosum and pyoderma gangrenosum). Less commonly, the hepatobiliary tract (e.g., primary sclerosing cholangitis [PSC]) and the eye (e.g., episcleritis, scleritis, and uveitis) are involved. Although the pathophysiology of EIMs is poorly understood, they are likely either manifestations of a primary systemic immune disease with variable expression amongst organs, or secondary phenomena to bowel inflammation. Additional pathophysiologic mechanisms may include aberrant lymphocyte homing mediated by ectopic expression of gut-specific chemokines and adhesion molecules, cross-reactivity between microbial and self-antigens, autoantibodies against epitopes shared by the intestine and extraintestinal tissues, elevated serum concentrations of cytokines, and alterations in innate immunity. Many EIMs independent of intestinal disease activity can be successfully treated with tumor necrosis factor (TNF) antagonists. The efficacy of vedolizumab-a monoclonal antibody targeting the α4β7 integrin-for the treatment of EIMs is uncertain, but data are emerging from post hoc analyses of randomized controlled trials, prospective and retrospective cohort studies, and case series. Vedolizumab may be effective in treating EIMs related to luminal disease activity (e.g., type 1 peripheral arthritis and erythema nodosum) but has not shown biochemical improvement in PSC. Its postulated role in the development of de novo EIMs is heavily confounded by the high proportion of patients previously exposed to TNF antagonists; new EIMs could result from TNF antagonist treatment cessation rather than being caused by vedolizumab. A common limitation of clinical studies is the lack of multidisciplinary involvement in the diagnosis and monitoring of EIMs, which may lead to misdiagnosis and overreporting. Future studies should rigorously measure EIMs in parallel with objective measures of luminal disease activity to provide more robust data on the relative efficacy of new drugs, especially as increasing numbers of gut-selective compounds enter clinical development.

Allergic and Immunologic Perspectives of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic immune-mediated inflammatory condition primarily involving the gastrointestinal tract. It includes Crohn's disease (CD), ulcerative colitis (UC), and a less common phenotype-indeterminate colitis. It is thought to result from a complex interplay of environmental, microbial, and host factors including genetic factors, although the exact mechanism is not known. Dietary factors have been shown to play a role in the pathogenesis of IBD and can potentially alter the intestinal microbiota as well as disrupt the immune function in the gut. CD is characterized by transmural inflammation, sometimes associated with granulomatous lesions, and involves the entire gastrointestinal tract but often spares the rectum. UC is characterized by mucosal inflammation typically confined to the colon and rectum. Although IBD is mostly seen in western world, recent data suggests that the incidence and prevalence are increasing worldwide. Enteral nutrition has been shown to be effective in inducing remission in pediatric population with CD; however, there is mixed data in adult population. Nutritional deficiencies such as vitamin D and zinc deficiency are often noted in IBD patients. Several extraintestinal manifestations are noted in patients with IBD. Some of them parallel with the disease activity and others are independent of the disease course. Assessment of IBD disease activity clinically, radiologically, if indicated, biochemically and endoscopically is important to guide therapy in IBD. To ensure comprehensive care, it is important to assess associated conditions such as nutritional and psychological well-being, as well as age appropriate health maintenance status prior to starting treatment for IBD. Several biologic agents including anti-tumor necrosis factor alpha (anti-TNF-α) drugs, anti-integrins, and antibodies to the p40 subunit of IL12/23 are approved for induction and maintenance of remission of IBD. Steroids are also often used for induction. Anti-metabolites and thiopurines are also useful either as monotherapy or in combination regimens. Potential side effects of anti-TNF-α drugs such as serious infections, malignancy, worsening of heart failure, and infusion-related reactions should be considered prior to starting these drugs. Anti-TNF-α drugs with or without immunomodulators (azathioprine, 6-mercaptopurine, methotrexate) are often used for the induction and maintenance of remission. Treating to target of endoscopic and clinical remission provides the best long-term outcomes. Our knowledge and understanding of IBD has grown significantly. However, there are several unanswered questions on pathogenesis, disease behavior, and drivers of inflammation in various patient subgroups which require further research.

The Spectrum of Extra-intestinal Manifestation of Crohn's Disease

Introduction Extra-intestinal manifestations (EIM) play an important role in the mortality, morbidity, and quality of life in patients with Crohn's disease (CD). Understanding the prevalence and clinical course of these manifestations is important to understand and manage CD. Materials and methods The hospital records of 103 patients diagnosed with CD between July 2016 and December 2019 at a tertiary care hospital in Pakistan were reviewed retrospectively. Baseline demographic and clinical characteristics including sex, age, follow-up duration, CD phenotype at diagnosis, clinical features, and course of EIMs were noted. The diagnosis of CD was based on clinical features in combination with endoscopic and radiologic findings. CD phenotype at diagnosis was assessed using the Montreal Classification by the World Congress of Gastroenterology (WCOG). Results The mean age at diagnosis of CD was 31 ±8 years. The most common age group as per the Montreal classification at diagnosis was 17-40 years (68.93%). The most common localization of disease was ileocolonic (70.87%), and the most common disease behavior was non-stricturing and non-penetrating (82.52%). In this study, 41 (39.8%) patients had a minimum of one EIM. The most common EIM was anal skin tags (29.12%), while 24 (23.30%) patients had elevated liver function tests (LFTs), three (2.91%) had peripheral arthritis, and 12 (11.65%) had cutaneous manifestations, the most common being erythema nodosum (7.76%). The most common ophthalmological manifestation was anterior uveitis (3.88%). Conclusions EIMs are prevalent in CD patients in Pakistan, yet very little is known about them. Further large-scale studies are needed to assess the frequency and impact of EIMs on patients with CD.

