Optimizing anti-TNF treatment in inflammatory bowel disease

Suspected anastomotic recurrence of Crohn disease after ileocolic resection: evaluation with CT enteroclysis

PURPOSE

To determine the utility of computed tomographic (CT) enteroclysis for characterization of the status of the anastomotic site in patients with Crohn disease who had previously undergone ileocolic resection.

MATERIALS AND METHODS

Written informed consent was prospectively obtained from all patients, and the institutional review board approved the study protocol. CT enteroclysis findings in 40 patients with Crohn disease who had previously undergone ileocolic resection were evaluated independently by two readers. Endoscopic findings, histopathologic findings, and/or the Crohn disease activity index was the reference standard. Interobserver agreement between the two readers was calculated with kappa statistics. Associations between CT enteroclysis findings and anastomotic site status were assessed at univariate analysis. The sensitivity, specificity, and accuracy of CT enteroclysis, with corresponding 95% confidence intervals (CIs), for the diagnosis of normal versus abnormal anastomosis and the diagnosis of anastomotic recurrence versus fibrostenosis were estimated.

RESULTS

Interobserver agreement regarding CT enteroclysis criteria was good to perfect (kappa = 0.72-1.00). At univariate analysis, stratification and anastomotic wall thickening were the two most discriminating variables in the differentiation between normal and abnormal anastomoses (P < .001). Stratification (P < .001) and the comb sign (P = .026) were the two most discriminating variables in the differentiation between anastomotic recurrence and fibrostenosis. In the diagnosis of anastomotic recurrence, severe anastomotic stenosis was the most sensitive finding (95% [20 of 21 patients]; 95% CI: 76.18%, 99.88%), both comb sign and stratification had 95% specificity (18 of 19 patients; 95% CI: 73.97%, 99.87%), and stratification was the most accurate finding (92% [37 of 40 patients]; 95% CI: 79.61%, 98.43%). In the diagnosis of fibrostenosis, both severe anastomotic stenosis and anastomotic wall thickening were 100% sensitive (eight of eight patients; 95% CI: 63.06%, 100.00%), and using an association among five categorical variables, including severe anastomotic stenosis, anastomotic wall thickening with normal or mild mucosal enhancement, absence of comb sign, and absence of fistula, yielded 88% sensitivity (seven of eight patients; 95% CI: 47.35%, 99.68%), 97% specificity (31 of 32 patients; 95% CI: 83.78%, 99.92%), and 95% accuracy (38 of 40 patients; 95% CI: 83.08%, 99.39%).

CONCLUSION

CT enteroclysis yields objective and relatively specific morphologic criteria that help differentiate between recurrent disease and fibrostenosis at the anastomotic site after ileocolic resection for Crohn disease.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.09091165/-/DC1.

Evolving paradigms in the pathogenesis of IBD

The pathogenesis of all immune-mediated inflammatory diseases has been carefully studied over the past several decades, but it is only recently that we have come to appreciate common pathways and genes. This is especially true for the inflammatory bowel diseases (IBD) Crohn's disease and ulcerative colitis, where a keener appreciation of the contributions of genetics, environment, and immune response have been dissected. In fact, in many ways, IBD has become the model for studying such disorders. The complex nature of interactions is continuing to be defined, and novel therapies targeting defects in these interactions have been developed and are being tested in the clinic. The era of bench to bedside has finally matured, and cures for debilitating diseases are now in sight. This review describes our current state of knowledge of each component of IBD pathogenesis. What has evolved is a clearer picture and novel targets for therapy.

Current directions of biologic therapies in inflammatory bowel disease

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory bowel diseases which can be difficult to control with conventional therapies. A greater understanding of their pathophysiology has led to new therapies that target specific molecules of the inflammatory cascade. Three anti-tumor necrosis factor (TNF) monoclonal antibodies have been developed. Infliximab and adalimumab can induce clinical response and sustained remission in CD. Infliximab is also effective in UC. Certolizumab pegol gives good short-term results but long-term efficacy has yet to be determined in other clinical trials. Therapies that target leucocyte trafficking (anti-integrins) have also been developed and are associated with good clinical response in CD. Natalizumab (anti-α4 integrin antibody) is associated with important side effects and is not used anymore in gastroenterology in Europe but is still used in the USA. Vedolizumab (MLN0002), an anti-α4β7 integrin antibody, has a good efficacy and safety profile. Monoclonal antibodies targeting other cytokines are also under development. For example, ustekinumab (CNTO 1275) inhibits interleukins 12 and 23. It is associated with a good clinical response in CD.

[Markers of the course of inflammatory bowel disease treated with immunomodulators or biological agents]

Immunosuppressive or biological treatment in patients with inflammatory bowel disease can modify the natural history of their disease, although these treatments are not universally effective and can have severe adverse effects. Attempts have been made to identify predictive factors of response to the various therapeutic options in order to aid the choice of the most appropriate therapeutic alternative in each patient. The possibility of modifying any one of these predictive factors would be of great interest since it would provide the opportunity to alter the course of the disease. Epidemiological, biological, clinical, endoscopic, radiological, genetic and even proteomic markers have been studied, in addition to others related to the disease itself or to specific treatments. The present article briefly discusses the real use of each of these markers and the evidence supporting their utility.

Optimizing the safety of biologic therapy for IBD

The introduction of biologic therapy for the treatment of IBD has substantially changed its management. The safety concerns associated with biologic therapies include the increased risk of infection, autoimmunity, development of lymphoma and demyelinating disease, and the risk of worsening heart failure. There are several strategies for minimizing the risks associated with biologic therapies. Pretreatment strategies include taking a proper history from the patient, physical examination of the patient, screening for latent tuberculosis and ruling out sepsis. Vaccination of patients against vaccine preventable diseases is also recommended. During treatment, patients should be closely monitored and any symptoms that develop should be dealt with early. Education of physicians and patients is also important to allow the early detection of any adverse events.

Abdominal sonographic changes after antibody to tumor necrosis factor (anti-TNF) alpha therapy in Crohn's Disease

Prospective study carried out on 24 consecutive patients with Crohn's Disease, using sonography to assess changes caused by biological therapy and its relationship with the clinical-biological response. The Crohn's Disease Activity Index, the plasma concentration of C-reactive protein and abdominal sonograms (to assess the thickness and Doppler flow grade of the bowel wall and to detect the presence of any complications) were carried out one week prior to the induction treatment and two weeks after. The biological therapy induced remission or a partial response in 46% and 25% of the patients, respectively. It also caused a significant reduction in the thickness of the bowel wall (P = 0.005) and Doppler flow (P = 0.02), leading to the disappearance of complications in 50% of the patients. Sonographic changes were significantly more marked in patients who achieved some type of clinical-biological response, in such a way that sonograms were improved in 65% (P = 0.001) and complications disappeared in 100% of patients (P = 0.005) compared to those patients who did not respond to treatment. However, sonographic normality was only achieved in five out of 17 (29%) reactive patients (P = 0.27). This fact may support the use of sonography as a technique for optimizing the biological treatment of Crohn's Disease.

