Optimizing anti-TNF treatment in inflammatory bowel disease

A novel tylophorine analog NK-007 ameliorates colitis through inhibition of innate immune response

In this study, we synthesized (±)-tylophorine malate (NK-007), an analog of tylophorine (DCB3503), and analyzed its anti-inflammatory effect in vivo using a dextran sulfate sodium (DSS)-induced colitis model and an acetic acid-induced colitis model. As indicated by disease activity index (DAI) and degree of macroscopic colonic damage, NK-007 can significantly suppress colitis. To delineate the underlying mechanism, we have explored the influence of NK-007 on the production of TNF-α by murine primary bone marrow-derived dendritic cells (BMDCs) as well as monocyte/macrophage cell line Raw 264.7 triggered by lipopolysaccharide (LPS). For both types of innate immune cells, NK-007 showed a potent TNF-α inhibitory effect, and has in addition reduced the expression of IL-12 in BMDCs. Moreover, Raw cells treated with NK-007 also showed decreased phosphorylation of NF-κB, which may explain the protective immune-regulatory effect of NK-007 for experimental colitis.

[Guidelines for the management of Crohn's disease]

Crohn's disease (CD) is a chronic inflammatory bowel disease (IBD) with uncertain etiopathogenesis. CD can involve any site of gastrointestinal tract from the mouth to anus and is associated with serious complications such as bowel strictures, perforations, and fistula formation. The incidence and prevalence rates of CD in Korea are still lower than those of Western countries, but have been rapidly increasing during the past decades. Although there are no definitive curative modalities for CD, various medical and surgical therapies are currently applied for diverse clinical situations of CD. However, a lot of decisions on the management of CD are made depending on the personal experiences and choices of physicians. To suggest preferable approaches to diverse problems of CD and to minimize the variations according to physicians, guidelines for the management of CD are needed. Therefore, IBD Study Group of the Korean Association for the Study of the Intestinal Diseases has set out to develop the guidelines for the management of CD in Korea. These guidelines were developed using the adaptation methods and encompass the treatment of inflammatory disease, stricturing disease, and penetrating disease. The guidelines also cover the indication of surgery, prevention of recurrence after surgery, and CD in pregnancy and lactation. These are the first Korean guidelines for the management of CD and the update with further scientific data and evidences is needed.

Innate immune signalling at the intestinal epithelium in homeostasis and disease

The intestinal epithelium--which constitutes the interface between the enteric microbiota and host tissues--actively contributes to the maintenance of mucosal homeostasis and defends against pathogenic microbes. The recognition of conserved microbial products by cytosolic or transmembrane pattern recognition receptors in epithelial cells initiates signal transduction and influences effector cell function. However, the signalling pathways, effector molecules and regulatory mechanisms involved are not yet fully understood, and the functional outcome is poorly defined. This review analyses the complex and dynamic role of intestinal epithelial innate immune recognition and signalling, on the basis of results in intestinal epithelial cell-specific transgene or gene-deficient animals. This approach identifies specific epithelial cell functions within the diverse cellular composition of the mucosal tissue, in the presence of the complex and dynamic gut microbiota. These insights have thus provided a more comprehensive understanding of the role of the intestinal epithelium in innate immunity during homeostasis and disease.

Nociceptin/orphanin FQ inhibition with SB612111 ameliorates dextran sodium sulfate-induced colitis

Inflammatory bowel diseases, primarily Crohn's disease and ulcerative colitis, are chronic inflammatory disorders of the gastrointestinal tract with unknown etiology. The majority of current therapeutic agents focus on controlling proinflammatory molecules. The neuropeptide nociceptin/orphanin FQ (N/OFQ) has been described as a potential immunomodulator for inflammatory bowel diseases. In this study, we asked whether the small molecule N/OFQ antagonist (-)-cis-1-methyl-7-[[4-(2,6-dichlorophenyl)piperidin-1-yl]methyl]-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ol (SB612111) would inhibit the development of dextran sodium sulfate-induced colitis in C57BL/6 mice. Inhibition of the N/OFQ receptor (NOP) by SB612111 significantly ameliorated the clinical disease course in these animals, as indicated by reduced fecal bleeding, improved recovery from diarrhea and weight loss, and a reduction in histopathological alterations. In addition, the inflammatory response in the colon was diminished, as demonstrated by reduced cytokine protein and messenger RNA expression for CXCL1/keratinocyte-derived chemokine, interferon-γ, interleukin-1β, interleukin-6, and tumor necrosis factor-α, some of which are known targets for the treatment of this devastating disease. Our results strongly support a role for the receptor-ligand pair NOP-N/OFQ in the pathogenesis of colitis. We conclude that inhibition of NOP receptors with small molecule inhibitors may constitute a novel, urgently needed approach for the treatment of inflammatory bowel diseases.

Pneumocystosis in a patient with Crohn's disease treated with combination therapy with adalimumab

Pneumocystis jirovecii pneumonia (PCP) is a potential complication of immunosuppression. Crohn's disease (CD) is an immune granulomatous disorder characterized by transmural inflammation that can affect any part of the gastrointestinal tract. Its treatment is based on steroids and immunosuppressants but in non-responders, biologic compounds such as anti-tumor necrosis factor alpha (TNF) antibodies have been used. Neutralization of TNF causes a decrease in the inflammatory response but increases susceptibility to opportunistic infections such as fungal infections. We report a young male with chronic diarrhea, fever and weight loss who was diagnosed with CD and began conventional treatment with immunosuppressants, but due to lack of response after several weeks, biologic therapy with adalimumab was initiated. Seven weeks later he developed persistent fever and upper respiratory symptoms. After chest CT, bronchoscopy and bronchial lavage, P. jirovecii was identified by silver staining and confirmed by immunofluorescence. To our knowledge this is the second case of pneumocystosis associated with the use of adalimumab in CD and the first reported Mexican case confirmed by microbiological and immunological studies in this setting.

Systematic review: antibodies and anti-TNF-α levels in inflammatory bowel disease

BACKGROUND

The associations between clinical efficacy and infusion reactions with anti-TNF-α drug levels and the presence of antibodies against the drug have been described. However, the clinical utility of these tests in routine clinical practice remains unclear.

AIMS

To examine the clinical significance of the development of antibodies against anti-TNF-α drugs and the relationship between the efficacy of these drugs and their serum levels. We also studied the clinical utility of testing for anti-TNF-α antibodies and measuring drug serum levels to optimise treatment of patients with inflammatory bowel disease (IBD) receiving these agents.