Uveitis manifestations in patients of the Swiss Inflammatory Bowel Disease Cohort Study

BACKGROUND

The knowledge about risk factors for the onset of uveitis manifestations in patients with inflammatory bowel disease (IBD) is still limited. Here, we aimed to provide an overview of the clinical factors associated with the onset of uveitis in the Swiss IBD Cohort Study (SIBDCS).

METHODS

We included epidemiological and clinical data from 1840 patients with Crohn's disease (CD) and 1426 patients with ulcerative colitis (UC) followed up in the SIBDCS between 2006 and 2018. Associations between disease characteristics and uveitis were assessed in univariate and multivariate analyses.

RESULTS

Overall, we identified 285 patients with uveitis. Uveitis was more frequent in patients with CD (11.1%; 205 of 1635) than UC (5.6%; 80 of 1346; odds ratio 2.11, p < 0.001). The occurrence of uveitis manifestations in patients with UC and CD was significantly associated with the onset of other extraintestinal manifestations, also in multivariate analyses. The onset of uveitis was associated with the hallmark features of severe disease in both CD and UC, including a higher clinical disease activity index and the use of immunomodulators or calcineurin inhibitors. In CD, uveitis was more frequent in females and showed a positive correlation with a positive family history of IBD.

CONCLUSIONS

Our data demonstrate that uveitis in IBD occurs more often in CD as well as in women and is associated with a more severe disease course. This might guide physicians' awareness in at-risk patients to the presence of uveitis extraintestinal manifestations and help to improve patient care.

The Pathogenesis of Extraintestinal Manifestations: Implications for IBD Research, Diagnosis, and Therapy

This article reports on the sixth scientific workshop of the European Crohn's and Colitis Organisation [ECCO] on the pathogenesis of extraintestinal manifestations [EIMs] in inflammatory bowel disease [IBD]. This paper has been drafted by 15 ECCO members and 6 external experts [in rheumatology, dermatology, ophthalmology, and immunology] from 10 European countries and the USA. Within the workshop, contributors formed subgroups to address specific areas. Following a comprehensive literature search, the supporting text was finalized under the leadership of the heads of the working groups before being integrated by the group consensus leaders.

The gut and the inflammatory bowel diseases inside-out: extra-intestinal manifestations

An increasing deal of attention is being conveyed on the extra-intestinal manifestations (EIM) of inflammatory bowel diseases (IBD). We compiled the present review in an attempt to upgrade the accuracy of the classification of such polymorphic entities. We focused on three patterns. First, the conventional EIM localized to bone and joints, to the eye, to the biliary tree and to the skin. Second, the so-called IBD-like syndromes accompanied by bone marrow-derived anomalies of innate or acquired immunity. Third, specific disorders of the skin and of the lungs. EIM are thought to derive from an altered gut permeability, the release of cross-reacting antigens, and subsequent peripheral inflammation; T helper 17 cells boosted by a polymorphic interleukin 23 circuitry would be the main effectors of this chain. Inflammatory bowel disease-like pictures would derive from inborn errors of the immune response causing undue inflammation home to the gut. Monogenic IBD belong to this subset, and are of specific pediatric interest. Psoriasis, chronic obstructive pulmonary disease, and IBD are all inflammatory disorders of the barrier organs: skin, lungs, and gut. The demonstration that specific antigen hyper- or hyporesponsiveness raised at any of the three districts can modulate the response of the other two sites, has led to the innovative concept of a system-wide mucosal immunological organ. An improved knowledge of these entities has not only a speculative importance, but can also bear a clinical impact, insofar as EIM prove often more disabling than the underlying IBD itself.

The difference in extraintestinal manifestations of inflammatory bowel disease for children and adults

Extraintestinal manifestations (EIMs) are frequently observed in adult and pediatric patients with inflammatory bowel disease (IBD). The most common EIMs involve the joints, skin, and eyes, but they can affect various organs and result in significant morbidity. Since EIMs can appear years before the diagnosis of IBD is made, clinicians should be aware of their various manifestations to help decrease diagnostic delay of IBD and establish appropriate treatment plans.

Gallbladder stones and gallbladder polyps associated with increased risk of colorectal adenoma in men

BACKGROUND AND AIMS

Most cases of colorectal cancer develop via an adenoma to carcinoma sequence. Gallbladder polyps share some risk factors with colorectal polyps. Little is known about the relationship between gallbladder diseases and different status of colorectal polyps by gender. This study was to investigate the association of gallbladder stones and polyps with colorectal adenomas by gender in a Taiwanese population.

METHODS

A total of 7066 eligible subjects who underwent a total colonoscopy as a part of health check-up between January 2001 and August 2009 were recruited. Colonoscopic findings were classified into polyp-free, non-neoplastic polyps and colorectal adenomas. Gallbladder stones and gallbladder polyps were diagnosed based on ultrasonographic findings.

RESULTS

There was a significant difference in the status of colon polyps between subjects with and without gallbladder polyps. However, the status of colon polyps was not significantly different between subjects with or without gallbladder stones. After adjusting obesity, fasting plasma glucose, and other variables, there was a positive relationship between gallbladder polyps and colorectal adenomas (odds ratio [OR]: 1.396, 95% confidence interval [CI]: 1.115-1.747) but not non-neoplastic polyps in all subjects. In men, gallbladder polyps (OR: 1.560, 95% CI: 1.204-2.019) and gallbladder stones (OR: 1.465, 95% CI 1.081-1.984) were positively associated with colorectal adenomas. In women, neither gallbladder polyps nor gallbladder stones were significantly related to colon polyps.

