Circulating soluble adhesion molecules in inflammatory bowel disease

Identification of Specific Biomarkers and Pathways in the Treatment Response of Infliximab for Inflammatory Bowel Disease: In-Silico Analysis

Background: Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. In biological therapy, infliximab became the first anti-tumor necrosis factor (TNF) agent approved for IBD. Despite this success, infliximab is expensive, often ineffective, and associated with adverse events. Prediction of infliximab resistance would improve overall potential outcomes. Therefore, there is a pressing need to widen the scope of investigating the role of genetics in IBD to their association with therapy response. Methods: In the current study, an in-silico analysis of publicly available IBD patient transcriptomics datasets from Gene Expression Omnibus (GEO) are used to identify subsets of differentially expressed genes (DEGs) involved in the pathogenesis of IBD and may serve as potential biomarkers for Infliximab response. Five datasets were found that met the inclusion criteria. The DEGs for datasets were identified using limma R packages through the GEOR2 tool. The probes’ annotated genes in each dataset intersected with DGEs from all other datasets. Enriched gene Ontology Clustering for the identified genes was performed using Metascape to explore the possible connections or interactions between the genes. Results: 174 DEGs between IBD and healthy controls were found from analyzing two datasets (GSE14580 and GSE73661), indicating a possible role in the pathogenesis of IBD. Of the 174 DEGs, five genes (SELE, TREM1, AQP9, FPR2, and HCAR3) were shared between all five datasets. Moreover, these five genes were identified as downregulated in the infliximab responder group compared to the non-responder group. Conclusions: We hypothesize that alteration in the expression of these genes leads to an impaired response to infliximab in IBD patients. Thus, these genes can serve as potential biomarkers for the early detection of compromised infliximab response in IBD patients.

Tissue Exposure does not Explain Non-Response in Ulcerative Colitis Patients with Adequate Serum Vedolizumab Concentrations

BACKGROUND AND AIMS

Some patients with ulcerative colitis [UC] do not respond to vedolizumab treatment despite adequate drug exposure in serum. This study aimed to investigate vedolizumab in tissue and questioned whether insufficient tissue exposure could explain non-response in UC patients with adequate serum vedolizumab concentrations.

METHODS

A paired serum sample and colonic mucosal biopsy was collected from 40 UC patients [20 endoscopic responders, 20 non-responders] at week 14 of vedolizumab treatment. Vedolizumab, soluble [s]-mucosal addressin cell adhesion molecule-1 [MAdCAM-1], s-vascular cell adhesion molecule-1 [VCAM-1] and s-intercellular adhesion molecule-1 [ICAM-1] were measured in serum and/or tissue. Endoscopic response was defined as Mayo endoscopic sub-score ≤1.

RESULTS

A significant positive correlation was observed between vedolizumab serum and colonic tissue concentrations [ρ = 0.84, p < 0.0001], regardless of the macroscopic inflammatory state of the tissue. Vedolizumab tissue concentrations were lower in non-responders than in responders [0.07 vs 0.11 µg/mg, p = 0.04]. In the subgroup of patients with adequate vedolizumab serum concentrations [>14.6 µg/mL], tissue vedolizumab was not significantly different between responders and non-responders [0.15 vs 0.13 µg/mg; p = 0.92]. Serum sMAdCAM-1 concentrations, but not serum sICAM-1 or sVCAM-1 concentrations, were significantly higher in responders than in non-responders with adequate vedolizumab serum concentrations [1.04 vs 0.83 ng/mL, p = 0.03].

CONCLUSIONS

Vedolizumab concentrations in colonic mucosal tissue of UC patients reflect the concentration in serum regardless of the macroscopic inflammatory state of the tissue. Our data show that insufficient tissue exposure does not explain non-response in UC patients with adequate serum vedolizumab concentrations.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on pouchitis in ulcerative colitis. Part 2: Treatment

Pouchitis treatment is a complex entity that requires a close medical and surgical relationship. The elective treatment for acute pouchitis is antibiotics. After a first episode of pouchitis it is recommended prophylaxis therapy with a probiotic mix, nevertheless it is not clear the use of this formulation for preventing a first episode of pouchitis after surgery. First-line treatment for chronic pouchitis is an antibiotic combination. The next step in treatment should be oral budesonide. Selected cases of severe, chronic refractory pouchitis may benefit from biologic agents, and anti-TNF α should be recommended as the first option, leaving the new biologicals for multi-refractory patients. Permanent ileostomy may be an option in severe refractory cases to medical treatment.

In Vitro Entero-Capillary Barrier Exhibits Altered Inflammatory and Exosomal Communication Pattern after Exposure to Silica Nanoparticles

The intestinal microvasculature (iMV) plays multiple pathogenic roles during chronic inflammatory bowel disease (IBD). The iMV acts as a second line of defense and is, among other factors, crucial for the innate immunity in the gut. It is also the therapeutic location in IBD targeting aggravated leukocyte adhesion processes involving ICAM-1 and E-selectin. Specific targeting is stressed via nanoparticulate drug vehicles. Evaluating the iMV in enterocyte barrier models in vitro could shed light on inflammation and barrier-integrity processes during IBD. Therefore, we generated a barrier model by combining the enterocyte cell line Caco-2 with the microvascular endothelial cell line ISO-HAS-1 on opposite sides of a transwell filter-membrane under culture conditions which mimicked the physiological and inflamed conditions of IBD. The IBD model achieved a significant barrier-disruption, demonstrated via transepithelial-electrical resistance (TER), permeability-coefficient (P_app) and increase of sICAM sE-selectin and IL-8. In addition, the impact of a prospective model drug-vehicle (silica nanoparticles, aSNP) on ongoing inflammation was examined. A decrease of sICAM/sE-selectin was observed after aSNP-exposure to the inflamed endothelium. These findings correlated with a decreased secretion of ICAM/E-selectin bearing exosomes/microvesicles, as evaluated via ELISA. Our findings indicate that aSNP treatment of the inflamed endothelium during IBD may hamper exosomal/microvesicular systemic communication.

Biomarkers Are Associated With Clinical and Endoscopic Outcomes With Vedolizumab Treatment in Ulcerative Colitis

Background

Vedolizumab inhibits α4β7-mediated lymphocyte trafficking and is effective in ulcerative colitis (UC). This study evaluated drug and biomarker concentrations and patient outcomes during vedolizumab treatment in UC.

Methods

Prospectively scored maintenance clinical (26.5 weeks; interquartile range [IQR], 16.3-37.0 weeks) and endoscopic (23.5 weeks; IQR, 16.8-35.6 weeks) outcomes were compared with serum vedolizumab concentrations, antivedolizumab antibodies, and serum biomarkers at baseline and weeks 2, 6, 14, and 26. A linear mixed-effects model compared biomarker trajectories over time between clinical and endoscopic remitters and nonremitters.