[Diagnosis and treatment guidelines for Helicobacter pylori infection in Korea]

Eleven years has passed since the guideline of the Korean College of Helicobacter and Upper Gastrointestinal Research group for H. pylori infection was produced in 1998. During this period the research for H. pylori has much progressed that H. pylori is now regarded as the major cause of gastric cancer. The seroprevalence of H. pylori in Korea was found to be decreased especially below the age of 40s and in the area of Seoul-Gyeonggi province, and annual reinfection rate of H. pylori has decreased up to 2.94%. In the aspect of diagnostic tests of H. pylori the biopsy is recommended in the body instead of antrum in the subjects with atrophic gastritis and/or intestinal metaplasia for the modified Giemsa staining or Warthin Starry silver staining. The urea breath test is the test of choice to confirm eradication when follow-up endoscopy is not necessary. Definite indication for H. pylori eradication is early gastric cancer in addition to the previous indications of peptic ulcer including scar and Marginal zone B cell lymphoma (MALT type). Treatment is also recommended for the relatives of gastric cancer patient, unexplained iron deficiency anemia, and chronic idiopathic thrombocytopenic purpura. One or two week treatment of proton pump inhibitor (PPI) based triple therapy consisting of one PPI and two antibiotics, clarithromycin and amoxicillin, is recommended as the first line treatment regimen. In the case of treatment failure, one or two weeks of quadruple therapy (PPI+metronidazole+tetracycline+bismuth) is recommended. Herein, Korean College of Helicobacter and Upper Gastrointestinal Research proposes a diagnostic and treatment guideline based on currently available evidence.

Infliximab and insulin resistance

Insulin resistance is the most important pathophysiologic feature of obesity, type 2 diabetes mellitus and prediabetic states. TNF-alpha, a proinflammatory cytokine, plays a pivotal role in the pathogenesis of inflammation-associated insulin resistance during the course of rheumatic diseases. Therapies aimed at neutralizing TNF-alpha, such as the monoclonal antibody infliximab, represent a novel approach for the treatment of rheumatic diseases and allow to obtain significant results in terms of control of the inflammatory process. In this article we reviewed the scientific evidence published in the literature about a potential role of TNF-alpha blockade in improving insulin resistance in non-diabetic rheumatic patients.

Orally administered L. lactis secreting an anti-TNF Nanobody demonstrate efficacy in chronic colitis

Inflammatory bowel disease (IBD) is a chronic inflammatory gastrointestinal disorder. Systemic treatment of IBD patients with anti-tumor necrosis factor (TNF)-alpha antibodies has proven to be a highly promising approach, but several drawbacks remain, including side effects related to systemic administration and high cost of treatment. Lactococcus lactis was engineered to secrete monovalent and bivalent murine (m)TNF-neutralizing Nanobodies as therapeutic proteins. These therapeutic proteins are derived from fragments of heavy-chain camelid antibodies and are more stable than conventional antibodies. L. lactis-secreted anti-mTNF Nanobodies neutralized mTNF in vitro. Daily oral administration of Nanobody-secreting L. lactis resulted in local delivery of anti-mTNF Nanobodies at the colon and significantly reduced inflammation in mice with dextran sulfate sodium (DSS)-induced chronic colitis. In addition, this approach was also successful in improving established enterocolitis in interleukin 10 (IL10)(-/-) mice. Finally, L. lactis-secreted anti-mTNF Nanobodies did not interfere with systemic Salmonella infection in colitic IL10(-/-) mice.In conclusion, this report details a new therapeutic approach for treatment of chronic colitis, involving in situ secretion of anti-mTNF Nanobodies by orally administered L. lactis bacteria. Therapeutic application of these engineered bacteria could eventually lead to more effective and safer management of IBD in humans.

Durability of infliximab in Crohn's disease: a single-center experience

BACKGROUND

Infliximab is effective maintenance for moderate to severe Crohn's disease (CD); however, problems with immunogenicity and decreased efficacy often complicate long-term use. Durability of infliximab maintenance therapy over multiple years has not been defined.

METHODS

This was a retrospective, observational study of CD patients who received maintenance infliximab for ≥1 year with the intention of ongoing maintenance. Patients were categorized into those who either discontinued treatment or continued maintenance therapy. We examined the impact of demographic, clinical characteristics, and prior episodic exposure on long-term durability of infliximab therapy and also examined the reasons for discontinuation of therapy.

RESULTS

A total of 153 CD patients received maintenance infliximab treatment beyond 1 year and 42 (27%) ultimately discontinued treatment. The mean duration of maintenance treatment at the time of discontinuation was 42.4 ± 19.1 months compared to a follow-up period of 49.4 ± 19.8 months in the cohort continuing therapy (P = 0.049). The main reasons for discontinuation were allergy/adverse reaction (44.2%) and decreased efficacy (38.2%). Use of concomitant immunosuppression was similar between the 2 groups (78.6% versus 83.8%, P = NS). However, the discontinued group had a higher rate of prior episodic dosing compared to CD patients who continued maintenance (28.8% versus 11.7%, P = 0.025), while there was no difference in the rate of intensified dosing (57.2% versus 50.5%, P = NS).

CONCLUSIONS

One-quarter of CD patients on long-term infliximab maintenance discontinued treatment. A history of prior episodic dosing was significantly associated with infliximab discontinuation, despite concomitant immunosuppression. These data emphasize the need for optimization of infliximab for successful long-term management.

New and emerging therapies for inflammatory bowel diseases

The inflammatory bowel diseases have undergone an explosion of discovery in the last 10 years. The overwhelming focus of this has been in genetics and immune mechanisms of disease. While the former has provided critical information on predisposing factors, the latter has resulted in a panoply of novel immune-based therapies and technologies. These range from an improved approach to the use of conventional immunomodulators, such as azathioprine and 6-mercaptopurine, to commonplace availability of anti-tumor necrosis factor agents such as infliximab and adalimumab, through to small molecule inhibition of immune mediators. Unusual treatments, such as helminth infestation, stem cell transplantation, and leucocytapheresis, all derive from the burgeoning understanding of pathogenesis. Most important to our successful use of these therapies will be a fundamental understanding of the patient phenotypes and genotypes that will dictate particular treatment approaches in the future.

Stevens-Johnson syndrome complicating adalimumab therapy in Crohn’s disease

The anti-tumor necrosis factor (TNF)α medications demonstrate efficacy in the induction of remission and its maintenance in numerous chronic inflammatory conditions. With the increasing number of patients receiving anti-TNFα agents, however, less common adverse reactions will occur. Cutaneous eruptions complicating treatment with an anti-TNFα agent are not uncommon, occurring in around 20% of patients. Adalimumab, a fully humanized antibody against TNFα, may be expected to cause minimal immune-mediated skin reactions compared to the chimeric monoclonal antibody, infliximab. We, however, report a case of Stevens-Johnson syndrome that required hospitalization and cessation of adalimumab in a patient with Crohn’s disease (CD). In this case report, a 29-year-old male with colonic and perianal CD with associated erythema nodosum and large joint arthropathy developed severe mucositis, peripheral rash and desquamation, fevers and respiratory symptoms concomitant with a second dose of 40 mg adalimumab after a 2 mo break from adalimumab therapy. Skin biopsies of the abdominal wall confirmed erythema multiforme and the patient was on no other drugs and infective etiologies were excluded. The patient responded rapidly to IV hydrocortisone and was able to be commenced on infliximab without recurrence of the Stevens-Johnson syndrome. Desquamating skin reactions have now been described in three of the TNFα antagonists (infliximab, etanercept and adalimumab). These reactions can be serious and prescribers need to be aware of the potential mucocutaneous side effects of these agents, especially as Stevens-Johnson syndrome is associated with significant morbidity and mortality.