CONCLUSIONS

Both gallbladder polyps and gallbladder stones were associated with an increased risk of colorectal adenomas in men but not in women. Gender difference was significant for the association between gallbladder lesions and colorectal polyps.

IBD immunopathogenesis: A comprehensive review of inflammatory molecules

Inflammatory molecules play a crucial role in the pathogenesis of inflammatory bowel disease (IBD) such as ulcerative colitis and Crohn's disease, both of which are chronic inflammatory conditions of the gastrointestinal tract. Abnormal expressions of pro- and anti-inflammatory molecules have been described to cause an imbalance to the gut innate and adaptive immunity, and recently a large portion of research in IBD has been geared towards identifying novel molecules that may be used as potential therapeutic targets. Understanding of these inflammatory molecules has suggested that although ulcerative colitis and Crohn's disease share many common clinical symptoms and signs, they are in fact two separate clinical entities characterized by different immunopathogenesis. In this review, we comprehensively discuss the roles of numerous inflammatory molecules including but not limited to cytokines, chemokines, inflammasomes, microRNAs and neuropeptides and their expression status in ulcerative colitis and Crohn's disease in relation to their effects on the overall intestinal inflammatory process.

Early detection of pancreatic cancer: impact of high-resolution imaging methods and biomarkers

High-resolution imaging methods (HRIMs) and biomarkers present the second step of pancreatic cancer (PC) diagnostics in at-risk individuals. These include patients with positive risk factors, early symptoms, nonresponders to the initial antidiabetic therapy, patients older than 50 years of age with new-onset unstable diabetes requiring insulin as well as patients with long-term insulin-non-dependent diabetes and recent (up to 6 months) failure of antidiabetic therapy. The procedures should be started without delay and the co-operation between the primary and tertiary medical centers is highly desirable. An early indication of HRIMs and biomarkers is a prerequisite for the diagnosis of a resectable PC. This publication reviews the recent contribution of HRIMs and biomarkers toward an early diagnosis of PC.

Immunopathogenesis of IBD: current state of the art

IBD is a chronic inflammatory condition of the gastrointestinal tract encompassing two main clinical entities: Crohn's disease and ulcerative colitis. Although Crohn's disease and ulcerative colitis have historically been studied together because they share common features (such as symptoms, structural damage and therapy), it is now clear that they represent two distinct pathophysiological entities. Both Crohn's disease and ulcerative colitis are associated with multiple pathogenic factors including environmental changes, an array of susceptibility gene variants, a qualitatively and quantitatively abnormal gut microbiota and a broadly dysregulated immune response. In spite of this realization and the identification of seemingly pertinent environmental, genetic, microbial and immune factors, a full understanding of IBD pathogenesis is still out of reach and, consequently, treatment is far from optimal. An important reason for this unsatisfactory situation is the currently limited comprehension of what are the truly relevant components of IBD immunopathogenesis. This article will comprehensively review current knowledge of the classic immune components and will expand the concept of IBD immunopathogenesis to include various cells, mediators and pathways that have not been traditionally associated with disease mechanisms, but that profoundly affect the overall intestinal inflammatory process.

The Risk of Colorectal Neoplasia in Patients with Gallbladder Diseases

Cholecystectomy is associated with an increased risk of colorectal cancer, but little is known about the relationship between gallbladder disease and colorectal adenoma. Gallbladder polyps and colorectal neoplasia (CRN) share several risk factors such as obesity, diabetes and metabolic syndrome, which might account for their association. In this study, we investigated whether asymptomatic patients with gallbladder disease are at increased risk of CRN and identified the factors to their association. The study population consisted of 4,626 consecutive, asymptomatic individuals drawn from a prospective health check-up cohort who underwent both ultrasonography and colonoscopy screening. The prevalence of CRNs in patients with gallbladder polyps or gallstones was significantly higher than that in the control group (32.1% vs. 26.8%; P = 0.032, 35.8% vs. 26.9%; P = 0.020). A multivariate regression analysis showed that gallbladder polyps were an independent risk factor for CRN [adjusted odds ratio (OR): 1.29; 95% confidence interval (CI); 1.03-1.62] whereas gallstones were not (adjusted OR: 1.14; 95% CI: 0.79-1.63). The adjusted OR for the risk of CRN was 1.12 for gallbladder polyps < 5 mm (95% CI, 0.85-1.46) and 1.79 for gallbladder polyps ≥ 5 mm (95% CI, 1.15-2.77). The prevalence of CRN increased with increasing polyp size (P trend = 0.022). Our results suggest that colorectal neoplasia is significantly related to gallbladder polyps, especially those ≥ 5 mm.

Extraintestinal Manifestations of Inflammatory Bowel Disease

Extraintestinal manifestations (EIM) in inflammatory bowel disease (IBD) are frequent and may occur before or after IBD diagnosis. EIM may impact the quality of life for patients with IBD significantly requiring specific treatment depending on the affected organ(s). They most frequently affect joints, skin, or eyes, but can also less frequently involve other organs such as liver, lungs, or pancreas. Certain EIM, such as peripheral arthritis, oral aphthous ulcers, episcleritis, or erythema nodosum, are frequently associated with active intestinal inflammation and usually improve by treatment of the intestinal activity. Other EIM, such as uveitis or ankylosing spondylitis, usually occur independent of intestinal inflammatory activity. For other not so rare EIM, such as pyoderma gangrenosum and primary sclerosing cholangitis, the association with the activity of the underlying IBD is unclear. Successful therapy of EIM is essential for improving quality of life of patients with IBD. Besides other options, tumor necrosis factor antibody therapy is an important therapy for EIM in patients with IBD.