METHODS

A systematic review was undertaken based on electronic searches of the PubMed database from the earliest record to February 2012. The reference lists of all relevant articles and abstracts from meetings were also consulted.

RESULTS

We observed a close relationship between trough levels of anti-TNF-α drug and maintenance of response to these drugs. The role of antibodies in loss of response seems to be limited to their effect favouring the clearance of the drug. The risk of infusion reactions, but not of delayed hypersensitivity reactions, is higher in patients with antibodies against the anti-TNF-α drug. Testing anti-TNF-α drug and antibody levels, together with clinical and endoscopic or radiological assessment, seems useful when attempting to optimise therapy and prevent inappropriate management of IBD patients.

CONCLUSION

Measurement of serum anti-TNF-α trough levels and antibody titres could prove useful in therapeutic drug monitoring in IBD patients treated with anti-TNF-α agents.

Epithelial barrier: an interface for the cross-communication between gut flora and immune system

Large numbers of environmental antigens, including commensal bacteria and food-derived antigens, constitutively interact with the epithelial layer of the gastrointestinal (GI) tract. Commensal bacteria peacefully cohabit with the host GI tract and exert multiple beneficial or destructive effects on their host. Intestinal epithelial cells (IECs) constitute the first physical and immunological protective wall against invasive pathogens and a cohabitation niche for commensal bacteria. As the physiological homeostasis of IECs is maintained by multiple biological processes such as apoptosis, autophagy, and the handling of endoplasmic reticulum stress, the aberrant kinetics of these biological events, which have genetic and environmental causes, leads to the development of host intestinal pathogenesis such as inflammatory bowel disease. In addition, IECs recognize and interact with commensal bacteria and give instructions to mucosal immune cells to initiate an immunological balance between active and quiescent conditions, eventually establishing intestinal homeostasis. The mucosal immune system regulates the homeostasis of gut microbiota by producing immunological molecules such as secretory immunoglobulin A, the production of which is mediated by IECs. IECs therefore play a central role in the creation and maintenance of a physiologically and immunologically stable intestinal environment.

Long-term efficacy and safety of infliximab in the treatment of Behçet's disease

PURPOSE

To assess the long-term efficacy and safety of infliximab therapy for the treatment of Behçet's disease patients with ocular involvement who failed to respond or did not tolerate conventional treatment.

METHODS

Retrospective study of 12 patients treated with infliximab at a starting dose of 5 mg/kg.

RESULTS

Infliximab was infused during a mean of 31.43 months. The mean follow-up period was 35.77 months (range: 6-94). All patients achieved remission, 7 of whom did not need any adjuvant immunosuppressive therapy and 9 of whom were able to discontinue systemic corticosteroids. Visual acuity remained stable or improved in 20/21 eyes. Ten patients did not report any side effect of the medication or those were mild and tolerable. We observed two major adverse events requiring withdrawal of infliximab.

CONCLUSIONS

Infliximab therapy is an effective biologic agent for the treatment of ocular inflammation in Behçet's disease unresponsive to the standard immunosuppressive therapy.

Colon-targeted cell-permeable NFκB inhibitory peptide is orally active against experimental colitis

For the purpose of development of orally active peptide therapeutics targeting NFκB for treatment of inflammatory bowel disease (IBD), two major barriers in oral delivery of therapeutic peptides, metabolic lability and tissue impermeability, were circumvented by introduction of a colon-targeted delivery system and cell permeable peptides (CPP) to NFκB inhibitory peptides (NIP). Suppression of NFκB activation was compared following treatment with various CPP conjugated NIPs (CPP-NIP). The most potent CPP-NIP was loaded in a capsule coated with a colon specific polymer, which was administered orally to colitic rats. The anti-inflammatory activity of the colon-targeted CPP-NIP was evaluated by measuring inflammatory indices in the inflamed colonic tissue. For confirmation of the local action of the CPP-NIP, the same experiment was done after rectal administration. Tissue permeability of the CPP-NIP was examined microscopically and spectrophotometrically using FITC-labeled CPP-NIP (CPP-NIP-FITC). NEMO binding domain peptide (NBD, TALDWSWLQTE) fused with a cell permeable peptide CTP (YGRRARRRARR), CTP-NBD, was most potent in inhibiting NFκB activity in cells. Colon-targeted CTP-NBD, but not colon-targeted NBD and CTP-NBD in an enteric capsule, ameliorated the colonic injury, which was in parallel with decrease in MPO activity and the levels of inflammatory mediators. Intracolonic treatment with CTP-NBD alleviated rat colitis and improved all the inflammatory indicators. CTP-NBD-FITC was detected at much greater level in the inflamed tissue than was NBD-FITC. Taken together, introduction of cell permeability and colon targetability to NIP may be a feasible strategy for an orally active peptide therapy for treatment of IBD.

Combination therapy of tacrolimus and infliximab reduces inflammatory response and dysmotility in experimental small bowel transplantation in rats

BACKGROUND

Intestinal transplantation initiates a functionally relevant inflammatory response by activation of resident macrophages within the muscularis associated with dysmotility. Infliximab is used successfully as a potent anti-inflammatory agent for the treatment of chronic inflammatory bowel diseases and as rescue therapy in acute steroid-resistant rejection in selected settings in clinical small bowel transplantation. We hypothesize that additional perioperative treatment with infliximab diminishes initiation of the inflammatory cascade and improves motility in small bowel grafts using a standard tacrolimus immunosuppressive protocol.

METHODS

Orthotopic intestinal transplantation was performed in rats. In two treatment groups (24/168 hr), infliximab was administered intravenously directly after reperfusion and tacrolimus was injected intramuscularly after transplantation and once a day. Two other treatment groups (24/168 hr) received standard immunosuppressive therapy with tacrolimus. Isogenic and allogenic transplanted vehicle-treated animals (24/168 hr) and native gut served as control.

RESULTS

Infliximab-treated grafts exhibited significantly less leukocyte infiltration at 24/168 hr after transplantation and at 168 hr significantly less apoptosis in the tunica muscularis compared with tacrolimus monotherapy. Additional infliximab treatment resulted in increased smooth muscle contractility (30%) after 24 hr compared with tacrolimus control.