Results

Thirty-two patients were included. Soluble (s)-tumor necrosis factor (TNF)-α, s-α4β7, s-mucosal addressin cell adhesion molecule (s-MAdCAM-1), and s-amyloid A (s-AA) significantly changed with treatment. A linear mixed-effects model demonstrated that s-α4β7 (P = 0.044) increased and s-MAdCAM-1 (P = 0.006) and s-vascular cell adhesion molecule-1 (s-VCAM-1, P = 0.001) decreased more rapidly in patients achieving clinical remission in maintenance. S-MAdCAM-1 (P = 0.005), s-intracellular adhesion molecule-1 (ICAM-1; P = 0.014), s-VCAM-1 (P < 0.001), and s-TNF (P = 0.052) decreased more rapidly in endoscopic remitters. In clinical remitters, higher week 14 (20.3 ng/mL vs 6.0 ng/mL; P = 0.013) and week 26 (14.1 ng/mL vs 8.6 ng/mL; P = 0.05) s-α4β7 were observed. In endoscopic remitters, week 2 (6.7 pg/mL vs 17.8 pg/mL; P = 0.038) and week 6 (3.9 pg/mL vs 15.6 pg/mL; P = 0.005) s-TNF and week 14 s-VCAM (589.1 ng/mL vs 746.0 ng/mL; P = 0.05) were lower.

Conclusion

Serum biomarkers were associated with outcomes in vedolizumab-treated UC patients. s-α4β7 increased, whereas s-MAdCAM-1, s-VCAM-1, s-ICAM-1, and s-TNF decreased more rapidly in remitters. At individual time points, induction s-TNF and maintenance s-VCAM-1 concentrations were lower, whereas maintenance s-α4β7 concentrations were higher in remitters.

The Innate and Adaptive Immune System as Targets for Biologic Therapies in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an immune-mediated inflammatory condition causing inflammation of gastrointestinal and systemic cells, with an increasing prevalence worldwide. Many factors are known to trigger and maintain inflammation in IBD including the innate and adaptive immune systems, genetics, the gastrointestinal microbiome and several environmental factors. Our knowledge of the involvement of the immune system in the pathophysiology of IBD has advanced rapidly over the last two decades, leading to the development of several immune-targeted treatments with a biological source, known as biologic agents. The initial focus of these agents was directed against the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) leading to dramatic changes in the disease course for a proportion of patients with IBD. However, more recently, it has been shown that a significant proportion of patients do not respond to anti-TNF-α directed therapies, leading a shift to other inflammatory pathways and targets, including those of both the innate and adaptive immune systems, and targets linking both systems including anti-leukocyte trafficking agents-integrins and adhesion molecules. This review briefly describes the molecular basis of immune based gastrointestinal inflammation in IBD, and then describes how several current and future biologic agents work to manipulate these pathways, and their clinical success to date.

Alicaforsen in the treatment of pouchitis

Alicaforsen is a 20-base antisense oligonucleotide inhibiting ICAM-1 production, which is an important adhesion molecule involved in leukocyte migration and trafficking to the site of inflammation. Hitherto, alicaforsen has been granted orphan drug designation and is prescribed as an unlicensed medicine in accordance with international regulation for the treatment of pouchitis and left-sided ulcerative colitis. Given the positive results evolving from one open-label trial and one case series in patients with chronic refractory pouchitis, US FDA has agreed to a rolling submission for a license application for the treatment of pouchitis, which has been recently initiated. Whether alicaforsen leads to higher endoscopic and clinical remission rates as placebo and whether the response can be maintained in the long-term in larger studies is yet unknown. An ongoing multicenter international Phase III trial will definitely address these unanswered questions.

The role of the intestinal microvasculature in inflammatory bowel disease: studies with a modified Caco-2 model including endothelial cells resembling the intestinal barrier in vitro

The microvascular endothelium of the gut barrier plays a crucial role during inflammation in inflammatory bowel disease. We have modified a commonly used intestinal cell model based on the Caco-2 cells by adding microvascular endothelial cells (ISO-HAS-1). Transwell filters were used with intestinal barrier-forming Caco-2 cells on top and the ISO-HAS-1 on the bottom of the filter. The goal was to determine whether this coculture mimics the in vivo situation more closely, and whether the model is suitable to evaluate interactions of, for example, prospective nanosized drug vehicles or contrast agents with this coculture in a physiological and inflamed state as it would occur in inflammatory bowel disease. We monitored the inflammatory responsiveness of the cells (release of IL-8, soluble intercellular adhesion molecule 1, and soluble E-selectin) after exposure to inflammatory stimuli (lipopolysaccharide, TNF-α, INF-γ, IL1-β) and a nanoparticle (Ba/Gd: coprecipitated BaSO₄ and Gd(OH)₃), generally used as contrast agents. The barrier integrity of the coculture was evaluated via the determination of transepithelial electrical resistance and the apparent permeability coefficient (P_app) of NaFITC. The behavior of the coculture Caco-1/ISO-HAS-1 was compared to the respective monocultures Caco-2 and ISO-HAS-1. Based on transepithelial electrical resistance, the epithelial barrier integrity of the coculture remained stable during incubation with all stimuli, whereas the P_app decreased after exposure to the cytokine mixture (TNF-α, INF-γ, IL1-β, and Ba/Gd). Both the endothelial and epithelial monocultures showed a high inflammatory response in both the upper and lower transwell-compartments. However, in the coculture, inflammatory mediators were only detected on the epithelial side and not on the endothelial side. Thus in the coculture, based on the P_app, the epithelial barrier appears to prevent a potential inflammatory overreaction in the underlying endothelial cells. In summary, this coculture model exhibits in vivo-like features, which cannot be observed in conventional monocultures, making the former more suitable to study interactions with external stimuli.

Alicaforsen, an antisense inhibitor of ICAM-1, as treatment for chronic refractory pouchitis after proctocolectomy: A case series

BACKGROUND AND AIMS

The published data about the efficacy of the intercellular adhesion molecule-1 (ICAM-1) antisense oligonucleotide termed alicaforsen in inflammatory bowel disease (IBD) is rather inconsistent. This case series analyzes its efficacy in chronic refractory pouchitis, after proctocolectomy.

METHODS

We performed a retrospective analysis on all patients who had received at least one dose of alicaforsen for IBD at three referral centers in Switzerland. We assessed the drug's efficacy in patients treated for chronic refractory pouchitis, by comparing the clinical and/or endoscopic disease activity at baseline with a 2-3-month follow-up visit.

RESULTS

We identified 22 patients who had received at least one dose. Among them, 13 patients were being treated for chronic refractory pouchitis. These patients had a median age of 38.0 years (95% CI 21.0-69.0) and five were female (38.5%). The median time since pouch surgery was 102.5 months (95% CI 16.0-288.0), with a median pouchitis duration of 16.0 months (95% CI 4.0-216.0). At 2-3 months after therapy, clinical and endoscopic disease activity was significantly reduced (stool frequency 9.0 versus 6.0, the Pouchitis Disease Activity Index (PDAI) clinical subscore was 4.0 versus 1.0, and the endoscopic disease activity was 4.0 versus 2.0). Clinical improvement was achieved in 11 out of 13 pouchitis patients (84.6%); however, a relapse was observed in nine of these patients (81.8%). The median time from clinical improvement to relapse was 16 weeks (95% CI 9.0-23.0).

CONCLUSIONS

Alicaforsen seemed to be efficacious in inducing clinical and/or endoscopic improvement in chronic refractory pouchitis and may be a promising treatment alternative in those patients; however, given the high proportion of relapse, one 6-week course of alicaforsen may not be sufficient.