Musculoskeletal manifestations in inflammatory bowel disease: a revisit in search of immunopathophysiological mechanisms

Inflammatory bowel diseases are chronic inflammatory disorders of multiple organ systems, primarily involving the gut, with chronic relapsing and remitting course. Musculoskeletal involvement is the most common extraintestinal manifestation. Distinct cell-mediated and humoral immunopathophysiological mechanisms have been identified underlying gut and joint inflammation in patients with inflammatory bowel disease and arthritis. Genetic polymorphisms in genes coding for NOD2 and IL12/IL23 complex lead to impaired antigenic handling in the gut and local immune dysregulation. The gut-synovial axis hypothesis implicates both environmental and host factors acting as triggers to initiate inflammation in genetically predisposed individuals, leading to priming of Th1 and Th17 lymphocytes in the gut and subsequent homing to the synovial tissue. Similar to gut, antibody-dependent cell-mediated cytotoxicity and complement-mediated cell lysis may also contribute to the joint damage. Involvement of peripheral joints occurs in 2 distinct manners, one being oligoarticular asymmetric arthritis associated with active disease and the other being polyarticular symmetric involvement of small joints. The axial involvement may include asymptomatic sacroiliitis, inflammatory back pain, and ankylosing spondylitis, running an independent clinical course. Noninflammatory involvement of the musculoskeletal system may present as osteopenia, osteonecrosis, fibromyalgia, or myopathies, leading to significant impact on quality of life.

The promise and pitfalls of serologic testing in inflammatory bowel disease

The role of IBD serologies is still evolving. However, as that evolution progresses, it will continue to provide important insights into the etiology of IBD and help define individualized treatment strategies for patients. The presence of multiple IBD antimicrobial antibodies and increased reactivity form a useful heuristic model to understand the evolution of CD. The role of ANCAs and autoantibodies in pathogenesis of UC is an area that requires further investigation. Although IBD serologies exhibit considerable diagnostic accuracy, it is unclear whether they will supplant simpler and more direct evaluations in making an initial diagnosis of UC or Crohn (Table 3). The utility of panels of IBD serologies to stratify and predict the course of CD has been an arena of fertile investigation. Developing individual treatment strategies based on the probability of developing complicated aggressive disease would be a significant advance in medical management of CD. However, if major clinical decisions are to be made based on these serologies, we will need more prospective critical studies from the time of diagnosis to define their clinical applicability and to demonstrate a true difference in outcomes.

Primary sclerosing cholangitis and disease distribution in inflammatory bowel disease

BACKGROUND & AIMS

The relationship between site of intestinal inflammation and primary sclerosing cholangitis (PSC) development in inflammatory bowel disease (IBD) has not been studied extensively, but may be important in understanding the pathogenesis of PSC. We aimed to determine patterns of disease distribution in IBD patients with and without PSC.

METHODS

We performed a 2-part study involving the following: (1) 2754 IBD patients and (2) 82 separate PSC patients attending the Irish National Liver Transplant Unit.

RESULTS

Fifty-nine of 2708 (2.2%) IBD patients had PSC. In ulcerative colitis patients, PSC incidence increased with increasing colonic involvement (P = .001) and was relatively rare in those without total colitis. Thirteen Crohn's disease patients had PSC, none with isolated small-bowel disease had PSC (P = .03). In study 2, the majority of ulcerative colitis patients with PSC had total colitis, whereas the remainder had disease extending at least to the left colon. In addition, all 10 PSC patients with Crohn's disease had colonic involvement.

CONCLUSIONS

An inflamed colon, but not small bowel, is important in PSC development and it is possible that bacterial translocation and subsequent portal bacteremia is important in PSC development in IBD.

The challenges in primary sclerosing cholangitis--aetiopathogenesis, autoimmunity, management and malignancy

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease, characterized by progressive inflammation and fibrosis of the bile ducts, resulting in biliary cirrhosis and is associated with a high risk of cholangiocarcinoma. The majority of patients are young, male and have coexisting inflammatory bowel disease. PSC is found with a prevalence of 10/100,000 in Northern European populations. The pathophysiology of PSC is a complex multistep process including immunological mechanisms, immunogenetic susceptibility and disorders of the biliary epithelia. The diagnosis is primarily based on endoscopic cholangiography although magnetic resonance imaging is increasingly used; biochemistry and immunoserology as well as histology play only a minor role. Due to the high risk of developing cholangiocarcinoma and also other tumours of the GI tract, surveillance strategies are essential, however they have yet to be established and evaluated. Biochemical parameters, clinical risk factors, endoscopic procedures and imaging techniques contribute to the early identification of patients at risk. Since medical therapy of PSC with ursodeoxycholic acid does not improve survival, to date, liver transplantation is the only option with a cure potential; if transplantation is accurately timed, transplanted PSC patients have an excellent rate of survival. However if cholangiocarcinoma is detected, a curative treatment is not possible in the majority of cases. The present review critically summarizes the current knowledge on the aetiopathogenesis of PSC and gives an overview of the diagnostic approaches, surveillance strategies and therapeutic options. Primary sclerosing cholangitis is a disease of unknown aetiology and without any further curative treatment options apart from liver transplantation. Therefore it may be regarded as the greatest challenge in hepatology today.