CONCLUSIONS

Dysmotility of transplanted small bowel results from reperfusion injury and acute rejection. Additional perioperative treatment with infliximab reduces early unspecific inflammatory responses and complements immunosuppressive therapy with tacrolimus.

Risk of post-operative complications associated with anti-TNF therapy in inflammatory bowel disease

There have been increasing concerns regarding the safety of perioperative anti-tumour necrosis factor (anti-TNF) α agents. We performed a literature review to evaluate the post-operative complications associated with perioperative anti-TNF use in patients with inflammatory bowel disease. A comprehensive review was performed with a literature search utilizing Pub Med, Cochrane, OVID and EMBASE databases according to published guidelines. To date, there are only data for infliximab. There are three published studies which have assessed post-operative complications with perioperative infliximab use in patients with Crohn’s disease (CD), four studies in ulcerative colitis (UC) patients, and one study on both CD and UC patients. Two out of the three studies in CD patients showed no increased post-operative complications associated with perioperative infliximab. Two out of four studies in UC patients also did not show an increase in post-operative complications, and the combined study with CD and UC patients did not show an increased risk as well. Study results could not be combined secondary to significant differences in study designs, patient population and definition of their endpoints. There appears to be a risk of post-operative complications associated with TNF therapy in some patients. Based on these data, careful patient selection and prospective data collection should be performed.

Update upon efficacy and safety of TNF-α inhibitors

The ongoing progresses in the knowledge of the pathogenic mechanisms of various immune-mediated and inflammatory diseases as well as the availability of innovative biotechnological approaches have led to the development of new drugs that add to conventional treatments. Among these, tumor necrosis factor (TNF)-α inhibitors, that is, infliximab, adalimumab, etanercept, golimumab and certolizumab pegol, are now available for clinical use. This editorial discusses the recent indications of TNF-α inhibitors, the pretreatment considerations, the reported adverse events and, finally, the recommendations for its use in pregnancy.

Medical management of inflammatory bowel disease among Canadian gastroenterologists

BACKGROUND

Little is known about physician perceptions of and practices in using infliximab - a biological agent that was approved in Canada for the treatment of Crohn's disease in 2001, and for ulcerative colitis in 2006.

OBJECTIVES

To describe Canadian gastroenterologists' use and perceptions of infliximab in the treatment of refractory inflammatory bowel disease (IBD), and to identify factors that may influence a gastroenterologist's decision to initiate infliximab therapy.

METHODS

A postal questionnaire was distributed to all practicing clinicians captured in the 2007 membership of the Canadian Association of Gastroenterology. Each physician was contacted up to a maximum of three times.

RESULTS

Of 466 questionnaires mailed out, responses were received from 336 (72%), with 292 respondents (63%) returning fully completed surveys. For 80% of respondents, IBD patients comprised less than 30% of their clinical practice. Most prescribed infliximab at an initial dose of 5 mg⁄kg (97%), prescribed loading doses at 0, 2 and 6 weeks (88%), premedicated with corticosteroids (74%), administered maintenance infusions at eight-week intervals (89%), co-administered immunosuppressive agents (81%) and continued infliximab 'indefinitely' as long as it was effective and well tolerated (76%). Most gastroenterologists (>70%) identified lack of drug insurance coverage and provincial funding criteria as important barriers to prescribing infliximab.

CONCLUSIONS

Most Canadian gastroenterologists exhibited similar practice patterns with respect to the use of infliximab for induction and maintenance therapy of IBD. Common barriers to the initiation of infliximab therapy were identified.

Impact of infliximab adherence on Crohn's disease-related healthcare utilization and inpatient costs

INTRODUCTION

Few published reports have described the impact of adherence with biologic agents on hospitalizations and inpatient costs in Crohn's disease (CD).

METHODS

A retrospective claims analysis using the IMS LifeLink Health Plan Claims Database between September 1, 2004 and June 30, 2009 was conducted. Continuous enrollment for 12 months before and 12 months after the index date was required. Patients were required to have ≥2 claims with an International Classification of Diseases, 9th Edition, Clinical Modification diagnosis code for CD (555.xx) preindex, be ≥18 years of age at index, and have ≥4 infliximab infusions with a gap no greater than 12 weeks between each infusion. Patients with 7-9 infliximab infusions (12 months postindex) were considered adherent; patients with 4-6 infliximab infusions were considered nonadherent.

RESULTS

In total, 638 patients were included in the analyses (mean age, 43 years; 58% female in the adherent group and 53% in the nonadherent group). The number of patients who met the definition of adherence was 466 (73%). A smaller proportion of adherent patients had a CD-related emergency room visit, compared with nonadherent patients (11% vs. 17%, P=0.029). A smaller proportion of adherent patients required CD-related hospitalization, compared with nonadherent patients (8% vs. 12%, P=0.117). Among those hospitalized, adherent patients had fewer mean [median] days in the hospital (5.9 [5] days), compared with nonadherent patients (12.8 [8] days, P=0.015). Mean [median] hospital costs were significantly lower for adherent patients ($13,427 [$9,352]), compared with nonadherent patients ($37,783 [$28,864], P=0.001). Multivariate analyses confirmed lower inpatient (P<0.001) costs for adherent versus nonadherent patients.

CONCLUSION

Adherence with infliximab therapy during the first year of treatment in patients with CD was associated with a shorter hospital length of stay and lower inpatient costs compared with nonadherent patients. Strategies for increasing adherence rates to infliximab maintenance therapy may be valuable in reducing hospitalizations and inpatient costs in patients with CD.

Safety of biologics in inflammatory bowel disease

Various biologic agents have been evaluated in patients with inflammatory bowel disease (eg, Crohn's disease ) and ulcerative colitis (UC). At present, only one, infliximab (humanized monoclonal anti-tumor necrosis factor-alpha antibody), is approved by the US Food and Drug Administration for induction and maintenance treatment in patients with active moderate to severe and/or fistulizing CD who are refractory to conventional therapy. Two recent trials, Active Ulcerative Colitis Trial (ACT) 1 and ACT 2, observed high efficacy of infliximab in inducting and maintaining clinical remission, mucosal healing, and corticosteroid-sparing effects in patients with moderate to severe UC. A plethora of randomized, double-blind, controlled and open-label, uncontrolled studies on large and small numbers of patients has assessed efficacy and safety of various biologic agents of potential use in treatment of inflammatory bowel disease. With respect to safety of biologic agents used for treatment, the most accurate data are available only in the case of infliximab. This is due to the fact that infliximab was evaluated in many more trials than any other biologic agent. Moreover, postmarketing experience also provides very valuable information about any side effects occurring during treatment with this agent.