The role of glycosylation in IBD

A number of genetic and immunological studies give impetus for investigating the role of glycosylation in IBD. Experimental mouse models have helped to delineate the role of glycosylation in intestinal mucins and to explore the putative pathogenic role of glycosylation in colitis. These experiments have been extended to human studies investigating the glycosylation patterns of intestinal mucins as well as levels of glycans of serum glycoproteins and expression of glycan receptors. These early human studies have generated interesting hypotheses regarding the pathogenic role of glycans in IBD, but have generally been restricted to fairly small underpowered studies. Decreased glycosylation has been observed in the intestinal mucus of patients with IBD, suggesting that a defective inner mucus layer might lead to increased bacterial contact with the epithelium, potentially triggering inflammation. In sera, decreased galactosylation of IgG has been suggested as a diagnostic marker for IBD. Advances in glycoprofiling technology make it technically feasible and affordable to perform high-throughput glycan pattern analyses and to build on previous work investigating a much wider range of glycan parameters in large numbers of patients.

Pouchitis: what every gastroenterologist needs to know

Pouchitis is the most common complication among patients with ulcerative colitis who have undergone restorative proctocolectomy with ileal pouch-anal anastomosis. Pouchitis is actually a spectrum of diseases that vary in etiology, pathogenesis, phenotype, and clinical course. Although initial acute episodes typically respond to antibiotic therapy, patients can become dependent on antibiotics or develop refractory disease. Many factors contribute to the course of refractory pouchitis, such as the use of nonsteroidal anti-inflammatory drugs, infection with Clostridium difficile, pouch ischemia, or concurrent immune-mediated disorders. Identification of these secondary factors can help direct therapy.

Infliximab for the treatment of pouchitis

Pouchitis is not a rare complication that develops after an ileal-pouch anastomosis, performed after colectomy in patients refractory to treatment or with complicated ulcerative colitis. This condition may become chronic and unresponsive to medical therapies, including corticosteroids, antibiotics and probiotics. The advent of biological therapies (tumor necrosis factor-α inhibitors) has changed the course of these complications. In particular, in these cases, infliximab (IFX) may represent a safe and effective therapy in order to avoid the subsequent operation for a permanent ileostomy. This article reviews the therapeutic effects of one of the most widely used anti-tumor necrosis factor-α molecules, IFX, for the treatment of complicated pouchitis (refractory to conventional treatment and/or fistulizing).

Activated eosinophils in association with enteric nerves in inflammatory bowel disease

Enteric neural dysfunction leads to increased mucous production and dysmotility in inflammatory bowel disease (IBD). Prior studies have shown that tissue eosinophilia is related to disease activity. We hypothesized that interactions between eosinophils and nerves contribute to neural dysfunction in IBD. Tissue from patients with intractable IBD, endoscopic biopsies from patients with steroid responsive IBD, both when active and quiescent, and control tissue were studied. Immunohistochemical studies showed that eosinophils localize to nerves in the mucosal layer of patients with Crohn’s disease (CD) (p<0.001) and ulcerative colitis (UC), (p<0.01). Eosinophils localized to substance P and choline acetyltransferase (ChAT) immunostained nerves. Real time PCR of laser capture micro-dissected enteric ganglia demonstrated Intercellular Adhesion Molecule 1 (ICAM-1) mRNA was increased 7-fold in UC (n = 4), (p = 0.03), and 10-fold in CD (n = 3), (p = 0.05). Compared with controls, eotaxin-3 (CCL-26) mRNA was increased 9-fold in UC (p = 0.04) and 15-fold in CD (p = 0.06). Eosinophil numbers correlated with disease activity, while deposition of major basic protein (MBP) and eosinophil Transforming Growth Factor β -1 (TGFβ-1) expression were seen in therapeutically responsive disease. These data indicate a significant localization of eosinophils to nerves in IBD, mediated through neurally expressed ICAM-1 and eotaxin-3. This cell/neural interaction may influence the function of nerves and contribute to symptoms in IBD.

Leukocyte migration in experimental inflammatory bowel disease

Emigration of leukocytes from the circulation into tissue by transendothelial migration, is mediated subsequently by adhesion molecules such as selectins, chemokines and integrins. This multistep paradigm, with multiple molecular choices at each step, provides a diversity in signals. The influx of neutrophils, monocytes and lymphocytes into inflamed tissue is important in the pathogenesis of chronic inflammatory bowel disease. The importance of each of these groups of adhesion molecules in chronic inflammatory bowel disease, either in human disease or in animal models, will be discussed below. Furthermore, the possibilities of blocking these different steps in the process of leukocyte extravasation in an attempt to prevent further tissue damage, will be taken into account.

Etiology of pouchitis

Restorative proctocolectomy with ileal-pouch anal anastomosis (RPC) is the operation of choice for ulcerative colitis (UC) patients requiring surgery. It is also used for patients with familial adenomatous polyposis (FAP). Pouchitis accounts for 10% of pouch failures. It is an idiopathic inflammatory condition that may occur in up to 50% of patients after RPC for UC. It is rarely seen in FAP patients after RPC. The etiology of pouchitis remains unclear. An overlap with UC is suggested by the frequency with which pouchitis affects patients with UC compared with FAP patients. There is significant clinical evidence implicating bacteria in the pathogenesis of pouchitis. Studies using culture and molecular methods demonstrate a dysbiosis of the pouch microbiota in pouchitis. Risk factors, genetic associations, and serological markers of pouchitis suggest that the interactions between the host immune responses and the pouch microbiota underlie the etiology of this idiopathic inflammatory condition. Here we present a detailed review of the data focusing on the pouch microbiota and the immune responses that support this hypothesis. We also discuss the contribution of luminal metabolic factors and the epithelial membrane in the etiology of this inflammatory process. The ileoanal pouch offers a unique opportunity to study the inter-relationships between the gut microbiota and host immune responses from before the onset of disease. For this reason the study of pouchitis could serve as a human model that significantly enhances our understanding of inflammatory bowel diseases in general.

Acute and chronic pouchitis--pathogenesis, diagnosis and treatment

Restorative proctocolectomy with ileal pouch-anal anastomosis has become the procedure of choice for the majority of patients with ulcerative colitis who require surgical treatment. Pouchitis, the most common long-term complication of the procedure, involves a spectrum of disease processes with heterogeneous risk factors, clinical features, disease courses and prognoses. In addition, clinical symptoms of pouchitis are not specific and often overlap with those of other inflammatory and functional pouch disorders, such as Crohn's disease of the pouch and irritable pouch syndrome. Pouchoscopy and biopsy, along with laboratory and radiographic evaluations, are often required for accurate diagnosis in patients with symptoms indicative of pouchitis. Dysbiosis has been implicated as a triggering factor for pouchitis, and concurrent infection with pathogens, such as Clostridium difficile, might contribute to disease relapse and exacerbation. Antibiotic therapy is the main treatment modality. However, the management of antibiotic-dependent and antibiotic-refractory pouchitis remains challenging. Secondary causes of pouchitis, such as ischaemia, NSAID use, the presence of concurrent primary sclerosing cholangitis and other systemic immune-mediated disorders, should be evaluated and properly managed.

Pouchitis and pouch dysfunction

Restorative proctocolectomy with ileal pouch-anal anastomosis has become the surgical treatment of choice for most patients with ulcerative colitis who require surgery. Although the surgical procedure offers a cure in some patients, postoperative inflammatory and noninflammatory complications are common. Pouchitis is the most common long-term complication of the procedure. Pouchitis represents a spectrum of disease processes with heterogeneous risk factors, clinical phenotypes, natural history, and prognosis. Accurate diagnosis and classification are important for proper treatment and prognosis.

