Mechanisms in failure of infliximab for Crohn's disease

Fatty Acid Oxidation Promotes Apoptotic Resistance and Proinflammatory Phenotype of CD4+ Tissue-resident Memory T cells in Crohn's Disease

BACKGROUND & AIMS

As the most abundant memory T cells and major source of tumor necrosis factor α in the intestinal mucosa of Crohn's disease (CD) patients, CD4+ tissue-resident memory T (TRM) cells play a critical role in CD pathogenesis. We investigated the role of metabolic reprogramming in the regulation of proinflammatory and apoptosis-resistant phenotype for CD4+ TRM cells.

METHODS

CD4+ TRM cells were collected from intestinal resection tissues from control and CD patients. Transcriptomic and metabolomic analysis were performed to identify metabolic characteristics of CD4+ TRM cells. Enzyme-linked immunosorbent assay and quantitative polymerase chain reaction experiments were used to assess cytokines level in CD4+ TRM cells; activation-induced cell apoptosis rate was evaluated by flow cytometry. Transwell assay and wound healing assay were performed to detect the effect of CD4+ TRM cells on the migration of normal intestinal epithelial cells.

RESULTS

Transcriptomic data combined with unbiased metabolomic analysis revealed an increased fatty acid oxidation (FAO) phenotype existed in CD4+ TRM cells from CD patients. The lipidomic data and stable isotope tracer experiments demonstrated that CD4+ TRM cells up-regulated their lipid lipolysis and fatty acid uptake to fuel FAO in CD patients. Mechanistically, the activated nuclear factor kappa B signaling increased transcription of genes involved in lipid lipolysis, fatty acid uptake, and oxidation in CD4+ TRM cells from CD patients. Targeting FAO of CD4+ TRM cells reversed their apoptosis-resistant and proinflammatory phenotype in CD patients.

CONCLUSIONS

CD4+ TRM cells process an accelerated FAO mediated by activated nuclear factor kappa B signaling in CD patients; targeting FAO could reverse their apoptosis-resistant and proinflammatory phenotype. These findings shed a new light on the pathogenic mechanism investigation and novel therapy development in CD patients.

The SYSCID map: a graphical and computational resource of molecular mechanisms across rheumatoid arthritis, systemic lupus erythematosus and inflammatory bowel disease

Chronic inflammatory diseases (CIDs), including inflammatory bowel disease (IBD), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are thought to emerge from an impaired complex network of inter- and intracellular biochemical interactions among several proteins and small chemical compounds under strong influence of genetic and environmental factors. CIDs are characterised by shared and disease-specific processes, which is reflected by partially overlapping genetic risk maps and pathogenic cells (e.g., T cells). Their pathogenesis involves a plethora of intracellular pathways. The translation of the research findings on CIDs molecular mechanisms into effective treatments is challenging and may explain the low remission rates despite modern targeted therapies. Modelling CID-related causal interactions as networks allows us to tackle the complexity at a systems level and improve our understanding of the interplay of key pathways. Here we report the construction, description, and initial applications of the SYSCID map (https://syscid.elixir-luxembourg.org/), a mechanistic causal interaction network covering the molecular crosstalk between IBD, RA and SLE. We demonstrate that the map serves as an interactive, graphical review of IBD, RA and SLE molecular mechanisms, and helps to understand the complexity of omics data. Examples of such application are illustrated using transcriptome data from time-series gene expression profiles following anti-TNF treatment and data from genome-wide associations studies that enable us to suggest potential effects to altered pathways and propose possible mechanistic biomarkers of treatment response.

Exploring the Potential of Fecal Microbiota Transplantation as a Therapy in Tuberculosis and Inflammatory Bowel Disease

This review explores the potential benefits of fecal microbiota transplantation (FMT) as an adjunct treatment in tuberculosis (TB), drawing parallels from its efficacy in inflammatory bowel disease (IBD). FMT has shown promise in restoring the gut microbial balance and modulating immune responses in IBD patients. Considering the similarities in immunomodulation and dysbiosis between IBD and TB, this review hypothesizes that FMT may offer therapeutic benefits as an adjunct therapy in TB. Methods: We conducted a systematic review of the existing literature on FMT in IBD and TB, highlighting the mechanisms and potential implications of FMT in the therapeutic management of both conditions. The findings contribute to understanding FMT's potential role in TB treatment and underscore the necessity for future research in this direction to fully leverage its clinical applications. Conclusion: The integration of FMT into the comprehensive management of TB could potentially enhance treatment outcomes, reduce drug resistance, and mitigate the side effects of conventional therapies. Future research endeavors should focus on well-designed clinical trials to develop guidelines concerning the safety and short- and long-term benefits of FMT in TB patients, as well as to assess potential risks.

The impact of anti-TNFα agents on weight-related changes: new insights from a real-world pharmacovigilance study using the FDA adverse event reporting system (FAERS) database

INTRODUCTION

Studies in patients with immune-mediated inflammatory diseases (IMIDs) have inconsistently suggested that anti-TNFα therapy may be associated with excessive weight gain.

AREAS COVERED

We performed a nested case/non-case analysis to investigate the anti-TNF-α inhibitor-associated body-changes in the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database. The risk was expressed as a measure of disproportionality using the reporting odds ratio (ROR) while adjusting for sex, drugs known to cause weight gain and reporter type. We also performed a time-to-onset (TTO) analysis of body weight-related events.

RESULTS

Infliximab was the most commonly involved TNF-α inhibitor in body weight-related changes, reaching an aROR of 1.42 (95%CI:1. 26; 1.59). An increased risk was especially found in patients affected by rheumatic disorders, both in the adult and pediatric population. The median TTO after the start of anti- TNFα therapy was about 6-7 months for both children and adults.

CONCLUSIONS

Given the potential effect of these agents on the excess weight gain in IMIDs patients, continuous attention for this side effect with appropriate counseling regarding lifestyle modifications are warranted, especially in those at high risk for obesity.

Peripheral inflammatory biomarkers define biotypes of bipolar depression

We identified biologically relevant moderators of response to tumor necrosis factor (TNF)-α inhibitor, infliximab, among 60 individuals with bipolar depression. Data were derived from a 12-week, randomized, placebo-controlled clinical trial secondarily evaluating the efficacy of infliximab on a measure of anhedonia (i.e., Snaith-Hamilton Pleasure Scale). Three inflammatory biotypes were derived from peripheral cytokine measurements using an iterative, machine learning-based approach. Infliximab-randomized participants classified as biotype 3 exhibited lower baseline concentrations of pro- and anti-inflammatory cytokines and soluble TNF receptor-1 and reported greater pro-hedonic improvements, relative to those classified as biotype 1 or 2. Pretreatment biotypes also moderated changes in neuroinflammatory substrates relevant to infliximab's hypothesized mechanism of action. Neuronal origin-enriched extracellular vesicle (NEV) protein concentrations were reduced to two factors using principal axis factoring: phosphorylated nuclear factorκB (p-NFκB), Fas-associated death domain (p-FADD), and IκB kinase (p-IKKα/β) and TNF receptor-1 (TNFR1) comprised factor "NEV1," whereas phosphorylated insulin receptor substrate-1 (p-IRS1), p38 mitogen-activated protein kinase (p-p38), and c-Jun N-terminal kinase (p-JNK) constituted "NEV2". Among infliximab-randomized subjects classified as biotype 3, NEV1 scores were decreased at weeks 2 and 6 and increased at week 12, relative to baseline, and NEV2 scores increased over time. Decreases in NEV1 scores and increases in NEV2 scores were associated with greater reductions in anhedonic symptoms in our classification and regression tree model (r² = 0.22, RMSE = 0.08). Our findings provide preliminary evidence supporting the hypothesis that the pro-hedonic effects of infliximab require modulation of multiple TNF-α signaling pathways, including NF-κB, IRS1, and MAPK.

Changes in Anthropometric Parameters After Anti-TNFα Therapy in Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

Background

Tumour necrosis factor (TNF)-α inhibitors have been widely used for the treatment of moderate-to-severe inflammatory bowel disease (IBD). TNFα also plays an important role in the regulation of weight homeostasis and metabolism and has been linked to variations in anthropometric responses. This relationship in patients with IBD has yet to be determined.

Objectives

Our objective was to evaluate the effects of TNFα inhibitors on changes in anthropometric measures in both adults and children with IBD through a systematic review and meta-analysis.

Methods

Multiple database searches identified studies involving children and adults with IBD and treated with TNFα inhibitors and reporting at least one primary outcome measure. Where possible, data were combined for meta-analysis. The primary outcomes included weight, body mass index (BMI), waist circumference, height, height/velocity, and fat and lean mass. Secondary outcomes included surrogate markers of disease activity. A random-effects model was used to estimate the standardised mean difference (SMD).