Intestinal inflammation and colorectal cancer: A double-edged sword?

Chronic inflammation is thought to be the leading cause of many human cancers including colorectal cancer (CRC). Accordingly, epidemiologic and clinical studies indicate that patients affected by ulcerative colitis and Crohn’s disease, the two major forms of inflammatory bowel disease, have an increased risk of developing CRC. In recent years, the role of immune cells and their products have been shown to be pivotal in initiation and progression of colitis-associated CRC. On the other hand, activation of the immune system has been shown to cause dysplastic cell elimination and cancer suppression in other settings. Clinical and experimental data herein reviewed, while confirming chronic inflammation as a risk factor for colon carcinogenesis, do not completely rule out the possibility that under certain conditions the chronic activation of the mucosal immune system might protect from colonic dysplasia.

Novel biological therapies for inflammatory bowel disease

The success of biological therapy is best advocated by infliximab (IFX), which has dramatically improved medical therapy for Crohn's disease and now has been shown to be effective in the treatment of ulcerative colitis. Other anti-tumor necrosis factor (TNF) compounds have been tested in the treatment of Crohn's disease and will soon appear in the therapeutic armament. However, neutralization of TNF does not seem to be the most important mechanism of action of these therapies. Apoptosis of activated T cells was demonstrated after IFX treatment, and this may be the key to its success. Thus, other therapies that induce apoptosis in activated T cells, such as visilizumab, have a great chance to be of benefit. Biological therapies applied in inflammatory bowel disease appear to be safe, although therapy-related adverse events clearly have been recognized.

Inflammatory bowel disease therapy: current state-of-the-art

PURPOSE OF REVIEW

The aim of this article is to review current evidence-based approaches to treatment of ulcerative colitis and Crohn's disease.

RECENT FINDINGS

The primary goal of treatment is to induce and to maintain remission in a safe and efficacious fashion. The 5-aminosalicylic acid (5-ASA) agents and oral steroids remain the first-line approach for the treatment of ulcerative colitis and Crohn's disease. The 'step-up' approach includes the use of immunomodulators [azathioprine (AZA), or 6-mercaptopurine (6-MP)] and newer biologic agents (infliximab, adalimumab, and natalizumab). The 'step-down' approach can also be considered individually on the basis of the severity of Crohn's disease.

SUMMARY

Current treatment regimens still involve medications with well known efficacy and safety profiles and progress to more potent treatments such as immunomodulators and biologic agents. Adverse events of potent treatment with biologics and immunomodulators have been recognized. In some cases, aggressive approaches with the use of more potent agents as first-line therapy has been proposed, but they are still not considered a routine approach.

Management of inflammatory bowel disease with infliximab and other anti-tumor necrosis factor alpha therapies

Inflammatory bowel disease (IBD), most commonly referring to Crohn's disease and ulcerative colitis, is a chronic and disabling condition with an increasing incidence in southern Europe. The etiology of IBD remains unknown, but the characteristic disproportionate inflammatory response in the gut may develop through various mechanisms at the cellular and subcellular level. Tumor necrosis factor (TNF) alpha is one crucial mediator of this abnormal immune response, and in recent years, biological therapies targeting TNFα have significantly improved the management of IBD refractory to conventional therapies. Infliximab is the best studied anti-TNFα agent, and is currently approved in the European Union for adults and children with Crohn's disease and adults with ulcerative colitis; adalimumab is indicated for Crohn's disease in adults but not children, while certolizumab was not approved in the European Union for Crohn's disease. Infliximab has confirmed efficacy in adults with Crohn's disease (including fistulizing disease) and ulcerative colitis, with benefits observed in both clinical remission and mucosal healing, it is similarly effective in children with Crohn's disease. Evidence suggests that early treatment with infliximab may improve the natural course of the disease. Adalimumab showed efficacy in adults with Crohn's disease and more limited data suggest efficacy in children with Crohn's disease. Although certolizumab pegol has also shown promising data in adults with Crohn's disease, data in children are lacking. Anti-TNFα agents are generally well tolerated, although careful monitoring for adverse events such as infections, infusion reactions, lymphomas and demyelinating diseases is warranted. A definitive causal relationship between anti-TNFα agents and various adverse events is difficult to establish, as the underlying disease and concomitant immunosuppression also predispose patients to such events. Infliximab has not been associated with an increased incidence of serious events, and adalimumab and certolizumab are also generally well tolerated in clinical trials. Both adalimumab and certolizumab pegol are associated with lower levels of drug antibodies compared with infliximab. Reactivation of latent tuberculosis is a potential risk with any anti-TNFα agent, and identification and treatment is required before initiating therapy. Although causal relationships are difficult to establish, caution is advised with anti-TNFα compounds in patients developing neurological symptoms suggestive of demyelinating disease, or in those at high risk of malignancy. Infliximab is also generally well tolerated in children; however, data are scarce for the other compounds. No increased risks associated with pregnancy have been observed for infliximab or adalimumab, but caution in pregnancy and during breast-feeding is currently advocated. In terms of future research, more long-term data are needed for both certolizumab pegol in Crohn's disease and adalimumab in ulcerative colitis. More research on the benefits of early biological treatment on disease progression is needed. In summary, the anti-TNFα inhibitors represent a momentous advance in the treatment of Crohn's disease and ulcerative colitis refractory to conventional treatments. They offer significant benefits in quality of life and mucosal healing, and may have the potential to change the evolution of the disease when given early.

Tumor necrosis factor alpha inhibitors as immunomodulatory antirejection agents after intestinal transplantation

We reported the successful administration of infliximab for late-onset OKT3-resistant rejection in two patients, who presented persistent ulcerative inflammation of the ileal graft after intestinal transplantation (ITX). Based on this experience, the present study demonstrated our long-term experience with infliximab for different types of rejection-related and inflammatory allograft alterations. Infliximab administration (5 mg/kg body weight (BW)) was initiated at a mean of 18.2 ± 14.1 months after transplantation. The number of administrations per patient averaged 8.4 ± 6.7. Repeat dosing was timed according to clinical signs and graft histology in addition to serum-levels of tumor necrosis factor alpha (TNFα), lipopolysaccharide binding protein (LBP) and C-reactive protein (CRP). Infliximab was successful in the following patients: patients with late-onset OKT3- and steroid-refractory rejection who presented persistent ulcerative alterations of the ileal graft (n = 5), patients with ulcerative ileitis/anastomositis, who did not show typical histological rejection signs (n = 2), and one patient with early-onset OKT3-resistant rejection. Infliximab was not successful in one patient with early-onset OKT3-resistant rejection that was accompanied by treatment-refractory humoral rejection. In conclusion, infliximab can expand therapeutic options for late-onset OKT3- and steroid-refractory rejection and chronic inflammatory graft alterations in intestinal allograft recipients.