A review of infliximab use in ulcerative colitis

BACKGROUND

Infliximab is a chimeric immunoglobulin G1kappa monoclonal antibody that binds with high affinity and specificity to the soluble form of tumor necrosis factor (TNF)-alpha, preventing it from binding to cellular receptors. Infliximab also binds to membranebound TNF-alpha found on inflammatory cell surfaces, inducing apoptosis. Currently, infliximab is used for the induction and maintenance of remission in Crohn's disease (CD), with documented success. Infliximab's efficacy in the treatment of ulcerative colitis (UC) is now being investigated due to the similarities in the pathophysiology of CD and UC.

OBJECTIVE

The aim of this study was to review and evaluate the current literature of infliximab use in steroid-refractory UC to assess its role in treatment.

METHODS

A search of MEDLINE was conducted (1950-November 2007). Key terms included, but were not limited to, infliximab, inflammatory bowel disease, ulcerative colitis, cost, and quality of life. Studies included for review were limited to English-language, full-text, randomized, double-blind, placebo-controlled trials. Clinical trials were reviewed and summarized.

RESULTS

Four controlled clinical trials of infliximab in the treatment of steroid-refractory UC were found and assessed. In a double-blind, randomized, controlled trial in 43 patients with moderately severe, glucocorticoid-resistant UC, infliximab and placebo were not significantly different with respect to clinical and sigmoidoscopic remission or quality of life 2 and 6 weeks after infliximab treatment. In a multicenter, randomized, double-blind, placebo-controlled study in 45 patients with moderately severe to severe glucocorticoid-resistant UC, infliximab was associated with a significantly reduced need for colectomy compared with placebo (29% vs 67%; P=0.017). The Active Ulcerative Colitis Trials (ACT) 1 and 2 together included 728 patients with moderate to severe glucocorticoid-resistant UC. The primary outcome, the rate of clinical response at 8 weeks, was significantly higher with infliximab compared with placebo (5 mg/kg: ACT 1, 69.4%, ACT 2, 64.5%; 10 mg/kg: ACT 1, 61.5%, ACT 2, 69.2%; placebo: ACT 1, 37.2%;, ACT 2, 29.3%; all, P < 0.001 vs placebo). Based on the data from ACT 1 and 2, infliximab was associated with improved health-related quality-of-life (HRQOL) scores based on the Inflammatory Bowel Disease Questionnaire and the 36-item Short Form Health Survey.

CONCLUSIONS

Current data suggest that infliximab is an effective alternative treatment option for patients with moderate to severe UC with an inadequate response to conventional glucocorticoid treatment. Further trials are needed to assess infliximab's impact on the treatment and progression of UC, the HRQL of patients with UC, and the economic impact on the health care system.

A pilot study comparing hydrocortisone premedication to concomitant azathioprine treatment in preventing loss of response to infliximab

OBJECTIVES

Antibodies to infliximab may lead to loss of response to infliximab (IFX) in Crohn's disease. Azathioprine (AZA) coadministration prevents the formation, whereas hydrocortisone (HC) premedication reduces the levels of antibodies to IFX. This pilot study aims at assessing the efficacy of these strategies to prevent loss of response to IFX.

METHODS

Eligible patients had active steroid-dependent luminal Crohn's disease and received IFX (5 mg/kg at weeks 0, 2, and 6 for induction and then scheduled q8 week for remission maintenance). Patients were stratified in a 1 : 1 ratio to oral AZA (2-2.5 mg/kg/day, stratum A) or HC premedication (250 mg intravenously, stratum B). Stratum A included only patients naive to AZA; stratum B included both AZA naive and intolerant patients. Steroids were tapered within 6-8 weeks. Patients were followed up with monthly clinical assessments, laboratory tests, Crohn's Disease Activity Index calculations, adverse-events check up, and adherence to treatment.

RESULTS

Overall, 23 patients received IFX/HC and 23 IFX/AZA. There were no differences at baseline in any patient-related or disease-related parameters. Seventeen (74%) patients on IFX/AZA completed the study; six patients were withdrawn for primary nonresponse (one patient), lost response to IFX (two patients), or AZA-related adverse events. Eighteen (78%) patients on IFX/HC completed the study; five patients were withdrawn for primary nonresponse (one patient), loss of response (two patients), or infusion reactions to IFX. No significant differences emerged between strata in clinical remission rates or lost response to IFX.

CONCLUSION

This prospective 2-year pilot study has not confirmed superiority of any available strategy to maintain the efficacy of IFX.

TNF-α blocking therapy in chronic inflammatory bowel disease

A TNF-α-blokkolók bevezetése drámai változást jelentett a kezelésre refrakter IBD-ben szenvedő betegek ellátásában. Az infliximab és adalimumab is bizonyítottan hatékony a közepesen súlyos-súlyos fokú CD-, valamint az infliximab UC-remisszió indukciójában és fenntartásában, bár refrakter CD esetében a betegek 20–30, UC-ben 30–40%-a ezen terápiás eljárásokra sem reagál. A két hasonló támadáspontú szert összehasonlító vizsgálatra nem került sor, és a tanulmányok direkt összevetése nem megbízható, azonban az általános állásfoglalás alapján lényeges különbség a vegyületek hatékonyságában nincs.

Preferential promotion of apoptosis of monocytes by Lactobacillus casei rhamnosus soluble factors

BACKGROUND & AIMS

Inflammatory bowel disease (IBD) is characterized by dense infiltrates of and defective apoptosis by mucosal cell populations. Some probiotics inhibit monocytes' expansion, although mechanisms remain unknown. Supernatants of Lactobacillus strains were investigated for inducing apoptosis of monocytes.

METHODS

Secreted factors produced by Lactobacillus strains were tested on human lymphocytes, monocytes and a human monocytic leukemia-cell line (THP-1). Cell death mechanisms were investigated by a variety of methods. Lipopolysaccharide (LPS)-induced proinflammatory cytokines (IL-1beta, IL-6, IL-8, TNF-alpha) and anti-inflammatory TGF-beta1 were determined.

RESULTS

Soluble factor(s) from Lactobacillus casei rhamnosus strain supernatants (LcrS) effectively induced apoptosis of immune cells. These were mainly soluble proteins (MW 5-30 kDa; LcrS(5-30)). For immune cells, but not human colonic epithelial carcinoma cells (HT-29), pretreatment with LcrS(5-30) significantly promoted apoptosis via a mitochondrial pathway. LcrS(5-30) suppressed pro-inflammatory cytokines and induced anti-inflammatory TGF-beta1.

CONCLUSIONS

Probiotic Lcr produced heat-stable molecules (MW range 5-30 kDa) that promoted immune cell apoptosis without affecting intestinal epithelial cells. LcrS(5-30) triggered apoptosis by a mitochondrial pathway, but not via TGF-beta signaling pathway. LcrS(5-30) also inhibited LPS-induced inflammatory cytokines by immune cells. Thus, LcrS(5-30) promotes apoptosis of immune cells, and suggests probiotics-based regimens for prevention of IBD.