Results

In total, 23 cohort studies (total 1167 participants) met the inclusion criteria. Meta-analysis was performed on 13 of these studies. In children, 6–29.3 months of anti-TNFα therapy had a small but statistically significant effect on weight (SMD 0.31; 95% confidence interval [CI] 0.12–0.49; P = 0.001) with a mean gain in z score of 0.30 (standard error [SE] 0.12). In adults, 2–22.4 months of treatment had a moderate effect on BMI (SMD 0.72; 95% CI 0.17–1.26; P = 0.010; mean gain 1.23 kg/m²; SE 0.21). A small but statistically significant increase in BMI z score was found in children (SMD 0.28; 95% CI 0.03–0.53; P = 0.026; mean change 0.31 ± standard deviation [SD] 0.14) after 12–29.3 months of therapy. A meta-analysis of four studies found a negligible but statistically significant increase in height (SMD 0.16; 95% CI 0.06–0.26; P = 0.002; mean change 0.17 z score [SE 0.05]). A negligible effect on fat mass (SMD 0.24; 95% CI −0.19–0.66; P = 0.272) was found in a meta-analysis of five studies. Of note, despite the high heterogeneity among the studies that addressed the issue, these results were also consistently supported by findings from studies not included in the meta-analysis and reviewed in the systematic review. Unfortunately, a lack of data meant we were unable to perform moderator analysis on observed heterogeneity.

Conclusion

Anti-TNFα treatment appears to be associated with an increase in body weight, BMI, and other anthropometric parameters. Given the differing courses of IBD between children and adults, this association should be considered before initiating biologics for undernourished, overweight, and obese patients.

Registration: PROSPERO registration number CRD42020163079.

Electronic supplementary material

The online version of this article (10.1007/s40259-020-00444-9) contains supplementary material, which is available to authorized users.

Combination therapy in inflammatory bowel disease - from traditional immunosuppressors towards the new paradigm of dual targeted therapy

BACKGROUND

Combining immunosuppressors has been proposed as a strategy to enhance treatment efficacy in Inflammatory Bowel Disease (IBD).

AIM

To summarize current evidence on combinations of targeted therapies with traditional immunosuppressors or with other targeted therapies.

METHODS

A literature search on PubMed and Medline databases was performed to identify relevant articles.

RESULTS

Current evidence supports that the combination of infliximab and thiopurines is more effective than monotherapy with both agents in inducing remission in Crohn's Disease and Ulcerative colitis. Data on other combinations of other biologics and traditional immunosuppressors is lacking or show conflicting results. Vedolizumab seems a potentially effective maintenance regimen after calcineurin inhibitors-based rescue therapy in acute severe ulcerative colitis, as an alternative to thiopurines. Dual Targeted Therapy, which is the combination of 2 targeted therapies, might be a reasonable choice in patients with concomitant IBD and extraintestinal manifestations, or in patients with medical-refractory IBD who lack valid alternatives. Combinations with thiopurines are associated with an increased risk of infections and lymphoma. Data on other combinations is scarcer, but no specific safety issue has emerged so far.

CONCLUSIONS

Combination therapies seem to be effective in selected patients, with an overall acceptable safety profile.

Maintaining infliximab induced clinical remission with azathioprine and 5-aminosalicylates in acute severe steroid-refractory ulcerative colitis has lower cost and high efficacy (MIRACLE): a multicenter study

Background/Aims

Infliximab (IFX) has been used to induce and maintain remission in patients with severe steroid-refractory ulcerative colitis (UC). Long-term use of biologics in developing countries is limited by high cost and frequent side effects. An optimal maintenance strategy in these patients needs to be established.

Methods

A retrospective analysis of maintenance of clinical remission with combination of azathioprine (AZA) and 5-aminosalicylates (5-ASA) in patients with severe steroid-refractory UC where IFX (5 mg/kg intravenously at weeks 0, 2, 6) had been used only as an induction therapy was done at 2 centers in India. Primary outcome was the proportion of patients maintaining corticosteroid-free sustained clinical remission (SCR) at the end of study period. Rates of relapse and cost of therapy were also analyzed.

Results

Of the 137 patients who received rescue IFX induction therapy, 77 (56.2%) achieved clinical remission (mean age 34.81 ± 13.32 years, 68.83% males, median follow-up 4 years, range 3 months to 6 years) and were included. Cumulative corticosteroid-free SCR was maintained in 68%, 59%, 42%, and 35% patients at 1, 2, 4, and 6 years respectively. Sixty-seven relapses were observed in 33 patients. Majority of the relapses (45/67, 67.16%) occurred within first 2 years of follow-up. Two relapses were managed with re-induction with IFX, one required colectomy, whereas all other responded to repeat course(s) of corticosteroids. Annual per capita maintenance therapy with 5-ASA and AZA was cheaper by US$ 4,526 compared to maintaining remission with IFX.

Conclusions

Clinical remission achieved with IFX induction therapy in severe steroid-refractory UC can be sustained over long time with a combination of AZA and 5-ASA.

Current Concepts of Pharmacotherapy in Crohn's Disease

BACKGROUND

The incidence of Crohn's disease (CD) is rising, and still many patients have to undergo repeated surgery due to failure of pharmacologic therapy.

RESULTS

While the introduction of anti-TNF agents started biologic therapy for CD and revolutionized the management of patients, the number of patients who do not respond to this treatment or lose their initial response to this treatment is still substantial. Therefore, the recent introduction of new therapeutic options with anti-integrins and new anti-cytokines was an important step to provide more effective treatment for our patients. Yet, next to new drugs also new treatment strategies have been proposed.

CONCLUSION

In this article, we will review these new aspects of pharmacologic therapy for CD -patients.

Therapeutic drug monitoring with vedolizumab in inflammatory bowel disease

Therapeutic drug monitoring (TDM) is a useful tool for decision-making process in patients with inflammatory bowel disease (IBD) treated with anti TNF-α drugs, especially when experiencing loss of response. Growing evidences support the existence of exposure-response relationship with vedolizumab, but the utility and the appropriate use of TDM in clinical practice is still under debate. In this review, we summarize all evidences supporting a TDM-guided approach for patients treated with vedolizumab, suggesting three potential scenarios: 1) early prediction of long-term outcomes; 2) verifying the best strategy in case of loss of response; 3) maximizing therapeutic efficacy during maintenance treatment. Vedolizumab through concentrations <20 µg/mL at week 6 and >12 µg/mL seem to be associated with more favorable outcomes. No comparative studies have been conducted so far to demonstrate the advantage of adopting a TDM-guided versus an empirical approach for managing primary or secondary nonresponses. The frequency of antibodies to vedolizumab detection is quite low (up to 4% in pivotal trials), suggesting, unlike of anti TNF-α agents, a low probability of experiencing an immune-mediated pharmacokinetic failure in clinical practice. Future prospective and controlled studies are warranted to establish the guidance on the use of a TDM-guided approach with vedolizumab in clinical practice.

Interleukin-22 receptor 1 is expressed in multinucleated giant cells: A study on intestinal tuberculosis and Crohn's disease

BACKGROUND

It is challenging to distinguish intestinal tuberculosis from Crohn's disease due to dynamic changes in epidemiology and similar clinical characteristics. Recent studies have shown that polymorphisms in genes involved in the interleukin (IL)-23/IL-17 axis may affect intestinal mucosal immunity by affecting the differentiation of Th17 cells.

AIM

To investigate the specific single-nucleotide polymorphisms (SNPs) in genes involved in the IL-23/IL-17 axis and possible pathways that affect susceptibility to intestinal tuberculosis and Crohn's disease.

METHODS

We analysed 133 patients with intestinal tuberculosis, 128 with Crohn's disease, and 500 normal controls. DNA was extracted from paraffin-embedded specimens or whole blood. Four SNPs in the IL23/Th17 axis (IL22 rs2227473, IL1β rs1143627, TGFβ rs4803455, and IL17 rs8193036) were genotyped with TaqMan assays. The transcriptional activity levels of different genotypes of rs2227473 were detected by dual luciferase reporter gene assay. The expression of IL-22R1 in different intestinal diseases was detected by immunohistochemistry.

RESULTS

The A allele frequency of rs2227473 (P = 0.030, odds ratio = 0.60, 95% confidence interval: 0.37-0.95) showed an abnormal distribution between intestinal tuberculosis and healthy controls. The presence of the A allele was associated with a higher IL-22 transcriptional activity (P < 0.05). In addition, IL-22R1 was expressed in intestinal lymphoid tissues, especially under conditions of intestinal tuberculosis, and highly expressed in macrophage-derived Langhans giant cells. The results of immunohistochemistry showed that the expression of IL-22R1 in patients with Crohn's disease and intestinal tuberculosis was significantly higher than that in patients with intestinal polyps and colon cancer (P < 0.01).