Animal models of colitis-associated carcinogenesis

Inflammatory bowel disease (IBD) is a group of chronic inflammatory disorders that affect individuals throughout life. Although the etiology and pathogenesis of IBD are largely unknown, studies with animal models of colitis indicate that dysregulation of host/microbial interactions are requisite for the development of IBD. Patients with long-standing IBD have an increased risk for developing colitis-associated cancer (CAC), especially 10 years after the initial diagnosis of colitis, although the absolute number of CAC cases is relatively small. The cancer risk seems to be not directly related to disease activity, but is related to disease duration/extent, complication of primary sclerosing cholangitis, and family history of colon cancer. In particular, high levels and continuous production of inflammatory mediators, including cytokines and chemokines, by colonic epithelial cells (CECs) and immune cells in lamina propria may be strongly associated with the pathogenesis of CAC. In this article, we have summarized animal models of CAC and have reviewed the cellular and molecular mechanisms underlining the development of carcinogenic changes in CECs secondary to the chronic inflammatory conditions in the intestine. It may provide us some clues in developing a new class of therapeutic agents for the treatment of IBD and CAC in the near future.

Therapy with anti-TNFα antibody enhances number and function of Foxp3(+) regulatory T cells in inflammatory bowel diseases

BACKGROUND

Inflammatory bowel diseases (IBDs) are associated with up-regulation of TNFα, hyperactivation of proinflammatory effector T cells (Teffs) and inefficient control by regulatory CD4(+) CD25(+) Foxp3(+) T cells (Tregs). The aim of this prospective study was to investigate the short-term impact of treatment of IBD patients with anti-TNFα antibodies (infliximab or adalimumab) on the frequency, phenotype, and suppressive function of Tregs.

METHODS

Active IBD patients including 16 with Crohn's disease and 9 with ulcerative colitis were treated with anti-TNFα mAb. PBMCs were harvested immediately before and 2 weeks after the first injection. The frequency and phenotype of circulating CD4(+) CD25(+) Foxp3(+) Tregs were analyzed by flow cytometry, and their suppressive function was assessed by the ability of purified CD4(+) CD25(+) CD127(-) Tregs to inhibit the proliferation of allogenic CD4(+) CD25(-) Teffs.

RESULTS

CD4(+) CD25(+) Foxp3(+) Treg frequency was significantly lower in active IBD patients than in controls (2.8% ± 0.4% vs. 4.6% ± 0.6%, respectively; P = 0.01). On day 14 following the first anti-TNFα infusion, the frequency of circulating Tregs was significantly enhanced in IBD patients (4.0% ± 0.5% vs. 2.8% ± 0.4%, before treatment; P = 0.001), with a 2- to 3-fold increase in the intensity of Foxp3 expression. In addition, infliximab treatment enhanced the suppressive function of circulating Tregs, as shown by inhibition of Teff proliferation at a 1:8 Treg/Teff ratio (28% ± 5% vs. 66% ± 10%, after treatment; P = 0.04).

CONCLUSIONS

These data demonstrate that anti-TNFα treatment of active IBD rapidly enhances the frequency of functional Foxp3(+) Tregs in blood and potentiates their suppressive function. This indicates that Treg potentiation may represent an unanticipated outcome of anti-TNFα biotherapy in IBD.

Anti-TNF-alpha treatment strategies: results and clinical perspectives

The advent of anti-TNF therapies has led to a significant expansion of the therapeutic armamentarium for inflammatory bowel diseases. Control of inflammation has been achieved with three biologic agents infliximab, adalimumab and certolizumab pegol. All agents are effective in both induction and maintenance of remission. For fistula healing in Crohn's disease, both infliximab and adalimumab have been shown to be effective, whereas for mucosal healing hard evidence is only available for infliximab. Anti-TNF agents appear to be more effective in patients who have a shorter disease history and who have not yet been treated with any of these agents. There is a clear tendency to use anti TNF therapy earlier in the course of inflammatory bowel disease, but predictive markers to select patients who really need these therapies are urgently needed.

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

BACKGROUND

The aim of this study was to evaluate the short- and long-term safety experience of infliximab treatment in patients with Crohn's disease (CD) in clinical practice.

METHODS

The medical records of 297 consecutive patients with CD treated with infliximab at the Beth Israel Deaconess Medical Center were reviewed for demographic features and adverse events.

RESULTS

The 297 patients received a total of 1794 infusions. Patients received a median of four infusions and had a median follow-up of 14.3 months. Forty-four patients (15%) experienced a serious adverse event, requiring the infusion to be stopped in 33 patients (11%). Acute infusion reactions occurred in 18 patients (6%) including respiratory problems in 10 patients (3%) and an anaphylactoid reaction in 1 patient (0.3%). Serum sickness-like disease occurred in one patient (0.3%) and three patients (1%) developed drug-induced lupus. One patient developed a probable new demyelination disorder. Eight patients (2.7%), all of whom were on concurrent immunosuppressants, developed a serious infection, one resulting in fatal sepsis. Six patients (2%) developed malignancies including two lymphomas and two skin cancers. A total of four (1.3%) deaths were observed (median age 72.5 years); two due to gastrointestinal bleeding, one due to sepsis, and one due to malignancy.

CONCLUSIONS

While short- and long-term infliximab therapy was generally well tolerated, serious adverse events occurred in 15% of patients including drug-induced lupus, fatal sepsis, and malignancy. Concomitant immunosuppressants were significantly associated with infections and deaths, particularly among elderly patients.