How to manage difficult Crohn's disease: optimum delivery of anti-TNFs

Crohn's disease is a chronic inflammatory condition that can involve any portion of the GI tract, leading to disabling symptoms and complications. Standard treatment with 5-aminosalicylic acid, antibiotics, corticosteroids and immunosuppressives has limited efficacy and is associated with serious potential adverse events. The anti-TNF-alpha agents are effective in the induction and maintenance of remission in luminal and fistulizing Crohn's disease. Recent evidence suggests that early treatment with anti-TNF agents and immunosuppressives may alter the natural history of the disease and prevent late complications. In those patients who have lost response to, or are intolerant of, a single anti-TNF agent, increasing the dose of the medication or switching to alternate biologic agents, such as another anti-TNF drug or natalizumab, have been shown to be effective treatments.

Incidence and clinical significance of immunogenicity to infliximab in Crohn's disease: a critical systematic review

BACKGROUND

Infliximab (IFX) is a chimeric (mouse/human) anti-TNF-alpha monoclonal antibody approved for the treatment of refractory luminal and fistulizing Crohn's disease (CD). It is a source of potential immunogenicity for humans, with the occurrence of anti-infliximab antibodies (ATIs), which are thought to interfere with the pharmacodynamics and/or pharmacokinetics of the compound. It remains unclear whether ATIs have any clinical importance for drug efficacy or safety. We review studies specifically evaluating the incidence of ATIs in CD and their impact on the efficacy and safety of IFX.

METHODS

A systematic review was undertaken by electronic searches of the PubMed and SCOPUS databases from earliest records to October 2008, as well as reference lists of all relevant articles and relevant abstracts from meetings.

RESULTS

The biological and clinical mechanisms of ATI development are poorly understood. The incidence of ATIs in vivo depends on multiple analytical and clinical factors, both patient- and treatment-related. The presence of ATIs is weakly and variably associated with clinical response or infusion reactions, but not with reactions relevant to clinical decision-making. Enormous variation in the methods of reporting ATIs and immunogenicity of IFX make almost any interpretation possible from different studies, but few have clinical relevance.

CONCLUSIONS

There is no clear evidence that ATIs have an impact on efficacy or safety, nor a need to measure or prevent them in clinical practice. Circulating drug concentration may be a more relevant measure of immunogenicity.

Advances in the pathogenesis and treatment of IBD

Crohn's disease and ulcerative colitis are chronic remitting and relapsing inflammatory bowel diseases. We present a typical case of Crohn's disease in a young woman and discuss potential treatment options. Crohn's disease and ulcerative colitis likely result from interaction of multiple genetic and environmental risk and protective factors. Both are diseases ultimately caused by immune dysregulation. Medical therapy is with mesalamine compounds, corticosteroids, immunomodulators and/or biologics that target TNFalpha signaling or alpha4-integrin-mediated trafficking. Investigational agents include those targeted against other cytokines and costimulatory molecules or designed to promote immune regulation such as exposure to helminths which is a focus of this review.

Efficacy of adalimumab for the management of inflammatory bowel disease in the clinical setting

BACKGROUND

Anti-tumor necrosis factor (TNF)-alpha medications are effective in Crohn's Disease (CD) and efficacious in ulcerative colitis (UC). Adalimumab has been available through the Australian Pharmaceutical Benefits Scheme since August 2008, but clinical experience for inflammatory bowel disease (IBD) in Australia is limited.

AIMS

To determine adalimumab efficacy for IBD in the Australian setting.

METHODS

Crohn's disease or UC/IBD unclassified (UC/IBDU) patients received adalimumab after failure of disease control with conventional therapies or loss of control by infliximab. Response/remission at 8 and 12 weeks were determined by the Crohn's Disease Activity Index (CDAI) and Colitis Activity Index (CAI). All patients received 160 mg (week 0), 80 mg (week 2), followed by 40 mg every-other-week (eow). Patients with a limited response at 8 weeks were considered for weekly adalimumab.

RESULTS

Of 38 CD patients 86.8% (33/38) had active luminal and 23.7% (9/38) fistulising disease at inclusion. Response occurred in 81.8% and 84.4% of luminal CD at 8 and 12 weeks, while 54.5% and 63.6% remitted respectively. 77.8% of fistulising CD responded and 55.6% remitted at 12 weeks. Fifteen CD patients had previously lost response to infliximab, and 86.7% of these responded and 53.3% remitted at 12 weeks. Of the seven UC/IBDU patients 43% and 14% responded, while 29% and 0% remitted at 8 and 12 weeks.

CONCLUSION

In CD, adalimumab is as, if not more, effective in the clinical setting than in the trials, and is effective in patients with an attenuated response to infliximab. Its efficacy is not as good in UC, but this requires further clarification.

All-trans retinoic acid down-regulates inflammatory responses by shifting the Treg/Th17 profile in human ulcerative and murine colitis

IBD is characterized by uncontrolled immune responses in inflamed mucosa, with dominance of IL-17-producing cells and deficiency of Treg cells. The aim of this study was to explore the effect and mechanisms of RA, the ligand of RARalpha, on immune responses in human and murine colitis. Colonic biopsies from patients with UC were cultured and treated with RA as the agonist of RARalpha or LE135 as the antagonist of RARalpha. Expressions of IL-17 and FOXP3 were detected by immunohistochemistry. Murine colitis was induced by intrarectal administration with TNBS at Day 1. Mice were then i.p.-treated with RA or LE135 daily for 7 days. Cytokine levels in the cultures of mouse LPMCs were measured. Expressions of FOXP3 and IL-17 in colon tissues or MLN were detected by immunohistological analysis. Body weight and colon inflammation were evaluated. RA treatment up-regulated FOXP3 expression and down-regulated IL-17 expression in colon biopsies of patients and in colon tissues and MLN of mice with colitis compared with controls. LPMCs from RA-treated mice produced lower levels of proinflammatory cytokines (TNF-alpha, IL-1beta, IL-17) but more regulatory cytokines (IL-10, TGF-beta) compared with that of untreated mice. LE135 showed the opposite effect of RA. Furthermore, RA ameliorated TNBS-induced colitis in a dose-dependent manner, as seen by improved body weight and colon inflammation. RA down-regulates colon inflammatory responses in patients with IBD in vitro and in murine colitis in vivo, representing a potential therapeutic approach in IBD treatment.

Positive role of CCAAT/enhancer-binding protein homologous protein, a transcription factor involved in the endoplasmic reticulum stress response in the development of colitis

Although recent reports suggest that the endoplasmic reticulum (ER) stress response is induced in association with the development of inflammatory bowel disease, its role in the pathogenesis of inflammatory bowel disease remains unclear. The CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP) is a transcription factor that is involved in the ER stress response, especially ER stress-induced apoptosis. In this study, we found that experimental colitis was ameliorated in CHOP-null mice, suggesting that CHOP exacerbates the development of colitis. The mRNA expression of Mac-1 (CD11b, a positive regulator of macrophage infiltration), Ero-1alpha, and Caspase-11 (a positive regulator of interleukin-1beta production) in the intestine was induced with the development of colitis, and this induction was suppressed in CHOP-null mice. ERO-1alpha is involved in the production of reactive oxygen species (ROS); an increase in ROS production, which is associated with the development of colitis in the intestine, was suppressed in CHOP-null mice. A greater number of apoptotic cells in the intestinal mucosa of wild-type mice were observed to accompany the development of colitis compared with CHOP-null mice, suggesting that up-regulation of CHOP expression exacerbates the development of colitis. Furthermore, this CHOP activity appears to involve various stimulatory mechanisms, such as macrophage infiltration via the induction of Mac-1, ROS production via the induction of ERO-1alpha, interleukin-1beta production via the induction of Caspase-11, and intestinal mucosal cell apoptosis.