Alterations in the immunohistochemical expression of Das-1 and CG-3 in colonic mucosal biopsy specimens helps distinguish ulcerative colitis from Crohn disease and from other forms of colitis

Distinction between ulcerative colitis (UC) and Crohn disease (CD) in mucosal biopsies is often difficult. Das-1 and CG-3 are monoclonal antibodies directed against an unknown colonic epithelial protein and human tropomyosin isoform-5, respectively, both show altered expression in patients with UC. In this study, we evaluated the utility of Das-1 and CG-3 in distinguishing UC from CD and from other types of colitis. One colonic biopsy specimen from each of 85 patients with confirmed UC (n=25), CD (n=15), lymphocytic (n=15), collagenous (n=15), and ischemic (n=15) colitis, and also 10 samples from normal controls, were stained for Das-1 and CG-3 using standard techniques. Reactivity for Das-1 and CG-3 was noted to be absent or present, and the location (ie, surface+/-crypt epithelium) and degree (weak or strong) of CG-3 staining was recorded. Loss of Das-1 staining occurred more frequently in UC (96%) compared with CD (20%), lymphocytic (20%), collagenous (13%), and ischemic colitis (0%) cases, as well as controls (10%, P<0.001 for all comparisons). CG-3 positivity in crypt epithelium was significantly more common in UC (52%) compared with the other groups (P< or =0.02 for all comparisons). The combination of strong crypt CG-3 staining and loss of Das-1 staining was noted in 44% of UC cases, but not in any other type of colitis (P=0.003 for all comparisons). We conclude that the patterns of Das-1 and CG-3 staining in colonic mucosal biopsies may be clinically useful in distinguishing UC from CD and from other colitidies.

A double-blind, placebo-controlled, randomized study of infliximab in primary sclerosing cholangitis

GOALS

To evaluate the safety and efficacy of infliximab in patients with primary sclerosing cholangitis.

STUDY

In this double-blind, placebo-controlled study, 24 patients with primary sclerosing cholangitis were screened and randomly assigned in a 2:1 ratio to receive infliximab (5 mg/kg) or placebo at weeks 0, 2, 6, 12, 18, and 24; patients were followed through week 52. The primary efficacy end point was a decrease of at least 50% in the serum alkaline phosphatase level from baseline to week 18. A blinded histologic assessment of liver biopsy samples, obtained at weeks 0 and 26, was performed using a predefined scoring system, including scores for inflammation, fibrosis, and cholestasis.

RESULTS

Patient enrollment was prematurely stopped when results of an interim analysis showed no significant treatment benefit. Of the 24 patients screened, 10 were enrolled (6 patients received infliximab). Mean alkaline phosphatase levels at weeks 0, 18, and 52 were 349, 330, and 389 U/L, respectively, for the infliximab group and 481, 438, and 391 U/L, respectively, for the placebo group. Liver biopsy samples were analyzed in 7 patients (4 infliximab); no apparent differences could be detected in any of the histologic parameters. In 3 of 4 infliximab-treated patients and 2 of 3 placebo-treated patients, the disease stage did not change after 6 months of treatment. No meaningful changes were detected in the symptom score. No serious drug-related adverse events were observed.

CONCLUSIONS

Study findings failed to demonstrate efficacy of infliximab in this small group of patients with established primary sclerosing cholangitis.

Tropomyosins in human diseases: ulcerative colitis

Ulcerative colitis (UC) is a form of chronic inflammatory bowel disease (IBD) that almost always affects the rectal mucosa and variable length of the colon in continuity and at times mucosa of the entire colon. It is not caused by any specific pathogen. Genetics, environmental factors and altered immune responses to dietary macromolecules, colonic bacteria and cellular proteins have been implicated in the pathogenesis of UC. Autoimmune response against cytoskeletal, microfilament protein tropomyosin (Tm) seems to play an important role in the pathogenesis of UC. The predominant colonic epithelial Tm isoform, hTm5, can induce both humoral (B-cells) and cellular (T-cells) response in patients with UC. Such responses are not seen in normal subjects and disease control subjects, such as patients with Crohn's disease (CD, another type of IBD) and patients with lupus. A novel observation that hTm5 is expressed on colon epithelial cell surface but not on small intestinal epithelial cells provides evidence for presentation to immune effector cells. This surface expression of hTm5 seems to be facilitated by a colon epithelial cell membrane associated protein, CEP, that acts as a chaperone for the trans-migration of hTm5 to the surface and both hTm5 and CEP are then released outside the cell. Both CEP and hTm5 expression are increased with pro-inflammatory cytokine, such as gamma-interferon. hTm5 expression in UC mucosa is also significantly increased compared to normal. Finally, autoantibodies against hTm5 observed both in circulation and in the colon mucosa of patients with UC are pathogenic causing colon epithelial cell destruction by antibody and complement mediated cytolysis.

Autoimmunity against human tropomyosin isoforms in ulcerative colitis: localization of specific human tropomyosin isoforms in the intestine and extraintestinal organs

BACKGROUND

Tropomyosins (TMs) are microfilament cytoskeletal proteins, and 5 major human TM isoforms (hTM1-5) are described. hTMs, particularly isoform 5 (hTM5), is capable of inducing autoantibodies and T-cell response in ulcerative colitis (UC). However, cellular localization of hTM isoforms in the colon and in extraintestinal organs commonly involved in UC is unknown.

METHODS

Using isoform-specific monoclonal antibodies, we localized hTMs through immunoperoxidase assay in normal colon (n = 12), small intestine (n = 14), esophagus (n = 10), skin (n = 19), eye (n = 12), gallbladder (n = 16), liver, including bile duct at the porta hepatis (n = 4), lungs (n = 4), and pancreas (n = 4).