CONCLUSION

High IL-22 expression seems to be a protective factor for intestinal tuberculosis. IL-22R1 is expressed in Langhans giant cells, suggesting that the IL-22/IL-22R1 system links adaptive and innate immunity.

Therapeutic Drug Monitoring is More Cost-Effective than a Clinically Based Approach in the Management of Loss of Response to Infliximab in Inflammatory Bowel Disease: An Observational Multicentre Study

BACKGROUND AND AIMS

Empirical dose intensification and therapeutic drug monitoring [TDM] of infliximab [IFX] trough levels [ITLs] and antibody to infliximab [ATI] assays are recognized approaches for managing loss of response [LoR] in patients with inflammatory bowel disease [IBD]. The aim of the study was to compare these two interventions in a clinical setting, in terms of effectiveness and cost savings.

METHODS

Consecutive IBD patients experiencing LoR were clinically managed according to a TDM algorithm. A historical group of empirically treated patients, for whom sera for ITLs and ATI assays had been collected, served as the control group. Clinical outcomes 12 weeks after the therapeutic interventions were compared between the two groups. A cost-minimization analysis was performed to compare the economic impact of these two approaches.

RESULTS

Ninety-six patients were enrolled prospectively and compared with 52 controls. The two cohorts were similar in characteristics and in the distribution of TDM results. In the prospective cohort, however, we observed less IFX dose escalations compared with in the controls [45% versus 71%, p = 0.003]. Also, more patients were switched to a different anti-TNFα in the prospective cohort than in the control cohort [25% versus 4%, p = 0.001]. The percentages of patients achieving a clinical response at 12 weeks were 52% and 54% for the prospective and control groups, respectively. By cost analysis, we estimated a savings of 15% if the TDM algorithm was applied.

CONCLUSIONS

In our population, applying a TDM algorithm for LoR to IFX resulted in less dose escalations, without loss of efficacy, compared with empirical adjustment. In addition, the TDM approach was cost-effective.

Time to clinical response and remission for therapeutics in inflammatory bowel diseases: What should the clinician expect, what should patients be told?

An awareness of the expected time for therapies to induce symptomatic improvement and remission is necessary for determining the timing of follow-up, disease (re)assessment, and the duration to persist with therapies, yet this is seldom reported as an outcome in clinical trials. In this review, we explore the time to clinical response and remission of current therapies for inflammatory bowel disease (IBD) as well as medication, patient and disease related factors that may influence the time to clinical response. It appears that the time to therapeutic response varies depending on the indication for therapy (Crohn's disease or ulcerative colitis). Agents with the most rapid time to clinical response included corticosteroids, calcineurin inhibitors, exclusive enteral nutrition, aminosalicylates and anti-tumor necrosis factor therapy which will work in most patients within the first 2 mo. Vedolizumab, methotrexate and thiopurines had a longer time to clinical response and can take several months to achieve maximal efficacy. Factors affecting the time to clinical response of therapies included use of concomitant therapy, disease duration, smoking status, disease phenotype and advanced age. There appears to be marked variation in time to clinical response for therapies used in IBD which is further influenced by disease and patient related factors. Understanding the expected time to therapeutic response is integral to inform further decision making, maintain a patient-centered approach and ensure treatment is given an appropriate timeframe to achieve maximal benefit prior to cessation.

Optimizing Treatment with TNF Inhibitors in Inflammatory Bowel Disease by Monitoring Drug Levels and Antidrug Antibodies

BACKGROUND

Biological tumor necrosis factor (TNF) inhibitors have revolutionized the treatment of inflammatory bowel disease and redefined treatment goals to include mucosal healing. Clinicians are faced with challenges such as inadequate responses, treatment failures, side effects, and high drug costs. The objective is to review optimization of anti-TNF therapy by use of personalized treatment strategies based on circulating drug levels and antidrug antibodies (Abs), i.e. therapeutic drug monitoring (TDM). Furthermore, to outline TDM-related pitfalls and their prevention.

METHODS

Literature review.

RESULTS

Circulating anti-TNF drug trough level is a marker for the pharmacokinetics (PK) of TNF inhibitors. Because of a number of factors, including antidrug antibodies, PK varies between and within patients across time leading to variable clinical outcomes. Differences in intestinal inflammatory phenotype influencing the pharmacodynamic (PD) responses to TNF inhibitors also affect treatment outcomes. As an alternative to handling anti-TNF-treated patients by empiric strategies, TDM identifies underlying PK and PD-related reasons for treatment failure and aids decision making to secure optimal clinical and economic outcomes. Although promising, evidence does not the support use of TDM to counteract treatment failure in quiescent disease. Use of TDM is challenged by methodological biases, difficulties related to differentiation between PK and PD problems, and temporal biases due to lack of chronology between changes in PK versus symptomatic and objective disease activity manifestations. Biases can be accommodated by knowledgeable interpretation of results obtained by validated assays with clinically established thresholds, and by repeated assessments over time using complimentary techniques.

CONCLUSIONS

TDM-guided anti-TNF therapy at treatment failure has been brought from bench to bedside.

New Insights into the Mechanisms of Action of Anti-Tumor Necrosis Factor-α Monoclonal Antibodies in Inflammatory Bowel Disease

Tumor necrosis factor alpha (TNF-α) has been widely accepted as a therapeutic target for inflammatory disorders including inflammatory bowel disease. Anti-TNF-α monoclonal antibodies (mAbs) including infliximab, adalimumab, golimumab, and certolizumab pegol have revolutionized therapy for these chronic inflammatory disorders. These agents are potent inhibitors of TNF-α, but significant evidence points to the fact that their actions extend beyond simple neutralization of the cytokine. Recent advances in understanding the mechanism of action of anti-TNF-α mAbs has discovered a number of previously unrecognized actions that are likely to be relevant in mediating their anti-inflammatory effects. Many of those actions are mediated by the binding of the antibodies to transmembrane TNF-α (tmTNF-α) and involve complex interactions with other molecular factors and cells. In this review, we have highlighted new information on the mechanism of actions of anti-TNF-α mAbs, from in vitro and in vivo studies. Despite obvious benefits in many patients, the clinical use of these antibodies are hampered by the fact that some patients do not respond to them, and among patients who do respond, many will develop recurrent disease despite continued dosing. Although pharmacokinetic factors explain some of the observed cases of partial or complete resistance to the effects of anti-TNF-α mAbs, other nonresponder patients may be resistant to those agents mechanism of action. A more thorough understanding of the mechanism of action of anti-TNF-α mAbs may allow the development of strategies to individualize therapy and to overcome resistance.

Individualized Therapy Is a Long-Term Cost-Effective Method Compared to Dose Intensification in Crohn's Disease Patients Failing Infliximab

BACKGROUND

In Crohn's disease patients failing infliximab therapy, interventions defined by an algorithm based on infliximab and anti-infliximab antibody measurements have proven more cost-effective than intensifying the infliximab regimen.

AIM

This study investigated long-term economic outcomes at the week 20 follow-up study visit and after 1 year. Clinical outcomes were assessed at week 20.

METHODS

Follow-up from a 12-week, single-blind, clinical trial where patients with infliximab treatment failure were randomized to infliximab intensification (5 mg/kg every 4 weeks) (n = 36), or algorithm-defined interventions (n = 33). Accumulated costs, expressed as mean costs per patient, were based on the Danish National Patient Registry.

RESULTS

At the scheduled week 20 follow-up study visit, response and remission rates were similar in all study subpopulations between patients treated by the algorithm or by infliximab intensification. However, the sum of healthcare costs related to Crohn's disease was substantially lower (31 %) for patients randomized to algorithm-based interventions than infliximab intensification in the intention-to-treat population: $11,940 versus $17,236; p = 0.005. For per-protocol patients (n = 55), costs at the week 20 follow-up visit were even lower (49 %) in the algorithm group: $8,742 versus $17,236; p = 0.002. Figures were similar for patients having completed the 12-week trial as per protocol (50 % reduction in costs) (n = 45). Among patients continuing the allocated study intervention throughout the entire 20-week follow-up period (n = 29), costs were reduced by 60 % in algorithm-treated patients: $7,056 versus $17,776; p < 0.001. Cost-reduction percentages remained stable throughout one year.

CONCLUSION

Economic benefit of algorithm-based interventions at infliximab failure is maintained throughout 1 year.