Pouchitis and pouch dysfunction

Restorative proctocolectomy with ileal pouch-anal anastomosis has become the surgical treatment of choice for most patients with ulcerative colitis who require surgery. Although the surgical procedure offers a cure in some patients, postoperative inflammatory and noninflammatory complications are common. Pouchitis is the most common long-term complication of the procedure. Pouchitis represents a spectrum of disease processes with heterogeneous risk factors, clinical phenotypes, natural history, and prognosis. Accurate diagnosis and classification are important for proper treatment and prognosis.

Colonic treatments and targets: issues and opportunities

The colon provides a plethora of therapeutic opportunities. There are multiple disease targets, drug molecules, and colon-specific delivery systems to be explored. Clinical studies highlight the potential for systemic delivery via the colon, and the emerging data on the levels of cell membrane transporters and metabolic enzymes along the gut could prove advantageous for this. Often efflux transporters and metabolic enzyme levels are lower in the colon, suggesting a potential for improved bioavailability of drug substrates at this site. The locoregional distribution of multiple metabolic enzymes (including cytochromes), efflux transporters (including P-glycoprotein and breast cancer resistance proteins), and influx transporters (including the solute carrier family) along the intestine is summarized. Local delivery to the colonic mucosa remains a valuable therapeutic option. New therapies that target inflammatory mediators could improve the treatment of inflammatory bowel disease, and old and new anticancer molecules could, when delivered topically, prove to be beneficial adjuncts to the current systemic or surgical treatments. New issues such as pharmacogenomics, chronotherapeutics, and the delivery of prebiotics and probiotics are also discussed in this review. Targeting drugs to the colon utilizes various strategies, each with their advantages and flaws. The most promising systems are considered in the light of the physiological data which influence their in vivo behavior.

Pouchitis: lessons for inflammatory bowel disease

PURPOSE OF REVIEW

One of the significant limitations to the investigation of inflammatory bowel disease (IBD) in humans is the impossibility of studying this condition from the beginning of the disease process to understand the individual contribution of the various microbiological and immunological components to its pathogenesis. Pouchitis can serve as a human model for IBD, as the time of the pouch creation is known, which allows to prospectively study the events that might eventually lead to the development of a form of intestinal inflammation (i.e., pouchitis) that mimics IBD.

RECENT FINDINGS

A considerable amount of progress has been made in the last few years on the mechanisms underlying the pathogenesis of pouchitis. Recent literature suggests that pouchitis may present a spectrum of disease processes, with a wide range of causes, risk factors, clinical phenotypes, disease courses, and prognoses. Genetic, microbiological, and immunological profiles in pouchitis were evaluated.

SUMMARY

Ileal pouch and pouchitis represent a valuable human model to study the evolution of bacterial communities and host-bacteria interactions in IBD by sequentially monitoring microbiological and immunological profile before, during, and after pouch construction and before and after development and treatment of pouchitis.

Pathogenesis of and unifying hypothesis for idiopathic pouchitis

Ileal pouch-anal anastomosis is the procedure of choice in the surgical management of refractory ulcerative colitis. Pouchitis affects up to 60% of patients following ileal pouch-anal anastomosis for ulcerative colitis. It overlaps significantly with ulcerative colitis such that improvements in our understanding of one will impact considerably on the other. The symptoms are distressing and impinge significantly on patients' quality of life. Despite 30 years of scientific and clinical investigation, the pathogenesis of pouchitis is unknown; however, recent advances in molecular and cell biology make a synergistic hypothesis possible. This hypothesis links interaction between epithelial metaplasia, changes in luminal bacteria (in particular sulfate-reducing bacteria), and altered mucosal immunity. Specifically, colonic metaplasia supports colonization by sulfate-reducing bacteria that produce hydrogen sulfide. This causes mucosal depletion and subsequent inflammation. Although in most cases antibiotics lead to bacterial clearance and symptom resolution, immunogenetic subpopulations can develop a chronic refractory variant of pouchitis. The aims of this paper are to discuss proposed pathogenic mechanisms and to describe a novel mechanism that combines many hypotheses and explains several aspects of pouchitis. The implications for the management of both pouchitis and ulcerative colitis are discussed.

Association between immune-associated disorders and adverse outcomes of ileal pouch-anal anastomosis

OBJECTIVES

Autoimmune disorders (ADs) frequently coexist with inflammatory bowel disease. The aim of the study was to determine whether coexisting AD in patients with ileal pouches increases the risk for chronic antibiotic-refractory pouchitis (CARP) and other inflammatory conditions of the pouch.

METHODS

A total of 622 patients seen in our Pouchitis Clinic were enrolled. We compared the prevalence of adverse outcomes of the pouch (including CARP, Crohn's disease of the pouch, and pouch failure) in patients with or without concurrent AD and assessed the factors for these adverse outcomes.

RESULTS

There were seven pouch disease categories: normal (N=60), irritable pouch syndrome (N=112), active pouchitis (N=131), CARP (N=67), Crohn's disease (N=131), cuffitis (N=83), surgical complications (N=36), and anismus (N=2). The prevalence of AD in these pouch disease categories was 4.5%, 12.5%, 9.2%, 13.4%, 10.7%, 3.8%, 1.5%, and 0%, respectively. The presence of at least one AD at time of pouch surgery was shown to be associated with a twofold increase in the risk for CARP (hazard ratio=2.29; 95% CI: 1.52, 3.46; P<0.001) and for pouch-associated hospitalization (hazard ratio=2.39; 95% CI: 1.59, 3.58; P<0.001). The presence of AD was not associated with increased risk for irritable pouch syndrome, active pouchitis, Crohn's disease, cuffitis, surgical complications, or pouch failure. Patients with Crohn's disease of the pouch had a 2.42 times higher risk for pouch failure (P=0.042) than these without. Active smoking or a history of smoking was shown to be associated with an increased risk for pouch-associated hospitalization and pouch failure.

CONCLUSIONS

AD appears to be associated with an increased risk for CARP, and the presence of the association between these AD and pouch disorders may stimulate further research on the link of these organ systems on an immunological basis.

Antisense inhibition of ICAM-1 expression as therapy provides insight into basic inflammatory pathways through early experiences in IBD

BACKGROUND

Alicaforsen (ISIS 2302), an antisense to intercellular adhesion molecule-1 (ICAM-1) (CD54), was designed to inhibit ICAM-1 expression. ICAM-1 seems to play a role in cell-mediated inflammation, specifically cell trafficking. For this reason, it may be useful in a variety of immune-mediated diseases, including inflammatory bowel disease.

OBJECTIVE

To evaluate the use of alicaforsen in clinical trials to understand its efficacy and side effects, as well as assess for evidence that may offer insight into disease pathways.

METHODS

We evaluate all of the available, published trials, with a focus on the prospective, randomized trials.

RESULTS/CONCLUSIONS

Systemic treatment for Crohn's disease has not revealed significant effect. Topical enemas for ulcerative colitis have demonstrated some effect in secondary outcomes, and initial studies in pouchitis are promising. In general, the compound has been well tolerated and safe.

Does the urinary excretion of alpha1-microglobulin and albumin predict clinical disease activity in ulcerative colitis?

INTRODUCTION

There remains some difficulty in determining disease activity during the development of inflammatory bowel disease (IBD). The excretion levels of some inflammatory response molecules increase as a result of the onset of this disease. We studied urinary alfa-1-microglobulin (alpha1-MG) and albumin levels in patients with active and inactive ulcerative colitis (UC) and investigated whether we could use these parameters as an activity index.

