Basiliximab (anti-CD25) in combination with steroids may be an effective new treatment for steroid-resistant ulcerative colitis

Adverse Effects of Immunosuppression: Infections

Immunosuppressive therapies are currently indicated for a wide range of diseases. As new agents emerge and indications evolve the landscape grows increasingly complex. Therapies can target pathologic immune system over-activation in rheumatologic or autoimmune disease, or conditioning and graft versus host disease (GVHD) prophylactic regimens may eliminate or inhibit host immune function to improve graft survival and risk of complication in solid organ transplantation (SOT) or hematopoietic stem cell transplantation (HSCT). With immunosuppressive therapy, infections occur. Complex disease states, host factors, and concomitant therapies contribute to a "net state" of immunosuppression that must be considered and may confound perceived increased infection risks in patients receiving treatment.

Targeting T cells in inflammatory bowel disease

T cells play a pivotal role in the immune response underlying inflammatory bowel disease (IBD) pathogenesis. On this basis, over the past 25 years several drugs have assessed to target T cells in IBD patients. Amongst anti-CD3 antibodies, visilizumab and foralumab did not show clinical efficacy in ulcerative colitis (UC) and Crohn's disease (CD) patients, respectively, whereas otelixizumab has been tested in vitro only. The anti-CD4 BF-5 and cM-T412, and the anti-CD25 basiliximab and daclizumab were not effective in CD and UC patients, respectively. The anti-NKG2D antibody NNC0142-0002 showed clinical benefit in CD patients, in particular in biologic naïve ones, in a randomized, double-blind, parallel-group, placebo-controlled trial. The anti-CD40L M90 and the GSK1349571A blocking calcium release-activated calcium (CRAC) channels, which are involved in the T cell activation and proliferation, were tested only in ex vivo/in vitro experiments. Apart from ustekinumab, all the other drugs targeting T cell-derived cytokines failed. The reinduction of lamina propria T cell apoptosis is a mechanism to modulate T cell survival exploited by cyclosporin A, azathioprine and anti-tumor necrosis factor-α agents, such as infliximab, adalimumab and golimumab. In this article, we review the drugs targeting T cells via surface receptors, via T cell-derived cytokines, via CRAC channels or by inducing apoptosis.

Histological Remission in Ulcerative Colitis: Under the Microscope Is the Cure

In recent years, the therapeutic goals in ulcerative colitis (UC) have become increasingly stringent. Histological features seem to be a reliable predictor of disease outcomes after therapy, and histological remission (HR) is the new frontier in the treatment of UC. Here, we first provide a historical perspective before reviewing indexes in the era of biologics; histology as a treatment goal in UC trials; the poor correlation between symptoms, endoscopy, and histology; and the impact of histology on disease outcomes. HR seems to be a promising end point for the treatment of UC because it is typically associated with better outcomes. Two new validated indexes are available to assess histology more accurately in trials, and they may also be applicable to clinical practice. Additional interventional trials are now necessary to establish definitions of HR and its potential for disease modification.

Current stage in inflammatory bowel disease: What is next?

In recent years, the incidence of inflammatory bowel disease (IBD) has been on the rise, extending to countries where it was infrequent in the past. As a result, the gap between high and low incidence countries is decreasing. The disease, therefore, has an important economic impact on the healthcare system. Advances in recent years in pharmacogenetics and clinical pharmacology have allowed for the development of treatment strategies adjusted to the patient profile. Concurrently, new drugs aimed at inflammatory targets have been developed that may expand future treatment options. This review examines advances in the optimization of existing drug treatments and the development of novel treatment options for IBD.

Histologic evaluation of ulcerative colitis: a systematic review of disease activity indices

BACKGROUND

Ulcerative colitis (UC) is an idiopathic inflammatory disorder. Currently, the main goals of treatment are to induce and maintain clinical and/or endoscopic remission. However, evidence indicates that persistent disease activity on colonic biopsies in the setting of clinical or endoscopic remission is an independent predictor of poor outcomes. A number of previous studies have proposed histologic indices for use in specific trials of UC. The aim of this study was to systematically review the existing histological indices for UC and assess their potential use in both patient management and clinical trials.

METHODS

We performed a systematic review of histological indices evaluating disease activity in UC. MEDLINE (Ovid), EMBASE (Ovid), PubMed, the Cochrane Library (CENTRAL), and Digestive Diseases Week (DDW) abstracts of randomized and/or controlled trials clinical trials were searched from inception to February 2013 for applicable studies. Data from these studies were reviewed and analyzed.

RESULTS

After systematically applying inclusion criteria, we identified 108 scientific articles including 88 clinical studies and 21 related clinical reviews. Eighteen indices of histological activity in UC were identified and reviewed.

CONCLUSIONS

Although multiple histological scoring indices for assessment of UC disease activity currently exist, none of these instruments were developed using a formal validation process and their operating properties remain poorly understood. Future studies are needed to address this deficiency.

The value of experimental models of colitis in predicting efficacy of biological therapies for inflammatory bowel diseases

During the last decade, biological therapies have an increasing share in the modern therapeutics of various diseases including inflammatory bowel diseases (IBD). Animal models of IBD have often been used to identify the targets of biological therapies, to test their relevance to disease pathogenesis, to assess their therapeutic efficacy in vivo, and to check for drug toxicity. In the field of inflammatory diseases the majority of biologics under development have failed to reach the clinic. This review examines the ability of preclinical data from animal models of IBD to predict success or failure of biologics in human IBD. Specifically, it describes the murine models of IBD, the mechanism of disease induction, the phenotype of the disease, its relevance to human IBD, and the specific immunological features of disease pathogenesis in each model and mainly compares the results of the phase II and III trials of biologics in IBD with preclinical data obtained from studies in animal models. Finally, it examines the possible reasons for low success in translation from bench to bedside and offers some suggestions to improve translation rates.