Infliximab reverses inflammatory muscle wasting (sarcopenia) in Crohn's disease

BACKGROUND

Muscle wasting or sarcopenia arising from chronic inflammation is found in 60% of patients with Crohn's disease. Transcriptional protein NF-κB reduces muscle formation through MyoD transcription and increases muscle breakdown by proteolysis.

AIM

As TNF is a potent activator of NF-κB, and anti-TNF agent infliximab (IFX) prevents NF-κB activation, to determine whether or not Crohn's patients treated with IFX gain muscle volume and strength.

METHODS

We performed a prospective, repeated-measures cohort study in adult Crohn's disease patients with an acute disease flare. Patients were instructed not to vary diet or activity. Concomitant medications were kept stable. At week 1 (pre-treatment), week 16 (post-IFX induction) and week 25 (post-first IFX maintenance dose), we assessed (i) MRI volume of quadriceps femoris at anatomical mid-thigh; (ii) maximal concentric quadriceps contractions strength at three specific speeds of contraction; (iii) physical activity by validated instrument (IPAQ); (iv) Three-day food record of intake and composition (food-weighing method); (v) Serum levels of IL6.

RESULTS

Nineteen patients (58% female; mean age 33.2 ± 10.7 years) were recruited. IFX increased muscle volume in both legs from baseline (right, 1505 cm(3) ) to week 25 (right, 1569 cm(3) ; P = 0.010). IFX also increased muscle strength in both legs from baseline (right 30°/s, 184.8 Nm) to week 25 (right 30°/s, 213.6 Nm; P = 0.002). Muscle volume gain correlated with male gender (P = 0.003). Significant gains in muscle volume and strength were unrelated to prednisolone use. Serum IL6 levels decreased by week 25 (P = 0.037).

CONCLUSION

The anti-TNF agent infliximab reverses inflammatory sarcopenia in patients with Crohn's disease.

Micheliolide, a new sesquiterpene lactone that inhibits intestinal inflammation and colitis-associated cancer

Inflammatory bowel diseases (IBD) are chronic inflammatory conditions of the gastrointestinal (GI) tract associated with an increased risk of colorectal cancer (CRC). Current treatments for both IBD and colitis-associated CRC suffer from numerous side effects. Parthenolide (PTL) is a sesquiterpene lactone with anti-inflammatory activity, and previous studies have demonstrated that PTL is a potent inhibitor of the NF-κB pathway. Micheliolide (MCL), substantially more stable than PTL in vivo, was recently developed, and this study aimed to decipher its suitability as therapeutic tool for IBD and IBD-associated diseases. Similar to PTL, MCL inhibited NF-κB activation and subsequent pro-inflammatory pathways activation in vitro. Pro-drug forms of both compounds inhibited the DSS-induced colitis when administrated intraperitoneally or encapsulated in a polysaccharide gel designed to release drugs in the colon. Interestingly, MCL was found to attenuate carcinogenesis in AOM/DSS-induced CRC, thus providing new candidate for the treatment of inflammatory bowel disease and CRC.

Clinical implications of measuring drug and anti-drug antibodies by different assays when optimizing infliximab treatment failure in Crohn's disease: post hoc analysis of a randomized controlled trial

OBJECTIVES

Cost-effective guidance of therapeutic strategy in Crohn's disease patients with secondary infliximab (IFX) treatment failure may be achieved by serum IFX and anti-IFX antibody (Ab) measurements by radioimmunoassay (RIA). This study investigated implications of using other techniques for this purpose.

METHODS

This is a post hoc analysis of randomized clinical trial including 66 Crohn's disease patients with IFX failure in whom IFX and anti-IFX Ab measurements by RIA had been used for therapeutic guidance. Samples were additionally assessed by enzyme-linked immunosorbent assay (ELISA), homogeneous mobility shift assay (HMSA), and functional cell-based reporter gene assay (RGA).

RESULTS

IFX detection was comparable between assays (82% RIA, 76% ELISA, 88% HMSA, and 74% RGA), and it correlated significantly (Pearson's r=0.91-0.97, P<0.0001). However, IFX concentrations varied systematically between all pair of assays except RIA-RGA. Anti-IFX Ab detection was variable (27% RIA, 9% ELISA, 33% HMSA, and 11% RGA), but correlated significantly (Pearson's r=0.77-0.96; P<0.0001). Anti-IFX Abs detected by RIA and HMSA were often from sera without drug-neutralizing activity (RGA). Assays agreed on classification of underlying mechanism for treatment failure in most cases (79-94%). The majority (74-88%) failed IFX owing to pharmacodynamic problems, or had noninflammatory pathophysiology for symptoms resembling relapse. Applied threshold for therapeutic vs. subtherapeutic IFX level influenced classifications. The four different assays did not differ in terms of the ability to predict response to interventions defined by the algorithm.

CONCLUSIONS

Despite variable analytical properties, common assays result in similar classifications and interventions in patients with IFX treatment failure, and with comparable clinical outcomes. Implications are, however, profound for the minority classified differently.

Individualised therapy is more cost-effective than dose intensification in patients with Crohn's disease who lose response to anti-TNF treatment: a randomised, controlled trial

OBJECTIVE

Although the reasons for secondary loss of response to infliximab (IFX) maintenance therapy in Crohn's disease vary, dose intensification is usually recommended. This study investigated the cost-effectiveness of interventions defined by an algorithm designed to identify specific reasons for therapeutic failure.

DESIGN

Randomised, controlled, single-blind, multicentre study. 69 patients with secondary IFX failure were randomised to IFX dose intensification (5 mg/kg every 4 weeks) (n=36) or interventions based on serum IFX and IFX antibody levels using the proposed algorithm (n=33). Predefined co-primary end points at week 12 were proportion of patients responding (Crohn's Disease Activity Index (CDAI) decrease ≥ 70, or ≥ 50% reduction in active fistulas) and accumulated costs related to treatment of Crohn's disease, expressed as mean cost per patient, based on the Danish National Patient Registry for all hospitalisation and outpatient costs in the Danish healthcare sector.

RESULTS

Costs for intention-to-treat patients were substantially lower (34%) for those treated in accordance with the algorithm than by IFX dose intensification: € 6038 vs € 9178, p<0.001. However, disease control, as judged by response rates, was similar: 58% and 53%, respectively, p=0.81; difference 5% (-19% to 28%). For per-protocol patients, treatment costs were even lower (56%) in the algorithm-treated group (€ 4062 vs € 9178, p<0.001) and with similar response rates (47% vs 53%, p=0.78; difference -5% (-33% to 22%)).

CONCLUSIONS

Treatment of secondary IFX failure using an algorithm based on combined IFX and IFX antibody measurements significantly reduces average treatment costs per patient compared with routine IFX dose escalation and without any apparent negative effect on clinical efficacy.

TRIAL REGISTRATION NO

NCT00851565.

The role of infliximab on paracetamol-induced hepatotoxicity in rats

Paracetamol has a reasonable safety profile when consumed in therapeutic doses. However, it could induce hepatotoxicity and even acute liver failure when taken at an overdose. Infliximab is tumor necrosis factor alpha (TNF-α) inhibitor agent, which has been developed as a therapeutic agent for TNF-α-mediated disease. It acts by binding and neutralizing TNF. The aim of our study was to evaluate the hepatoprotective activity of infliximab on paracetamol-induced hepatotoxicity and to understand the relationship between the TNF-α and paracetamol-induced liver injury. Fifty-six rats were divided into eight groups as each composed of seven rats: (1) intact, (2) 7 mg/kg infliximab, (3) 140 mg/kg NAC, (4) 2 g/kg paracetamol, (5) 2 g/kg paracetamol + 140 mg/kg NAC, (6) 2 g/kg paracetamol + 3 mg/kg infliximab, (7) 2 g/kg paracetamol + 5 mg/kg infliximab and (8) 2 g/kg paracetamol + 7 mg/kg infliximab groups. Liver function tests including lipid peroxidation levels were analyzed and histopathological changes of liver were also observed. There were statistically significant increases in the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), levels of TNF-α and malondialdehyde (MDA) and decreases in the activity of superoxide dismutase (SOD) and level of glutathione (GSH) in the group treated with paracetamol. Infliximab administration dramatically reduced serum ALT, AST and TNF-α level. Also, it restored GSH, SOD and decreased MDA levels in liver. Liver histopathological examination showed that infliximab administration antagonized paracetamol-induced liver pathological damage. The results of present study suggest that infliximab has significant hepatoprotective activity on paracetamol-induced hepatotoxicity.