METHODS

The study was carried out at Gazi University Faculty of Medicine, Nephrology and Gastroenterology Departments, between December 2003 and March 2006. In total, 35 patients (male/female: 16/19, mean age: 38.3+/-2.4 years) and 13 healthy controls (male/female: 6/7, mean age: 35.8+/-2.8 years) were enrolled in the study. Nineteen patients had symptoms of active disease and the remaining 16 patients had inactive disease.

RESULTS

There was a significant difference in serum C-reactive protein (CRP), urinary albumin excretion, and alpha1-MG excretion levels between patients and controls. Patients with active disease had significantly higher serum CRP and alpha1-MG levels than those with inactive disease and controls. Patients with active disease had higher microalbuminuria levels than inactive patients, but this difference was not statistically significant. Urinary albumin and alpha1-MG excretion did not correlate with serum CRP levels.

CONCLUSION

The present study suggests that, as with CRP, urinary levels of albumin and alpha1-MG increase during the active period of UC. During the inactive period, concentrations of these parameters are comparable to controls. The measurement of alpha1-MG and/or microalbuminuria could provide information on disease severity and response to treatment.

Pouchitis

While restorative proctocolectomy with ileal pouch-anal anastomosis has significantly improved the quality of life in patients with underlying ulcerative colitis who require surgery, complications can occur. Pouchitis as the most common long-term complication represents a spectrum of disease processes ranging from acute, antibiotic-responsive type to chronic antibiotic-refractory entity. Accurate diagnosis using a combined assessment of symptoms, endoscopy and histology and the stratification of clinical phenotypes is important for treatment and prognosis the disease. The majority of patients respond favorably to antibiotic therapy. However, management of chronic antibiotic-refractory pouchitis remains a challenge.

Adhesion molecules in chronic ulcerative colitis

BACKGROUND AND AIMS

The adhesion molecule expression in colonic mucosa is pivotal for transition from quiescent to active stage of ulcerative colitis (UC). The aim of the present study is to reveal the adhesion molecule profile of colonic mucosa in the active stage of UC and in remission.

MATERIALS AND METHODS

Biopsy specimens obtained from 14 patients with UC (seven with active disease and seven with UC in remission) and from seven controls were used. Immunohistochemistry was performed with antibodies against ICAM-1, VCAM-1, E-selectin, LFA-1, Mac-1, and VLA-4.

RESULTS

In controls, slight ICAM-1 positivity was observed on thety endothelium of blood vessels of the mucosal and submucosal layer and only single ICAM-1-, Mac-1-, and LFA-1-positive cells were found. In all patients with UC, the endothelium of venules in the edematous mucosal and submucosal layers was ICAM-1-, VCAM-1-, and E-selectin-positive. Numerous ICAM-1- and LFA-1-positive and less VCAM-1-, Mac-1-, and VLA-4-positive inflammatory cells were detected in mucous layers of acute UC. In specimens of UC in remission, the inflammatory cells positive for the studied adhesion molecules were significantly less in number in the mucosa and submucosa (p < 0.05).

CONCLUSIONS

Based on the increased expression of ICAM-1, VCAM-1, and their ligands LFA-1 and VLA-4 in patients with UC, we can conclude that these adhesion molecules play a key role in the adherence of lymphocytes and macrophages to endothelial cells maintaining the chronic inflammation. Presence of E-selectin on endothelial cells of venules could be a sign of relapse after remission in UC.

The serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble gp130 (sgp130) in different tumour stages. Correlation between the two parameters in progression of malignancy

Cell adhesion molecules are cell surface glycoproteins that may act as mediators in the metastatic process. In this study we measured serum levels of the soluble intercellular adhesion molecule-1 (sICAM-1) in 74 patients with various tumours, divided into four groups according to tumour stage and previous therapy. Serum values of sgp130 were determined in the same patients. As controls we took healthy persons (n=18 for sICAM-1; n=28 for sgp130). Two parameters were determined by ELISA. The serum values of sICAM-1 were significantly elevated compared to controls in stages III + IV both without and after previous chemo/radiotherapy (P<0.05). In stages I + II without or with previous therapy there was no significance. The serum values of sgp130 were increased significantly at each tumour stage both without and after therapy. There were significant correlations between the values of sICAM-1 and sgp130 in patients with progression (tumour stage III + IV without therapy P<0.01; after chemo/radiotherapy P<0.05). To our knowledge this relationship between the two serum parameters has never before been reported. The simultaneous measurement of sICAM-1 and sgp130 could be important in the evaluation of the clinical progression of malignant diseases.

Pouchitis: a spectrum of diseases

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical treatment of choice for ulcerative colitis and familial adenomatous polyposis patients who require surgery. Pouchitis is the most common long-term complication after IPAA. Patients with pouchitis represent a heterogeneous group in terms of pathogenesis, clinical presentation, disease course, and prognosis, suggesting a wide range of disease mechanisms. Before the diagnosis of pouchitis is made, other inflammatory and non-inflammatory disease conditions, such as Crohn's disease, cuffitis, and irritable pouch syndrome, should be ruled out. Pouch endoscopy is the most important tool for diagnosis and differential diagnosis. Accurate diagnosis and classification are essential for appropriate management. Although the majority of patients with pouchitis respond to antibiotic therapy, a subset of these patients cannot achieve remission by means of antibiotics and thus require anti-inflammatory or immunosuppressive treatment.

An enema formulation of alicaforsen, an antisense inhibitor of intercellular adhesion molecule-1, in the treatment of chronic, unremitting pouchitis

BACKGROUND

Pouchitis is the major long-term complication of ileal pouch-anal anastomosis for ulcerative colitis. The incidence of pouchitis is as high as 50% several years after surgery. Two-thirds of pouchitis patients suffer recurrence. Of those who recur, one-quarter suffer from chronic, unremitting pouchitis. Current treatments for this disorder are disappointing.

AIM

To determine whether a topically administered enema formulation of ISIS 2302 (alicaforsen), an antisense inhibitor of intercellular adhesion molecule-1, can improve the clinical symptoms, endoscopic mucosal appearance and mucosal histology in patients with chronic, unremitting pouchitis, a disorder in which this molecule is over-expressed.

METHODS

In an open-label, uncontrolled study, 12 patients with chronic, unremitting pouchitis were treated with 240 mg alicaforsen antisense enema nightly for 6 weeks. Clinical evaluation and endoscopy were performed at baseline and at weeks 3, 6 and 10. Pouchoscopy with biopsy was carried out at baseline and at weeks 6 and 10. The primary end-point was the reduction from baseline of the Pouchitis Disease Activity Index (PDAI) at week 6. Secondary end-points included the PDAI at week 10. Safety was evaluated by analysing the adverse events, vital signs and laboratory parameters.

RESULTS

After 6 weeks of nightly alicaforsen enema, a statistically significant (n = 12, P = 0.001) reduction in the PDAI from baseline (11.42) to week 6 (6.83) was observed. Mean reductions in the endoscopy sub-score from baseline (5.25) to week 3 (3.08) and week 6 (2.58) were statistically significant (P = 0.0039 and P = 0.0005, respectively). The mean reductions in clinical symptom sub-score from baseline (3.75) to week 3 (2.33) and week 6 (2.25) were also statistically significant (P = 0.0156 and P = 0.0117, respectively). Ten of the 12 patients achieved a mucosal appearance score of 0 or 1 at endoscopy. Five of the 12 patients (42%) had a non-statistically significant decrease in the histology component of their PDAI from baseline to week 6. By week 6, seven of the 12 patients (58%) were in remission, as defined by PDAI < 7, with a mean decrease from baseline in PDAI score of six points. The alicaforsen enemas were well tolerated and no serious side-effects were noted.