Loss of response and requirement of infliximab dose intensification in Crohn's disease: a review

OBJECTIVES

To review the frequency with which infliximabloses its effect and dose "intensification" is required for Crohn's disease treatment.

METHODS

Bibliographical searches were performed in MEDLINE, and European (ECCO) and American (DDW) Congresses. Studies evaluating loss of efficacy and requirement of infliximab dose intensification-defined either as an increase of the infliximab dose (generally from 5 mg/kg to 10 mg/kg) or as a decrease in the frequency of infusion (to as often as every 4 weeks)-in Crohn's disease patients were included.

RESULTS

Sixteen studies evaluating the incidence of loss of response to infliximab in Crohn's disease patients were found. A total of 2,236 patients were included (the majority of them receiving a three-dose induction regimen at weeks 0, 2, and 6, followed by maintenance therapy every 8 weeks), providing 6,284 patient-years of follow-up. The mean percentage of patients with loss of infliximab response was 37%. However, as the follow-up time varied markedly among studies, the risk of losing response to infliximab is better expressed as the incidence of this complication per patient-year of follow-up. Therefore, the annual risk for loss of infliximab response was calculated to be 13% per patient-year.

CONCLUSIONS

A variable but relevant proportion of Crohn's disease patients on long-term infliximab treatment lose response. This may be interpreted in two different but compatible ways: a positive view, highlighting that infliximab therapy is relatively durable, with the majority of patients predicted to continue infliximab treatment at least during the first year; or a negative view, interpreting that a significant proportion of Crohn's disease patients-more than 10% per patient-year of infliximab treatment-on long term will lose response and will require an increase in dose and/or decrease in infusion interval.

Modulation of inflammatory response via alpha2-adrenoceptor blockade in acute murine colitis

Inflammatory bowel disease (IBD) is characterized by heavy production of proinflammatory cytokines such as tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta. Interactions of the autonomic nervous system with local immune cells play an important role in the development of IBD, and the balance of autonomic nerve function is broken in IBD patients with sympathetic overactivity. However, the function of catecholamines in the progress of colitis is unclear. In this study, we examined the role of catecholamines via alpha2-adrenoreceptor in acute murine colitis. The expression of tyrosine hydroxylase (TH) and dopamine b-hydroxylase (DBH), two rate-limiting enzymes in catecholamine synthesis, was detected by immunohistochemistry in murine colitis. Murine colitis was induced by dextran sodium sulphate or trinitrobenzene sulphonic acid (TNBS), and the mice were administered RX821002 or UK14304, alpha2-adrenoceptor antagonists or agonists. Colitis was evaluated by clinical symptoms, myeloperoxidase assay, TNF-alpha and IL-1beta production and histology. Lamina propria mononuclear cells (LPMCs) from mice with TNBS colitis were cultured in the absence or presence of RX821002 or UK14304, and stimulated further by lipopolysaccharide. TH and DBH are induced in LPMCs of inflamed colon, the evidence of catecholamine synthesis during the process of colitis. RX821002 down-regulates the production of proinflammatory cytokines from LPMCs, while UK14304 leads to exacerbation of colitis. Together, our data show a critical role of catecholamines via alpha2-adrenoreceptors in the progress of acute colitis, and suggest that use of the alpha2-adrenoceptor antagonist represents a novel therapeutic approach for the management of colitis.

Management of Crohn's disease in adults

Guidelines for clinical practice are intended to suggest preferable approaches to particular medical problems as established by interpretation and collation of scientifically valid research, derived from extensive review of published literature. When data that will withstand objective scrutiny are not available, a recommendation may be made based on a consensus of experts. Guidelines are intended to apply to the clinical situation for all physicians without regard to specialty. Guidelines are intended to be flexible, not necessarily indicating the only acceptable approach, and should be distinguished from standards of care that are inflexible and rarely violated. Given the wide range of choices in any health-care problem, the physician should select the course best suited to the individual patient and the clinical situation presented. These guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee. Expert opinion is solicited from the outset for the document. The quality of evidence upon which a specific recommendation is based is as follows: Grade A: Homogeneous evidence from multiple well-designed randomized (therapeutic) or cohort (descriptive) controlled trials, each involving a number of participants to be of sufficient statistical power. Grade B: Evidence from at least one large well-designed clinical trial with or without randomization, from cohort or case-control analytic studies, or well-designed meta-analysis. Grade C: Evidence based on clinical experience, descriptive studies, or reports of expert committees. The Committee reviews guidelines in depth, with participation from experienced clinicians and others in related fields. The final recommendations are based on the data available at the time of the production of the document and may be updated with pertinent scientific developments at a later time.

A new agent for tumour necrosis factor-alpha inhibition: In vitro effects of dipyridamole in Crohn's disease

BACKGROUND

Tumour necrosis factor-alpha (TNF-alpha) plays a central role in inflammatory cascade in Crohn's disease (CD). Our study aims to investigate the in vitro effects of dipyridamole (DP) on the TNF-alpha and interleukin-10 (IL-10) production in the intestinal mononuclear cells of CD patients.

MATERIAL AND METHODS

Thirteen patients with CD and in 17 healthy individuals underwent colonoscopy and biopsy samples were taken. Cultured mononuclear cells were preincubated with DP1 (0.7 microg/ml), DP2 (1.25 microg/ml), methotrexate (MTX)1 (0.5 nmol/L) and MTX2 (1.5 nmol/L). These cells were then stimulated with lipopolysaccaride (LPS) and phytohemagglutinin (PHA). The levels of TNF-alpha and IL-10 in supernatants were measured with standard immunoassay monoclonal antibody method.

RESULTS

An appropriate cell culture could be obtained in 10 patients with CD and 12 healthy individuals. In LPS stimulated cells, MTX1 and MTX2 were superior to DP1 and DP2 in suppressing TNF-alpha in both groups. In PHA stimulated cells, while MTX1 was superior to DP1, MTX2 and DP2 had an equivalent effect in CD patients (p<0.05, p>0.05, respectively). In LPS-stimulated cells DP2 was significantly superior to MTX2 in increasing IL-10 levels in both groups (p<0.05). In PHA stimulated cells, DP1 and DP2 caused a higher increase in IL-10 levels compared with MTX1 and MTX2 in CD group (p<0.05).

CONCLUSIONS

Dipyridamole suppresses TNF-alpha similar with MTX. It seems to be superior to MTX in increasing IL-10 levels. Addition of DP to anti-TNF medications may create a synergy in cytokine modulation.