Solution of the structure of the TNF-TNFR2 complex

Tumor necrosis factor (TNF) is an inflammatory cytokine that has important roles in various immune responses, which are mediated through its two receptors, TNF receptor 1 (TNFR1) and TNFR2. Antibody-based therapy against TNF is used clinically to treat several chronic autoimmune diseases; however, such treatment sometimes results in serious side effects, which are thought to be caused by the blocking of signals from both TNFRs. Therefore, knowledge of the structural basis for the recognition of TNF by each receptor would be invaluable in designing TNFR-selective drugs. Here, we solved the 3.0 angstrom resolution structure of the TNF-TNFR2 complex, which provided insight into the molecular recognition of TNF by TNFR2. Comparison to the known TNFR1 structure highlighted several differences between the ligand-binding interfaces of the two receptors. Additionally, we also demonstrated that TNF-TNFR2 formed aggregates on the surface of cells, which may be required for signal initiation. These results may contribute to the design of therapeutics for autoimmune diseases.

Perioperative infliximab application ameliorates acute rejection associated inflammation after intestinal transplantation

As we have shown in the past, acute rejection-related TNF-α upregulation in resident macrophages in the tunica muscularis after small bowel transplantation (SBTx) results in local amplification of inflammation, decisively contributing to graft dysmotility. Therefore, the aim of this study is to investigate the effectiveness of the chimeric-monoclonal-anti-TNF-α antibody infliximab as perioperative single shot treatment addressing inflammatory processes during acute rejection early after transplantation. Orthotopic, isogenic and allogenic SBTx was performed in rats (BN-Lewis/BN-BN) with infliximab treatment. Vehicle and IV-immunoglobulin-treated animals served as controls. Animals were sacrificed after 24 and 168 h. Leukocyte infiltration was investigated in muscularis whole mounts by immunohistochemistry, mediator mRNA expression by Real-Time-RT-PCR, apoptosis by TUNEL and smooth muscle contractility in a standard organ bath. Both, infliximab and Sandoglobulin® revealed antiinflammatory effects. Infliximab resulted in significantly less leukocyte infiltration compared to allogenic controls and IV-immunoglobulin, which was accompanied by lower gene expression of MCP-1 (24 h), IFN-γ (168 h) and infiltration of CD8-positive cells. Smooth muscle contractility improved significantly after 24 h compared to all controls in infliximab treated animals accompanied by lower iNOS expression. Perioperative treatment with infliximab is a possible pharmaceutical approach to overcome graft dysmotility early after SBTx.

Serious infections in patients with inflammatory bowel disease receiving anti-tumor-necrosis-factor-alpha therapy: an Australian and New Zealand experience

BACKGROUND AND AIM

Anti-tumor-necrosis-factor-alpha (anti-TNF-α) medications are effective in inflammatory bowel disease (IBD), but have an increased risk of tuberculosis (TB) and serious infections. The aim of this study was to examine the Australian/New Zealand experience of serious infections and TB in IBD patients receiving anti-TNF-α therapy from 1999-2009.

METHODS

Serious infections, defined as 'requiring hospital admission' and TB cases in patients receiving, or within 3 months following, anti-TNF-α therapy were analyzed across Australia and New Zealand. Patient demographics, IBD medications, duration of anti-TNF-α therapy, and infection details were collected.

RESULTS

A total of 5562 IBD patients were managed across the centers. Of these, 489 (16.8%) Crohn's disease and 137 (5.2%) ulcerative colitis patients received anti-TNF-α therapy. There were three cases of latent TB that received prophylaxis prior to anti-TNF-α therapy. No cases of active TB were reported. Fourteen (2.2%) serious infections occurred. Seven occurred in patients receiving anti-TNF-α therapy for less than 6 months, including two cases of primary Varicella zoster (VZV), two cases of Pneumocystis jiroveci pneumonia, two cases of Staphylococcus aureus bacteremia, and one severe flu-like illness. Six patients were taking additional immunosuppressive medications. The other seven infections occurred after 6 months (mean 32.6 ± 24.3 months) and included one case of primary VZV, one flu-like illness, and five bacterial infections. All infections resolved with treatment.

CONCLUSION

TB is a very rare complication of anti-TNF-α therapy in Australia and New Zealand. Serious infections are uncommon but early opportunistic infections with Pneumocystis jiroveci pneumonia suggest a need for vigilance in patients on multiple immunosuppressive medications. VZV vaccination prior to immunosuppressive therapy should be considered in VZV-naïve patients.

Maintenance of clinical benefit in Crohn's disease patients after discontinuation of infliximab: long-term follow-up of a single centre cohort

BACKGROUND

Tumour necrosis factor-blockade with infliximab has advanced the treatment of Crohn's disease. While infliximab is efficacious, it remains to be determined whether patients who enter clinical remission with an anti-tumour necrosis factor therapy can have their treatment stopped and retain the state of remission.

AIM

To assess in patients with Crohn's disease who obtained infliximab-induced remission, the proportion who relapsed after infliximab discontinuation.

METHODS

This longitudinal cohort study examined patients from a University-based IBD referral centre. Forty eight patients with Crohn's disease in full clinical remission and who then discontinued infliximab were followed up for up to 7 years. Crohn's disease relapse was defined as an intervention with Crohn's disease medication or surgery.

RESULTS

Kaplan-Meier analysis of the proportion of patients with sustained clinical benefit demonstrated that 50% relapsed within 477 days after infliximab discontinuance. In contrast, 35% of patients remained well, and without clinical relapse, up to the end of the nearly 7-year follow-up.

CONCLUSIONS

In patients with Crohn's disease with an infliximab-induced remission, stopping infliximab results in a predictable relapse in a majority of patients. Nevertheless, a small percentage of patients sustain a long-term remission.

Drug targeting strategies for the treatment of inflammatory bowel disease: a mechanistic update

The therapeutic management of inflammatory bowel disease (IBD) represents the perfect scenario for drug targeting to the site(s) of action. While existing formulation-based targeting strategies include rectal dosage forms and oral systems that target the colon by pH-, time-, microflora- and pressure-triggered drug release, novel approaches for site-specific delivery in IBD therapy will target the inflamed intestine per se rather than intestinal region. The purpose of this article is to present a mechanistic update on the strategies employed to achieve minimal systemic exposure accompanied by maximal drug levels in the inflamed intestinal tissue. The introduction of biological agents, micro/nanoparticulate carriers including liposomes, transgenic bacteria, and gene therapy opportunities are discussed, as well as the challenges remaining to be achieved in the targeted treatment of IBD.