Clinical use and mechanisms of infliximab treatment on inflammatory bowel disease: a recent update

The pathogenesis and treatment of inflammatory bowel disease (IBD) have been recently advanced, while it is still challenged with high morbidity and poor prognosis. Infliximab, a monoclonal antibody of tumor necrosis factor (TNF), has emerged as an efficient treatment with many clinical benefits such as quick disease activity reduction and IBD patient life quality improvement. However, the biological effects of infliximab on IBD need to be elucidated. This paper reviewed the clinical use and recently advanced biological action of infliximab on IBD. By forming the stable complex with the soluble or the membrane form of TNF in fluid environment or on cell surface of immune cell, fibroblast, endothelium, and epithelium, infliximab quenches TNF activity and performs the important biological actions which lead to amelioration and remission of immune responses. The mechanisms of infliximab treatment for IBD were intensively discussed. The recent advances on two topics including predictors and side effects of infliximab treatment were also reviewed.

Hematopoietic stem cell transplantation for curing children with severe autoimmune diseases: is this a valid option?

The cure of children with severe AD, especially patients with severe, progressive, and therapy-resistant autoimmunity, represents a challenge for current medical practice. The idea of HSCT as a promising therapeutic opportunity was borne accidentally from finding patients who, after undergoing HSCT for a hematological indication, were cured of a concomitant AD. Thus, over the last two decades, HSCT has been extensively investigated, and it has become an appealing therapy for rheumatological (juvenile rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis) and hematological diseases (immune cytopenias). Recently, interesting results have been also described in type 1 diabetes mellitus and Crohn's disease. Although the use of HSCT has been steadily rising in the last few years, many questions are still open, especially after the discoveries of many new biological agents. Given the low incidence of ADs in children, most of the data about the use of the HSCT for these diseases are taken from a mixed cohort of adults and children. The aim of this review is to summarize the published studies and to try to answer the question as to whether this procedure can be considered a promising approach.

Candidate mucosal and surrogate biomarkers of inflammatory bowel disease in the era of new technology

OBJECTIVE

There is increasing knowledge of the pathophysiology behind inflammatory bowel disease (IBD) although the exact mechanism is far from fully understood. In the era of new technology, over the last years molecular approaches have shed light on the inflammatory mechanisms and their metabolic end products. This opens for a molecular fingerprinting that can be used in the biomarker field of IBD. There is a great need of biomarkers for prediction of clinical outcome and prognostic biomarker for prediction of therapeutic effects in IBD. Although the biomarker concept is old, so far very few really useful biomarkers exist in IBD.

MATERIAL AND METHODS

Here, we review the predictive and prognostic biomarkers in IBD in the era of new technologies with emphasis on the potential of molecular fingerprinting.

RESULTS

Very few candidate biomarkers have been documented. The most promising candidate predictor is tumor necrosis factor-α, but there is a lack of validation.

CONCLUSION

So far, there are few biomarkers documented in IBD, but we are at the start of a new scientific field that will be of great value for the handling of the disease.

Serum immune-activation potency and response to anti-TNF-α therapy in Crohn's disease

AIM: To study whether immune-activation stage in serum of adult Crohn’s disease (CD) patients correlates with disease activity and with treatment response to anti-tumor necrosis factor-α (TNF-α) therapy.

METHODS: Serum samples were obtained from 15 adult CD patients introduced to anti-TNF-α therapy. The individual stage of immune activation was studied applying our new in vitro assay, in which target cells (donor derived peripheral blood mononuclear cells) were cultured with patient serum and the T-cell activation induced by the patient serum was studied using a panel of markers for effector [interferon γ (IFNγ), interleukin (IL)-5] and regulatory T-cells [forkhead transcription factor 3 (FOXP3) and glucocorticoid-induced tumour necrosis factor receptor (GITR)]. The endoscopic disease activity was assessed with the Crohn’s disease endoscopic index of severity (CDEIS) before and 3 mo after therapy with an anti-TNF-α agent.

RESULTS: Low induction of FOXP3 and GITR in target cells cultured in the presence of patient serum was associated with high disease activity i.e. CDEIS assessed before therapy (r = -0.621, P = 0.013 and r = -0.625, P = 0.013, respectively). FOXP3 expression correlated inversely with pre-treatment erythrocyte sedimentation rate (r = -0.548, P = 0.034). Low serum induced FOXP3 (r = -0.600, P = 0.018) and GITR (r = -0.589, P = 0.021) expression and low IFNγ secretion from target cells (r = -0.538, P = 0.039) associated with treatment response detected as a decrease in CDEIS.

CONCLUSION: The immune-activation potency in the patient serum prior to anti-TNF-α therapy reflected intestinal inflammation and the therapeutic response.

Mucosal biomarkers in inflammatory bowel disease: Key pathogenic players or disease predictors?

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders of the bowel, including ulcerative colitis and Crohn’s disease. A single etiology has not been identified, but rather the pathogenesis of IBD is very complex and involves several major and minor contributors, employing different inflammatory pathways which have different roles in different patients. Although new and powerful medical treatments are available, many are biological drugs or immunosuppressants, which are associated with significant side effects and elevated costs. As a result, the need for predicting disease course and response to therapy is essential. Major attempts have been made at identifying clinical characteristics, concurrent medical therapy, and serological and genetic markers as predictors of response to biological agents. Only few reports exist on how mucosal/tissue markers are able to predict clinical behavior of the disease or its response to therapy. The aim of this paper therefore is to review the little information available regarding tissue markers as predictors of response to therapy, and reevaluate the role of tissue factors associated with disease severity, which can eventually be ranked as “tissue factor predictors”. Five main categories are assessed, including mucosal cytokines and chemokines, adhesion molecules and markers of activation, immune and non-immune cells, and other mucosal components. Improvement in the design and specificity of clinical studies are mandatory to be able to classify tissue markers as predictors of disease course and response to specific therapy, obtain the goal of achieving “personalized pathogenesis-oriented therapy” in IBD.

Ameliorative effects of bombesin and neurotensin on trinitrobenzene sulphonic acid-induced colitis, oxidative damage and apoptosis in rats

AIM: To investigate the effects of bombesin (BBS) and neurotensin (NTS) on apoptosis and colitis in an ulcerative colitis model.

METHODS: In this study, a total of 50 rats were divided equally into 5 groups. In the control group, no colitis induction or drug administration was performed. Colitis was induced in all other groups. Following the induction of colitis, BBS, NTS or both were applied to three groups of rats. The remaining group (colitis group) received no treatment. On the 11th d after induction of colitis and drug treatment, blood samples were collected for TNF-α and IL-6 level studies. Malondialdehyde (MDA), carbonyl, myeloperoxidase (MPO) and caspase-3 activities, as well as histopathological findings, evaluated in colonic tissues.

RESULTS: According to the macroscopic and microscopic findings, the study groups treated with BBS, NTS and BBS + NTS showed significantly lower damage and inflammation compared with the colitis group (macroscopic score, 2.1 ± 0.87, 3.7 ± 0.94 and 2.1 ± 0.87 vs 7.3 ± 0.94; microscopic score, 2.0 ± 0.66, 3.3 ± 0.82 and 1.8 ± 0.63 vs 5.2 ± 0.78, P < 0.01). TNF-α and IL-6 levels were increased significantly in all groups compared with the control group. These increases were significantly smaller in the BBS, NTS and BBS + NTS groups compared with the colitis group (TNF-α levels, 169.69 ± 53.56, 245.86 ± 64.85 and 175.54 ± 42.19 vs 556.44 ± 49.82; IL-6 levels, 443.30 ± 53.99, 612.80 ± 70.39 and 396.80 ± 78.43 vs 1505.90 ± 222.23, P < 0.05). The colonic MPO and MDA levels were significantly lower in control, BBS, NTS and BBS + NTS groups than in the colitis group (MPO levels, 24.36 ± 8.10, 40.51 ± 8.67 and 25.83 ± 6.43 vs 161.47 ± 38.24; MDA levels, 4.70 ± 1.41, 6.55 ± 1.12 and 4.51 ± 0.54 vs 15.60 ± 1.88, P < 0.05). Carbonyl content and caspase-3 levels were higher in the colitis and NTS groups than in control, BBS and BBS + NTS groups (carbonyl levels, 553.99 ± 59.58 and 336.26 ± 35.72 vs 209.76 ± 30.92, 219.76 ± 25.77 and 220.34 ± 36.95; caspase-3 levels, 451.70 ± 68.27 and 216.20 ± 28.17 vs 28.60 ± 6.46, 170.50 ± 32.37 and 166.50 ± 30.95, P < 0.05).

CONCLUSION: The results of this study suggest BBS and NTS, through their anti-inflammatory actions, support the maintenance of colonic integrity and merit consideration as potential agents for ameliorating colonic inflammation.