Tumor necrosis factor alpha activates transcription of the NADPH oxidase organizer 1 (NOXO1) gene and upregulates superoxide production in colon epithelial cells

NADPH oxidase 1 (Nox1) is a multicomponent enzyme consisting of p22(phox), Nox organizer 1 (NOXO1), Nox1 activator 1, and Rac1. Interleukin-1beta, flagellin, interferon-gamma, and tumor necrosis factor alpha (TNF-alpha) similarly induced Nox1 in a colon cancer cell line (T84), whereas only TNF-alpha fully induced NOXO1 and upregulated superoxide-producing activity by ninefold. This upregulation was canceled by knockdown of NOXO1 with small interfering RNAs. TNF-alpha rapidly phosphorylated p38 mitogen-activated protein kinase and c-Jun N-terminal kinase 1/2, followed by phosphorylation of c-Jun and c-Fos and appearance of an AP-1 binding activity within 30 min. We cloned the 5' flank of the human NOXO1 gene (-3888 to +263 bp), and found that the region between -585 and -452 bp, which contains consensus elements of YY-1, AP-1, and Ets, and the GC-rich region encoding three putative binding sites for SP-1, was crucial for TNF-alpha-dependent promoter activity. Serial mutation analysis of the elements identified an AP-1 binding site (from -561 to -551 bp, agtAAGtcatg) as a crucial element for TNF-alpha-stimulated transcription of the human NOXO1 gene, which was also confirmed by the AP-1 decoy experiments. Thus, TNF-alpha acts as a potent activator of Nox1-based oxidase in colon epithelial cells, suggesting a potential role of this oxidase in inflammation of the colon.

Anti-inflammatory effect of buckwheat sprouts in lipopolysaccharide-activated human colon cancer cells and mice

In conducting an in vitro screening of ethanol extracts from various natural foods using a human colon cancer cell line (CoLoTC cells), an extract of buckwheat sprouts (ExtBS) was found to express significant anti-inflammatory activity. The anti-inflammatory activity of ExtBS was confirmed by oral administration of lipopolysaccharide (LPS) to mice. Inflammatory cytokines (interleukin 6 and tumor necrosis factor alpha) were markedly up-regulated in the spleen and liver from LPS-administrated mice, and combinatory treatment with LPS and ExtBS decreased up-regulation of them in both cytokines. Both serum cytokine levels corresponded to their gene expressions in tissues, but no anti-inflammatry effect in mice was observed when ExtBS was treated intraperitoneally. ExtBS oral administration also showed protective activity as to hepatic injury induced by galactosamine/LPS treatment. Based on these data, we suggest that ExtBS contains anti-inflammatory compounds.

Structure-function relationship of tumor necrosis factor (TNF) and its receptor interaction based on 3D structural analysis of a fully active TNFR1-selective TNF mutant

Tumor necrosis factor (TNF) is an important cytokine that suppresses carcinogenesis and excludes infectious pathogens to maintain homeostasis. TNF activates its two receptors [TNF receptor (TNFR) 1 and TNFR2], but the contribution of each receptor to various host defense functions and immunologic surveillance is not yet clear. Here, we used phage display techniques to generate receptor-selective TNF mutants that activate only one TNFR. These TNF mutants will be useful in the functional analysis of TNFR. Six amino acids in the receptor binding interface (near TNF residues 30, 80, and 140) were randomly mutated by polymerase chain reaction. Two phage libraries comprising over 5 million TNF mutants were constructed. By selecting the mutants without affinity for TNFR1 or TNFR2, we successfully isolated 4 TNFR2-selective candidates and 16 TNFR1-selective candidates, respectively. The TNFR1-selective candidates were highly mutated near residue 30, whereas TNFR2-selective candidates were highly mutated near residue 140, although both had conserved sequences near residues 140 and 30, respectively. This finding suggested that the phage display technique was suitable for identifying important regions for the TNF interaction with TNFR1 and TNFR2. Purified clone R1-6, a TNFR1-selective candidate, remained fully bioactive and had full affinity for TNFR1 without activating TNFR2, indicating the usefulness of the R1-6 TNF mutant in analyzing TNFR1 receptor function. To further elucidate the receptor selectivity of R1-6, we examined the structure of R1-6 by X-ray crystallography. The results suggested that R31A and R32G mutations strongly influenced electrostatic interaction with TNFR2, and that L29K mutation contributed to the binding of R1-6 to TNFR1. This phage display technique can be used to efficiently construct functional mutants for analysis of the TNF structure-function relationship, which might facilitate in silico drug design based on receptor selectivity.

Involvement of IL-17A in the pathogenesis of DSS-induced colitis in mice

To investigate the etiological implication of IL-17A in inflammatory bowel disease (IBD), dextran sodium sulfate (DSS) was administered to the mice deficient for the IL-17A gene. They showed only faint manifestations of colitis, as revealed by body weight loss, shrinkage in the colon length, serum haptoglobin concentration, and disease activity index. Although the mortality rate of WT mice reached approximately 60%, more than 90% of the IL-17A KO mice survived the DSS treatment. Histological change was also marginal in the IL-17A KO intestine, in which epithelial damage and inflammatory infiltrates were not obvious and the myeloperoxidase activity elevated only slightly. G-CSF and MCP-1 were abundantly produced in WT mouse intestine, whereas the production of these chemokines was drastically hampered in IL-17A-null intestine. The present results show that IL-17A plays a pivotal role in the pathogenesis of DSS-induced colitis, while MCP-1 and G-CSF may be crucially involved in the IL-17A-induced inflammation.

Patterns of infliximab use among Crohn's disease patients in a community setting

BACKGROUND

Information on infliximab use in a community setting is important to understand patterns of medication use and to anticipate and plan for costs associated with the drug. We sought to understand predictors of initiation and discontinuation of infliximab in the community-based setting of Kaiser Permanente, Northern California, which provides integrated care to its members.

METHODS

The cohort study was set during 1998-2006. Predictors of initiation were assessed among 494 Crohn's disease (CD) patients who initiated infliximab and 2470 CD patients who did not initiate infliximab (controls). Data were obtained through linkage of computerized clinical information and were analyzed using logistic regression and Cox survival analysis.

RESULTS

Infliximab infusions have increased rapidly since 2001, with no evidence of leveling off. Initiators were appreciably younger than controls (P < 0.001), but were similar to controls with respect to sex and race/ethnicity. The presence of at least 1 comorbidity was related to a modest increase in the risk of initiating (compared with none: 1 comorbidity, odds ratio [OR] = 1.52 with 95% confidence interval [CI] 1.16-2.00; 2 comorbidities, OR = 1.38 with CI 0.89-2.13). By 3 years after initiating, only 20% of patients remained on infliximab.

CONCLUSIONS

In a community-based setting infliximab use has steadily increased. Age and comorbidity are associated with initiation, but sex and race/ethnicity are not. More information is needed to determine why, in this community-based setting, a large number of patients on infliximab discontinued their treatment.(Inflamm Bowel Dis 2008).

Laparoscopic ileocolic resection versus infliximab treatment of distal ileitis in Crohn's disease: a randomized multicenter trial (LIR!C-trial)

Background

With the availability of infliximab, nowadays recurrent Crohn's disease, defined as disease refractory to immunomodulatory agents that has been treated with steroids, is generally treated with infliximab. Infliximab is an effective but expensive treatment and once started it is unclear when therapy can be discontinued. Surgical resection has been the golden standard in recurrent Crohn's disease. Laparoscopic ileocolic resection proved to be safe and is characterized by a quick symptom reduction.

