A pilot study on the use of the humanized anti-interleukin-2 receptor antibody daclizumab in active ulcerative colitis

Autoimmune diseases association study with the KIAA1109-IL2-IL21 region in a Tunisian population

Autoimmune diseases (ADs) share several genetic factors resulting in similarity of disease mechanisms. For instance polymorphisms from the KIAA1109-interleukin 2 (IL2)-IL21 block in the 4q27 chromosome, has been associated with a number of autoimmune phenotypes. Here we performed a haplotype-based analysis of this AD related region in Tunisian patients. Ten single nucleotide polymorphisms (rs6534347, rs11575812, rs2069778, rs2069763, rs2069762, rs6852535, rs12642902, rs6822844, rs2221903, rs17005931) of the block were investigated in a cohort of 93 systemic lupus erythematosus (SLE), 68 ulcerative colitis (UC), 39 Crohn's disease (CD) patients and 162 healthy control subjects of Tunisian origin. In SLE population, haplotypes AGCAGGGTC, AGAAGAGTC, AGAAGGGTC and AGCCGAGTC provided significant evidence of association with SLE risk (p = 0.013, 0.028, 0.018 and 0.048, respectively). In the UC population, haplotype AGCCGGGTC provided a susceptibility effect for UC (p = 0.025). In the CD population, haplotype CAGGCC showed a protective effect against the development of CD (p = 0.038). Haplotype AAGGTT provided significant evidence to be associated with CD risk (p = 0.007). Our results support the existence of the associations found in the KIAA1109/IL2/IL21 gene region with ADs, thus confirms that the 4q27 locus may contribute to the genetic susceptibility of ADs in the Tunisian population.

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.

Investigational new drugs in the treatment of inflammatory bowel disease: a review

The unraveling of the immuno-pathobiology of inflammatory bowel disease (IBD) in the past three decades has ushered in a new era of translational medicine. The biotechnology revolution has resulted in a paradigm shift in how clinicians view and treat IBD. Anti-tumor necrosis factor (TNF)-α strategies using infliximab and adalimumab currently dominate the therapeutic arena. Better understanding of how these biologicals work is driving the quest for loftier therapeutic goals of achieving mucosal healing, sustaining deep remission, and even modifying the natural history of IBD. However, not all patients respond to anti-TNF drugs. Immune-mediated adverse reactions and loss of efficacy with time also limit their use. There are many investigational drugs undergoing active clinical trials. Many have not fulfilled their early promises but some are potentially making the transition from bench to trial and to the bedside in the near future. Clinicians and investigators need to underpin our excitement with caution for the unknown long-term consequences of modulating cytokines and selective adhesion molecules in human. Here we provide an overview of investigational new drugs and other therapeutic strategies currently undergoing clinical trials in IBD.

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.

[Case of drug-induced colitis like ulcerative colitis during IL-2 therapy for multiple bone metastasis after operation of kidney cancer]

A 60-year-old man underwent retroperitoneal laparoscopic nephrectomy for left renal tumor (cT1bN0M0).The histopathological examination revealed Kidney cancer grade 3 pT1b. The following evaluations revealed multiple bone metastasis. The IFN-gamma with radiation therapy were performed. However the disease was progressive. So IL-2 70 million units per day 5 times a week started. The patient started to complain lower abdominal pain and watery diarrhea from administration day 28th. Blood test showed eosinophilia. At this point side effect of IL-2 therapy was suspected, then IL-2 was discontinued. But abdominal symptoms had continued. Consulting with a digestive physician, he diagnose as drug-induced colitis like ulcerative colitis by colon endoscopy. The symptoms were gradually improved by an antiallergic agent on our assumption that eosinophilia was concerned in this colitis. Many articles have reported that IL-2 was associated with the clinical mechanism of ulcerative colitis, but there seems no reports about such complications before. This case could suggest IL-2 relates to ulcerative colitis.

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.

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.