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.

TNF-α BLOCKAGE IN A MOUSE MODEL OF SCI

The aim of our study was to evaluate in vivo the therapeutic efficacy of genetic inhibition of TNF-alpha using TNF-R1 knockout mice in an experimental model of spinal cord trauma. Spinal cord injury was induced by the application of vascular clips to the dura via a four-level T5-T8 laminectomy. To elucidate whether the observed anti-inflammatory status is related to the inhibition of TNF-alpha, we also investigated the effect of infliximab, a TNF-alpha-soluble receptor construct, on spinal cord damage. Pharmacological and genetic TNF-alpha inhibition significantly reduced the degree of (1) spinal cord inflammation and tissue injury (histological score), (2) neutrophil infiltration (evaluated by myeloperoxidase activity), (3) cytokine expression (TNF-alpha), (4) and apoptosis (terminal deoxynucleotidyltransferase-mediated uridine triphosphate end labeling staining, Bax, Bcl-2, and Fas-L expression). In a separate set of experiments, we have also demonstrated that TNF-alpha inhibition significantly ameliorated the recovery of limb function (evaluated by motor recovery score). Taken together, our results demonstrate that inhibition of TNF-alpha reduces the development of inflammation and tissue injury associated with spinal cord trauma, suggesting a possible role of TNF-alpha on the pathogenesis of spinal cord injury.

The effect of the cholinergic anti-inflammatory pathway on experimental colitis

Inflammatory bowel diseases (IBD) are characterized by proinflammatory cytokines, tissue damage and loss of neuron in inflamed mucosa, which implies the cholinergic anti-inflammatory pathway may be destroyed during the process of inflammatory response. In the study, we identified the effect of cholinergic agonist as anabaseine (AN) and nicotinic receptor antagonist as chlorisondamine diiodide (CHD) on trinitrobenzene sulfonic acid (TNBS)-induced colitis, to investigate the potential therapeutic effect of the cholinergic anti-inflammatory pathway on IBD. Experimental colitis was induced by TNBS at day 1, 10 mug AN or 1.5 mug CHD was injected i.p. to mouse right after the induction of colitis, and repeated on interval day till the mice were sacrificed at day 8. Colonic inflammation was examined by histological analysis, myeloperoxidase (MPO) activity, and the production of tumour necrosis factor (TNF)-alpha in tissue. Lamina propria mononuclear cells (LPMC) were isolated, and NF-kappaB activation was detected by western blot. The mice with colitis treated by AN showed less tissue damage, less MPO activity, less TNF-alpha production in colon, and inhibited NF-kappaB activation in LPMC, compared with those mice with colitis untreated, whereas the mice with colitis treated by CHD showed the worst tissue damage, the highest MPO activity, the highest TNF-alpha level, and enlarged NF-kappaB activation in LPMC. Agonist of the cholinergic anti-inflammatory pathway inhibits colonic inflammatory response by downregulating the production of TNF-alpha, and inhibiting NF-kappaB activation, which suggests that modulating the cholinergic anti-inflammatory pathway may be a new potential management for IBD.

Early changes in rectal nitric oxide and mucosal inflammatory mediators in Crohn's colitis in response to infliximab treatment

BACKGROUND

Treatment with tumor necrosis factor-alpha monoclonal antibody (infliximab) reduces clinical activity and intestinal inflammation in Crohn's disease.

AIM

To study the time-course of the effects of infliximab with reference to mucosal cytokine and inducible nitric oxide synthase expression.

METHODS

Thirty-two patients with Crohn's disease were treated with single dose infliximab (5 mg/kg). Disease activity was assessed days 1, 3, 7 and 28 using Harvey-Bradshaw index. Rectal nitric oxide levels were determined and rectal biopsies collected before treatment, 1 h after infusion and on days 3, 7 and 28. Immunohistochemical staining against inducible nitric oxide synthase, tumor necrosis factor-alpha, interleukin-1beta and interferon-gamma were performed.

RESULTS

Clinical response was seen in 14 patients with down-regulation of global immunohistochemistry expression, reaching nadir day 3. Rectal nitric oxide was increased at baseline (3578 +/- 1199 parts per billion, ppb) compared with controls (89 +/- 13 ppb) (P < 0.001). In patients with clinical response, rectal nitric oxide decreased from 3926 +/- 1687 ppb to 1050 +/- 428 ppb day 28 (P < 0.05).

CONCLUSIONS

Down-regulation of mucosal inflammatory mediators occurs after infliximab. Rectal nitric oxide levels parallel down-regulation of inducible nitric oxide synthase, tumor necrosis factor-alpha, interleukin-1beta and interferon-gamma and may serve as a quantitative biomarker of intestinal inflammation.

Sex steroid regulation of macrophage migration inhibitory factor in normal and inflamed colon in the female rat

BACKGROUND AND AIMS

Sex steroids influence IBD symptoms. Macrophage migration inhibitory factor (MIF), a target of sex steroids in other inflammatory models, promotes interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha release in colitis. We investigated whether estradiol and progesterone influence MIF, IL-1beta, and TNF-alpha production in experimental colitis.

METHODS

Colonic MIF, IL-1beta, and TNF-alpha levels were measured in cyclic and ovariectomized rats, with or without estradiol benzoate (EB) or progesterone (P) replacement. MIF distribution was assessed by immunohistochemistry. Cytokines, myeloperoxidase activity, macroscopic damage, and plasma corticosterone were assessed 24 hours after intrarectal trinitrobenzene sulfonic acid (TNBS), with and without neutralizing anti-MIF antibody. Effects of EB and P on myeloperoxidase activity and MIF concentration were also assessed at 7 days in dextran sulfate sodium-induced colitis.

RESULTS

Basal IL-1beta and TNF-alpha contents did not fluctuate during the estrous cycle, while MIF concentrations increased from estrus (estrogen dominance) to metestrus (P dominance; P < .05). EB and P treatment mimicked these effects in ovariectomized rats, and similarly altered MIF immunostaining. Progesterone dominance aggravated TNBS colitis in comparison with estrogen. Progesterone enhanced TNBS-induced MIF (P < .001) and TNF-alpha (P < .01) production, while EB decreased MIF (P < .01) and IL-beta levels (P < .01). Anti-MIF antibody prevented P-mediated up-regulation of TNF-alpha, improved TNBS colitis, and enhanced plasma corticosterone. At 7 days after dextran sulfate sodium, EB decreased myeloperoxidase activity and MIF concentration, while P had no effect.

CONCLUSIONS

Estrogen decreases while progesterone increases MIF production in the female rat colon. Changes in basal MIF contents may affect colon susceptibility to inflammation, by modulating TNF-alpha and IL-1beta production during early stages of colitis.

Predictive value of mucosal TNF-alpha transcripts in steroid-refractory Crohn's disease patients receiving intensive immunosuppressive therapy

BACKGROUND

Concentrations of proinflammatory cytokines are increased in the intestinal mucosa of patients with active Crohn's disease (CD). In a prospective study we investigated whether cytokines can predict long-term remission (>6 months) in patients with steroid-refractory CD receiving treatment with infliximab or cyclophosphamide, followed by azathioprine or methotrexate.

METHODS

Cytokine transcripts were quantified using real-time polymerase chain reaction (PCR) in mucosal biopsies from 19 patients with active, steroid-refractory CD before and 8 weeks after initiation of therapy. Patients were treated with cyclophosphamide (monthly treatment of 750 mg cyclophosphamide intravenously) or infliximab (5 mg/kg body weight) and were followed until relapse of the disease. Statistical analysis was performed to identify predictive factors to discriminate between patients with or without long-term remission.

RESULTS

Seventeen out of 19 patients achieved remission of the disease, two patients were nonresponders, while six out of 17 patients exhibited an early recurrence. Pretreatment TNF-alpha, IL-18, MRP-14, and IL-8 transcripts were significantly correlated with long-term remission. While several cytokines, most importantly MMP-1, determined after 8 weeks were able to predict patients achieving long-term remission, only a decrease of TNF-alpha levels after 8 weeks was predictive. Overall, statistical analysis identified lower pretreatment TNF-alpha levels as the strongest predictor of long-term remission among baseline variables.

CONCLUSIONS

Quantification of mucosal TNF-alpha transcripts prior to therapy allows identification of patients achieving long-term remission upon immunosuppression with infliximab or cyclophosphamide. Real-time PCR might have considerable potential in the analysis of disease activity and subsequent clinical management of patients with immunosuppressive therapies.