Targeting T and B lymphocytes in inflammatory bowel diseases: lessons from clinical trials

Both innate and adaptive immunity play an important role in the pathogenesis of inflammatory bowel diseases (IBDs). There is strong evidence that especially activated T cells initiate and perpetuate inflammation and tissue destruction. The increased numbers of CD4+ T cells in the intestinal wall of IBD patients may be explained by enhanced influx/activation and decreased apoptosis of these cells. Several studies have demonstrated that the gut-homing receptors CCR9 and α4β7 are selectively induced on T cells during their priming in intestinal inflamed sites. Whereas targeting of activated CD4+ T cells by specific antibody strategies or neutralization of key T-cell cytokines such as IL-2 or IFN-γ has not been effective in human IBD, blocking migration of activated leukocytes, e.g. T cells into the inflamed tissue by specific antibodies such as vedolizumab, seems highly effective. Recently it could also been demonstrated that administration of antigen-specific regulatory T cells to patients with refractory Crohn's disease was not only well tolerated but showed promising results. The role of B cells in human IBD is less clear. B-cell depletion has so far only been studied in ulcerative colitis where rituximab (anti-CD20) therapy failed. Therefore, although the therapeutic targeting of 'inflammatory' T and B cells was not successful in IBD, especially T cells remain key players in IBD. Targeting either T-cell migration or the use of regulatory T cells appears as the most promising 'T-cell-directed' therapies in the future.

The challenges of stratifying patients for trials in inflammatory bowel disease

Immunotherapy with biological agents or small molecules is revolutionising the treatment of chronic inflammatory disease in humans; however, a significant proportion of patients fail to respond or lose responsiveness. This is particularly evident in inflammatory bowel disease (IBD), a group of chronic, immune-mediated disorders of the gastrointestinal tract. Different responsiveness to treatment in IBD can be explained by substantial disease heterogeneity, which is being increasingly recognised by genetic and immunological studies. The current enthusiasm for stratified medicine suggests that it may become possible to identify clinical, immunological, biochemical or genetic biomarkers to target immunotherapy to patients more likely to respond. Here, we identify and highlight the opportunities and the challenges of this strategy in the context of IBD.

From model to mechanism: lessons of mice and men in the discovery of protein biologicals for the treatment of inflammatory bowel disease

Successful therapeutics for inflammatory bowel disease (IBD) must be able to reverse effectively the complex processes involved in the manifestation of inflammatory pathology in intact tissues. Although studies of human tissue samples are important to confirm the biological rationale for developing a particular therapeutic, in vivo rodent models of IBD provide a biological 'flask' in which therapeutics can be tested in a more representative setting. Moreover, gene targeting and transgenic technologies in rodents have exponentially increased the repertoire of available IBD models and provided insight into possible contributions that certain genes may have in the pathogenesis of disease. These models have been key in generating the current arsenal of biological therapeutics that are available, or are presently under investigation, for the treatment of IBD patients.

The role of biologic agents in the management of non-infectious uveitis

INTRODUCTION

Uveitis is an intriguing group of disorders characterized by inflammation of the uveal tract. Due to the potential grave consequences of the disease process, it is important to assess the various therapeutic options available for treating uveitis, and their outcomes.

AREAS COVERED

This review discusses the use of conventional agents in the management of uveitis, including discussion of the molecular and clinical properties of corticosteroids, antimetabolites, calcineurin inhibitors and alkylating agents and their side effects. In addition, it also discusses the molecular and clinical properties of novel biologic agents and their side effects. Moreover, recommendations as to when biologic agents should be employed are also discussed.

EXPERT OPINION

We recommend that in general (except in selected cases of Adamantiades-Behçet's disease) biologics should not be used as a first-line therapy for uveitis due to inconvenience, high cost, and potential immunosuppressive effects. However, many biologics are potent in inducing drug-free remission of uveitis and may be employed to manage recurrent diseases or diseases not responsive to conventional agents.

Molecular targets in the treatment of alcoholic hepatitis

Alcohol related costs to health and society are high. One of the most serious complications of alcohol misuse to the individual is the development of alcoholic hepatitis (AH), a clinical syndrome of jaundice and progressive inflammatory liver injury in patients with a history of recent heavy alcohol use. It has a poor outcome and few existing successful therapies. The use of glucocorticoids in patients with severe AH is still controversial and there remains a group of patients with glucocorticoid-resistant disease. However, as our understanding of the pathogenesis of the condition improves there are opportunities to develop new targeted therapies with specific actions to control liver inflammation without having a detrimental effect on the immune system as a whole. In this article we review the molecular mechanisms of AH concentrating on the activation of the innate and adaptive immune response. We consider existing treatments including glucocorticoids, anti-tumor necrosis factor therapy and pentoxifylline and their limitations. Using our knowledge of the disease pathogenesis we discuss possible novel therapeutic approaches. New targets include pro-inflammatory cytokines such as interleukin (IL)-17, chemokines and their receptors (for example IL-8, CXCL9 and CXCR3) and augmentation of anti-inflammatory molecules such as IL-10 and IL-22. And there is also future potential to consider combination therapy to selectively modulate the immune response and gain control of disease.

Biological therapies for inflammatory bowel disease: controversies and future options

Over the last few years, advances in understanding the pathogenesis of inflammatory bowel disease, together with progress in biotechnology, have led to the availability of several biological drugs that have dramatically changed the therapeutic approach to these disorders. Indeed, several molecules targeting crucial inflammatory cytokines, blocking T-cell activation/proliferation or the recruitment of inflammatory cells into the inflamed bowel, have been discovered and commercialized. However, the increasing use of biological agents has raised some concerns regarding their short- and long-term safety. This review offers a critical evaluation of the efficacy and safety of biological agents in the management of both Crohn's disease and ulcerative colitis. In addition, promising therapeutic options are discussed.

Steroid-resistant asthma

Steroid-resistant asthma (SRA) refers to patients with symptoms consistent with asthma who show very poor or no response at all to high doses of inhaled or even of systemic corticosteroids. The current article reviews the SRA related literature focusing on the problems associated with the definition of SRA (especially its association with difficult to control, or severe asthma), its various phenotypes, its molecular basis, and the potential treatment options. The article also discusses the limitations of some of the key criteria used for the determination of SRA and proposes a modified set of criteria that are more applicable to children.

Basiliximab does not increase efficacy of corticosteroids in patients with steroid-refractory ulcerative colitis

BACKGROUND & AIMS

Basiliximab is a chimeric monoclonal antibody that binds CD25 and thereby inhibits interleukin (IL)-2-mediated proliferation of lymphocytes. IL-2 might contribute to the resistance of T cells to corticosteroids. We investigated the efficacy and safety of basiliximab as a corticosteroid-sensitizing agent in patients with corticosteroid-refractory ulcerative colitis (UC).

METHODS

We studied 149 patients with moderate to severe UC (Mayo score ≥6 and endoscopic subscore ≥2) despite treatment for at least 14 days with oral prednisone (40-50 mg/day). Subjects were randomly assigned to groups that were given 20 mg (n = 46) or 40 mg (n = 52) basiliximab or placebo (n = 51) at weeks 0, 2, and 4. All subjects received 30 mg/day prednisone through week 2; the dose was reduced by 5 mg each week to 20 mg/day, which was maintained until week 8. At week 8, we compared the rates of clinical remission (Mayo score ≤2, no subscore >1) for patients given basiliximab with the rate for patients given placebo.

RESULTS

Twenty-eight percent of patients given placebo, 29% of those given the 40-mg dose of basiliximab, and 26% of those given the 20-mg dose of basiliximab achieved clinical remission (P = 1.00 vs placebo for each dose). Basiliximab was generally well tolerated. Six subjects who received basiliximab had serious adverse events (6.1%) compared with 2 who received placebo (3.9%; P = .72). In subjects given basiliximab, incomplete saturation of CD25 (<50%) on peripheral T cells was associated with the presence of anti-basiliximab antibodies (odds ratio, 21; 95% confidence interval, 2.4-184).

CONCLUSIONS

Basiliximab does not increase the effect of corticosteroids in the induction of remission in outpatients with corticosteroid-resistant moderate to severe UC.

Cytokine blockade in inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) are chronic disabling diseases with significant morbidity. A deregulated immune response towards the intestinal microbiota is thought to play an important role in the pathogenesis of IBD, and thus biological therapies targeting key molecules such as cytokines have been designed. Several anti-TNF-α agents are currently being used to treat Crohn's disease and ulcerative colitis. Although these molecules dramatically improved the treatment of patients, side effects and the development of antidrug antibodies limits their application. There is thus an urgent need for alternative approaches to decrease inflammation and limit immunogenicity. Small neutralizing molecules, active immunization, gene silencing, selective transcription inhibitors and delivery of agents through the oral route are some of the currently developed strategies to meet these needs. In parallel, neutralizing antibodies targeting other pathways of the immune system have been developed and tested. Antibodies targeting IL-12/IL-23 pathways, and proinflammatory cytokines such as IFN-γ, IL-17A, IL-2 and IL-6 often showed an initial promising result, but for none of these agents efficacy has unequivocally been established. Administration of the regulatory cytokines IL-10 and IL-11 also failed to induce reproducible clinical effects. This article focuses on the anti-TNF therapies and the current challenges with monoclonal antibody therapies, discusses the innovative strategies targeting cytokine pathways to decrease inflammation in the bowel, and summarizes the recently developed agents neutralizing proinflammatory cytokines.

Preventive and therapeutic effects of tacrolimus in an interleukin-10-deficient mouse model of colitis

OBJECTIVE

To investigate the preventive and therapeutic effects of tacrolimus on colonic inflammation in interleukin-10-deficient (IL-10(-/-)) mice, which spontaneously develop T-cell-mediated colitis.

METHODS

Tacrolimus or prednisolone, an anti-inflammatory glucocorticoid, was administered to IL-10(-/-) mice with pre- or post-symptomatic colitis. Effects on colonic inflammation were examined by measuring indices of colitis such as colonic weight/length ratio, cell infiltration, and goblet cell depletion. Effects on cytokine production in colonic lamina propria mononuclear cells (LPMCs) isolated from IL-10(-/-) mice were also examined.

RESULTS

Tacrolimus prevented development of colitis and improved already-developed colitis. Prednisolone prevented the development of colitis, but had no effect on already-developed colitis. Tacrolimus completely inhibited IFN-γ and TNF-α production of activated T-cells in LPMCs, but only partially inhibited IFN-γ, TNF-α, and IL-12 production of activated monocytes/macrophages in LPMCs. Prednisolone inhibited cytokine production in both cell types but exhibited greater potency on monocytes/macrophages than on T-cells.

CONCLUSION

These results suggest that the preventive and therapeutic effect of tacrolimus in IL-10(-/-) mice colitis might be attributed to the inhibition of colonic T-cell activation rather than monocyte/macrophage activation. T-cell immunosuppression may thus be a promising strategy for treating colonic inflammation.

In vitro steroid resistance correlates with outcome in severe alcoholic hepatitis

Steroids improve the outcome in alcoholic hepatitis (AH), but up to 40% of patients fail to respond adequately. Interleukin-2 (IL-2) exacerbates steroid resistance in vitro. We performed a prospective study to determine if intrinsic steroid sensitivity correlates with response to steroids in individuals with severe AH and if IL-2 receptor blockade can reverse this. Peripheral blood mononuclear cells (PBMCs) were isolated from 20 patients with AH and a Maddrey's score >32. Patients were treated with oral prednisolone plus full supportive measures. Clinical resistance to oral steroid treatment was defined as a drop in serum bilirubin of <25% within 7 days or death within 6 months. In vitro steroid resistance was measured in PBMC using the dexamethasone suppression of lymphocyte proliferation assay and repeated after the addition of the anti-IL-2 receptor (anti-CD25) monoclonal antibody, basiliximab. Suppression of lymphocyte proliferation <60% was considered to indicate steroid resistance. In all, 82% (9/11) of in vitro steroid-resistant patients were dead at 6 months as compared to 21% (2/9) of steroid-sensitive patients (P = 0.03). Similarly, 91% (10/11) of in vitro steroid-resistant patients failed to show a significant fall in bilirubin at day 7 as compared to 44% (4/9) of steroid-sensitive patients (P < 0.05). Basiliximab improved the maximal proliferation count in 91% (10/11) of in vitro steroid-resistant patients (P = 0.003).

CONCLUSION

Clinical outcome of steroid therapy in this patient cohort correlated with in vitro steroid resistance. IL-2 blockade improved in vitro steroid sensitivity. This suggests that intrinsic lack of steroid sensitivity may contribute to poor clinical response to steroids in severe AH. IL-2 receptor blockade represents a possible mechanism to overcome this.

Recent advances in cytokines: therapeutic implications for inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) are complex and chronic disabling conditions resulting from a dysregulated dialogue between intestinal microbiota and components of both the innate and adaptive immune systems. Cytokines are essential mediators between activated immune and non-immune cells, including epithelial and mesenchymal cells. They are immunomodulatory peptides released by numerous cells and these have significant effects on immune function leading to the differentiation and survival of T cells. The physiology of IBD is becoming a very attractive field of research for development of new therapeutic agents. These include cytokines involved in intestinal immune inflammation. This review will focus on mechanisms of action of cytokines involved in IBD and new therapeutic opportunities for these diseases.

Emerging drugs for uveitis

INTRODUCTION

Uveitis is a challenging disease covering both infectious and noninfectious conditions. The current treatment strategies are hampered by the paucity of randomized controlled trials and trials comparing the efficacy of different agents.

AREAS COVERED

This review describes the current and future treatments of uveitis. A literature search was performed in PUBMED from 1965 to 2010 on drugs treating ocular inflammation with emphasis placed on more recent, larger studies. Readers should gain a basic understanding of current treatment strategies beginning with corticosteroids and transitioning to steroid sparing agents. Steroid sparing agents include antimetabolites such as methotrexate, azathioprine and mycophenolate mofetil; calcineurin inhibitors which include cyclosporine, tacrolimus; alkylating agents which include cyclophosphamide and chlorambucil; and biologics which include the TNF-α inhibitors infliximab, adalimumab and etanercept and daclizumab, IFN-α(2a) and rituximab.

EXPERT OPINION

Newer agents are typically formulated from existing drugs or developed based on new advances in immunology. Future treatment will require a better understanding of the mechanisms involved in autoimmune diseases and better delivery systems in order to provide targeted treatment with minimal side effects.

New and emerging biologics in the treatment of inflammatory bowel disease: quo vadis?

Inflammatory bowel diseases (IBD) are pathological conditions characterized by chronic inflammation that is primarily the consequence of dysregulation of the immune response. Over the last decade, the advances in the pathophysiology of IBD have paved the way for the development of a number of biological agents that selectively target specific molecules and/or pathways involved in gut inflammation. Although numerous, so far, the only biological therapeutics that are approved for the treatment for IBD are monoclonal antibodies against tumor necrosis factor alpha. This paper systematically reviews the mechanismof-action, efficacy, short-term and, where available, long-term safety of biological agents that target molecules other than tumor necrosis factor alpha, in IBD.

T-cell-directed therapies in inflammatory bowel diseases. Clin Sci (Lond). 2010;118:707-715. [PMID: 20350293 DOI: 10.1042/cs20100027]

Gut inflammation occurring in patients with IBDs (inflammatory bowel diseases) is associated with exaggerated and poorly controlled T-cell-mediated immune responses, which are directed against normal components of the gut flora. T-cells accumulate in the inflamed gut of IBD patients as a result of multiple mechanisms, including enhanced recruitment of cells from the bloodstream, sustained cell cycling and diminished susceptibility of cells to undergo apoptosis. Activated T-cells produce huge amounts of cytokines, which contribute to amplify and sustain the ongoing mucosal inflammation. Strategies aimed at interfering with T-cell accumulation and/or function in the gut have been employed with clinical success in patients with IBDs. In the present article, we review the available results showing that T-cell-directed therapies are useful to dampen the tissue-damaging immune response in IBDs.

Injecting drugs by a tube from appendix stump to colon may be a good method for dealing with refractory ulcerative colitis

Ulcerative colitis is a kind of nontransmural chronic inflammatory bowel disease which mainly affects colon and rectum, it has a classic character of the relapsing and remitting course. The main symptoms of ulcerative colitis are intermittent bloody diarrhea, rectal urgency, and tenesmus. As a chronic disease, it can disable and disrupt the daily life of patients. The main treatments for ulcerative colitis are medical management and surgical management, but the drugs used by traditional way have many severe side effects and invalid for refractory ulcerative, and traditional surgery has many complications, so we propose a new treatment of ulcerative colitis, which is the combination of drugs and a little surgery-appendectomy: injecting drugs by a tube from appendix stump to colon after appendectomy by laparoscope, this treatment can decrease the side effects of oral drugs and increase the drug levels as topical managements. Our hypotheses might be an effect way to deal with refractory ulcerative colitis especially total or upper ulcerative colitis, and it is a treatment with little wound and few complications.

Emerging drugs for the treatment of ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic, relapsing inflammatory disorder of the colon for which the etiology is currently unknown. At present, strategies to treat UC are primarily targeted to control inflammation during active phases of disease as well as maintain remission during quiescence. As such, several unmet needs in the treatment of UC still remain. In recent years, basic research has led to the recognition of several key factors in the pathogenesis of UC, translating into the development of several novel therapeutic agents.

OBJECTIVE

The aim of this study is to review emerging therapies that may advance the treatment and improve the overall care of UC patients.

METHODS

An extensive literature search on published manuscripts and meeting proceedings has been performed to provide a comprehensive review of future drug therapies to treat UC.

RESULTS/CONCLUSION

The translational application of new discoveries in the basic understanding of UC pathogenesis is continuing and critical for the development of novel treatment strategies. Design of novel biologic therapies to treat UC has the challenge of addressing potential safety issues, while more traditional drugs should be further developed to facilitate patient compliance to treat this chronic, debilitating disease.

Management of acute severe ulcerative colitis

Ulcerative colitis is a chronic relapsing and remitting inflammatory disorder that can generally be managed successfully with maintenance oral medications. However, approximately 15% of patients with ulcerative colitis will develop a severe exacerbation and require hospitalization. While many patients with acute severe ulcerative colitis will respond to a short course of intravenous corticosteroids, up to a third will fail to improve. In these patients with steroid-refractory colitis, the choice is between rescue medical therapy with ciclosporin or infliximab, or surgery. Well-timed rescue medical therapy is generally safe when administered by experienced physicians, and is effective in the majority of cases. Surgery is unavoidable in some cases, but is the treatment of choice in others. While ileal pouch-anal anastomosis offers the prospect of life without a permanent ileostomy, there are issues with its long-term functional outcome.

The plant sterol guggulsterone attenuates inflammation and immune dysfunction in murine models of inflammatory bowel disease

Inflammatory bowel diseases (IBD) are chronic inflammatory and relapsing diseases of the gut that may manifest as either Crohn's disease (CD) or ulcerative colitis (UC). CD and UC are immunologically different diseases characterized by exacerbated Th1 and Th2 response. T-cell resistance against apoptosis contributes to inappropriate T-cell accumulation and the perpetuation of chronic mucosal inflammation. In the present study we have investigated the effect exerted by guggulsterone (GS) a plant derived steroid isolated from the gum resin of the Commiphora mukul tree, in two models of intestinal inflammation induced in mice by trinitro-benzene sulfonic acid (TNBS) and oxazolone. We provided evidence that E-GS protects mice against development of sign and symptoms of colon inflammation. E-GS effectively attenuated the severity of wasting disease and the fecal score and colon inflammation as assessed by measuring the macroscopic- and microscopic-damage scores. Administration Z-GS failed to ameliorate colon inflammation in TNBS-induced colitis and had a partial effect in oxazolone-induced colitis. In vitro, mechanistic studies carried out using CD4+ cells isolated from the intestinal lamina propria demonstrate that GS effectively regulates the function of effector T cells by modulating cell signaling activation pathway caused by CD3/CD28. The net biological effects resulting from exposure to GS includes attenuation of generation of interleukin-2 and -4 and interferon-gamma as well as T cell proliferation. In conclusion, GS is an anti-inflammatory compound with the capacity to prevent and ameliorate T-cell-induced colitis. These data ground the use of GS, a natural cholesterol-lowering agent, in the treatment of chronic inflammatory diseases.

Glucocorticoids and the emerging importance of T cell subsets in steroid refractory diseases

Glucocorticoids remain the first-line treatment for a range of autoimmune and allergic diseases. However, 30% of patients fail to achieve disease control at tolerable systemic doses and continue to have an increased immune response with poor clinical outcome. This steroid refractory (SR) phenotype has previously been attributed to enhanced expression of inactive glucocorticoid receptor isoforms and cytokine-mediated suppression of glucocorticoid (GC) signaling, in particular by interleukin-2. These mechanisms are discussed, with emphasis on recent evidence for the role of the CD4(+)CD25(int) and GC-induced T regulatory cell subsets in perpetrating SR disease.

Steroid-refractory severe ulcerative colitis: what are the available treatment options?

Approximately 15% of patients with ulcerative colitis will experience a severe episode requiring hospitalization. Although intravenous corticosteroids are the current first-line therapy for these patients, about 30% of patients do not respond to corticosteroids and require either an alternative anti-inflammatory agent or surgery. Ciclosporin has proven its efficacy in a number of controlled trials in this setting and is characterized by high early response rates. Patients who respond to ciclosporin and avoid colectomy are more likely to retain their colon if they bridge to immunomodulators in the medium term. Infliximab has also demonstrated efficacy in reducing early colectomy rates and longer term data are awaited. Other agents, such as tacrolimus and basiliximab, and leukocytapheresis, have been studied in small trials and may be alternative options. Key issues remain as to what should be first- and second-line therapies, when surgery should be undertaken, and the risk of switching between immunosuppressants in these critical patients.

IL-2 receptor beta-chain signaling controls immunosuppressive CD4+ T cells in the draining lymph nodes and lung during allergic airway inflammation in vivo

IL-2 influences both survival and differentiation of CD4(+) T effector and regulatory T cells. We studied the effect of i.n. administration of Abs against the alpha- and the beta-chains of the IL-2R in a murine model of allergic asthma. Blockade of the beta- but not the alpha-chain of the IL-2R after allergen challenge led to a significant reduction of airway hyperresponsiveness. Although both treatments led to reduction of lung inflammation, IL-2 signaling, STAT-5 phosphorylation, and Th2-type cytokine production (IL-4 and IL-5) by lung T cells, IL-13 production and CD4(+) T cell survival were solely inhibited by the blockade of the IL-2R beta-chain. Moreover, local blockade of the common IL-2R/IL-15R beta-chain reduced NK cell number and IL-2 production by lung CD4(+)CD25(+) and CD4(+)CD25(-) T cells while inducing IL-10- and TGF-beta-producing CD4(+) T cells in the lung. This cytokine milieu was associated with reduced CD4(+) T cell proliferation in the draining lymph nodes. Thus, local blockade of the beta-chain of the IL-2R restored an immunosuppressive cytokine milieu in the lung that ameliorated both inflammation and airway hyperresponsiveness in experimental allergic asthma. These findings provide novel insights into the functional role of IL-2 signaling in experimental asthma and suggest that blockade of the IL-2R beta-chain might be useful for therapy of allergic asthma in humans.

Tacrolimus (FK506) for induction of remission in refractory ulcerative colitis

BACKGROUND

There are a limited number of treatment options for patients with refractory ulcerative colitis. Animal models of inflammatory bowel disease and uncontrolled studies in humans suggest that tacrolimus may be effective treatment for ulcerative colitis.

OBJECTIVES

This review aims to evaluate the efficacy of tacrolimus for induction of remission in patients with corticosteroid refractory ulcerative colitis.

SEARCH STRATEGY

MEDLINE (PubMed), The Cochrane Central Register of Controlled Trials, the IBD/FBD review group specialized register and the ISI-Research Institute were searched (January 1997 to November 2007) to identify relevant studies all randomized trials.

SELECTION CRITERIA

Each author independently reviewed potentially relevant studies to determine eligibility based on the pre-specified criteria.

DATA COLLECTION AND ANALYSIS

A data extraction form was developed and used to extract data from included studies. Two authors independently extracted data. Data were analyzed using Review Manager (RevMan 4.2.9). The primary outcomes were induction of remission and clinical improvement, as defined by the studies and expressed as a percentage of the patients randomized (intention to treat analysis).

MAIN RESULTS

One randomized controlled trial comparing high target serum concentration and low target serum concentration tacrolimus versus placebo was identified and included in the review. Clinical remission was observed in 19% (4/21) of patients in the high target serum concentration group, in 9% (2/22) in the low target serum concentration group and in 5% (1/20) in the placebo group (OR 2.27; 95% CI 0.35 to 14.75). A statistically significant benefit for clinical improvement at two weeks was observed. Clinical improvement was observed in 62% (13/21) of patients in the high target serum concentration group, in 36% (8/22) in the low target serum concentration group and in 10% (2/20) in the placebo group (OR 8.66; 95% CI 1.79 to 42.00; RD 0.39; 95% CI 0.20 to 0.59; NNT = 3). Patients in the high serum target concentration group were significantly more likely than placebo patients to experience adverse events related to treatment (P = 0.043). Finger tremor (n = 6) was the most common adverse event in the tacrolimus group. Other adverse events included: gastroenteritis, sepsis, sleepiness, hot flush, headache, queasiness and stomach discomfort.

AUTHORS' CONCLUSIONS

Tacrolimus may be effective for short-term clinical improvement in patients with refractory ulcerative colitis. However, these results should be interpreted with caution due to the small number of patients enrolled in the trial and other study limitations. Insufficient treatment and follow-up intervals prevent any conclusions with regard to long term safety and efficacy. The use of tacrolimus in the clinical setting requires careful consideration of risks versus benefits as well as close monitoring for adverse events. More data from well designed and controlled studies are needed to determine the long-term efficacy and safety of tacrolimus.

Crohn's disease: beyond antagonists of tumour necrosis factor

In the past few years, antagonists of tumour necrosis factor have resulted in unforetold therapeutic benefits in Crohn's disease, but the magnitude and duration of responses are variable. New agents are therefore needed. Their development has benefited from advances in the understanding of the pathophysiology of this disease. Uncontrolled activation of the acquired immune system has an important role, and lymphocytes, cytokines, and adhesion molecules are broadly targeted for therapeutic intervention. With increasing evidence of an implication of the innate immune system and the intestinal epithelium, the therapeutic paradigm is also shifting from mere immunosuppression to the reinforcement of the intestinal barrier. We review mechanisms of actions of new drugs and the efficacy and adverse events from data from clinical trials. We discuss future directions, including new strategies with optimum endpoints.

Therapeutic options in acute severe ulcerative colitis

Ulcerative colitis is a relapsing-remitting inflammatory disease affecting the colon and is associated with considerable morbidity. In acute severe attacks, there continues to be an associated mortality rate of 1-2%, even in specialist units. During an acute severe exacerbation, approximately two-thirds of patients will respond to intravenous corticosteroid therapy, the accepted first-line therapy in such cases. For steroid-refractory patients, options are limited to surgery (colectomy) or second-line agents, such as ciclosporin or infliximab, used in an attempt to salvage the colon. Considerable debate exists over the optimal management of such patients. During the last decade, an increased understanding of the pathogenesis of inflammatory bowel disease has led to the rapid development of other biological agents, such as basiliximab and visilizumab. Novel methods, such as leucopheresis, have been studied and other established immunomodulatory agents, such as tacrolimus, have also been suggested. The purpose of this review is to highlight some of the areas of recent development in the treatment of acute severe ulcerative colitis and review important safety data, with a particular emphasis on biological agents.

Biological agents for ulcerative colitis: hypes and hopes

Ulcerative colitis (UC) is an idiopathic chronic inflammatory disease of the colonic mucosa. Over the last decade, the increasing knowledge on the pathogenic mechanisms underlying intestinal inflammation has led to the development of a number of biological agents, mainly addressed to molecules and/or pathways demonstrated to have a pathogenic role in UC. In UC, clinical course and therapeutic decisions mainly depend on disease activity and extent. While therapeutic approach to mild-to-moderate UC by using aminosalicylates and corticosteroids has been well established, treatment of severe UC is far from being satisfactory. A severe attack of UC remains a challenge to be managed jointly by gastroenterology, surgery, and intensive care units. However, the recent introduction of biological therapies has led to promising changes in the management of UC patients. Aim of this paper is to review the recent advances and future perspectives for the use of biological agents in UC.

CD4+CD25(int) T cells in inflammatory diseases refractory to treatment with glucocorticoids

Up to 30% of patients with autoimmune, allergic, and lymphoproliferative diseases are refractory to glucocorticoid therapy. The present study was undertaken to investigate whether such steroid resistance (SR) is limited to a subpopulation of CD4(+) T cells and, as IL-2 is a putative driver of SR, whether T cell SR is associated with CD25 expression. We show that SR patients have a characteristic subgroup of activated CD4(+) T cells that continue to proliferate despite exposure to high-dose Dexamethasone (Dex), demonstrate that CD4(+)CD25(-) cells are exquisitely sensitive to Dex whereas CD4(+)CD25(int) cells are highly SR, and further find that the combination of an anti-CD25 mAb with Dex enhances suppression of T cell proliferation compared with each agent alone. We therefore conclude that SR is not a general property of all lymphocytes but resides in T cell subpopulations, which are prevalent in SR patients and express intermediary levels of CD25. As a result, we propose a new paradigm for SR disease in which glucocorticoid therapy positively selects SR cells, generating a population of drug-resistant lymphocytes that perpetuate on-going inflammation.

Treatment of inflammatory bowel disease: a review of medical therapy

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the gastrointestinal tract. While a cure remains elusive, both can be treated with medications that induce and maintain remission. With the recent advent of therapies that inhibit tumor necrosis factor (TNF) alpha the overlap in medical therapies for UC and CD has become greater. Although 5-ASA agents have been a mainstay in the treatment of both CD and UC, the data for their efficacy in patients with CD, particularly as maintenance therapy, are equivocal. Antibiotics may have a limited role in the treatment of colonic CD. Steroids continue to be the first choice to treat active disease not responsive to other more conservative therapy; non-systemic steroids such as oral and rectal budesonide for ileal and right-sided CD and distal UC respectively are also effective in mild-moderate disease. 6-mercaptopurine (6-MP) and its prodrug azathioprine are steroid-sparing immunomodulators effective in the maintenance of remission of both CD and UC, while methotrexate may be used in both induction and maintenance of CD. Infliximab and adalimumab are anti-TNF agents approved in the US and Europe for the treatment of Crohn's disease, and infliximab is also approved for the treatment of UC.

Novel therapeutic options in the inflammatory bowel disease world

Advances in the understanding of the pathogenesis of inflammatory bowel disease have encouraged the development of many new therapies targeted at specific and non-specific mediators of the inflammatory bowel disease inflammatory pathway. The role of these therapies, including novel anti-tumour necrosis factor-alpha agents, anti-adhesion molecules, recombinant cytokines, myeloid growth factors, helminths, and probiotics, in the management of paediatric onset inflammatory bowel disease is promising and warrants further investigation.

Safety of biologic therapy

Several biologic agents have been assessed in patients with inflammatory bowel disease (IBD; Crohn's disease [CD] and ulcerative colitis [UC]). Until recently, only infliximab (humanized monoclonal anti-TNF-alpha antibody) had been approved by the Food and Drug Administration (FDA) to induce and maintain remission in patients with active mild to moderate and/or fistulizing Crohn's disease who are refractory to conventional therapy. Two recent trials, ACT 1 and ACT2, observed high efficacy of infliximab in inducing and maintaining clinical remission, mucosal healing, and corticosteroid-sparing effects in patients with moderate to severe UC. This agent also was recently approved by the FDA for the treatment of ulcerative colitis to reduce signs and symptoms, to induce clinical remission and healing of the intestinal mucosa, and to eliminate the use of corticosteroids in patients with moderately to severely active UC who have had an inadequate response to conventional therapy. There have been many randomized, double-blind, controlled and open-label uncontrolled studies of large and small numbers of patients assessing the efficacy and safety of various biologic agents considered potentially useful in the treatment of IBD. Among all the biologic agents, infliximab has the most robust data on safety. This is because it has been evaluated in many more trials than has any other biologic agent. In addition, postmarketing experience provides very valuable information about adverse events occurring during treatment with this agent.

Inflammatory bowel disease: clinical aspects and established and evolving therapies

Crohn's disease and ulcerative colitis are two idiopathic inflammatory bowel disorders. In this paper we discuss the current diagnostic approach, their pathology, natural course, and common complications, the assessment of disease activity, extraintestinal manifestations, and medical and surgical management, and provide diagnostic and therapeutic algorithms. We critically review the evidence for established (5-aminosalicylic acid compounds, corticosteroids, immunomodulators, calcineurin inhibitors) and emerging novel therapies--including biological therapies--directed at cytokines (eg, infliximab, adalimumab, certolizumab pegol) and receptors (eg, visilizumab, abatacept) involved in T-cell activation, selective adhesion molecule blockers (eg, natalizumab, MLN-02, alicaforsen), anti-inflammatory cytokines (eg, interleukin 10), modulation of the intestinal flora (eg, antibiotics, prebiotics, probiotics), leucocyte apheresis and many more monoclonal antibodies, small molecules, recombinant growth factors, and MAP kinase inhibitors targeting various inflammatory cells and pathways. Finally, we summarise the practical aspects of standard therapies including dosing, precautions, and side-effects.

The fundamental basis of inflammatory bowel disease

Two broad hypotheses have arisen regarding the fundamental nature of the pathogenesis of inflammatory bowel diseases (IBDs, which include ulcerative colitis and Crohn disease). The first contends that primary dysregulation of the mucosal immune system leads to excessive immunologic responses to normal microflora. The second suggests that changes in the composition of gut microflora and/or deranged epithelial barrier function elicits pathologic responses from the normal mucosal immune system. Here we examine these hypotheses and conclude that IBD is indeed characterized by an abnormal mucosal immune response but that microbial factors and epithelial cell abnormalities can facilitate this response.

Current therapy of inflammatory bowel disease in children

Ulcerative colitis (UC) and Crohn disease (CD) are chronic intestinal inflammatory diseases that can present as bloody diarrhea, abdominal pain, and malnutrition. Collectively, these disorders are referred to as inflammatory bowel disease (IBD). All patients with IBD share a common pathophysiology. However, there are a number of developmental, psychosocial, and physiologic issues that are unique to the approximate, equals 20% of patients that present during childhood or adolescence. These include the possibility of disease-induced delays in linear growth or physical development, differences in drug dosing, and the changes in social and cognitive development that occur as children move from school-age years into adolescence and early adulthood. Gastroenterologists caring for these children must therefore develop an optimal regimen of pharmacologic therapies, nutritional management, psychologic support, and properly timed surgery (when necessary) that will maintain disease remission, minimize disease and drug-induced adverse effects, and optimize growth and development. This article reviews current approaches to the management of patients with UC and CD and highlights issues specific to the treatment of children with IBD. The principal medical therapies used to induce disease remission in patients with UC are aminosalicylates (for mild disease), corticosteroids (for moderate disease), and cyclosporine (ciclosporin) (for severe disease). If a patient responds to the induction regimen, maintenance therapies that are used to prevent disease relapse include aminosalicylates, mercaptopurine, and azathioprine. Colectomy with creation of an ileal pouch anal anastomosis (J pouch) has become the standard of care for patients with severe or refractory colitis and results in an improved quality of life in most patients. Therefore, the risks associated with using increasingly potent immunosuppressant agents must be balanced in each case against a patient's desire to retain their colon and avoid a temporary or potentially permanent ileostomy. Decisions about drug therapy in the management of patients with CD are more complex and depend on both the location (e.g. gastroduodenal vs small intestinal vs colonic), as well as the behavior of the disease (inflammatory/mucosal vs stricturing vs perforating) in a given patient. Induction therapies for CD typically include aminosalicylates and antibiotics (for mild mucosal disease), nutritional therapy (including elemental or polymeric formulas), corticosteroids (for moderate disease), and infliximab (for corticosteroid-resistant or fistulizing disease). Aminosalicylates, mercaptopurine, azathioprine, methotrexate, and infliximab can be used as maintenance therapies. Because surgical treatment of CD is not curative, it is typically reserved for those patients either with persistent symptoms and disease limited to a small section of the intestine (e.g. the terminal ileum and cecum) or for the management of complications of the disease including stricture or abdominal abscess. When surgery is necessary, maintenance medications administered postoperatively will postpone recurrence. Patients with UC and CD are at risk for the development of micronutrient deficiencies (including folate, iron, and vitamin D deficiencies) and require close nutritional monitoring. In addition, patients with UC and CD involving the colon are at increased risk of developing colon cancer, and should be enrolled into a colonoscopy surveillance program after 8-10 years of disease duration.

Review article: steroid resistance in inflammatory bowel disease - mechanisms and therapeutic strategies

BACKGROUND

Steroid resistance in inflammatory bowel disease presents a difficult clinical challenge. The advent of biological therapies coupled with an increasing understanding of the pathogenesis of inflammatory bowel disease has provided new therapeutic options.

METHODS

We review the available literature of the mechanisms behind steroid resistance. In addition, we outline some of the options available for treating those patients who fail to respond adequately to glucocorticoids.

RESULTS

Approximately 30% of patients prescribed glucocorticoids will not achieve clinical remission. Many such patients are offered immunosuppressive or, recently, biological agents. However, these agents are ineffective in a large proportion of patients. Immunosuppressive agents only bring 40-60% of patients into remission, and biological agents typically induce remission in just 40% of patients. In this review, the possible explanations for glucocorticoid resistance are discussed. Recent evidence suggests that in many patients it is mediated by interleukin-2. Basiliximab, a biological agent that interrupts interleukin-2 signalling, has shown significant benefit in early clinical studies.

CONCLUSIONS

Patients who fail to respond to steroid therapy should have alternative agents introduced in a timely fashion. Steroid refractory inflammatory bowel disease remains a difficult condition to treat, but new therapies and managements are emerging.

Focus on mechanisms of inflammation in inflammatory bowel disease sites of inhibition: current and future therapies

Anti-TNF antibodies were the first biologic agents registered to treat patients who have CD and, more recently, patients who have UC. The sequence of events underlying the inflammatory reaction in IBD is extremely complex, however, and involves both the innate and antigen-driven adaptive immune system. Novel therapies are directed at several key players of this cascade. Blockade of T-cell proliferation and activation and inhibition of T-cell cytokines has been most extensively targeted by clinical trials in humans. Inhibition of adhesion molecules and the use of selected growth factors seem to have therapeutic potential. Restoration of regulatory T-cell and dendritic-cell function is still waiting to be explored in clinical trials. Although an increasing number of biologic therapies for IBD are being developed, the discovery of the full spectrum of treatment modalities is only beginning. Often, however, the clinical efficacy of biologic agents is investigated, and for some molecules is established, before mechanisms of action are specifically explored. Eight years after the Food and Drug Administration approved infliximab for the treatment of luminal CD, it is not known how this anti-TNF antibody actually dampens inflammation in IBD. The advent of newer anti-TNF agents is only postponing the answer.