Neuroimmune regulation of ventilator-induced lung injury

RATIONALE

Ventilator-induced lung injury (VILI) contributes to the mortality in patients with acute lung injury by increasing inflammation. Recent evidence suggests that stimulation of the cholinergic antiinflammatory pathway may be an attractive way to attenuate inflammatory injury.

OBJECTIVES

To determine the role of vagus nerve signaling in VILI and establish whether stimulation of the vagus reflex can mitigate VILI.

METHODS

We performed bilateral vagotomy in a mouse model of high-tidal volume-induced lung injury. We performed pharmacological and electrical vagus nerve stimulation in a rat model of VILI following ischemia/reperfusion injury. To determine the contribution of the alpha 7 acetylcholine nicotinic receptor to pulmonary cell injury, we exposed human bronchial epithelial cells to cyclic stretch in the presence of specific agonist or antagonist of the alpha 7 receptor.

MEASUREMENTS AND MAIN RESULTS

Vagotomy exacerbates lung injury from VILI in mice as demonstrated by increased wet-to-dry ratio, infiltration of neutrophils, and increased IL-6. Vagal stimulation attenuates lung injury in rats after ischemia/reperfusion injury ventilated with high-volume strategies. Treatment of both mice and rats with the vagus mimetic drug semapimod resulted in decreased lung injury. Vagotomy also increased pulmonary apoptosis, whereas vagus stimulation (electrical and pharmacological) attenuated VILI-induced apoptosis. In vitro studies suggest that vagus-dependent effects on inflammation and apoptosis are mediated via the α7 nicotinc acetylcholine receptor-dependent effects on cyclic stretch-dependent signaling pathways c-jun N-terminal kinase and tumor necrosis factor receptor superfamily, member 6.

CONCLUSIONS

Stimulation of the cholinergic antiinflammatory reflex may represent a promising alternative for the treatment of VILI.

Targeting IL-23 in human diseases

IMPORTANCE OF THE FIELD

IL-23 is one of the most intriguing cytokine for its many immunological functions, which are the basis of its important role in host defense but also of its possible contribution to the pathogenesis of several diseases.

AREAS COVERED IN THIS REVIEW

The literature and patents about IL-23 pathway and their targeting in therapeutic potential applications. Findings published within the last 5 years receive particular attention.

WHAT THE READER WILL GAIN

An overview of the emerging role of IL-23 in physiological and pathological conditions and a review of the different approaches (IL-23 pathway-based) currently used for autoimmune diseases and cancer therapies and the results obtained both in preclinical models and in clinical trials.

TAKE HOME MESSAGE

Inhibition/targeting of IL-23 may be a good and novel therapeutic strategy, especially in the treatment of diseases like psoriasis, for which current treatments show more pronounced side effects than those of IL-23-blocking and employed as part of specific patient-tailored therapies in inflammatory bowel diseases.

Biological therapies of inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by increasing morbidity and, if suboptimally treated, poor prognosis. Recent evidence strongly suggests that dysfunctional immune responses play an important role in the pathogenesis of IBD. Therefore, immunologically downregulating the overactivated innate and adaptive immune responses may be a better approach to treat IBD than currently used pharmaceutical therapies. In recent years, many new biological therapies have been developed. These therapies are shown to be effective for inducing remission, preventing complications, improving life quality of the patients, and reducing hospitalization and surgical rates. This article introduces and discusses these new biological agents that have been used effectively in clinic for IBD patients.

Mechanisms by which inflammation may increase intestinal cancer risk in inflammatory bowel disease

Patients with ulcerative colitis and Crohn's disease are at increased risk of developing intestinal cancers via mechanisms that remain incompletely understood. However, chronic inflammation and repeated events of inflammatory relapse in inflammatory bowel disease (IBD) expose these patients to a number of signals known to have tumorigenic effects including persistent activation of the nuclear factor-kappaB and cyclooxygenase-2/prostaglandin pathways, release of proinflammatory mediators such as tumor necrosis factor-alpha and interleukin-6, and enhanced local levels of reactive oxygen and nitrogen species. These inflammatory signals can contribute to carcinogenesis via 3 major processes: 1) by increasing oxidative stress, which promotes DNA mutagenesis thus contributing to tumor initiation; 2) by activating prosurvival and antiapoptotic pathways in epithelial cells, thereby contributing to tumor promotion; and 3) by creating an environment that supports sustained growth, angiogenesis, migration, and invasion of tumor cells, thus supporting tumor progression and metastasis. The present review integrates clinical and basic research observations in an attempt to provide a comprehensive understanding of how inflammatory processes may contribute to intestinal cancer development in IBD patients.

Pre-operative management is associated with low rate of post-operative morbidity in penetrating Crohn's disease

BACKGROUND

Ileocaecal resection for penetrating Crohn's disease is still challenging with a high rate of post-operative morbidity and faecal diversion.

AIM

To report retrospectively the results of pre-operative management for penetrating Crohn's disease focusing on the rate of post-operative major morbidities and need for faecal diversion.

METHODS

Between 1997 and 2007, 78 patients with penetrating Crohn's disease underwent a first ileocaecal resection after a pre-operative management consisting in bowel rest, nutritional therapy, intravenous antibiotics, weaning off steroids and immunosuppressors, and drainage of abscesses when appropriate.

RESULTS

Resection was performed for terminal ileitis associated with (n = 41), abscesses (n = 37) or both (n = 5). A pre-operative nutritional therapy was performed in 50 patients (68%) for 23 days (range, 7-69 days) along with a weaning off steroids and immunosuppressors. A diverting stoma was performed for six patients (7.7%). There was no post-operative death. Post-operative complications were classified as minor in 10 patients (12.8%), and major in four patients (5%). Overall, the post-operative course was uneventful in 58 patients (74%).

CONCLUSION

Pre-operative management for penetrating Crohn's disease allowed ileocaecal resection with low rates of post-operative morbidity and faecal diversion.

Impact of prior irregular infliximab dosing on performance of long-term infliximab maintenance therapy in Crohn's disease

BACKGROUND

Infliximab is efficacious in the management of moderate to severe Crohn's disease (CD). There are limited data regarding performance of infliximab in patients who require reinitiation of maintenance dosing following previous irregular exposure.