CONCLUSIONS

Antisense enema to intercellular adhesion molecule-1 is safe and well tolerated. In an open-label trial, it appeared to improve the PDAI score, clinical symptoms and endoscopic mucosal appearance. It may also improve the histology. In the light of the responses observed in this trial, a randomized, placebo-controlled trial is warranted.

Infliximab in refractory pouchitis complicated by fistulae following ileo-anal pouch for ulcerative colitis

AIM

To determine the efficacy of infliximab in the treatment of chronic refractory pouchitis complicated by fistulae following ileal pouch-anal anastomosis for ulcerative colitis.

METHODS

This open study included seven patients (four females, three males) with chronic refractory pouchitis complicated by fistulae. Pouchitis was diagnosed by clinical, endoscopic and histological criteria. The sites of the fistulae were as follows: pouch-bladder in one, vaginal in three, perianal in two, and both vaginal and perianal in one. Extra-intestinal manifestations (erythema nodosum, arthralgia) were present in four patients. Crohn's disease was carefully excluded in all patients after re-evaluation of the history, re-examination of the original proctocolectomy specimen and examination of the proximal small bowel. All patients had been treated with antibiotics and three with steroids. Patients received infliximab, 5 mg/kg, at 0, 2 and 6 weeks. Azathioprine (2.5 mg/kg) was also started for all patients as bridge therapy. Clinical response was classified as complete, partial or no response. Fistulae closure was classified as complete (cessation of fistulae drainage and total closure of all fistulae), partial (a reduction in the number, size, drainage or discomfort associated with fistulae) or no closure. The pouchitis disease activity index and quality of life were also used as outcome measures.

RESULTS

Clinically, all patients improved. At the 10-week follow-up, six of the seven patients had a complete clinical response, and five had complete fistulae closure. At the 10-week follow-up, the median pouchitis disease activity index decreased from 12 (baseline) (range, 10-15) to 5 (range, 3-8); the median quality of life decreased from 37 points (range, 33-40) to 14 (range, 9-18). Erythema nodosum and arthralgia showed complete remission soon after the first infusion of infliximab.

CONCLUSIONS

These preliminary results indicate that infliximab may be recommended for the treatment of refractory pouchitis complicated by fistulae following ileal pouch-anal anastomosis for ulcerative colitis.

Mediators of Inflammation in Children with Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) in children remains a challenging problem. Crohn disease and ulcerative colitis are characterized by an activation of intestinal mononuclear cells and T-cells within the inflammed lesions. In the present study, we determined whether circulating inflammatory mediators, such as interleukins and adhesion molecules, may represent useful markers of immune activation in vivo. Serum concentrations of IL-2, IL-6, IL-8, IL-10, sIL-2R, sICAM-1 and sVCAM-1 were measured by a quantitative enzyme-linked immunosorbent assay (ELISA) in 18 patients with IBD and 25 healthy subjects matched for age and sex (control group). According to our results, all the inflammatory mediators are significantly increased in patients with IBD as compared to the control group. Pro-inflammatory mediators (IL-6, IL-8, IL-10) are elevated in the serum of patients with active disease, suggesting that they act as naturally occuring initiators of the acute inflammatory process. Increased IL-2 and sIL-2R levels reflect T-cell activation. Increased circulating sICAM-1 and sVCAM-1 levels may reflect increased adhesiveness and signal transmission across cells, probably as a result of shedding of the parent molecule during local cellular immunoresponses in vivo. The measurement of inflammatory mediators may be a useful adjunct to the clinical assessment and to the routine laboratory testing of IBD pediatric patients.

Correlation between circulating soluble ICAM-1 and prednisolone-induced amelioration of ulcerative colitis

BACKGROUND

A soluble form of intercellular adhesion molecule-1 (sICAM-1) shed from endothelial cells is present in the circulation. Whether the circulating molecules represent passive turnover of surface ICAM-1 or may have some active functions in the inflammatory process is unknown. Glucocorticoids (e.g. prednisolone) are cornerstones in the treatment of acute exacerbations of ulcerative colitis (UC), and influence of the leucocyte/endothelial interaction appears to be part of their mode of action. The aim of the present study was therefore to evaluate the ICAM-1-shedding through measurements of sICAM-1 concentrations during prednisolone treatment of UC patients.

METHODS

Prednisolone (40 mg) was prescribed to 15 patients with severe disease activity. At inclusion, and after 2 weeks of treatment, plasma sICAM-1 levels were measured using the ELISA technique.

RESULTS

The concentrations of sICAM-1 were significantly decreased during treatment from median 256.2 (ng/ml) (interquartile range 239.7-321.0 ng/ml) to 220.4 ng/ml (196.0-276.3 ng/ml) (P < 0.01). This reduction correlated with a decrease in disease activity (r(s) = 0.8; P < 0.003).

CONCLUSIONS

sICAM-1 seems to be a poor diagnostic tool, but since plasma sICAM-1 concentrations decreased during the treatment period, it might prove to be applicable as an activity marker in the individual patient.

Role of cell adhesion molecules in leukocyte recruitment in the liver and gut

This article reviews the evidence that adhesion molecules are critical in leukocyte recirculation and pathogenesis of diseases affecting the closely related tissues of the liver and gut, which offer novel opportunities for treatment.

Circulating soluble vascular adhesion protein 1 in patients with inflammatory bowel disease

OBJECTIVE

A dysregulated local immune defence with a constant influx of leucocytes provides a basis for continuous intestinal inflammation in ulcerative colitis and Crohn's disease. Since vascular adhesion protein 1 (VAP-1) is one of the adhesion molecules that mediates lymphocyte binding to endothelium, we investigated the levels of soluble VAP-1 (sVAP-1) in the sera of inflammatory bowel disease (IBD) patients compared with healthy controls.

METHODS

sVAP-1 serum levels were measured in 161 IBD patients (90 ulcerative colitis, 71 Crohn's disease) and 93 controls using a commercially available enzyme-linked immunosorbent assay (ELISA). sVAP-1 levels were correlated with disease activity and localization. In 42 patients, sVAP-1 levels were measured in both the active and inactive phases of the disease.

RESULTS

sVAP-1 serum levels were detected in all control and IBD subjects. Mean sVAP-1 levels were 365.5 +/- 153.5 ng/ml in ulcerative colitis patients, 336.4 +/- 172.8 ng/ml in Crohn's disease patients, and 344.7 +/- 150.4 ng/ml in healthy controls. The differences between the groups were not significant. No association between disease activity or disease localization and sVAP-1 was found.

CONCLUSIONS

sVAP-1 serum concentrations are not significantly different in IBD and healthy control subjects. sVAP-1 serum levels are of no value in the assessment of disease activity or severity of inflammation in patients with IBD.