RESULTS

There is intense expression of hTM5, but not other isoforms, in the epithelium of the colon, gallbladder, and skin. In the eye, hTM5 is expressed only in the nonpigmented ciliary epithelium. Although extrahepatic and interlobar large ductal biliary epithelium was positive, bile canaliculi at the portal tract are negative. The immunoreactivity in epithelial cells from these organs is diffuse cytoplasmic and along the periphery. In colon epithelium, there is intense expression along basolateral areas and luminal (apical) surface. In the small intestinal epithelium, however, hTM5 expression is weak and distinctly different than in the colon. hTM5 was not detected in the squamous epithelium of the esophagus, although it was strongly positive in the skin. hTM1, hTM2, and hTM3 are localized predominantly in smooth muscle of the intestine and blood vessel wall but not the epithelium. HTM4 is localized in the endothelial cells and basement membrane of the colonic epithelium.

CONCLUSIONS

hTM5 is the predominant isoform in the epithelium of colon and extraintestinal organs commonly involved in UC. The unique expression of hTM5 may allow its interaction with effector immune cells involved in the immunopathogenesis of UC and its extraintestinal manifestations.

Utility of immunohistochemistry in distinguishing primary adenocarcinomas from metastatic breast carcinomas in the gastrointestinal tract

CONTEXT

Breast carcinoma often metastasizes to the gastrointestinal tract, especially the stomach, where it is frequently difficult to distinguish from a primary gastric carcinoma.

OBJECTIVE

To evaluate the utility of immunohistochemical stains in differentiating primary gastric carcinomas from metastatic breast carcinomas.

DESIGN

Mucosal biopsy specimens from 47 adenocarcinomas involving the gastrointestinal tract (28 primary gastric carcinomas and 19 metastatic breast carcinomas) and 16 control cases of primary breast carcinomas without metastasis were immunohistochemically stained for estrogen receptor protein (ER), progesterone receptor protein (PR), gross cystic disease fluid protein (GCDFP), human epidermal growth factor receptor 2 protein, cytokeratin (CK) 5/6, CK/7, CK/20, a panel of mucin glycoprotein antigens (MUC2, MUC3, MUC5AC, and MUC6), monoclonal antibody DAS-1, and caudal-type homeobox transcription factor CDX2 and compared between primary and metastatic adenocarcinomas.

RESULTS

Highly significant proportions of metastatic breast carcinomas were positive for ER (72%), PR (33%), GCDFP (78%), and CK5/6 (61%) compared with primary gastric carcinomas (ER, 0%; PR, 0%; GCDFP, 0%; and CK5/6, 14%) (P < .001, P = .002, P < .001, and P = .004, respectively). Of these immunostains, ER, PR, and GCDFP were 100% specific. Primary breast tumors and their metastases showed a similar phenotypic profile. In contrast, primary gastric carcinomas showed significantly higher proportions of cases that stained with CK20 (50%), MUC2 (54%), MUC5AC (71%), MUC6 (39%), DAS-1 (43%), and CDX2 (67%) compared with metastatic breast carcinomas (CK20, 0%; MUC2, 24%; MUC5AC, 6%; MUC6, 0%; DAS-1, 0%; and CDX2, 0%) (P = .001, P = .01, P < .001, P = .02, P = .009, and P < .001, respectively). No significant differences were observed with regard to any of the other immunostains (human epidermal growth factor receptor 2 protein, CK7, and MUC3) between the patient groups.

CONCLUSIONS

Estrogen receptor protein, PR, GCDFP, CK5/6, CK20, MUC5AC, MUC6, DAS-1, and CDX2 are helpful in distinguishing primary gastric carcinomas from metastatic breast carcinomas. Of these, ER, PR, and GCDFP are highly specific for metastatic breast carcinomas, whereas CK20, DAS-1, MUC2, MUC5AC, MUC6, and CDX2 are highly specific for primary gastric carcinomas.

Primary sclerosing cholangitis and hepatitis C virus infection

Two cases of primary sclerosing cholangitis with hepatic C virus infection in a 62-year-old man and a 60-year-old woman are presented. The infection in the man was eradicated with interferon therapy in 1992. Seven years thereafter, endoscopic retrograde cholangiography revealed a diffuse 2.5-cm-long stenotic lesion in the common bile duct which was consequently resected. Histological examination of the resected specimen revealed proliferation of epithelial cells, plasma cell infiltration, and fibrosis in the submucosal layer of the common bile duct. The human leukocyte antigen DR loci were 2 and 9. In the woman, a 6-month course of interferon therapy in 1992 failed to eradicate the infection. Cholangiography in 1999 revealed multiple narrowings and dilatations of intra- and extrahepatic bile ducts. Ultrasound guided biopsy of the liver in 1992 had revealed onionskin lesions around the bile duct epithelium in the portal tract. The human leukocyte antigen DR locus was 2. From these findings, the 2 cases were diagnosed as primary sclerosing cholangitis. Further studies may provide insights into the relation between the pathogenesis of the disease and the infection.

Oral immune regulation using colitis extracted proteins for treatment of Crohn’s disease: Results of a phase I clinical trial

AIM: To evaluate safety and possible efficacy of induction of oral immune regulation using colitis extracted proteins (CEP) in Crohn’s disease (CD) subjects.

METHODS: Ten CDs were treated orally with autologous CEP thrice weekly for 16 wk. Subjects were monitored for CDAI and IBDQ. Immune modulatory effect was assessed by T-lymphocyte FACS analysis, CEP-specific IFNγ ELISPOT assay and cytokine levels.

RESULTS: Induction of oral immune regulation significantly ameliorated disease activity. All (10/10) subjects had clinical response (CDAI ≤ 70) and 7/10 achieved clinical remission (CDAI ≤ 150). Significant increase in mean IBDQ score was noted (134±9 vs 164±12). No treatment-related adverse events were noted. High levels of CEP-specific IFNγ spot forming colonies were detected in five subjects prior to treatment and in all five, a marked decrease was observed. The CD4+/CD8+ lymphocyte ratio and peripheral NKT cell numbers increased significantly, in 7/10 and in 5/10 subjects, respectively. Significant increase in serum IL-10 and IL-4 levels was observed in 7/10 subjects during treatment period.