The objective of this study is to compare infliximab treatment with laparoscopic ileocolic resection in patients with recurrent Crohn's disease of the distal ileum with respect to quality of life and costs.

Methods/design

The study is designed as a multicenter randomized clinical trial including patients with Crohn's disease located in the terminal ileum that require infliximab treatment following recent consensus statements on inflammatory bowel disease treatment: moderate to severe disease activity in patients that fail to respond to steroid therapy or immunomodulatory therapy. Patients will be randomized to receive either infliximab or undergo a laparoscopic ileocolic resection. Primary outcomes are quality of life and costs. Secondary outcomes are hospital stay, early and late morbidity, sick leave and surgical recurrence. In order to detect an effect size of 0.5 on the Inflammatory Bowel Disease Questionnaire at a 5% two sided significance level with a power of 80%, a sample size of 65 patients per treatment group can be calculated. An economic evaluation will be performed by assessing the marginal direct medical, non-medical and time costs and the costs per Quality Adjusted Life Year (QALY) will be calculated. For both treatment strategies a cost-utility ratio will be calculated. Patients will be included from December 2007.

Discussion

The LIR!C-trial is a randomized multicenter trial that will provide evidence whether infliximab treatment or surgery is the best treatment for recurrent distal ileitis in Crohn's disease.

Trial registration

Nederlands Trial Register NTR1150

Thalidomide effect in endothelial cell of acute radiation proctitis

AIM

To determine whether thalidomide prevents microvascular injury in acute radiation proctitis in white rats.

METHODS

Fourteen female Wistar rats were used: six in the radiation group, six in the thalidomide group, and two in normal controls. The radiation and thalidomide groups were irradiated at the pelvic area using a single 30 Gy exposure. The thalidomide (150 mg/kg) was injected into the peritoneum for 7 d from the day of irradiation. All animals were sacrificed and the rectums were removed on day 8 after irradiation. The microvessels of resected specimens were immunohistochemically stained with thrombomodulin (TM), von Willebrand Factor (vWF), and vascular endothelial growth factor (VEGF).

RESULTS

The microscopic scores did not differ significantly between the radiation and thalidomide groups, but both were higher than in the control group. Expression of TM was significantly lower in the endothelial cells (EC) of the radiation group than in the control and thalidomide groups (P<0.001). The number of capillaries expressing vWF in the EC was higher in the radiation group (15.3+/-6.8) than in the control group (3.7+/-1.7), and the number of capillaries expressing vWF was attenuated by thalidomide (10.8+/-3.5, P<0.001). The intensity of VEGF expression in capillaries was greater in the radiation group than in the control group and was also attenuated by thalidomide (P=0.003).

CONCLUSION

The mechanisms of acute radiation-induced proctitis in the rats are related to endothelial cell injury of microvessel, which may be attenuated with thalidomide.

Minimizing infliximab toxicity in the treatment of inflammatory bowel disease

BACKGROUND

Infliximab is a widely used biological agent for the treatment of inflammatory bowel disease, and has a favorable risk/benefit ratio.

AIM

It is useful to know that patients treated with infliximab are exposed to developing adverse events that could be reduced with a prudent and a rational clinical approach and by optimizing the treatment protocol.

METHODS

PubMed (including Epub) was searched in October 2006 and again in March 2007.

RESULTS

The high immunogenic potential of infliximab determines the antibodies that inhibit the effect of infliximab and the appearance of subsequent acute and delayed infusion reactions. Infliximab has an immunomodulatory effect, thus increasing the risk of serious and latent infections. Screening for tuberculosis, HBV, opportunistic or latent infections, heart failure, and haematological, neurological and hepatological disorders must be performed before infliximab therapy. There is no definitive evidence that infliximab increases the risk of neoplasia. Mortality in infliximab-treated patients does not appear increased compared to the controls.

CONCLUSIONS

Infliximab safety is similar to that of conventional immunomodulators and patients treated had similar rates of mortality, neoplasm and lymphoma as patients not treated with infliximab. Patients treated with infliximab have an increased risk of serious infections but it is not related to infliximab therapy.

Retrospective analysis of old-age colitis in the Dutch inflammatory bowel disease population

AIM: To describe the characteristics of Dutch patients with chronic inflammatory bowel disease (IBD) first diagnosed above 60 years of age-a disease also known as old-age colitis (OAC) and to highlight a condition that has a similar appearance to IBD, namely segmental colitis associated with diverticular disease (SCAD).

METHODS: A retrospective longitudinal survey of patient demographic and clinical characteristics, disease characteristics, diagnostic methods, management and course of disease was performed. The median follow-up period was 10 years.

RESULTS: Of a total of 1100 IBD patients attending the Department of Gastroenterology, 59 (5%) [median age 82 years (range 64-101); 25 male (42%)] were identified. These patients were diagnosed with ulcerative colitis (n = 37, 61%), Crohn’s disease (n = 14, 24%), and indeterminate colitis (n = 8, 15%). Remission was induced in 40 (68%) patients within a median interval of 6 mo (range 1-21) and immunosuppressive therapy was well tolerated. Histological evaluation based on many biopsy samples and the course of the disease led to other diagnosis, namely SCAD instead of IBD in five (8%) patients.

CONCLUSION: OAC is not an infrequent problem for the gastroenterologist, and should be considered in the evaluation of older patients with clinical features suggestive of IBD. Extra awareness and extensive biopsy sampling are required in order to avoid an erroneous diagnosis purely based on histological mimicry of changes seen in SCAD, when diagnosing IBD in the presence of diverticulosis coli.

Safety and efficacy of infliximab therapy in active behcet's uveitis: an open-label trial

In this open-label trial, ten male patients with active Behcet's uveitis were enrolled. Initially, two infliximab infusions (5 mg/kg) were given at weeks 0 and 2. The patients continued to receive conventional therapy on recurrence of severe uveitis (RSU) attack. The patients with further attack were regularly given infliximab infusions every 8 weeks. In cases of further RSU attacks, the infusion interval was reduced to 6 weeks. The total follow-up period was 3 years. The patients were monitored for RSU, visual acuity and adverse effects. Reduction in the doses of prednisolone was also monitored. After receiving two infliximab infusions at weeks 0 and 2, three patients remained attack-free and seven patients had another RSU attack between 8th and 47th week. These patients were regularly given infliximab at 8-week intervals. Five out of seven patients remained attack-free. In two patients who had further attack, infusion frequency was increased to 6 weeks. There was a remarkable improvement in visual acuity with no significant adverse reaction except mild respiratory tract infection (two patients), headache (one patient) and mild infusion reaction (one patient). Infliximab is a safe and effective drug for the management of Behcet's uveitis. Selection of optimal dose and frequency of infusion required standardization for individual patient.

Proteomics for prediction and characterization of response to infliximab in Crohn's disease: a pilot study

OBJECTIVES

Infliximab is the first anti-TNFalpha accepted by the Food and Drug Administration for use in inflammatory bowel disease treatment. Few clinical, biological and genetic factors tend to predict response in Crohn's disease (CD) patient subcategories, none widely predicting response to infliximab.