Antibody blockade of ICAM-1 and VCAM-1 ameliorates inflammation in the SAMP-1/Yit adoptive transfer model of Crohn's disease in mice

BACKGROUND & AIMS

Integrins (alpha(4) and beta(2)) and their endothelial ligands vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) play key roles in leukocyte recruitment to areas of inflammation. ICAM-1 and VCAM-1 are expressed in inflamed intestinal tissues. This study investigates a possible causative role of adhesion molecules ICAM-1, VCAM-1, and alpha(4) integrins in mediating the inflammatory response in a murine model of Crohn's disease (CD).

METHODS

CD4+ mesenteric lymph node cells from SAMP-1/Yit donor mice were adoptively transferred into major histocompatibility complex-matched severe combined immunodeficiency disease mice. Six weeks later, these mice were left untreated or treated for 3 days with monoclonal antibodies (mAbs) to ICAM-1, VCAM-1, or both, and alpha(4), or both ICAM-1 and alpha(4), dexamethasone, or nonblocking isotype control antibodies. On day 4 after treatment, tissues were investigated for expression of ICAM-1, VCAM-1, and for severity of inflammation using a semiquantitative inflammatory score. Dexamethasone treatment resolved all measures of intestinal inflammation.

RESULTS

Blocking either ICAM-1, VCAM-1, or alpha(4) integrins had no significant beneficial effect. However, blocking ICAM-1 and alpha(4), or blocking ICAM-1 and VCAM-1, showed a 70% resolution of the active inflammation, but not chronic inflammation.

CONCLUSIONS

These findings suggest that blocking ICAM-1 and VCAM-1 may have therapeutic benefit for the acute inflammatory component of Crohn's disease.

Quantification of mucosal leucocyte endothelial cell interaction by in vivo fluorescence microscopy in experimental colitis in mice

Leucocyte recruitment to sites of intestinal inflammation is a crucial, multi-step process that leads ultimately to the accumulation of cells in the inflamed tissue. We established a new in vivo model system of experimental colitis to quantify leucocyte-endothelial cell interaction and leucocyte extravasation in the inflamed mucosa of the colon. Furthermore, we investigated the pathophysiological role of ICAM-1 in the intestinal microcirculation in vivo. Using the model of dextran sodium sulphate (DSS)-induced acute and chronic colitis in mice, in vivo microscopy was performed in the colonic submucosal postcapillary venules and the submucosal collecting venules in normal or inflamed murine colonic segments. ICAM-1 expression was blocked by an anti-ICAM-1 monoclonal antibody or by suppressing NF-kappaB activation by gliotoxin. Significant increases in leucocyte adhesiveness (51-fold in postcapillary venules, 30-fold in collecting venules, P < 0.01) and extravasation (6.5-fold) could be demonstrated as early as day 2 of DSS-application in acute colitis (P < 0.01). This was paralleled by increases in both the histological damage scores and myeloperoxidase activities. In chronic dextran sodium sulphate-induced colitis significant increases in leucocyte-endothelium interactions and leucocyte extravasation were observed. Blocking ICAM-1 expression with a monoclonal antibody or gliotoxin, leucocyte sticking and extravasation were significantly down-regulated in vivo compared to controls (> 70%; P < 0.01). This new model system offers the possibility to specifically assess the role of adhesion molecules in the colonic mucosa in vivo as well as to investigate and quantify the effectiveness of experimental therapeutic approaches in acute or chronic intestinal inflammation.

Soluble adhesion molecules in inflammatory bowel disease

BACKGROUND

Soluble adhesion molecules are elevated in a number of inflammatory conditions.

AIMS

To investigate the correlation of soluble intercellular adhesion molecule-1 (sICAM-1) and sE-selectin with the activity of inflammatory bowel disease (IBD).

METHODS

sICAM-1 and sE-selectin were measured by an enzyme-linked immunosorbent assay (ELISA) in 53 patients with ulcerative colitis (UC) and 38 patients with Crohn's disease (CD).

RESULTS

Patients with active UC and CD had significantly higher sICAM-1 than patients with inactive disease and controls. Patients with pancolitis had significantly higher levels than patients with distal colitis. There was a significant difference in sE-selectin levels between patients with active CD and control sICAM-1. sE-selectin did not correlate with the Harvey Bradshaw index (HBI). C-reactive protein (CRP) and microalbuminuria were better markers than sICAM-1 or sE-selectin which correlated with serum tumour necrosis factor (TNF)-alpha.

CONCLUSION

sICAM-1 and sE-selectin are elevated in the serum of patients with IBD but CRP and microalbuminuria reflect clinical disease activity more accurately. This study does not support the routine use of soluble adhesion molecules as disease activity markers in IBD.

Differential role of selectins in experimental colitis

BACKGROUND AND AIMS

The role of selectins in experimental colitis remains unknown. The aims of this study were to characterize the time-course expression of selectins in trinitrobenzene sulfonic acid (TNBS)-induced colitis, the functional role of selectins in colonic leukocyte-endothelial cell interactions, and the therapeutic usefulness of selectin blockade in this model.

METHODS

Control and TNBS-induced colitic rats were studied. Expression of P- and E-selectin was assessed by the radiolabeled antibody technique, and L-selectin by flow cytometry. Leukocyte-endothelial cell interactions were studied in colonic venules by using intravital microscopy under basal conditions and after P-, E-, or L-selectin immunoblockade. Additional groups of animals were treated with anti-P-selectin antibody, a nonbinding antibody, or dexamethasone, for 7 days.

RESULTS

P-selectin and E-selectin expression were markedly up-regulated in colitic rats. Increased leukocyte rolling was abrogated by anti-P-selectin, but only attenuated by anti-E- or anti-L-selectin antibodies. Only pretreatment with anti-P- selectin decreased leukocyte adhesion. Animals chronically treated with dexamethasone, but not with anti- P-selectin, had significantly lower macroscopic and histologic damage scores, colon weight, and myeloperoxidase (MPO) activity than those treated with nonbinding antibody.

CONCLUSIONS

P-selectin plays a key role on leukocyte rolling and its blockade attenuates leukocyte adhesion in TNBS-induced colitis. However, treatment with an anti-P-selectin antibody does not significantly improve colitis.

New immunologic treatments for inflammatory bowel disease

After many years with little progress in new treatments for patients with inflammatory bowel disease, there is now rapid expansion of a new class of immunologic agents. These agents are designed to disrupt proinflammatory pathways at specific sites. Monoclonal antibodies to tumor necrosis factor-alpha (TNF-alpha) are already transforming the lives of some patients with previously intractable Crohn disease, and further TNF-alpha directed therapies are being developed. Clinical trials are now underway on agents that inhibit adhesion molecules and antiinflammatory cytokines, while attempts are being made to actively immunize against TNF-alpha. Promising data continue to be reported, although long-term safety data are still mostly unavailable. Although these agents are proving to be very effective in the treatment of patients with Crohn disease, their use should continue to be restricted while indications and dose regimens are defined.

Established and emerging biological activity markers of inflammatory bowel disease

Assessment of disease activity in inflammatory bowel disease (IBD), i.e., ulcerative colitis (UC) and Crohn's disease (CD), is done using clinical parameters and various biological disease markers. Ideally, a disease marker must: be able to identify individuals at risk of a given disorder, be disease specific, mirror the disease activity and, finally, be easily applicable for routine clinical purposes. However, no such disease markers have yet been identified for IBD. In this article, classical disease markers including erythrocyte sedimentation rate, acute phase proteins (especially orosomucoid and CRP), leukocyte and platelet counts, albumin, neopterin, and beta2-microglobulin will be reviewed together with emerging disease markers such as antibodies of the ANCA/ASCA type, cytokines (e.g., IL-1, IL-2Ralpha, IL-6, IL-8, TNF-alpha, and TNF-alpha receptors) and with various adhesion molecules. It is concluded that none of the pertinent laboratory surrogate markers of disease activity in IBD are specific or sensitive enough to replace basic clinical observation such as the number of daily bowel movements, general well-being, and other parameters in parallel. Further studies are highly warranted to identify and assess the clinical importance and applicability of new laboratory markers for the diagnosis or the disease activity of IBD.