CONCLUSION: Immune regulation via oral administration of CEP is a safe and possibly effective treatment for subjects with moderate CD and may provide means of antigen-specific immune modulation.

The clinical utility of the Das-1 monoclonal antibody in identifying adenocarcinoma of the colon metastatic to the liver in fine-needle aspiration tissue

BACKGROUND

The cytologic diagnosis of adenocarcinoma in a liver mass usually is straightforward. Identifying where the adenocarcinoma arose from is much more problematic. The Das-1 immunostain is directed against a colon specific antigen and has shown excellent sensitivity and specificity for adenocarcinoma of the colon in surgical pathology studies. In the current study, the authors examined the clinical utility of the Das-1 immunostain in the setting of fine-needle aspiration cell block material from the liver.

METHODS

The cell block material from 77 fine-needle aspiration biopsy specimens from the liver were studied. These included 17 hepatocellular carcinomas, 20 colon adenocarcinomas that were metastatic to the liver, and 40 other malignancies, predominantly adenocarcinomas, that were metastatic to the liver from a variety of primary tumor sites. Each case was stained with the Das-1 immunostain using the avidin-biotin complex method and evaluated in a blinded fashion for membranous and/or cytoplasmic staining. The diagnoses were unblinded and correlated with staining and clinical history.

RESULTS

Thirteen of 20 metastatic colon carcinoma samples exhibited immunostaining whereas only 2 of the remaining 57 samples of malignancy exhibited immunostaining.

CONCLUSIONS

The results of the current study suggest that the Das-1 immunostain may prove to be helpful in identifying adenocarcinomas in the liver as arising from the colon.

Pancreatic and biliary tract disorders in inflammatory bowel disease

Hepatobiliary disorders occur frequently in patients with IBD, with PSC and cholangiocarcinoma being the most clinically significant for endoscopists. Endoscopic therapy for PSC is effective in improving symptoms, biochemical parameters, and radiographic abnormalities. Endoscopic therapy may also confer survival benefit, but this has yet to be confirmed in randomized, controlled trials. Treatment should be restricted to those individuals with a rapid decline in liver function testing or those with recurrent cholangitis. Cholangiocarcinoma is a serious complication of PSC and carries an extremely poor prognosis. ERCP with brush cytology has a relatively low sensitivity and the diagnosis is usually made after the disease has become metastatic. Malignant biliary obstruction can be palliated by endoscopic stenting. Photodynamic therapy is a promising experimental technique that may confer symptomatic and survival benefit in patients with nonresectable, advanced cholangiocarcinoma. IBD patients also have an elevated risk for developing acute and chronic pancreatitis as well as pancreatic insufficiency. The majority of cases of acute pancreatitis are likely due to medication side effects and local structural complications of IBD. The remainder may possibly represent true extraintestinal manifestations of IBD. Chronic pancreatitis is frequently subclinical, but may be accompanied by clinically relevant exocrine insufficiency. ERCP is the test of choice for the diagnosis of chronic pancreatitis, but the role of endoscopy in the therapeutic management of IBD-associated chronic pancreatitis remains to be defined.

Experimental colitis attenuates development of toxin-induced cholangitis in rats

Primary sclerosing cholangitis frequently occurs in association with ulcerative colitis. This close association may be due to colitis predisposing patients to bile ductular injury. Therefore, we determined the susceptibility of rats with experimental colitis to toxin-induced cholangitis. Sprague-Dawley rats received 2,4,6-trinitrobenzene-sulfonic-acid (TNBS) or ethanol vehicle intracolonically. Seven days later, rats received either the biliary epithelial cell toxin alpha-naphthylisothiocyanate (ANIT) or vehicle and were killed 24 hr later. Liver histology, serum biochemistries and tumor-necrosis factor-alpha (TNF-alpha), and hepatic interleukin-10 (IL-10) mRNA were determined. TNBS-treated rats showed extensive macroscopic colonic damage and a 10-fold increase in myeloperoxidase activity compared to ethanol-treated controls. ANIT-treated noncolitic rats showed portal inflammation centered on damaged bile ducts (cholangitis), which was markedly attenuated in ANIT-treated colitic rats. Hepatic IL-10 mRNA was twofold higher in colitic compared to noncolitic rats, with no difference in serum TNF-alpha. In conclusion, experimental colitis attenuates the development of toxin-induced cholangitis in rats, possibly by up-regulating hepatic IL-10 expression.

Extraintestinal manifestations of inflammatory bowel disease

Numerous extraintestinal diseases have been associated with IBD. The role of the gastrointestinal tract in host response to the foreign antigens present in the gut makes the enteric immune system highly susceptible to any external perturbation to the system. Dysregulation of the enteric immune response results in pathology in various organs outside of the gut. The site-specific manifestations of this immune response are not understood fully. Better understanding of the pathogenesis of IBD and the complex interactions between the gut immune system and the extraintestinal systems would provide insights into the development of many of these extraintestinal manifestations. Much is unknown about the presence of cardiac, pulmonary, and hematologic diseases in patients with IBD. True association or coincidental presence of the diseases in these organ systems with IBD requires better delineation. An important consideration in all patients with IBD presenting with extraintestinal manifestations should be a careful search for medication-related complications.