Novel strategies for the treatment of inflammatory bowel disease: Selective inhibition of cytokines and adhesion molecules

The etiology of inflammatory bowel disease (IBD) has not yet been clarified and immunosuppressive agents which non-specifically reduce inflammation and immunity have been used in the conventional therapies for IBD. Evidence indicates that a dysregulation of mucosal immunity in the gut of IBD causes an overproduction of inflammatory cytokines and trafficking of effector leukocytes into the bowel, thus leading to an uncontrolled intestinal inflammation. Such recent advances in the understanding of the pathogenesis of IBD created a recent trend of novel biological therapies which specifically inhibit the molecules involved in the inflammatory cascade. Major targets for such treatment are inflammatory cytokines and their receptors, and adhesion molecules. A chimeric anti-TNF-α monoclonal antibody, infliximab, has become a standard therapy for CD and it is also likely to be beneficial for UC. Several anti-TNF reagents have been developed but most of them seem to not be as efficacious as infliximab. A humanized anti-TNF monoclonal antibody, adalimumab may be useful for the treatment of patients who lost responsiveness or developed intolerance to infliximab. Antibodies against IL-12 p40 and IL-6 receptor could be alternative new anti-cytokine therapies for IBD. Anti-interferon-γ and anti-CD25 therapies were developed, but the benefit of these agents has not yet been established. The selective blocking of migration of leukocytes into intestine seems to be a nice approach. Antibodies against α4 integrin and α4β7 integrin showed benefit for IBD. Antisense oligonucleotide of intercellular adhesion molecule 1 (ICAM-1) may be efficacious for IBD. Clinical trials of such compounds have been either recently reported or are currently underway. In this article, we review the efficacy and safety of such novel biological therapies for IBD.

Management of refractory ulcerative colitis

A physician's approach to patients with ulcerative colitis (UC) who are refractory to standard first-line therapies must be thoughtful and systematic and include the individual's physical and emotional state as the physician examines the various dietary, medical, and surgical options currently available. It is of foremost importance to confirm that the refractory patient's symptoms are not simply due to dietary indiscretion, concomitant bowel infection (especially with Clostridium difficile), an incorrect diagnosis (eg, colitis due to infection, NSAIDs, ischemia, diverticulitis, or Crohn's disease), or even a concomitant diagnosis (eg, celiac sprue, pancreatic insufficiency, functional bowel disorder, laxative or sorbitol intake). The ability to quickly assess the status of the colonic mucosa with flexible sigmoidoscopy aids in the ability to distinguish patients with refractory inflammation from those with other diagnoses. The initiation and optimization of the long-term purine analogues azathioprine (AZA) or 6-mercaptopurine (6-MP) remain the backbone of medical therapy for patients with refractory UC. For those unresponsive to corticosteroids, quicker induction of remission may necessitate infliximab, cyclosporine, or tacrolimus. Successful induction and maintenance with AZA, 6-MP, and/or infliximab should be followed by long-term therapy with these agents. Cessation of therapy often leads to relapse. Novel therapies under investigation hold the promise of offering more options for both the induction and maintenance of remission in refractory UC patients. Discussions of surgical intervention should not be put off as a last resort but rather included in the overall treatment plan offered to the patient.

How important is onset of action in ulcerative colitis therapy?

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

Positioning novel biologic, probiotic, and apheresis therapies for Crohn's disease and ulcerative colitis

Traditional medications for inflammatory bowel disease are small molecule drugs, most of which were developed for use in other diseases before being found to be efficacious for the treatment of ulcerative colitis or Crohn's disease. Recently, several exciting alternative approaches to the medical treatment of inflammatory bowel disease have been developed. These include biologic, probiotic, and apheresis therapies that offer certain advantages over traditional drug therapy for inflammatory bowel disease. The purpose of this review is to assess the current state of knowledge about novel biologic, probiotic, and apheresis therapies and to analyze how best to incorporate these therapies into evolving management paradigms of inflammatory bowel disease.

Immunomodulatory benefits of cyclosporine A in inflammatory bowel disease

Etiopathogenesis of mucosal inflammation in inflammatory bowel disease remains a complex and enigmatic field; various factors (genetic, environmental and microbial) trigger an event that activates intestinal immune and nonimmune systems culminating in inflammation and tissue injury. Specifically, both innate and adaptive immune systems seem to play important roles in the pathophysiology of this disease. Cyclosporine A represents a macrolide immune modulator with primary inhibitory effects on T helper lymphocyte production of interleukin-2, and other cytokines leading to altered T-lymphocyte and B-lymphocyte function. The diversity of its therapeutic outcome reported in inflammatory bowel disease may be due to the intricate immuno-pathogenic profile of the disease and the variety of the applied dose-dependent courses of therapy. Cyclosporine A exerts additional actions on other components of the inflammatory infiltrate, including neutrophils and mast cells, thereby appearing to be a multi-dynamic therapeutic approach, although with potential drawbacks, that may be applied alone or combined with other immunomodulatory agents in inflammatory bowel disease patients. Because cyclosporine A induces apoptosis of T-lymphocytes responsible for perpetuation of the chronic inflammatory process in the disease with potential tumorigenic effect, it may exert a further inhibitory effect on cancer development in inflammatory bowel disease patients, and can be combined with other relative agents, such as rapamycin, which also promotes T-lymphocyte apoptosis. Therefore, recently established multifactorial action of cyclosporine A in relation to the pathogenesis of the disease can open new horizons for prospective, controlled trials in large cohorts, aiming to emphasize cyclosporine A's potential.

Biologic Therapy for Inflammatory Bowel Disease

Despite all of the advances in our understanding of the pathophysiology of inflammatory bowel disease (IBD), we still do not know its cause. Some of the most recently available data are discussed in this review; however, this field is changing rapidly and it is increasingly becoming accepted that immunogenetics play an important role in the predisposition, modulation and perpetuation of IBD. The role of intestinal milieu, and enteric flora in particular, appears to be of greater significance than previously thought. This complex interplay of genetic, microbial and environmental factors culminates in a sustained activation of the mucosal immune and non-immune response, probably facilitated by defects in the intestinal epithelial barrier and mucosal immune system, resulting in active inflammation and tissue destruction. Under normal situations, the intestinal mucosa is in a state of 'controlled' inflammation regulated by a delicate balance of proinflammatory (tumour necrosis factor [TNF]-alpha, interferon [IFN]-gamma, interleukin [IL]-1, IL-6, IL-12) and anti-inflammatory cytokines (IL-4, IL-10, IL-11). The mucosal immune system is the central effector of intestinal inflammation and injury, with cytokines playing a central role in modulating inflammation. Cytokines may, therefore, be a logical target for IBD therapy using specific cytokine inhibitors. Biotechnology agents targeted against TNF, leukocyte adhesion, T-helper cell (T(h))-1 polarisation, T-cell activation or nuclear factor (NF)-kappaB, and other miscellaneous therapies are being evaluated as potential therapies for IBD. In this context, infliximab is currently the only biologic agent approved for the treatment of inflammatory and fistulising Crohn's disease. Other anti-TNF biologic agents have emerged, including CDP 571, certolizumab pegol (CDP 870), etanercept, onercept and adalimumab. However, ongoing research continues to generate new biologic agents targeted at specific pathogenic mechanisms involved in the inflammatory process. Lymphocyte-endothelial interactions mediated by adhesion molecules are important in leukocyte migration and recruitment to sites of inflammation, and selective blockade of these adhesion molecules is a novel and promising strategy to treat Crohn's disease. Therapeutic agents that inhibit leukocyte trafficking include natalizumab, MLN-02 and alicaforsen (ISIS 2302). Other agents being investigated for the treatment of Crohn's disease include inhibitors of T-cell activation, peroxisome proliferator-activated receptors, proinflammatory cytokine receptors and T(h)1 polarisation, and growth hormone and growth factors. Agents being investigated for treatment of ulcerative colitis include many of those mentioned for Crohn's disease. More controlled clinical trials are currently being conducted, exploring the safety and efficacy of old and new biologic agents, and the search certainly will open new and exciting perspectives on the development of therapies for IBD.

