Drug-Induced Enterocolitis Syndrome (DIES) is a drug-induced hypersensitivity reaction non-IgE mediated involving the gastrointestinal system that occurs 2 to 4 h after drug administration. Antibiotics, specifically amoxicillin or amoxicillin/clavulanate, represent the most frequent drugs involved. Symptoms include nausea, vomiting, abdominal pain, diarrhea, pallor, lethargy, and dehydration, which can be severe and result in hypovolemic shock. The main laboratory finding is neutrophilic leukocytosis. To the best of our knowledge, 12 cases of DIES (9 children-onset and 3 adult-onset cases) were described in the literature. DIES is a rare clinically well-described allergic disease; however, the pathogenetic mechanism is still unclear. It requires to be recognized early and correctly treated by physicians.

This study assessed the efficacy and safety of briakinumab, a human anti-IL-12/23p40 monoclonal antibody, compared with placebo for the induction and maintenance of remission in patients with moderately to severely active Crohn's disease.

In this phase 2b, multicenter, double-blind, parallel group study, 246 patients stratified by prior tumor necrosis factor-antagonist use and response, were randomized (1:1:1:3) to 4 intravenous induction regimens: placebo, 200, 400, or 700 mg briakinumab, at weeks 0/4/8. At week 12, responders in the placebo or 400-mg induction groups entered the maintenance phase with the same regimen, whereas responders in the 700-mg induction group were rerandomized (1:1:1) to receive placebo, 200, or 700 mg briakinumab at weeks 12/16/20. At week 24, patients in remission stopped receiving study drug (withdrawal phase) until relapse. Patients experiencing relapse, nonresponders, and nonremitters could enter the open-label phase.

The primary end point of clinical remission at week 6 was not met. There were numerically greater rates of remission and response at 6, 12, or 24 weeks in patients treated with briakinumab. The safety and tolerability profile of briakinumab was similar in the induction and maintenance phases of the trial.

Briakinumab showed a similar safety and tolerability profile to placebo in the induction and maintenance phases, and comparable rates of serious adverse events, adverse events leading to discontinuation, and malignancy. These data provide support for the potential efficacy of briakinumab and other IL-12/23 inhibitors in the treatment of moderate-to-severe Crohn's disease.

Tumour necrosis factor-α (TNF-α) has been reported to play a central role in intestinal barrier dysfunction in many diseases; however, the precise role of the TNF-α receptors (TNFRs) has not been well defined using in vivo models. Our previous data showed that enteral nutrient deprivation or total parenteral nutrition (TPN) led to a loss of intestinal epithelial barrier function (EBF), with an associated upregulation of TNF-α and TNFR1. In this study, we hypothesized that TNF-α plays an important role in TPN-associated EBF dysfunction. Using a mouse TPN model, we explored the relative roles of TNFR1 vs. TNFR2 in mediating this barrier loss. C57/BL6 mice underwent intravenous cannulation and were given enteral nutrition or TPN for 7 days. Tumour necrosis factor-α receptor knockout (KO) mice, including TNFR1KO, TNFR2KO or TNFR1R2 double KO (DKO), were used. Outcomes included small intestine transepithelial resistance (TER) and tracer permeability, junctional protein zonula occludens-1, occludin, claudins and E-cadherin expression. In order to address the dependence of EBF on TNF-α further, exogenous TNF-α and pharmacological blockade of TNF-α (Etanercept) were also performed. