Treatment of ulcerative colitis in the cottontop tamarin using antibody to tumour necrosis factor alpha

IBD and Bile Acid Absorption: Focus on Pre-clinical and Clinical Observations

Inflammatory bowel disease (IBD) causes chronic inflammation affecting the GI tract. It is classified as consisting of Crohn’s Disease (CD) and Ulcerative Colitis (UC). Bile Acid absorption is altered in both pre-clinical models of Inflammatory Bowel Disease (IB) and in human IBD. The bile acid transporter apical sodium dependent bile acid transporter (ASBT) showed decreased expression in rats with TNBS colitis. Decreased ASBT expression has also been described in murine, canine and rabbit models of intestinal inflammation. Human IBD studies have shown that an inflamed ileum can interrupt enterohepatic recirculation of bile acid, which could be due to inflammatory cytokine induced repression of the ASBT promoter. There are different hypotheses as to why ASBT is downregulated during CD. In addition, one study has demonstrated the beneficial effect of a glucocorticoid on ASBT expression, when treating IBD. Our aim in this paper was to systematically review various aspects of bile acid malabsorption in animal models of intestinal inflammation, as well as in IBD.

Xinhuang Tablets Improve Intestinal Barrier Function via Regulating Epithelial Tight Junctions in Dextran Sulfate Sodium-Induced Ulcerative Colitis Mice

Intestinal mucosal barrier dysfunction is involved in the pathogenesis of inflammatory bowel disease, including ulcerative colitis (UC). Xinhuang tablets (XHTs) have been prescribed for several kinds of inflammatory diseases, including UC, whereas its possible underlying molecular mechanisms had never been explored. Mouse model of UC was constructed by DSS treatment and followed by XHT treatment. Disease activity index, histopathological of colonic tissue, tumor necrosis factor-alpha (TNF-α), and serum amyloid A (SAA) levels in serum were further assessed. The underlying mechanism was further explored by determination of the expression of epithelial tight junction-related protein. XHT administration ameliorated dextran sulfate sodium (DSS)-induced clinical symptoms, colonic histological injury, and decreased the circulating levels of TNF-α and SAA. Moreover, XHT treatment significantly increased the protein levels of zona occludens (ZO)-1, whereas decreased the levels of phosphorylation of Elk-1. In conclusion, this study confirmed the therapeutic effects of XHT treatment on UC in a DSS-induced mouse model, and indicated that by increasing expression of epithelial tight junctions and decreasing phosphorylation of Elk-1 might be one of the underlying mechanisms of XHT treatment on UC.

SRC-3 protects intestine from DSS-induced colitis by inhibiting inflammation and promoting goblet cell differentiation through enhancement of KLF4 expression

Goblet cell loss, which leads to the reduction of mucin secretion, is a hallmark of ulcerative colitis (UC). We previously reported that steroid receptor coactivator 3 (SRC-3), a transcriptional coactivator, contributes to host defense against Citrobacter rodentium by recruiting neutrophils, suggesting a role of SRC-3 in intestine homeostasis. However, the biological role of SRC-3 in UC remains unclear. Here, we showed that SRC-3^-/- mice were more susceptible to dextran sulfate sodium (DSS)-induced colitis compared with wild-type mice after oral administration of 2% DSS dissolved in drinking water. After oral administration of 2% DSS, SRC-3^-/- mice displayed higher mortality rate, significant body weight loss, and higher clinical symptom scores compared to wild-type mice. SRC-3^-/- mice suffered a severe loss of mature colonic goblet cells, leading to more severe histopathology and more proinflammatory cytokine production. Mechanistically, SRC-3^-/- mice exhibited a decreased expression of transcription factor KLF4 in the colons, which is responsible for colonic goblet cell differentiation and maturation. At the molecular level, SRC-3 cooperated with c-Fos to promote KLF4 expression at the transcriptional level. These results demonstrate that SRC-3 can ameliorate DSS-induced colitis by inhibiting inflammation and promoting colonic goblet cell differentiation and maturation through enhancing the expression of transcriptional factor KLF4, which is responsible for colonic goblet cell differentiation and maturation.

CBLB502 administration protects gut mucosal tissue in ulcerative colitis by inhibiting inflammation

BACKGROUND

Ulcerative colitis (UC) is a nonspecific inflammatory disease for which medications and therapeutic strategies have only been moderately successful. CBLB502, a toll-like receptor 5 (TLR5) agonist derived from Salmonella flagellin, exhibits anticancer and radioprotective activities via modulation of TLRs and the nuclear factor kappa B (NF-κB) signaling pathway and can protect against acute renal ischemic failure. In this study, we intend to examine the effects of CBLB502 on both TLR responses and the interleukin (IL) and NF-κB signaling pathways in UC treatment.

METHODS

The UC mouse model was prepared in BALB/c mice by administering 2,4,6-trinitrobenzene sulfonic acid (TNBS). CBLB502 was used as the therapeutic drug. After CBLB502 therapy, the IL and tumor necrosis factor-α (TNF-α) levels were measured by ELISA. Total RNA and protein of colon samples was extracted.

RESULTS

We found that CBLB502 had a distinctive therapeutic effect in the UC model. In control group animals, IL-10 expression in serum was 91.48±24.38 ng/mL; this was higher than in the model group (59.36±14.46 ng/mL, P<0.05) or the treatment group (54.29±5.83 ng/mL, P<0.05). In model group animals, the concentration of TNF-α in serum was 140.11±12.70 ng/mL, which was lower than protein levels in the control group (173.86±29.26 ng/mL, P<0.05). The mRNA levels of TLR1, 2, 3, 4, 6, 7, 8, and 9 in the CBLB502 treatment group were significantly lower than in the model group (P<0.05). Western blot revealed that CBLB502 also reduced NF-κB expression in the mouse colon, but that NF-κB expression was not significantly lower than the model group.

CONCLUSIONS

CBLB502 can reduce mucosal damage induced by TNBS and inhibit inflammation and TLR expression. The inhibition of UC by CBLB502 is strictly TLR-IL-dependent and is dose-dependent within the efficacious dose range. Therefore, our results suggested that CBLB502 might be a candidate drug for the treatment of UC.

Serum albumin and body weight as biomarkers for the antemortem identification of bone and gastrointestinal disease in the common marmoset

The increasing use of the common marmoset (Callithrix jacchus) in research makes it important to diagnose spontaneous disease that may confound experimental studies. Bone disease and gastrointestinal disease are two major causes of morbidity and mortality in captive marmosets, but currently no effective antemortem tests are available to identify affected animals prior to the terminal stage of disease. In this study we propose that bone disease and gastrointestinal disease are associated disease entities in marmosets and aim to establish the efficacy of several economical antemortem tests in identifying and predicting disease. Tissues from marmosets were examined to define affected animals and unaffected controls. Complete blood count, serum chemistry values, body weight, quantitative radiographs, and tissue-specific biochemical markers were evaluated as candidate biomarkers for disease. Bone and gastrointestinal disease were associated, with marmosets being over seven times more likely to have either concurrent bone and gastrointestinal disease or neither disease as opposed to lesions in only one organ system. When used in tandem, serum albumin <3.5 g/dL and body weight <325 g identified 100% of the marmosets affected with concurrent bone and gastrointestinal disease. Progressive body weight loss of 0.05% of peak body weight per day predicted which marmosets would develop disease prior to the terminal stage. Bone tissue-specific tests, such as quantitative analysis of radiographs and serum parathyroid hormone levels, were effective for distinguishing between marmosets with bone disease and those without. These results provide an avenue for making informed decisions regarding the removal of affected marmosets from studies in a timely manner, preserving the integrity of research results.

Opportunistic infections with anti-tumor necrosis factor-α therapy in inflammatory bowel disease: meta-analysis of randomized controlled trials

OBJECTIVES

Several anti-tumor necrosis factor-α (TNFα) antibodies have demonstrated efficacy in Crohn's disease (CD) and ulcerative colitis (UC). These drugs carry the theoretical risk of opportunistic infection, but no systematic review and meta-analysis has examined this issue specifically.

METHODS

MEDLINE, EMBASE, and the Cochrane central register of controlled trials were searched (through to November 2012). Randomized controlled trials (RCTs) recruiting adults with active or quiescent CD or UC comparing anti-TNFα therapy with placebo were eligible. Dichotomous data were pooled to obtain a relative risk (RR) of opportunistic infection, with a 95% confidence interval (CI). The number needed to harm (NNH) was estimated from the reciprocal of the risk difference from the meta-analysis.

RESULTS

The search strategy identified 20,563 citations, 21 of which were eligible, reporting 22 separate RCTs with between 2 and 56 weeks of follow-up. In total, there were 39 (0.9%) opportunistic infections among 4,135 patients allocated to anti-TNFα therapy, compared with 9 (0.3%) among 2,919 assigned to placebo. Among patients receiving active therapy these included eight cases of Mycobacterium tuberculosis, eight cases of herpes simplex infection, six cases of oral or esophageal candidiasis, six cases of herpes zoster infection, two cases of varicella-zoster virus infection, two cases of cytomegalovirus or Epstein-Barr virus infection, and one case of Nocardia infection. The RR of developing an opportunistic infection was significantly higher with anti-TNFα therapy (2.05; 95% CI 1.10-3.85, NNH=500; 95% CI 200-1,567). The RR of tuberculosis infection was 2.52 (95% CI 0.62-10.21).

CONCLUSIONS

Anti-TNF therapy doubles the risk of opportunistic infections in inflammatory bowel disease patients. This underlines the importance of adherence to guidelines for their prevention and management.

Active and passive anticytokine immune therapies: current status and development

Anticytokine (AC) immune therapies derived from vaccine procedures aim at enhancing natural immune defense mechanisms ineffective to contain abnormally produced cytokines and counteract their pathogenic effects. Given their short half-life, cytokines, the production of which by effector immune cells (T and B lymphocytes, antigen-presenting cells (APCs), natural killer (NK) and endothelial cells) is inducible and controlled by negative feedback regulation, (1) exert locally their signaling to paracrine/autocrine target responder cells carrying high-affinity membrane receptors and (2) are commonly present at minimal concentration in the body fluid (lymph, serum). Aberrant signaling triggered by cytokines, uncontrolly released by effector immune cells or produced by cancer and other pathologic cells, contribute to the pathogenesis of chronic diseases including cancer, viral infections, allergy, and autoimmunity. To block these ectopic cytokine signaling and prevent their pathogenic effects, AC Abs supplied either by injections (passive AC immune therapy) or elicited by immunization with cytokine-derived immunogenes called Kinoids (active AC immune therapy) proved to be experimentally effective and safe. In this review, we detailed the rationale and the requirements for the use of AC immunotherapies in humans, the proof of efficacy of these medications in animal disease models, and their current clinical development and outcome, including adverse side effects they may generate. We particularly show that, to date, the benefit:risk ratio of AC immune therapies is highly positive.

Efficacy of biological therapies in inflammatory bowel disease: systematic review and meta-analysis

OBJECTIVES

Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory disorders of the gastrointestinal tract of unknown etiology. Evidence for treatment of the condition with biological therapies exists, but no systematic review and meta-analysis has examined this issue in its entirety.

METHODS

MEDLINE, EMBASE, and the Cochrane central register of controlled trials were searched (through to December 2010). Trials recruiting adults with active or quiescent CD or UC and comparing biological therapies (anti-tumor necrosis factor-α (TNFα) antibodies or natalizumab) with placebo were eligible. Dichotomous symptom data were pooled to obtain relative risk (RR) of failure to achieve remission in active disease and RR of relapse of activity in quiescent disease once remission had occurred, with a 95% confidence interval (CI).

RESULTS

The search strategy identified 3,061 citations, 27 of which were eligible. Anti-TNFα antibodies and natalizumab were both superior to placebo in inducing remission of luminal CD (RR of no remission=0.87; 95% CI 0.80-0.94 and RR=0.88; 95% CI 0.83-0.94, respectively). Anti-TNFα antibodies were also superior to placebo in preventing relapse of luminal CD (RR of relapse=0.71; 95% CI 0.65-0.76). Infliximab was superior to placebo in inducing remission of moderate to severely active UC (RR=0.72; 95% CI 0.57-0.91).

CONCLUSIONS

Biological therapies were superior to placebo in inducing remission of active CD and UC, and in preventing relapse of quiescent CD.

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.

Current status of monoclonal antibody therapy for the treatment of inflammatory bowel disease

Crohn's disease and ulcerative colitis are complex diseases that have required the use of multiple modalities to aid in treatment. With an increasing understanding of the underlying pathogenetic mechanisms and identification of specific therapeutic targets, monoclonal antibody treatment has been an ideal strategy for inducing and maintaining remission in these patients. This article addresses approved agents and the supporting data justifying their use in Crohn's disease and ulcerative colitis, the safety of and immunologic reactions to these agents, as well as newer agents for treatment.

Inflammatory bowel disease

Insights into inflammatory bowel disease (IBD) are advancing rapidly owing to immunologic investigations of a plethora of animal models of intestinal inflammation, ground-breaking advances in the interrogation of diseases that are inherited as complex genetic traits, and the development of culture-independent methods to define the composition of the intestinal microbiota. These advances are bringing a deeper understanding to the genetically determined interplay between the commensal microbiota, intestinal epithelial cells, and the immune system and the manner in which this interplay might be modified by relevant environmental factors in the pathogenesis of IBD. This review examines these interactions and, where possible, potential lessons from IBD-directed, biologic therapies that may allow for elucidation of pathways that are central to disease pathogenesis in humans.

Inhibition of phosphoinositide 3-kinase ameliorates dextran sodium sulfate-induced colitis in mice

The critical role of phosphoinositide 3-kinase gamma (PI3Kgamma) in inflammatory cell activation and recruitment makes it an attractive target for immunomodulatory therapy. 5-Quinoxilin-6-methylene-1,3-thiazolidine-2,4-dione (AS605240), a potent PI3Kgamma inhibitor, has been reported to ameliorate chronic inflammatory disorders including rheumatoid arthritis, systemic lupus erythematosus, and atherosclerosis. However, its in vivo effect on intestinal inflammation remains unknown. Here we evaluated the protective and therapeutic potentials of AS605240 in mice with dextran sodium sulfate (DSS)-induced acute and chronic colitis. Our results showed that AS605240 improved survival rate, disease activity index, and histological damage score in mice administered DSS in both preventive and therapeutic studies. AS605240 treatment also significantly inhibited the increase in myeloperoxidase levels, macrophage infiltration, and CD4(+) T-cell number in the colon of DSS-fed mice. The DSS-induced overproduction of colonic proinflammatory cytokines including interleukin (IL)-1beta, tumor necrosis factor-alpha, and interferon-gamma was significantly suppressed in mice undergoing AS605240 therapy, whereas colonic anti-inflammatory cytokines such as IL-4 were up-regulated. The down-regulation of the phospho-Akt level in immunological cells from the inflamed colon tissue and spleen of AS605240-treated mice was detected both by immunohistochemical analysis and Western blotting. These findings demonstrate that AS605240 may represent a promising novel agent for the treatment of inflammatory bowel disease by suppressing leukocyte infiltration as well as by immunoregulating the imbalance between proinflammatory and anti-inflammatory cytokines.

Inflammatory bowel disease

Insights into inflammatory bowel disease (IBD) are advancing rapidly owing to immunologic investigations of a plethora of animal models of intestinal inflammation, ground-breaking advances in the interrogation of diseases that are inherited as complex genetic traits, and the development of culture-independent methods to define the composition of the intestinal microbiota. These advances are bringing a deeper understanding to the genetically determined interplay between the commensal microbiota, intestinal epithelial cells, and the immune system and the manner in which this interplay might be modified by relevant environmental factors in the pathogenesis of IBD. This review examines these interactions and, where possible, potential lessons from IBD-directed, biologic therapies that may allow for elucidation of pathways that are central to disease pathogenesis in humans.

Infliximab in ulcerative colitis

Infliximab, a monoclonal anti-TNF-alpha antibody, is commonly used for treatment of moderate to severe Crohn's disease (CD). Its role in the treatment for ulcerative colitis (UC) remains controversial. We review the role of TNF-alpha in the pathogenesis of UC and describe the randomized, double-blind, placebo-controlled trials and systematic reviews that assess the efficacy of infliximab in the treatment of moderate to severe UC.

Infliximab for pediatric ulcerative colitis: a retrospective Italian multicenter study

BACKGROUND

Infliximab (IFX), the chimeric anti TNFalpha antibody, an established treatment for Crohn's disease in adults and in children, is used less frequently in ulcerative colitis (UC).

AIM OF THE STUDY

To report the clinical course of pediatric patients with active UC receiving IFX.

PATIENTS AND METHODS

Charts of 22 patients were reviewed (13 male, 9 female): 4 with a severe UC attack refractory to systemic corticosteroids (CS); 18 with a protracted course, of which 16 CS-dependent and 2 CS-resistant. The baseline therapeutic program consisted of 3 consecutive intravenous infusions (0, 2, 6 weeks) of IFX (5 mg/kg), followed by a retreatment schedule (infusion every 8 weeks); azathioprine (AZA) was administered chronically in all. Clinical evaluation was done with the Lichtiger Colitis Activity Index (LCAI). Follow-up was performed until week 54. LCAI >/= 9 was considered treatment failure; a LCAI

RESULTS

All 22 patients began the study with a LCAI > 9: 12 had a full response and were on remission at week 54 and did not receive CS (8 on IFX re-treatment and AZA, 4 on AZA alone); 6 had a partial response; 4 were non responders. Colectomy was performed in 7 patients, beyond the period of the acute attack in all but one.

CONCLUSIONS

In children with severe ulcerative colitis IFX is a valuable treatment for inducing remission, avoiding emergency colectomy; retreatment may be offered to maintain remission.

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MESH Headings

• Adolescent
• Antibodies, Monoclonal/therapeutic use
• Azathioprine/therapeutic use
• Child
• Colitis, Ulcerative/drug therapy
• Drug Therapy, Combination
• Female
• Humans
• Immunosuppressive Agents/therapeutic use
• Infliximab
• Italy
• Male
• Remission Induction
• Retrospective Studies
• Salvage Therapy

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Grants Collapse

Affiliation(s)

S Cucchiara Division Pediatric Gastroenterology and Hepatology, Department of Pediatrics, University of Rome "La Sapienza", Rome, Italy.
E Romeo
F Viola
M Cottone
M Fontana
G Lombardi
V Rutigliano
G L de'Angelis
T Federici

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Collaborators Collapse

Infliximab: the evidence for its place in therapy in ulcerative colitis

INTRODUCTION

Refractory ulcerative colitis has a high, unmet medical need for avoiding steroid dependency and avoiding colectomy. Controlled trials with biologic agents have recently been reported.

AIMS

We aimed to review the current evidence supporting the use of the monoclonal antitumor necrosis factor antibody, infliximab, in active ulcerative colitis and determine its current place in therapy.

EVIDENCE REVIEW

Although faced with initial conflicting data particularly in steroid-refractory patients, two large, placebo-controlled trials have shown that intravenous infliximab induces and maintains clinical improvement in a clinically significant proportion of patients when used with scheduled re-treatment. Infliximab also spares steroids and induces endoscopic remission in moderately ill patients. In fulminant colitis unresponsive to intravenous steroids, one placebo-controlled trial indicates that infliximab is able to prevent colectomy in this patient population. Evidence for cost effectiveness and avoidance of colectomy long term are still lacking.

PLACE IN THERAPY

Infliximab 5 mg/kg induction at 0, 2, and 6 weeks, and every 8 weeks thereafter should be considered in patients with moderately to severely active ulcerative colitis failing medical therapy. Steroid-dependent and steroid-refractory patients also qualify for infliximab therapy.

Effects of the macrolide drug tylosin on chronic diarrhea in rhesus macaques (Macaca mulatta)

Diarrhea is the gastrointestinal disease most frequently encountered in captive rhesus macaques. The precise pathogenic mechanisms underlying chronic diarrhea in nonhuman primates are not well understood, but a persistent inflammatory component has been implicated strongly. This study evaluated the inflammatory changes in the colon of macaques with diarrhea and assessed the efficacy of a 10-d course of tylosin in a cohort of 21 animals with chronic diarrhea. Stool quality was evaluated daily, and fecal consistency was scored. Colonoscopies were performed; biopsy samples were characterized histologically and assayed for expression of TNFalpha mRNA. Blood samples collected pre-, mid-, and post-treatment were assayed for C-reactive protein (CRP). The results indicated that 63% of the animals receiving tylosin showed improvement in stool quality, compared with 10% in the sham-treated group. Histologically, 82% of animals in the tylosin-treated group had a reduction in the severity of colonic lesions post-treatment, compared with 40% of animals in the sham group. The amount of TNFalpha mRNA before treatment did not differ from that afterward in either tylosin- or sham-treated animals. CRP levels serially decreased in tylosin-treated monkeys; the average post-treatment CRP value for tylosin-treated animals was 11.96 +/- 3.86 microg/ml compared with 26.48 +/- 4.86 microg/ml for sham-treated controls. In conclusion, tylosin significantly improved the fecal consistency score, significantly decreased colonic inflammation, and significantly decreased serum CRP levels post-treatment in rhesus macaques with chronic diarrhea.

Anti-TNF antibodies: lessons from the past, roadmap for the future

Tumor necrosis factor alpha (TNF) is an important cell-signaling component of the immune system. Since its discovery over 20 years ago, much has been learned about its functions under normal and disease conditions. Nonclinical studies suggested a role for TNF in chronic immune-mediated inflammatory diseases, such as rheumatoid arthritis, Crohn's disease, and psoriasis, and therefore neutralizing monoclonal antibodies specific to human TNF were developed for clinical evaluation. Treatment with anti-TNF monoclonal antibodies (infliximab, adalimumab, and certolizumab pegol) has been shown to provide substantial benefit to patients through reductions in both localized and systemic expression of markers associated with inflammation. In addition, there are beneficial effects of anti-TNF treatment on markers of bone and cartilage turnover. Further exploration of changes in these markers and their correlation with clinical measures of efficacy will be required to allow accurate prediction of those patients most in need of these treatments. Both the clinical and commercial experience with these anti-TNF antibodies provide a wealth of information regarding their pharmacological effects in humans.

The role of TNFalpha in ulcerative colitis

Standard of care for ulcerative colitis involves long-term pharmacotherapy or colectomy. Approximately 20% to 30% of patients eventually require a colectomy because patients either do not respond or cannot tolerate the currently available pharmacotherapies. Advances in our knowledge of the pathophysiology of ulcerative colitis have highlighted the importance of cytokines such as tumor necrosis factor alpha (TNFalpha) in the inflammatory process. TNFalpha is a proinflammatory mediator that plays an integral role in the pathogenesis of inflammatory bowel disease. In addition, mounting evidence indicates a genetic association between TNFalpha and ulcerative colitis. Furthermore, increased TNFalpha levels have been demonstrated in studies of patients with ulcerative colitis. TNFalpha is likely an important component in the pathophysiology of ulcerative colitis, and thus agents targeting TNFalpha in ulcerative colitis have been studied. Recent randomized controlled trials have confirmed that biologic anti-TNFalpha therapy is effective in ulcerative colitis. Soluble TNFalpha receptors or biologic agents that suppress or inhibit TNFalpha production may also show therapeutic promise.

Predictors of early response to infliximab in patients with ulcerative colitis

BACKGROUND

Our objective is to report the outcome of infliximab (IFX) in ulcerative colitis (UC) patients from a single center and to identify predictors of early clinical response.

METHODS

The first 100 UC patients (45 female; median age, 37.9 years) who received IFX at a single center were included. Eighty-four patients received 5 mg/kg IFX, and 37 patients received a 3-dose IFX induction at weeks 0, 2, and 6. The Mayo endoscopic subscore, assessed by sigmoidoscopy before inclusion, was 1, 2, and 3 in 5%, 52%, and 43% of patients, respectively. Sixty percent had pancolitis, 63% were on concomitant immunosuppressive therapy, 9% were active smokers, 64% had C-reactive protein > or =5 mg/dL, and 44% were pANCA+/ASCA-. Five patients received IFX because of severe acute colitis refractory to intravenous corticosteroids.

RESULTS

Early complete and partial clinical responses were observed in 41% and 24% of patients. Patients with early clinical response were significantly younger than nonresponders (median age, 35.7 versus 41.6 years, P = 0.041). Patients who were pANCA+/ASCA- had a significantly lower early clinical response (55% versus 76%; odds ratio [OR] = 0.40 (0.16-0.99), P = 0.049). Concomitant immunosuppressive therapy and the use of an IFX induction scheme did not influence early clinical response. Only 1 of 5 patients who received IFX for acute steroid-refractory colitis required colectomy within 2 months.

CONCLUSIONS

IFX is an efficient therapy in UC, as shown by 65% early clinical response. A pANCA+/ASCA- serotype and an older age at first IFX infusion are associated with a suboptimal early clinical response.

Systematic review: Infliximab therapy in ulcerative colitis

AIM

To perform a systematic review and meta-analysis on the efficacy and tolerance of infliximab in ulcerative colitis.

SELECTION OF STUDIES

evaluating efficacy of infliximab in ulcerative colitis. For the meta-analysis, randomized clinical trials comparing infliximab vs. placebo/steroids.

SEARCH STRATEGY

electronic and manual. Study quality: independently assessed by two reviewers.

DATA SYNTHESIS

meta-analysis combining the odds ratios (OR).

RESULTS

Thirty-four studies (896 patients) evaluated infliximab therapy in UC, with heterogeneous results. Mean short-term (2.3 weeks) response and remission with infliximab was 68% (95% CI 65-71%) and 40% (36-44%). Mean long-term (8.9 months) response and remission was 53% (49-56%) and 39% (35-42%). Five randomized double-blind studies compared infliximab with placebo, the meta-analysis showing an advantage (P < 0.001) of infliximab in all endpoints (short-/long-term response/remission): ORs from 2.7 to 4.6, and number-needed-to-treat (NNT) from 3 to 5. Similar infliximab response was calculated independently of the indication (steroid-refractory/non-steroid-refractory) or the dose (5/10 mg/kg). Adverse effects were reported in 83% and 75% of the infliximab and placebo-treated patients (OR = 1.52; 95% CI 1.03-2.24; number-needed-to-harm (NNH) was 14).

CONCLUSION

Infliximab is more effective than placebo, with an NNT from 3 to 5, for the treatment of moderate-to-severe UC, achieving clinical remission in 40% of the patients at approximately 9 months of follow-up. Further studies are necessary to confirm the long-term efficacy of infliximab in ulcerative colitis.

Infliximab in ulcerative colitis

Infliximab is effective for treatment of moderate-to-severe UC and is recommended for patients who have had an inadequate response to medical therapy or who are intolerant of or do not desire to take the potential risk of using specific agents including immunomodulators (cyclosporine A, azathioprine, or 6-mercaptopurine), corticosteroids, and, potentially, mesalamine. Future trials are needed to assess the efficacy of infliximab with immunomodulators to see if additional benefit is achieved so that the risk-benefit ratio is positive. Based on the favorable efficacy of infliximab for UC therapy, the ground work has been established for evaluating infliximab and addressing some of the many unanswered questions and also for assessing other anti-TNF agents and streamlining the anti-TNG antibody to improve efficacy, reduce side effects, and ease administration.

Infliximab and ulcerative colitis

Tumour necrosis factor (TNF)-alpha is an inflammatory cytokine that plays a main role in the inflammatory process underlying inflammatory bowel disease (IBD). Despite the fact that the cytokine profiles associated with ulcerative colitis (UC) and Crohn's disease (CD) are classically considered different (a Th2 pattern in UC and a Th1 pattern in CD), there are several evidences in vitro and in vivo that TNF-alpha has an important role in UC. For this reason, infliximab, the chimeric monoclonal antibody to TNF-alpha, has been evaluated in the therapy of UC. The drug has been evaluated in different clinical settings both in adults and in children: in moderate-severe steroid-dependent UC, in severe refractory UC as rescue therapy, in active non-steroid-refractory UC, in resistant pouchitis and in maintenance of moderate-severe UC responsive to infliximab. On the basis of the randomised controlled trials (RCTs), it is possible to draw the following conclusions for adults: infliximab seems active in severe steroid-refractory UC, allowing colectomy to be spared even if further controlled trials are needed with a larger sample of patients adopting strict and well-defined inclusion criteria. The drug seems active in inducing remission after 8 weeks in steroid-refractory patients, in patients taking steroids (even if it is not clear at which dosage of steroid dependence the drug is more active) and also in patients failing aminosalicylates therapy. The long-term response of infliximab in comparison to placebo in these subgroups of patients is not clinically impressive even if it is statistically significant. Further trials are warranted in order to establish the role of infliximab in steroid-dependent UC (defined with clear criteria), in maintaining remission after severe UC, in non-steroid-dependent moderate-severe UC and in refractory pouchitis. For children it is not possible to draw the same conclusions, due to a lack of RCTs, despite the encouraging data coming from open studies, mainly in steroid-refractory UC.

Molecular mechanism of tumor necrosis factor-alpha modulation of intestinal epithelial tight junction barrier

A TNF-alpha-induced increase in intestinal epithelial tight junction (TJ) permeability has been proposed to be an important proinflammatory mechanism contributing to intestinal inflammation in Crohn's disease and other inflammatory conditions. Previous studies from our laboratory suggested that the TNF-alpha-induced increase in intestinal TJ permeability was mediated by an increase in myosin light chain kinase (MLCK) protein expression. However, the molecular mechanisms that mediate the TNF-alpha increase in intestinal TJ permeability and MLCK protein expression remain unknown. The purpose of this study was to delineate the intracellular and molecular mechanisms that mediate the TNF-alpha-induced increase in intestinal TJ permeability; using an in vitro intestinal epithelial model system consisting of filter-grown Caco-2 intestinal epithelial monolayers. To examine the molecular mechanisms involved in the TNF-alpha regulation of intestinal TJ barrier, we identified and cloned for the first time a functionally active MLCK promoter region. TNF-alpha treatment of filter-grown Caco-2 monolayers transfected with plasmid vector containing the MLCK promoter region produced an increase in MLCK promoter activity and MLCK transcription. The TNF-alpha-induced increase in MLCK transcription corresponded to a sequential increase in MLCK protein expression, MLCK activity, and Caco-2 TJ permeability. The TNF-alpha-induced increase in MLCK promoter activity was mediated by NF-kappaB activation, and the inhibition of NF-kappaB activation prevented the TNF-alpha-induced increase in promoter activity and the subsequent increase in MLCK protein expression and Caco-2 TJ permeability. The TNF-alpha-induced activation of MLCK promoter was mediated by binding of the activated NF-kappaB p50/p65 dimer to the downstream kappaB binding site (-84 to -75) on the MLCK promoter region; deletion of the kappaB binding site prevented the TNF-alpha increase in promoter activity. Additionally, siRNA silencing of NF-kappaB p65 also prevented the TNF-alpha increase in MLCK promoter activity. In conclusion, our findings indicated that the TNF-alpha-induced increase in intestinal epithelial TJ permeability was mediated by NF-kappaB p50/p65 binding and activation of the MLCK promoter. NF-kappaB p50/p65 activation of the MLCK promoter then leads to a stepwise increase in MLCK transcription, expression and activity, and MLCK-mediated opening of the intestinal TJ barrier.

Anti-tumour necrosis factor therapy for ulcerative colitis: evidence to date

Infliximab, the chimeric monoclonal antibody directed against tumour necrosis factor (TNF)-alpha, has profoundly changed therapy for Crohn's disease (CD). However, for ulcerative colitis (UC), before the publication of ACT 1 and ACT 2 (Active Ulcerative Colitis Trials 1 and 2), there were only a few open-label and controlled trials that evaluated the role of infliximab in the treatment of UC. Results from these earlier studies were equivocal and ambiguous. However, the ACT 1 and ACT 2 trials were large, randomised and placebo-controlled, and have shown that infliximab is significantly more efficacious than placebo in treating both corticosteroid-responsive and -refractory moderate to severe UC. Data from these two studies showed that in patients with moderate to severe UC, treatment with infliximab (5 and 10 mg/kg), compared with placebo, led to significantly higher rates of clinical response, clinical remission and mucosal healing. However, a significant proportion of patients who were receiving oral corticosteroids at the start of the trials, remained on corticosteroids despite infliximab therapy. Additionally, the safety profile of the drug was found to be similar to what has been reported in clinical studies of infliximab in patients with CD. On the basis of currently available data, we use infliximab as a remission-inducing agent in patients who have moderate to severe UC and are either refractory to or intolerant of mesalazine (5-ASA) products and immunomodulators. Moreover, infliximab seems to be a reasonable therapeutic modality for remission maintenance in those patients with UC in whom mesalazine products and immunomodulators have failed. Although data are limited, infliximab may be considered as a remission-inducing agent in patients with moderate to severe UC which is refractory to oral corticosteroids. However, the role of infliximab in the treatment of UC patients who are dependent on oral corticosteroids is still unclear and, therefore, should be considered only in patients who cannot be successfully transitioned to or are intolerant of oral immunomodulators. Furthermore, infliximab may be an alternative to ciclosporin (cyclosporin) in hospitalised patients with severe to moderately severe but not fulminant UC who do not respond to intravenous corticosteroids. At present, there is insufficient evidence to advocate using infliximab as a first-line agent for UC patients with mild or moderate to severe disease. Future randomised, controlled trials with clearly defined patient populations should further help to clarify the definitive role of infliximab in the therapeutic scheme for UC.

The role of the tumor necrosis factor receptor in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice

We investigated the effect of TNBS administration using TNF-receptor knockout mice to elucidate the role of TNF receptors in chronic inflammation of the colon. Histologically, inflammatory cell scores showed no significant differences among TNBS-administered groups, while tissue damage scores were significantly lower in TNFR-1KO and TNFR-1,2KO than in WT. The apoptotic indexes of lamina propria mononuclear cells (LPMC) of all TNBS-administered groups were significantly lower than that of controls. TNF-alpha mRNA expression in the colon was significantly higher in all TNBS-administered groups than in controls. And NF-kappa B activities were enhanced in WT and TNFR-2KO compared with controls. Our data indicate that the TNF/TNFR-1 signaling system mediates mucosal damage through the enhancement of NF-kappa B activity and that continuous infiltration of TNF-producing cells, probably a key pathogeneses of colitis, may be closely associated with defective apoptosis of LPMC, which is possibly independent of the TNF/TNFR signaling system in TNBS-induced colitis.

Non-human primate models of experimental autoimmune encephalomyelitis: Variations on a theme

Despite years of intensive research into multiple sclerosis (MS) scientists have not yet succeeded in developing an absolute therapy for the treatment of this disabling disease of the human central nervous system. The wide immunological gap between inbred rodent strains and the heterogeneous human population is probably the single most important factor that hampers the translation of scientific principles developed in rodents into effective therapies for MS. Because of the closer immunological proximity to humans, non-human primates provide useful experimental models that may help to bridge this gap. Here we review the models of experimental autoimmune encephalomyelitis in rhesus macaques and common marmosets. We will discuss the salient points of the models and suggest how these may represent the spectrum of inflammatory demyelinating diseases of the central nervous system in humans.

The role of cytokine gene polymorphisms in determining disease susceptibility and phenotype in inflammatory bowel disease

BACKGROUND AND AIMS

Emerging data indicate that alterations in cytokine synthesis may play a role in inflammatory bowel disease (IBD) pathogenesis. The differential production of cytokines has been linked to single nucleotide polymorphisms in gene promoter regions, signal sequences, and gene introns. The aim of this study was to assess the relationship between polymorphisms involving five cytokine genes (TNF-alpha, TGF-beta, IL-10, IL-6, and IFN-gamma), and IBD susceptibility and disease phenotype.

METHODS

Cytokine genotyping was performed utilizing polymerase chain reaction. The specific gene polymorphisms that were probed for included: -1082(G/A), -819(T/C), and -592(A/C) in the IL-10 promoter, -308(G/A) in the TNF-alpha promoter, codon 10 (T/C), and codon 25 (G/C) of the TGF-beta signal sequence, +874(T/A) of intron 1 of IFN-gamma, and -174(C/G) in the IL-6 promoter.

RESULTS

A total of 193 IBD patients (138 Crohn's disease (CD) and 55 ulcerative colitis (UC)) and 92 controls were evaluated. No association between IBD, UC, or CD susceptibility and the cytokine gene polymorphisms were found. Patients with ileocolonic CD were more likely to possess the IL-6 -174 GG genotype compared to those with nonileocolonic disease (p= 0.006). Patients with ileal CD were more likely to possess the IL-6 -174 GC genotype compared to those with nonileal disease (p= 0.0004). An increased number of CD patients with isolated colonic disease possessed the IL-6 -174 CC genotype compared to those with nonisolated colonic disease (p= 0.032).

CONCLUSION

The cytokine gene polymorphisms studied here do not appear to influence IBD susceptibility. There does, however, appear to be an influence on disease phenotype, particularly on CD site.

Intestinal adenocarcinoma with pancreas and lymph node metastases in a captive cotton-top tamarin (Saguinus oedipus)

A case of intestinal adenocarcinoma with metastases to the pancreas and regional lymph node was found in a 9-year-old, captive female cotton-top tamarin (Saguinus oedipus) with intermittent diarrhea. At necropsy, the tumor mass was located in the ileo-cecal junction causing circumferential thickening and annular stenosis. Microscopically, the lesions at primary and metastatic sites showed typical features of mucinous adenocarcinoma as seen in humans, including intracellular and extracellular mucin production and characteristic appearance of a signet ring of the tumor cells. The diagnosis was confirmed by histological evaluation, positive cytokeratin immunostain, and mucin production demonstrated by PAS and Alcian blue stain. It is speculated that the development of intestinal carcinoma was partly attributable to the excessive absorption of a diet of refined food, unbalanced nutrition, and the nature of these animals to develop stress easily.

Medical therapy for ulcerative colitis 2004

There continue to be evolutionary changes in the management of ulcerative colitis despite the fact that, aside from a variety of aminosalicylate formulations, no new therapies have been approved over the past few decades. Nevertheless, debates continue regarding the optimization of treatment with aminosalicylates and the short- and long-term benefits of immunomodulation in ulcerative colitis. This article focuses on the most recent clinical studies pertaining to the management of ulcerative colitis and explores both the advances and controversies pertaining to aminosalicylate therapy, corticosteroids, cyclosporine, and the purine antimetabolites. Novel therapeutic approaches--including preliminary experience with biological therapies directed at tumor necrosis factor and other cytokines, adhesion molecules, growth factors, and probiotics--will be reviewed. Recent data regarding potential chemoprevention in long-standing ulcerative colitis and management of postoperative complications and pouchitis will also be discussed.

TNF-alpha-induced increase in intestinal epithelial tight junction permeability requires NF-kappa B activation

Crohn's disease (CD) patients have an abnormal increase in intestinal epithelial permeability. The defect in intestinal tight junction (TJ) barrier has been proposed as an important etiologic factor of CD. TNF-alpha increases intestinal TJ permeability. Because TNF-alpha levels are markedly increased in CD, TNF-alpha increase in intestinal TJ permeability could be a contributing factor of intestinal permeability defect in CD. Our purpose was to determine some of the intracellular mechanisms involved in TNF-alpha modulation of intestinal epithelial TJ permeability by using an in vitro intestinal epithelial system consisting of filter-grown Caco-2 monolayers. TNF-alpha produced a concentration- and time-dependent increase in Caco-2 TJ permeability. TNF-alpha-induced increase in Caco-2 TJ permeability correlated with Caco-2 NF-kappa B activation. Inhibition of TNF-alpha-induced NF-kappa B activation by selected NF-kappa B inhibitors, curcumin and triptolide, prevented the increase in Caco-2 TJ permeability, indicating that NF-kappa B activation was required for the TNF-alpha-induced increase in Caco-2 TJ permeability. This increase in Caco-2 TJ permeability was accompanied by down-regulation of zonula occludens (ZO)-1 proteins and alteration in junctional localization of ZO-1 proteins. TNF-alpha modulation of ZO-1 protein expression and junctional localization were also prevented by NF-kappa B inhibitors. TNF-alpha did not induce apoptosis in Caco-2 cells, suggesting that apoptosis was not the mechanism involved in TNF-alpha-induced increase in Caco-2 TJ permeability. These results demonstrate for the first time that TNF-alpha-induced increase in Caco-2 TJ permeability was mediated by NF-kappa B activation. The increase in permeability was associated with NF-kappa B-dependent downregulation of ZO-1 protein expression and alteration in junctional localization.

Infliximab for refractory ulcerative colitis or indeterminate colitis: an open-label multicentre study

BACKGROUND

The efficacy of infliximab in ulcerative colitis (UC) and indeterminate colitis has been poorly assessed and preliminary results are conflicting.

METHODS

The records of 30 patients treated with infliximab for ulcerative colitis (n=19) or indeterminate colitis (n=11) were reviewed. Infliximab was given because of steroid resistance (n=18), dependence (n=5) or intolerance (n=7); five patients had failed on cyclosporin; 19 patients had a severe flare-up.

RESULTS

Median duration of follow-up was 10 months. In 28 patients with active disease, the response rate was 75% at day 7, with 43% having a complete remission, and 50% at month 1, with 32% having a complete remission. Among the 22 responders, the probability of relapse was 73% at month 6. The probability of complete remission without steroids, taking into account the re-treatment for relapse (n=11), was 57% (95% confidence interval (CI): 45% to 69%) at month 6. The probability of colectomy was 33% (95% CI: 23% to 43%) at month 12. In indeterminate colitis, response rate was only 50% at day 7 and 30% at month 1. Concomitant use of antimetabolite agents was associated with better results.

CONCLUSIONS

Infliximab was able to induce a rapid response in some patients with UC or indeterminate colitis refractory to conventional treatment. Long-term results were less favourable, with frequent relapses, and about one-third of the patients required a colectomy.

Infliximab in moderately severe glucocorticoid resistant ulcerative colitis: a randomised controlled trial

BACKGROUND

Tumour necrosis factor production is increased in the mucosa of patients with active ulcerative colitis. The benefits of infliximab in Crohn's disease are established. We investigated its efficacy in ulcerative colitis.

METHODS

We conducted a randomised placebo controlled trial of infliximab (5 mg/kg) in the treatment of glucocorticoid resistant ulcerative colitis. Infusions were given at weeks 0 and 2. Disease activity and quality of life were recorded over eight weeks of follow up. Remission was defined as an ulcerative colitis symptom score (UCSS) of < or =2 and/or Baron score of 0 at week 6. Patients not in remission were offered open label infliximab 10 mg/kg and reviewed two weeks later.

RESULTS

After two weeks, there was no statistically significant difference between the infliximab and placebo groups in the proportion of patients with a Baron score of 0 (13% (3/23) v 5% (1/19) (95% confidence interval (CI) -9% to 24%); p=0.74). After six weeks, remission (UCSS < or =2) rates were 39% (9/23) versus 30% (6/20) (95% CI -19 to 34%; p=0.76). The median improvement in UCSS was 3 for the infliximab group and 2.5 for the placebo group (p=0.82, Mann-Whitney U test). A Baron score of 0 was likely in either group (26% (6/23) v 30% (6/20) (95% CI -30% to 23%); p=0.96). Improvement in the IBDQ and EuroQol was not significantly different between the groups (p=0.22 and 0.3, respectively, Mann-Whitney U test). Twenty eligible patients were given open labelled infusions. Remission was achieved in 3/11 (27%) patients initially treated with infliximab and in 1/9 (11%) patients treated with placebo.

CONCLUSION

These data do not support the use of infliximab in the management of moderately active glucocorticoid resistant ulcerative colitis.

Antisense oligonucleotide blockade of tumor necrosis factor-alpha in two murine models of colitis

Tumor necrosis factor-alpha (TNF-alpha) is a key cytokine involved in the pathogenesis of inflammatory bowel disease. We have developed a second-generation antisense oligonucleotide (ISIS 25302) specific for murine TNF-alpha and have evaluated this oligonucleotide in two models of gut inflammation of distinct etiology. ISIS 25302 decreased TNF-alpha mRNA in a dose- and sequence-dependent manner in vitro in the mouse macrophage cell line P388D1. It also reduced TNF-alpha mRNA in vivo, in whole adipose tissue and in macrophages isolated from the adipose tissue of db/db mice, a strain with constitutively high expression of TNF-alpha. ISIS 25302 significantly reduced disease activity index scores in mice with both an acute and a chronic form of dextran sodium sulfate (DSS)-induced colitis. It also significantly improved histopathological scores in interleukin (IL)-10-deficient mice. This was accompanied by reductions in both the basal and lipopolysaccharide-stimulated secretion of TNF-alpha and interferon-gamma in colonic organ cultures from IL-10 -/- mice. In this model, efficacy was obtained with both a prophylactic treatment regimen or a therapeutic dosing protocol begun after colitis was already present. In both the DSS and IL-10 -/- models, scrambled and mismatch control oligonucleotides were largely without effect, suggesting that ISIS 25302 was exerting its effects through a sequence-dependent antisense mechanism.

Efficacy of anti-tumor necrosis factor therapy in patients with ulcerative colitis

OBJECTIVES

Tumor necrosis factor-alpha (TNF-alpha) is an important cytokine involved in the pathogenesis of inflammatory bowel disease. The monoclonal antibody to TNF-alpha, infliximab, is effective in treating Crohn's disease. Preclinical studies suggest the importance of TNF-alpha in treating ulcerative colitis (UC). We report the effectiveness of infliximab for UC and examine factors predictive of response to medication.

METHODS

Data from all UC patients receiving infliximab at four institutions were analyzed. Disease activity was determined by the Disease Activity Index.

RESULTS

A total of 27 patients with active UC received inpatient (37%) and outpatient (63%) infliximab as single (52%) or multiple (two to 15) infusions (48%). Twelve patients (44%) achieved remission and six patients (22%) had partial response. Nine patients had no response; five subsequently underwent total colectomy. The median time to achieve response and remission was 4 days and the median duration 8 wk. Nine of the 18 patients who responded experienced 19 relapses; 18 of these relapses (95%) were successfully treated with repeat infusions. Steroid-refractory patients were less likely to respond to infliximab therapy than were steroid-responsive patients (33% vs 83%; p = 0.026). No other factors were predictive of response to infliximab. Two patients developed serious adverse events, including death in one case.

CONCLUSIONS

Preliminary evidence suggest effectiveness of infliximab in the treatment of UC, including medically refractory severe disease. Individuals who are refractory to corticosteroids, however, may be unlikely to respond to infliximab. A randomized controlled trial is necessary to further investigate the efficacy of infliximab in patients with UC.

Infliximab for treatment of steroid-refractory ulcerative colitis

BACKGROUND

Success achieved in two subtypes of Crohn's disease has persuaded a few investigators to experiment the monoclonal anti-tumour necrosis factor antibody infliximab in the treatment of ulcerative colitis. So far, however, the results (achieved in some 30 steroid-refractory patients included in two independent full-papers) indicate a rate of initial response of 50% and of remission of 25%.

AIMS

To analyse data of an open trial conducted on consecutive steroid-refractory severely ill patients admitted to our referral Unit.

PATIENTS AND METHODS

In 9 months, infliximab was given to 8 patients (4 male, 4 female aged 20-60 years) with uncontrolled ulcerative colitis of whom 6 were non-responders to parenteral steroids. All received the first infliximab dose as an intravenous infusion of 5 mg/kg.

RESULTS

Of the 8, 4 (50%) did not respond to the first injection and were submitted to urgent colectomy; the other four responded clinically. Two have maintained clinical remission for 7 months, without the need for steroids; both have received daily azathioprine at 2 mg/kg, and only one has received two further infliximab injections. Of the other two, one received a second injection at week 5, despite this relapsed, and underwent elective colectomy at that time; the other relapsed at 6 months and showed a partial response to a repeat infliximab infusion. Thus, the rate of sustained response is 2/8 (25%) in this study.

CONCLUSION

These results, achieved in an open uncontrolled fashion, seem to reflect those of other independent studies. In our opinion, these findings warrant an in-depth reappraisal of the indication to use infliximab as rescue treatment for refractory ulcerative colitis.

Anti-tumour necrosis factor alpha (infliximab) in the treatment of severe ulcerative colitis: result of an open study on 13 patients

BACKGROUND

Conventional treatment options for patients with severe steroid-refractory ulcerative colitis include intravenous cyclosporine, which is frequently burdened by toxicity, or colectomy. Preliminary data suggest a benefit from anti-tumour necrosis factor alpha (Infliximab) therapy in patients with steroid refractory ulcerative colitis.

AIM

To evaluate the efficacy of Infliximab in the treatment of severe ulcerative colitis refractory to conventional therapy

PATIENTS AND METHODS

A series of 13 patients with severe ulcerative colitis, refractory to therapy with methyl-prednisolone, 60 mg daily for seven or more days, were treated with a single intravenous infusion of Infliximab 5 mg/kg.

RESULTS AND CONCLUSIONS

Of these 13 patients, 10 (77%) had a clinical response to therapy defined by a clinical activity index 10 on two consecutive days. In 2 patients (15%) total colectomy was necessary on account of clinical worsening whilst one patient refused surgery and was lost to follow-up. All patients who responded showed very rapid clinical improvement, within 2 to 3 days of infusion. Infusion with Infliximab produced no significant adverse events. The mean time of follow-up was 10.1 months (range 5-12; during this time, 9 out of 10 patients (90%) maintained clinical remission and were able to discontinue corticosteroid therapy. Infliximab appears to be an effective agent for inducing long-standing remission in refractory patients with severe ulcerative colitis.

Antinerve growth factor treatment prevents intestinal dysmotility in Trichinella spiralis-infected rats

Nerve growth factor (NGF) could be involved in the development of hyperalgesia as well as in nervous remodeling consequence of inflammation. Both dysmotility and increase of visceral sensitivity have been described in functional gastrointestinal disorders such as irritable bowel syndrome. Trichinella spiralis-infected rats show an exacerbated spontaneous motility and a significant increase of the excitatory response to cholecystokinin (CCK), both associated with a reversible inflammatory process and the hypertrophy of the muscle layers. In this study we determined the intestinal expression of NGF mRNA by polymerase chain reaction and NGF by enzyme-linked immunosorbent assay. We implanted serosal strain gauge transducers on duodenum, jejunum, and ileum of anesthetized Sprague-Dawley rats to record circular muscle contractions. The experimental protocol included the evaluation of intestinal spontaneous motor activity (SMA), the response to CCK-8, and the ascending contraction induced by electrical mucosal stimulation. This protocol was performed in healthy and infected nontreated rats, in healthy rats with an NGF antibody treatment (1.6 mg/rat i.p.), and in infected rats with the same treatment applied at 0 or 3 days postinfection. NGF and NGF mRNA levels in the bowel were increased during inflammation. Although anti-NGF treatments did not prevent or reverse inflammatory response, the treatment was effective in preventing the motor alterations induced by the T. spiralis infection, i.e., inhibited increased SMA, reversed altered response to CCK, and reversed in part exacerbated response to electrical stimulation.

HSP70 protects against TNF-induced lethal inflammatory shock

The heat shock (HS) response is a universal response activated after exposure to various stimuli. The major HS protein (HSP) is the 72 kDa HSP70 with strong homology in different eukaryotic species. We demonstrate that HS treatment of mice leads to a strong induction of HSP70 in several organs and confers significant protection against lethality induced by tumor necrosis factor (TNF). HS prevents high production of interleukin-6 and nitric oxide and reduces severe damage and apoptosis of the enterocytes in the bowel. Mice deficient in the inducible hsp70.1 gene were no longer protected by HS treatment. We show that HS can be applied successfully in an antitumor protocol based on TNF and interferon-gamma, leading to a significant inhibition of lethality but not to a reduction of antitumoral capacity.

Infliximab as a novel therapy for pediatric ulcerative colitis

OBJECTIVES

The role of infliximab (anti-tumor necrosis factor alpha antibody) therapy in ulcerative colitis (UC) is not well defined. There are only two reports published describing its use in UC. The authors describe their experience with open-label use of infliximab in children with moderate to severe UC.

METHODS

The authors collected data on all consecutive pediatric patients with UC who received infliximab at The Children's Hospital of Philadelphia until July 2001. The primary measured outcome was clinical response at 2 days and 2 weeks after infliximab infusion, as measured by the Lichtiger colitis activity index (LCAI) score and the Physician Global Assessment (PGA). Tolerance of the infusions and adverse events were recorded.

RESULTS

Nine patients qualified for clinical response analysis. The median Lichtiger colitis activity index score decreased from 11 before the infusion to 1 at 2 days and 2 weeks after the infusion, respectively (P = 0.01 for 2 days and 2 weeks). Seven of nine (77%) patients had decreased activity of their disease measured by the Physician Global Assessment. Corticosteroid therapy was discontinued in six (66%) patients. An infusion reaction developed (generalized pruritus and facial flushing) in two patients and an elevated anti-nuclear antibody (ANA) titer of 1:1280 developed in one patient.

CONCLUSION

Infliximab is associated with short-term clinical improvement in children and adolescents with moderate to severe UC.

A critical assessment of new therapies in inflammatory bowel disease

The only therapy in inflammatory bowel disease (IBD), which up to the mid-1990s was disease modifying, was immunosuppression with azathioprine. Other 'standard' therapies in IBD were merely symptomatic. With the advent of biological therapies, especially the chimeric monoclonal anti-TNF antibody infliximab, we start to target specific pathogenic disease mechanisms, which allow thorough suppression of the disease process and healing of the bowel in the long term. Moreover, infliximab is the only drug up to the present that allows short-term healing of fistulizing Crohn's disease. This therapy is, however, associated with problems of immunogenicity. The formation of antibodies to infliximab jeopardizes the efficacy and is associated with infusion reactions. Optimization of anti-TNF strategies will occur in the coming years. Another promising therapy is antagonization of alpha4 integrins and hence, of migration of inflammatory cells to the intestine. It can be expected that more simple therapies using small molecules that inhibit the key cytokines or pro-inflammatory processes will take over in the next decade. In the current and future approach to IBD therapy immunosuppression with azathioprine or 6-MP and methotrexate play a central role. At the present time, the combination of infliximab with azathioprine or methotrexate can be regarded as the new standard for the therapy of refractory Crohn's disease. In ulcerative colitis (UC) much less progress has been made and the value of biological therapy as well as of long-term management with immunosuppression remains controversial. Probiotics are an attractive treatment option for IBD but studies so far are small and data are not yet convincing.

Biological and novel therapies for inflammatory bowel disease in children

During the past decade, a tremendous wealth of information regarding the pathogenesis, genetics, and therapy of IBD has been discovered. Judging by the number of new publications published every month in scientific journals and the great enthusiasm at scientific meetings, this outstanding pace surely will continue. In the near future, clinicians may be able to classify IBD into several subtypes depending on patients' cytokine and gene profiles. For example, two groups of researchers recently have identified mutation in the NOD2 gene, which is associated with susceptibility to CD. This identification may allow the clinician to better predict outcome and response to medical therapy. At the same time, several promising new therapies are being investigated. Technologic advances will continue to result in the development of potent and specific agents that will control and possibly correct the abnormal inflammatory processes responsible for pediatric IBD.

Infliximab for refractory ulcerative colitis

Eight patients with active ulcerative colitis (UC), refractory to usual combination medical therapy, were treated with a single i.v. dose of chimeric monoclonal antibody to recombinant human tumor necrosis factor alpha; many of these patients were scheduled for surgical colectomy because of their active disease. All patients responded extremely well to a single 5 mg/kg infusion of infliximab, with marked improvement after the infusion clinically, colonoscopically, and histologically on colonic biopsy. There were no significant complications or side effects; mean duration of remission has not been determined because none of the patients have relapsed. Infliximab appears to be a potent agent for inducing remission in refractory patients with ulcerative colitis.

Integrating anti-tumor necrosis factor therapy in inflammatory bowel disease: current and future perspectives

Crohn's disease and ulcerative colitis are two idiopathic inflammatory disorders of the GI tract. Manifestations of disease can be severe and lead to long term therapy with a variety of medications and/or surgery. Standard medical therapy consists of agents that either treat suppurative complications or modulate the inflammatory cascade in a nonspecific manner. Many specific chemokine and cytokine effectors that promote intestinal inflammation have been identified. Such work has led to experimental clinical trials with a variety of cytokine antagonists. Compounds directed against one such cytokine, tumor necrosis factor alpha (TNF), have demonstrated the greatest clinical efficacy to date. This is consistent with scientific observations that suggest a central role for TNF in the inflammatory cascade. Infliximab is a chimeric monoclonal antibody against TNF that has been demonstrated to be effective for the treatment of Crohn's disease. Infliximab is Food and Drug Administration approved for the treatment of Crohn's disease. There exist several other TNF antagonists in various phases of investigation, including the monoclonal antibody CDP 571, the fusion peptide etanercept, the phosphodiesterase inhibitor oxpentifylline, and thalidomide. The clinical efficacy of these agents and the role of TNF in the pathogenesis of inflammatory bowel disease is reviewed.