Low molecular weight heparin as adjuvant therapy in active ulcerative colitis

BACKGROUND

Heparin given intravenously has shown beneficial effects in the treatment of refractory ulcerative colitis in open trials. Low molecular weight heparin (LMWH) offers advantages in the method of administration but have not been evaluated in inflammatory bowel disease conditions.

AIM

To assess the tolerability and safety of subcutaneous self-administered LMWH in outpatients with refractory ulcerative colitis and to evaluate any potential adjuvant therapeutic effect.

PATIENTS AND METHODS

Twelve patients with mild to moderately active ulcerative colitis were included in the trial. The patients had either responded poorly to treatment with conventional therapy, including oral and/or rectal glucocorticosteroids, or had experienced a rapid relapse during or shortly after GCS therapy. Dalteparin sodium 5000 units s.c. injection was administered twice daily for 12 weeks. Patients were monitored for possible adverse events and changes in clinical symptoms, and endoscopic and histological scores were analysed. Leucocyte scanning was performed at inclusion and at the end of the study.

RESULTS

Tolerability and compliance were excellent and no serious adverse events occurred. Eleven patients improved symptomatically and six (50%) attained complete remission after 12 weeks of treatment. Endoscopic, scintigraphic and histological scores were found to be significantly improved.

CONCLUSION

Self-administered LMWH given s.c. may be a safe adjuvant therapy for patients with active, glucocorticosteroids-refractory ulcerative colitis. A controlled trial should be undertaken to confirm the positive effects found in this study.

In situ expression of E-selectin and intercellular adhesion molecule-1 in chronic inflammatory diseases of the gastrointestinal tract

AIM

The study of cell adhesion molecules contributes to our understanding of the inflammatory mechanisms which include the endothelial activation of newly formed or pre-existing vessels, the increase of inflammatory cells' adhesive capability and their migration into perivascular tissues. The aim of the present study was to investigate the local presence and the extent of expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1) in the mucosa of patients with chronic gastritis, chronic inflammatory bowel disease, and controls, as well as to identify possible correlations between in situ expression of the above adhesion molecules and degree of inflammatory activity or therapeutic response.

DESIGN

In cryostat tissue sections we examined the immunohistochemical expression and localization of E-selectin and the intercellular adhesion molecule-1 (ICAM-1). Our specimens consisted of 27 cases of chronic gastritis, 42 cases of ulcerative colitis, and 15 cases of Crohn's disease.

RESULTS

E-selectin was expressed in capillary endothelia as well as on neutrophils, located either in the lamina propria or in the glandular epithelia or lumina. This marker's expression was associated with the active phase of ulcerative colitis (p<0.0005) and possibly of chronic gastritis (p=0.06). ICAM-1 immunolabelling was localized in endothelia and chronic inflammatory components which had passed through the vascular walls. This marker's immunoreactivity was generally increased in all our specimens compared to normal mucosa and generally tended to correlate with chronic phases of the inflammatory process (p<0.10).

CONCLUSIONS

E-selectin regulates the accumulation of neutrophils in the early stages of the inflammatory process and is thus associated at least with the active phase of ulcerative colitis. Whether any post-therapy alteration of E-selectin immunopositivity seems to indicate a good response to drug therapy is well worth investigating in ulcerative colitis patients. ICAM-1 immunoreactivity in lymphoplasmacytic infiltrates might serve as a marker of chronic immune stimulation, which is potentially responsible for the persistence of the inflammatory disorders.

Novel therapies for inflammatory bowel disease

Looking back at successes and failures in newer approaches to treating IBD, it is tempting--although still difficult--to draw conclusions about pathogenesis. When a therapy proves effective, do clinicians truly know how it works? Even with a therapy as specific as anti-TNF antibody, it is not clear if the benefit is attributable to simple binding and clearance of TNF-alpha or to binding on the cell surface and subsequent deletion of the activated macrophage. When a drug appears to be less effective than preclinical models suggest, can failures in effectiveness from delivery or dosing be differentiated? The disappointing results of clinical trials with IL-10--so at odds with the prediction of benefit from animal models--bring into question the validity of those models as well as the soundness of design of the clinical trials on which efficacy of IL-10 is judged. The variability of response even to the most narrowly targeted agents suggests that these diseases are far more heterogeneous in humans than in their murine counterparts. Clinicians are only just beginning to recognize subclinical markers of response, and it may soon be possible to predict response on the basis of genetic composition. For the moment, however, the field of pharmacogenetics is embryonic. Challenges in developing new therapeutic strategies include not only identifying novel agents, but also improving the definitions of clinical endpoints and defining efficacy at the biologic level. Only through considered evaluation of clinical evidence may clinicians determine which therapies should remain novelties and which should become an accepted part of the armamentarium.

Serum levels of soluble intercellular adhesion molecule-1 (ICAM-1, CD54) in patients with non-small-cell lung cancer: correlation with histological expression of ICAM-1 and tumour stage

The expression of the intercellular adhesion molecule-1 (ICAM-1, CD54) seems to have an influence on the metastatic behaviour of tumour cells via immunological mechanisms. Recently, a soluble form of ICAM-1 was identified in physiological fluids. We analysed the serum levels of sICAM-1 in patients with non-small-cell lung cancer (NSCLC) and healthy individuals using a sandwich ELISA technique. Sera from 51 patients with NSCLC were tested for sICAM-1 (46 male, five female; age 38-81 years, median 64 years), 29 of whom presented with localized and 26 with metastatic disease. The control group consisted of 40 healthy individuals (20 smokers, 20 non-smokers). Immunohistochemical analysis of ICAM-1 in tumour cells was performed in 20 cases. Patients with NSCLC had significantly higher serum levels of sICAM-1 compared with healthy non-smokers (P = 0.00001) and smokers (P= 0.0328). Metastatic disease was associated with higher sICAM-1 than localized tumours (P = 0.0013). Only 11 out of 23 patients with localized NSCLC had sICAM-1 levels >300 ng ml(-1), compared with 25 out of 28 patients with metastatic disease. Histological expression of ICAM-1 was positively correlated with serum slCAM-1 (P = 0.0399). No difference was observed between histological tumour types with regard to sICAM-1 or NSCLC expression of ICAM-1. In sequential analysis (13 patients), rising sICAM-1 levels predicted a short-term fatal outcome (P = 0.0054) but, overall, sICAM-1 levels did not correlate with prognosis. In the control group, smokers showed significantly higher levels than non-smokers (P = 0.0016). In contrast to patients with NSCLC, sICAM-1 in the control group was correlated to the leucocyte count (r = 0.580, P = 0.003). In conclusion, serum levels of sICAM-1 seem to be associated with tumour burden and histological expression of ICAM-1 in patients with NSCLC. However, the (patho-) physiological role of ICAM-1 in NSCLC remains to be determined.