DESIGN AND METHODS

Twenty CD patients showing clinical response or non response to infliximab were used for serum proteomic profiling on Surface Enhanced Lazer Desorption Ionisation-Time of Flight-Mass Spectrometry (SELDI-TOF-MS), each before and after treatment. Univariate and multivariate data analysis were performed for prediction and characterization of response to infliximab.

RESULTS

We obtained a model of classification predicting response to treatment and selected relevant potential biomarkers, among which platelet aggregation factor 4 (PF4). We quantified PF4, sCD40L and IL-6 by ELISA for correlation studies.

CONCLUSIONS

This first proteomic pilot study on response to infliximab in CD suggests association between platelet metabolism and response to infliximab and requires validation studies on a larger cohort of patients.

New therapeutic strategies for treatment of inflammatory bowel disease

Although the precise etiology of inflammatory bowel disease (IBD) still remains unclear, considerable progress has been made in the identification of cytokine-mediated signaling pathways involved in the inflammatory process. Recent data have clearly shown that these pathways induce augmented intestinal T-cell activation and thus resistance to apoptosis, which is a central process in disease pathogenesis, as it impairs mucosal homeostasis. Therefore, novel therapeutic strategies aim at restoring activated effector T-cell susceptibility to apoptosis in the gut, based on a pathophysiological rationale. This development is best exemplified by the emergence of agents that target the TNF pathway, IL-6 trans-signaling, and the IL-12/IL-23 pathway. These compounds give hope for the development of new strategies aiming at more effective and less toxic therapies for IBD.

The probiotic Escherichia coli strain Nissle 1917 induces gammadelta T cell apoptosis via caspase- and FasL-dependent pathways

Human gammadelta T cells play a vital role in the innate and adaptive immune response to microbial antigens by acting as antigen-presenting cells while at the same time being capable of directly activating CD4(+) T cells. Pathogenic microbes or loss of tolerance toward the host's own microflora trigger many diseases including inflammatory bowel diseases. We previously demonstrated that Escherichia coli Nissle 1917 directly interacts with the adaptive immune system by regulating central T cell functions. Here we aimed to investigate whether E. coli Nissle regulates gammadelta T cell function, thereby linking the innate and adaptive immune system. In our study, we demonstrate that, in contrast to the other probiotic strains tested, E. coli Nissle increased activation, cell cycling and expansion of gammadelta, but not alphabeta T cells. In gammadelta T cells, E. coli Nissle reduced tumor necrosis factor-alpha secretion but increased IL-6 and CXCL8 release. However, after activation, only E. coli Nissle induced gammadelta T cell apoptosis, mediated via Toll-like receptor-2 by caspase- and FasLigand-dependent pathways. gammadelta T cells play an important role in the recognition of microbial antigens and the perpetuation of inflammatory processes. The demonstration that E. coli Nissle, but not the other bacteria tested, profoundly regulate gammadelta T cell function contributes to explaining the biological function of this probiotic strain in inflammatory diseases and provides us with a better understanding of the role of gammadelta T cells.

A comparative study of the preventative effects exerted by three probiotics, Bifidobacterium lactis, Lactobacillus casei and Lactobacillus acidophilus, in the TNBS model of rat colitis

AIMS

The intestinal anti-inflammatory effects of three probiotics with immunomodulatory properties, Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium lactis, were evaluated and compared in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis.

METHODS AND RESULTS

Colitis was induced in rats by intracolonic administration of 10 mg of TNBS dissolved in 0.25 ml of 50% ethanol. Each probiotic was administered orally (5x10(8) CFU suspended in 0.5 ml of skimmed milk) for 3 weeks, starting 2 weeks before the administration of TNBS. Colonic damage was evaluated histologically and biochemically 1 week after TNBS instillation. The results obtained revealed that all probiotics assayed showed intestinal anti-inflammatory effects, macroscopically evidenced by a significant reduction in the colonic weight/length ratio. Only B. lactis showed a lower incidence of diarrhoea in comparison with untreated rats. Biochemically, all probiotics restored colonic glutathione levels, depleted as a consequence of the oxidative stress of the inflammatory process. Bifidobacterium lactis treatment reduced colonic tumour necrosis factor (TNF)-alpha production, and inducible nitric oxide synthase (iNOS) and cyclo-oxygenase-2 (COX-2) expression; L. acidophilus administration reduced colonic leukotriene B4 production and iNOS expression and L. casei intake was associated with a decrease in colonic COX-2 expression.

CONCLUSION

The three probiotics assayed have shown intestinal anti-inflammatory activity in the TNBS model of rat colitis, although each probiotic shows its own anti-inflammatory profile.

SIGNIFICANCE AND IMPACT OF THE STUDY

These probiotics could be considered as potential adjuvants in the treatment of inflammatory bowel disease, although more studies are required in order to demonstrate their efficacy in humans.

Current view of the immunopathogenesis in inflammatory bowel disease and its implications for therapy

Although the aetiology of inflammatory bowel disease (IBD) remains unknown, the pathogenesis is gradually being unravelled, seeming to be the result of a combination of environmental, genetic, and immunological factors in which an uncontrolled immune response within the intestinal lumen leads to inflammation in genetically predisposed individuals. Multifactorial evidence suggests that a defect of innate immune response to microbial agents is involved in IBD. This editorial outlines the immunopathogenesis of IBD and their current and future therapy. We present IBD as a result of dysregulated mucosal response in the intestinal wall facilitated by defects in epithelial barrier function and the mucosal immune system with excessive production of cytokines growth factors, adhesion molecules, and reactive oxygen metabolites, resulting in tissue injury. Established and evolving therapies are discussed in the second part of this editorial and at the end of this section we review new therapies to modulate the immune system in patients with IBD.

Tanshinone IIA ameliorates trinitrobenzene sulfonic acid (TNBS)-induced murine colitis

Inflammatory bowel diseases are characterized by proinflammatory cytokines, oxidative stress, and tissue damage. Recently, tanshinone had been shown to act as an antioxidant, and to have anti-inflammatory bioactivity. The study was carried out to investigate the effect of tanshinone IIA on the inflammatory response of experimental colitis. Murine colitis was induced by trinitrobenzene sulfonic acid (TNBS). Ten or 20 mg tanshinone IIA was administrated to mice 4 h before the induction of colitis, and repeated daily until the mice were sacrificed. Colonic inflammation was examined by histological analysis, myeloperoxidase (MPO) activity, and the production of proinflammatory cytokines in colonic tissue. Activation of nuclear factor-kappa B was identified by western blot and immunohistochemistry, and oxidative stress was shown by glutathione (GSH) level in tissue. The mice with colitis treated by tanshinone IIA showed less tissue damage, lower MPO activity, less production of TNF-alpha and IL-1beta, a higher level of GSH in colonic tissue, and downregulated activation of nuclear factor-kappa B in lamina propria mononuclear cells, compared with those of the untreated colitis group. Our data indicates that tanshinone IIA inhibits inflammatory response of colitis by downregulating the production of proinflammatory cytokines, and attenuating oxidative stress, which suggests that tanshinone IIA may be a new potential management for inflammatory bowel diseases.