METHODS

This was a retrospective, observational study of CD patients treated with maintenance infliximab beyond 3 years. Maintenance infliximab infusion regimens were categorized as scheduled maintenance (SM) (maintenance infusions q < or =8 weeks after loading) or prior irregular (PI) (no loading, gap in therapy >8 weeks prior to or during maintenance therapy). We examined differences in need for medical and surgical hospitalizations as well as associated healthcare costs between the 2 groups.

RESULTS

In all, 104 CD patients met criteria for 3-year maintenance infliximab treatment (SM n = 64; PI n = 40). The rates of CD-related surgeries (60.9% and 55.0%, P = not significant [N.S.]) and medical hospitalizations (35.9% and 37.5%, P = N.S.) prior to infliximab initiation was similar between the 2 groups. However, the rate of medical (26.5% versus 47.5%, P = 0.035) and surgical hospitalizations (21.8% versus 48.7%, P = 0.009) were significantly lower in the SM compared to the PI group. During the third year of treatment the excess costs per patient for the PI group compared to the SM group amounted to $11,464 in spite of both cohorts being on SM therapy.

CONCLUSIONS

Patients who begin and continue an uninterrupted maintenance dosing regimen had a lower incidence of hospitalization and surgery than those who received an irregular or interrupted regimen prior to beginning an SM regimen.

Role of the tumor necrosis factor antagonists in the treatment of inflammatory bowel disease: an update

Crohn's disease and ulcerative colitis represent the two major forms of inflammatory bowel disease (IBD). Recent research points out the role of uncontrolled intestinal inflammation in the pathogenesis of IBD. Therefore, there is a growing interest in developing novel biologic therapies targeting specific molecules of the inflammatory cascade. Among them, anti-tumor necrosis factor (anti-TNF) agents (i.e. infliximab, adalimumab, certolizumab pegol) have proved to be effective, particularly for patients with refractory IBD. These biological therapies have changed, at least partially, the clinical course and medical management of IBD. However, the administration of anti-TNF drugs has also been associated with serious side-effects, which have raised concerns on the application of these drugs in clinical practice. The goal of this review is to provide an update and analyze the pros and cons of using anti-TNF therapies in the treatment of IBD.

Clinical utility of measuring infliximab and human anti-chimeric antibody concentrations in patients with inflammatory bowel disease

OBJECTIVES

Human anti-chimeric antibodies (HACAs) and subtherapeutic infliximab concentrations are associated with decreased duration of response. We evaluated the clinical utility of measuring HACA and infliximab concentrations.

METHODS

The medical records of patients with inflammatory bowel disease (IBD) who had HACA and infliximab concentrations measured were reviewed to determine whether the result affected clinical management.

RESULTS

One hundred fifty-five patients had HACA and infliximab concentrations measured. The main indications for testing were loss of response to infliximab (49%), partial response after initiation of infliximab (22%), and possible autoimmune/delayed hypersensitivity reaction (10%). HACAs were identified in 35 patients (23%) and therapeutic infliximab concentrations in 51 patients (33%). Of 177 tests assessed, the results impacted treatment decisions in 73%. In HACA-positive patients, change to another anti-tumor necrosis factor (TNF) agent was associated with a complete or partial response in 92% of patients, whereas dose escalation had a response of 17%. In patients with subtherapeutic infliximab concentrations, dose escalation was associated with complete or partial clinical response in 86% of patients whereas changing to another anti-TNF agent had a response of 33%. Patients with clinical symptoms and therapeutic infliximab concentrations were continued at the same dose 76% of the time and had no evidence of active inflammation by endoscopic/radiographic assessment 62% of the time.

CONCLUSIONS

Measurement of HACA and infliximab concentration impacts management and is clinically useful. Increasing the infliximab dose in patients who have HACAs is ineffective, whereas in patients with subtherapeutic infliximab concentrations, this strategy may be a good alternative to changing to another anti-TNF agent.

Perianal fistulae in Crohn's Disease: current and future approaches to treatment

: affecting sphincter integrity and continence. Traditional surgical and medical approaches are not without their limitations and may result in either comorbidity, such as fecal incontinence, or incomplete healing of the fistulae. Over the last 2 decades these limitations have led to a paradigm shift toward the use of biomaterials, and more recently cell-based therapies, which have met with variable degrees of success. This review discusses the traditional and current methods of treatment, as well as emerging and possible alternative approaches that may improve fistula healing.

Kinoids: a family of immunogens for active anticytokine immunotherapy applied to autoimmune diseases and cancer

The complex homeostasis of tissues is coordinated by the cytokine network and imbalances in this network may result in chronic immune disorders. Key specific cytokines, such as TNF-α, IFN-α, IL-4 or VEGF have been demonstrated to be overproduced or abnormally released in the microenvironment of pathologic tissues. These findings have opened up the way to passive immunotherapy with anticytokine monoclonal antibodies. Even though passive immunotherapy has proved to be efficient, it is hampered by specific limitations. The discovery of a family of immunogens, the kinoids, consisting of inactivated cytokine derivatives, has led some to propose them for active immunotherapy as an alternative to passive immunotherapy. This review focuses on kinoids – on their validation in experimental mouse models and ongoing clinical trials. The advantages offered by this active immune therapy in terms of efficacy, safety and patient compliance will be stressed.

Emerging drugs to treat Crohn's disease

IMPORTANCE OF THE FIELD

Inflammatory bowel diseases are chronic inflammatory diseases that comprise of two forms - Crohn's disease (CD) and ulcerative colitis (UC) - characterized by aberrant responses to luminal bacteria in genetically susceptible individuals. Whereas inflammation is limited to the large intestine in patients with UC, CD can affect all parts of the gastrointestinal tract. During disease exacerbations, pharmacological or surgical intervention is usually needed to re-establish remission; however, current therapeutic interventions cannot cure CD. As a subgroup of patients with CD will not be able to remain in remission with available drugs or suffer from side effects, new therapeutic strategies are needed.

AREAS COVERED IN THIS REVIEW

This review focuses on emerging drugs in the treatment of CD and reviews data on their efficacy and safety. An extensive review of the available literature was undertaken using MEDLINE to identify relevant studies.

WHAT THE READER WILL GAIN

The reader will learn about current therapeutic strategies in patients with CD and gain insights into emerging new drugs.

TAKE HOME MESSAGE

As modification of the clinical course of CD becomes the therapeutic paradigm, potential future treatments have to induce mucosal healing in order to prevent long-term complications. New biologics show promising results.

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.