Mechanisms of diarrhea in the interleukin-2-deficient mouse model of colonic inflammation

Colitis in interleukin-2-deficient (IL-2(-/-)) mice resembles ulcerative colitis in humans. We studied epithelial transport and barrier function in IL-2(-/-) mice and used this model to characterize mechanisms of diarrhea during intestinal inflammation. (22)Na(+) and (36)Cl(-) fluxes were measured in proximal colon. Net Na(+) flux was reduced from 4.0 +/- 0.5 to 0.8 +/- 0.5 micromol.h(-1).cm(-2), which was paralleled by diminished mRNA and protein expression of the Na(+)/H(+) exchanger NHE3. Net Cl(-) flux was also decreased from 2.2 +/- 1.6 to -2.7 +/- 0.6 micromol.h(-1).cm(-2), indicating impaired Na(+)-Cl(-) absorption. In distal colon, aldosterone-induced electrogenic Na(+) absorption was 6.1 +/- 0.9 micromol.h(-1).cm(-2) in controls and was abolished in IL-2(-/-) mice. Concomitantly, mRNA expression of beta- and gamma-subunits of the epithelial sodium channel (ENaC) was reduced. Epithelial barrier was studied in proximal colon by impedance technique and mannitol fluxes. In contrast to ulcerative colitis, epithelial resistance was increased and mannitol fluxes were decreased in IL-2(-/-) mice. This was in accord with the findings of reduced ion transport as well as increased expression of tight junction proteins occludin and claudin-1, -2, -3, and -5. In conclusion, the IL-2(-/-) mucosa exhibits impaired electroneutral Na(+)-Cl(-) absorption and electrogenic Na(+) transport due to reduced mRNA and protein expression of NHE3 and ENaC beta- and gamma-subunit mRNA. This represents a model of early intestinal inflammation with absorptive dysfunction due to impaired transport protein expression/function while epithelial barrier is still intact. Therefore, this model is ideal to study regulation of transporter expression independent of barrier defects.

Regulatory T cells and inflammatory bowel diseases

Crohn's disease and ulcerative colitis are two major forms of human inflammatory bowel diseases (IBD). Their etiology is unknown, but increasing evidence indicate that immune mechanisms play an important role. It is well known that immune responses in the intestine remain in a state of controlled inflammation, suggesting that not only active suppression by regulatory T (TR) cells plays an important role in the normal intestinal homeostasis, but also its dysregulation leads to the development of IBD. This article reviews the unique aspects of TR cells and discuss how these control the intestinal homeostasis.

Single-dose daclizumab induction therapy in patients with liver transplantation

AIM: To investigate the efficacy and safety of a single-dose daclizumab induction therapy in orthotopic liver transplantation (OLTx).

METHODS: A retrospective study was made for 54 cases of OLTx in recent three years. The daclizumab group consisted of 23 cases of OLTx who received single-dose of 2 mg/kg intravenously after postoperative 24 hours. The control group consisted of the remaining 31 patients. Additional immunosuppressors included steroids, mycomphenolate mofetil, facrolimus or microemulsion cyclosporine used in all patients. Meta-statistical analysis was made for general data, incidence of acute rejection and infection, postoperative clinical course, complications and prognosis between two groups.

RESULTS: Pretransplant demographies were not significantly different between two groups. In the induction group there were significantly less acute rejection episodes (5 of 23, 21.74%) than those in the control group (12 of 31, 38.71%), which were proved by pathologic diagnosis (P < 0.05). The incidence of infection at the early stage was not significantly different between two groups.

CONCLUSION: Induction therapy with single-dose of daclizumab is safe and effective and appears to be able to reduce the incidence of acute rejection.