Effect of concurrent elemental diet on infliximab treatment for Crohn's disease

BACKGROUND

Infliximab and elemental diet (ED) have been shown to be effective in the management of Crohn's disease. However, few experiences have been reported regarding their combination therapy. The aim of the present study was to investigate the efficacy and safety of infliximab in Japanese patients, the first such study in Asia, as well as the effect of concomitant ED.

METHODS

One hundred and ten consecutive patients receiving infliximab were followed up to week 16 after the last infusion, and clinical response and primary outcome were collected. A response was defined as a reduction in Harvey-Bradshaw Index for inflammatory disease and closure of fistula in fistulizing disease.

RESULTS

Out of 75 inflammatory and 35 fistulizing disease patients, 68 (90.7%) and 25 (71.4%) responded at week 4, and 38 (50.7%) and 14 (40.0%) continued to respond until week 16, respectively. Interestingly, inflammatory disease patients with concurrent ED had a significantly higher response rate at week 16 (68.4%) than those without ED (32.4%, P = 0.0026). The effects of ED were independent of the usage of azathioprine and smoking habit.

CONCLUSIONS

Infliximab was clinically useful in the treatment of Crohn's disease in Japanese patients as well as in those in Western countries. The efficacy of concurrent ED was suggestive and should be confirmed in a randomized controlled study.

Probiotics modulate inflammatory cytokine secretion from inflamed mucosa in active ulcerative colitis

Enteric microflora of ulcerative colitis patients becomes aberrant. The abnormal interaction between microflora and intestinal mucosal immune system leads the mucosal inflammation. Probiotic administration may recover the commensal microflora and normalise the host-microbial interaction. In this experiment, we cocultured colonic biopsies from active ulcerative colitis patients with bifidobacterium to investigate the modulation effect of probiotics on inflamed colonic tissues and its possible mechanism. Colonic biopsies from active ulcerative colitis were cocultured for 24 h with Bifidobacterium longum. Tumour necrosis factor (TNF)-alpha and interleukin (IL)-8 in supernatants were measured using enzyme-linked immunosorbent assays, the biopsies were fixed using paraffin and the expression of NF-kappaB P65 of tissues was studied using immunohistochemical staining. The concentrations of TNF-alpha and IL-8 in supernatants of tissues cocultured with probiotics were lower than those cultured alone. The number of lamina propria mononuclear cells (LPMC) with nuclear factor-kappa B (NF-kappaB) P65 positive in cocultured tissues was also decreased. When cocultured with inflamed tissues of active ulcerative colitis, probiotics could inhibit NF-kappaB activation in LPMC and down-regulate inflammatory cytokine secretion from inflamed tissues of active ulcerative colitis.

Oral p38 mitogen-activated protein kinase inhibition with BIRB 796 for active Crohn's disease: a randomized, double-blind, placebo-controlled trial

BACKGROUND & AIMS

The p38 mitogen-activated protein kinase (MAPK) regulates the expression of proinflammatory cytokines, which play a critical role in the pathophysiology of Crohn's disease (CD). This study investigated the efficacy and safety of BIRB 796, a highly potent inhibitor of p38 MAPK, in chronic active CD.

METHODS

In a multicenter, multinational trial, 284 patients with moderate to severe CD were randomized to receive placebo, or 10, 20, 30, or 60 mg of BIRB 796 twice daily for 8 weeks. Clinical endpoints were based on standard safety assessments, CD Activity Index, C-reactive protein levels, and quality of life (Inflammatory Bowel Disease Questionnaire). In a substudy, the Crohn's Disease Endoscopic Index of Severity and histologic results of biopsy specimens were assessed.

RESULTS

No clinical efficacy (primary end point, clinical remission; secondary end point, clinical response; Inflammatory Bowel Disease Questionnaire; Crohn's Disease Endoscopic Index of Severity) was seen for BIRB 796 in comparison with placebo. A significant, dose-dependent decrease of C-reactive protein level was observed transiently after BIRB 796 after 1 week with a return to baseline level over time. The incidence of adverse events was comparable between all treatment groups, with the exception of a mild increase of transaminase levels that was seen more frequently in the BIRB 796 groups. Geographic center effects were observed with Russian centers producing distinctly higher remission and response rates and lower adverse event rates than in other countries in both placebo and active treatment groups.

CONCLUSIONS

There was no evidence for clinical efficacy of BIRB 796 in CD. A remarkable difference in the course of CD exists between Russia and non-Russian centers.

Role of the IBD5 susceptibility locus in the inflammatory bowel diseases

The field of inflammatory bowel disease genetics plays a leading role in the genetics of complex traits. One of the first genetic loci for a complex trait to be identified by genome-wide linkage scans and confirmed by multiple studies was IBD1 for Crohn's disease. Shortly after this initial success, a second susceptibility locus, the IBD5 risk haplotype, was discovered and unequivocally replicated. In this review, we examine the genetics and potential functional implications of the IBD5 locus on disease susceptibility, prognosis, classification, and treatment. In addition, we discuss the challenges faced when the region identified by association contains multiple genes that are not easily separated by recombination-the primary tool of the human geneticist.

How important is onset of action in ulcerative colitis therapy?

Pharmacotherapy is the cornerstone of management in ulcerative colitis. However, controversy remains over optimal medical strategies. Specifically, differences in the onset of action of various drug therapies are thought to influence the achievement and maintenance of remission of disease, yet this is poorly characterised. There is a wide range of recent data concerning aminosalicylates, with much debate as to the relative merits of the various formulations and delivery systems. Meta-analyses confirm the efficacy of aminosalicylates for the induction and maintenance of remission and suggest that the newer agents are comparable in efficacy to sulfasalazine. Among aminosalicylates, data from clinical trials reveal that the onset of action is earlier with balsalazide than mesalazine. Although the efficacy of the newer 5-aminosalicylate agents is no greater than that of sulfasalazine, they have better adverse effect profiles. Factors such as tolerability and adherence appear more important than onset of action in long-term maintenance. Corticosteroids have long been used in the treatment of ulcerative colitis, yet there is a paucity of data regarding this. They have a rapid onset of action but considerable systemic adverse effects. Therefore, corticosteroids are reserved for disease that fails to respond to other agents or for primary therapy in patients with severe disease, although there is no universal acceptance of a threshold at which to initiate corticosteroid treatment.Rectal preparations of both aminosalicylates and corticosteroids have been developed in an attempt to exert a more rapid and direct onset of action while minimising adverse systemic effects. In clinical trials, topical preparations of both aminosalicylates and corticosteroids are effective in inducing remission. However, patient acceptability and proximal extent of disease dictate selection of a topical agent more than concern with rate of onset.A wide range of immunomodulators have been investigated in patients with steroid-refractory ulcerative colitis. The thioguanine derivatives are the most widely used but have a limited evidence base to support this use with controlled trials providing equivocal results regarding efficacy in severe ulcerative colitis. In addition, the thioguanine derivatives have a protracted onset of action and a considerable serious adverse effect profile. Calcineurin inhibitors and methotrexate have a more rapid onset of action than the thiopurines but have even less data to support their widespread use. They are widely regarded as salvage therapy and further data are required. Regarding biological agents, infliximab revolutionised the treatment of Crohn's disease, yet results in ulcerative colitis have been disappointing. Further trials are ongoing with great anticipation for more favourable data. The practical clinical implications of any differences between the agents depend on patient satisfaction with various therapies. Noncompliance is a major concern in maintenance therapy and is probably associated with relapse. Dose administration schedules and acceptability of therapy appear to be important factors in adherence. Overall, it is not clear that onset of action has a major influence on patient adherence and addressing issues of compliance may have more direct clinical impact.

Efficacy of infliximab in Crohn's disease. Results of a retrospective multicenter study with a 15-month follow-up

OBJECTIVES

To evaluate prescription practices and response to infliximab treatment for Crohn's disease (CD).

PATIENTS AND METHODS

The files of CD patients treated with at least one infusion of infliximab treated in gastroenterology units belonging to university teaching hospitals of the Parisian hospitals group (Assistance Publique-Hôpitaux de Paris (AP-HP) during the year 2000 were analyzed retrospectively.

RESULTS

One hundred and thirty-seven patients (36.0 +/- 12.7 years, 92 females) from 12 centers were studied. Indication for treatment was fistulae or perianal disease in 39% of patients, active Crohn's disease in 45% and mixed conditions in 16%. Mean follow-up was 15.2 +/- 7.2 months. The overall response rate was 85%. No predictive factor of sustained remission could be identified. The mean time to relapse was to 3.9 +/- 3.1 months. Thirty-eight patients were on maintenance therapy at the end of the follow up; 37% exhibiting progressive lost of response to treatment. Immunosuppressive therapy was added to infliximab in 78% of cases but response to infliximab was not modified by addition of immunosuppressive drugs. Adverse events, most frequently minor, were noted in 23% of the patients.