Hepatobiliary disease in inflammatory bowel disease

Many hepatobiliary diseases are seen in IBD. PSC is the most common, occurring in 7.5% of patients with UC. The cause of PSC is not well understood, but PSC seems to be associated with genetic susceptibility, sharing some immunologic abnormalities with UC. A characteristic cholangiogram in a patient with abnormal liver function tests usually establishes the diagnosis. Liver biopsy is not essential but can help make the diagnosis of small duct PSC in patients with a normal cholangiogram. There are no medications that treat PSC effectively. Endoscopic dilation of dominant strictures reduces the frequency of cholangitis and may improve survival. OLT remains the only proven treatment of advanced PSC. Cholangiocarcinoma is a feared complication of PSC that is difficult to diagnose. Cholelithiasis, PBC, portal vein thrombosis, and hepatic abscess are hepatobiliary disorders that occur less frequently in IBD patients.

Immunomodulation of experimental colitis: the role of NK1.1 liver lymphocytes and surrogate antigens--bystander effect

The imbalance between Th1 pro-inflammatory and Th2 anti-inflammatory cytokine-producing cells plays a major role in the pathogenesis of inflammatory bowel disease (IBD). Induction of oral tolerance to colitis-extracted proteins was previously shown to down-regulate the anti-colon immune response, thereby alleviating experimental colitis. Immune bystander effect and liver-associated lymphocytes expressing the NK1.1 marker (NK1.1(+) LAL) have been suggested as being important in tolerance induction. The aims of the present study were to determine whether oral administration of inflammatory and non-inflammatory colon-extracted proteins of different species can induce peripheral immune tolerance and alleviate experimental colitis; and to examine the role of NK1.1(+) LAL in oral tolerance induction. Colitis was induced in C57/B6 mice by intracolonic instillation of trinitrobenzene sulphonic acid (TNBS). Mice received six oral doses of colonic proteins extracted from TNBS-colitis colonic wall, or normal colonic wall, from four different species. Standard clinical, macroscopic, and microscopic scores were used for colitis assessment. Serum interferon gamma (IFNgamma) and interleukin 10 (IL10) levels were measured by ELISA. To evaluate the role of NK1.1(+) LAL in maintaining the balance between immunogenic and tolerogenic subsets of cells, their cytotoxicity functions were tested in tolerized and non-tolerized-mice. The administration of mouse-derived colitis-extracted proteins, or of surrogate proteins extracted from normal mouse colon, or from rat or human inflammatory colons, was found to alleviate experimental colitis. Tolerized mice had less diarrhoea; showed a marked reduction of colonic ulceration, intestinal and peritoneal adhesions, wall thickness, and oedema; and demonstrated a significant improvement of all microscopic parameters for colitis. Induction of tolerance led to an increase in IL10 and a decrease in IFNgamma serum levels. NK1.1(+) LAL cytotoxicity function increased markedly in tolerized mice. In contrast, mice fed with proteins extracted from normal rat, rabbit, and human colon, or from rabbit inflammatory colon, developed severe colitis, with a marked increase in IFNgamma and a decrease in IL10 serum levels, and down-regulation of NK1.1(+) LAL function. This study has shown that oral tolerance can be induced in experimental colitis by means of the feeding of surrogate antigens; this alleviates experimental colitis. NK1.1(+) LAL cytotoxicity function is associated with peripheral tolerance induction and may help to maintain the Th1/Th2 immune balance.

Colon epithelial cellular protein induces oral tolerance in the experimental model of colitis by trinitrobenzene sulfonic acid

Rectal administration of trinitrobenzene sulfonic acid (TNBS) produces chronic colitis in experimental animals. However, the role of epithelial cellular protein(s) in this model is unknown. We examined whether oral tolerance can be induced in this model with colon epithelial cell proteins and whether it is organ specific. Rats were fed five times with extracts of LS-180 human colon cancer cells or HT 1080 human fibroblast cells. Syngeneic normal rat colon or small intestinal extracts were fed to separate groups of rats. After oral feedings, each rat received TNBS by enema. Rats were killed 15 days later, and the following were measured: gross and histologic disease score, weight, thickness, and myeloperoxidase values of colon and serum interferon-gamma (IFN-gamma) and transforming growth factor-beta (TGF-beta) levels. Rectal TNBS alone produced severe colitis with a 26% mortality rate. Rats fed LS-180 or rat colon extract before TNBS enema were protected, as evidenced by reductions in mortality rate, disease scores, and myeloperoxidase values. However, rats fed HT 1080 or small intestine extract lacked such protection. To examine the possible mechanism of the oral tolerance, T lymphocytes from mesenteric lymph nodes and spleen of LS-180 extract-fed rats were passively transferred to naive rats, and this was followed by TNBS enema. These rats showed clear protection. Protected animals had low IFN-gamma and high TGF-beta levels. This study demonstrates that cellular protein(s) from human colon epithelial cells, but not from human fibroblasts, can induce oral tolerance in experimental colitis. This oral tolerance is mediated by primed mesenteric and splenic T lymphocytes.

Aetiopathogenesis of primary sclerosing cholangitis

The aetiology and pathogenesis of PSC have not yet been clearly defined. The hypothesis that PSC is an immune mediated disease is supported by associations with HLA haplotypes, the presence of autoantibodies, increased levels of total serum immunoglobulins and the association with other autoimmune diseases. PSC does not, however, have many of the characteristics of classical autoimmunity, particularly the usual female preponderance of disease and lack of a good response to immunosuppression. Non-immune mechanisms such as bacterial infection, ischaemia and toxicity are also clearly important in the development of the disease and these factors may trigger peribiliary inflammation and cytokine-induced hepatic fibrosis. PSC may be triggered in genetically susceptible individuals by toxic or infectious agents gaining access to the liver via a diseased and permeable colon.