CONCLUSION

This retrospective study confirms the efficacy and safety of infliximab in CD.

Infliximab dependency in a national cohort of children with Crohn's disease

AIM

The aim was to evaluate the pattern of responsiveness and to monitor side effects of episodic administration of infliximab in children with active Crohn's disease (CD) treated in Denmark from 1999 to 2003.

MATERIAL AND METHODS

The National Danish Crohn Colitis Database of infliximab was used to identify all Danish CD patients treated at pediatric departments with infliximab. The clinical outcome was assessed by pattern recognition of the disease course 30 days after the first infliximab infusion and 90 days after intended end of treatment.

RESULTS

During a 3 year period, infliximab was given to 24 CD patients (9 male/15 female) aged median 15.4 (range 9.8-18.6) years with a median disease duration of 26 (range 0.7-93) months and a median number of infusions of 6 (range 2-11). Five milligrams of infliximab per kilogram infusions were given intravenously. Immediate response was as follows: 8 (33%) patients achieved complete response (CR), 10 (42%) partial response (PR), and 6 (25%) no response (NR). Long-term response was as follows: 7 (29%) patients achieved prolonged response (PRO), defined as maintenance of CR or PR, 10 (42%) were infliximab dependent (ID), defined as relapse of symptoms requiring reinfusions of infliximab to regain CR or PR, and 6 (25%) had NR. Six (25%) patients needed surgery during or after treatment with infliximab. Side effects were seen in four (17%) patients. No serious events were noted.

CONCLUSION

Seventy-one percent of the children appeared to benefit (PRO or ID) from infliximab treatment with minor side effects when given episodically. Among these patients, two response patterns were recognized: PRO after ending infliximab treatment (29%) or dependency on reinfusions of infliximab (42%).

Effect of different tumor necrosis factor (TNF) reactive agents on reverse signaling of membrane integrated TNF in monocytes

Reverse signaling of transmembrane TNF (mTNF) contributes to the versatility of this cytokine superfamily. Previously, we could demonstrate that mTNF acting as receptor confers resistance to bacterial lipopolysaccharide in monocytes and macrophages (MO/MPhi). Reverse signaling can be induced by incubation with the monoclonal anti-TNF antibody 195F and other TNF antagonists, such as the humanized monoclonal antibody infliximab and the humanized soluble TNF receptor construct etanercept, respectively, all in former or present clinical use. Here, we addressed the question whether there are differences in modulating the LPS response in MO/MPhi among these three antagonists. Whereas 195F and infliximab suppress both, the release of an LPS-induced endothelial cell apoptotic factor and proinflammatory cytokines, etanercept only protected against the LPS-triggered apoptosis activity, but left the LPS-induced cytokine release unchanged. These data could have clinical impact with regard to TNF neutralization strategies.

Role of tumor necrosis factor receptors in an animal model of acute colitis

TNF-alpha is known to play an important role in inflammatory bowel disease (IBD); however, the pathophysiological role of its receptors is still under study. Acute colitis was induced in rats by intracolonic administration of trinitrobenzene sulfonic acid (TNBS). Control rats received the ethanol vehicle. Rats were sacrificed 72 h later and samples of tissue and fluids were collected. There was a significant increase in the protein levels of sTNF-alpha, sTNFRI, and sTNFRII in the peritoneal fluid (PF) of experimental rats. TNF-alpha, TNFRI, and TNFRII mRNA expression was increased significantly in the colon of experimental animals compared to controls. TRAF3 and TRAF5 expression was also significantly higher, as was that of the adhesion molecules ICAM-1 and E-selectin. The increased expression of TNF-alpha, TNFRs, and the associated signaling factors in the colon of this rat model of IBD provides further evidence for their involvement in the promotion of inflammation and tissue damage. In addition, increased levels of sTNFRs in the PF of experimental rats--particularly sTNFRII--may be involved in the development of colitis by serving as a reservoir of TNF-alpha, and thus provide a novel therapeutic target for IBD.

A randomized, placebo-controlled trial of certolizumab pegol (CDP870) for treatment of Crohn's disease

BACKGROUND & AIMS

To investigate the efficacy and safety of certolizumab pegol (a polyethylene-glycolated Fab' fragment of anti-tumor necrosis factor, CDP870) in Crohn's disease.

METHODS

In a placebo-controlled, phase II study, 292 patients with moderate to severe Crohn's disease received subcutaneous certolizumab 100, 200, or 400 mg or placebo at weeks 0, 4, and 8. The primary end point was the percentage of patients with a clinical response at week 12 (a Crohn's Disease Activity Index decrease of > or = 100 points or remission [Crohn's Disease Activity Index < or = 150 points]) in the intent-to-treat population.

RESULTS

All certolizumab doses produced significant clinical benefit over placebo at week 2 (placebo, 15.1%; certolizumab 100 mg, 29.7% [P = .033]; 200 mg, 30.6% [P = .026]; 400 mg, 33.3% [P = .010]). At all time points, the clinical response rates were highest for certolizumab 400 mg, greatest at week 10 (certolizumab 400 mg, 52.8%; placebo, 30.1%; P = .006) but not significant at week 12 (certolizumab 400 mg, 44.4%; placebo, 35.6%; P = .278). Patients with baseline C-reactive protein levels of 10 mg/L or greater (n = 119) showed clearer separation between active treatment and placebo (week 12 clinical response: certolizumab 400 mg, 53.1%; placebo, 17.9%; P = .005; post hoc analysis) owing to a lower placebo response rate than patients with C-reactive protein levels of less than 10 mg/L. Adverse events were similar among groups.

CONCLUSIONS

Certolizumab 400 mg may be effective and is well tolerated in patients with active Crohn's disease. High placebo response rates in the large patient subgroup with low C-reactive protein levels may have obscured statistical separation between certolizumab and placebo. Ongoing phase III trials are necessary to establish the clinical efficacy of certolizumab.

Diallyl trisulfide inhibits tumor necrosis factor-alpha expression in inflammed mucosa of ulcerative colitis

The present study aimed to investigate the effect of diallyl trisulfide (DATS) on tumor necrosis factor (TNF)-alpha expression in inflammed mucosa of ulcerative colitis and its possible mechanism. Colonic biopsies from ulcerative colitis were treated with 0, 1, 5, and 10 microM DATS for 24 hr. Lactate dehydrogenase (LDH) activities and concentrations of TNF-alpha in supernatants were measured. mRNA expressions of TNF-alpha in biopsies were analyzed by RT-PCR. The expression of NF-kappaB P65 in tissues was studied by immunohistochemistry. Concentrations of TNF-alpha in supernatants of biopsies treated with 5 and 10 microM DATS were lower than those of untreated biopsies. There were fewer lamina propria mononuclear cells whose NF-kappaB P65 expression in nuclei was positive, and less mRNA expression of TNF-alpha in biopsies treated with 10 microM DATS than in untreated biopsies. There were no differences in LDH activities in supernatants between tissues treated with DATS and untreated tissues. DATS could downregulate TNF-alpha production and inhibit NF-kappaB activation in lamina propria mononuclear cells of inflammed mucosa, without any effect on the viability of colonic tissue cells.

Increased levels of NF-kappaB inhibitors (IkappaBalpha and IkappaBgamma) in the intestinal mucosa of Crohn's disease patients during infliximab treatment

The treatment with infliximab is employed successfully in Crohn's disease (CD) but predictors of efficacy are lacking. Activation of the transcription factor NF-kB has been demonstrated in CD and its inhibition is one of the mechanisms by which anti-inflammatory agents exert their effects. We evaluated the production of TNFalpha by peripheral blood mononuclear cells (PBMC) and the levels of NF-kappaB family molecules in the intestinal mucosa during infliximab therapy in 12 patients. TNFalpha was assayed on supernatants of PBMC culture stimulated with PHA or LPS. Immunohistochemistry was also done on intestinal biopsies. In six patients, Western blot analysis of the NF-kappaB subunit Rel-A, and its inhibitors IkappaBalpha and IkappaBgamma was performed on intestinal biopsies and PBMC. The TNFalpha production by LPS stimulated PBMC showed mild changes, while it was increased by PHA-stimulated PBMC after treatment. The number of inflammatory cells in the intestinal mucosa was reduced (p<0.002) by the treatment. In five out of six cases we detected an increase of the IkappaBalpha and IkappaBgamma)inhibitor levels in intestinal biopsies after treatment. An increase of IkappaB inhibitors levels could be one of the mechanisms by which infliximab decreases NF-kappaB activity and exerts its anti-inflammatory effects.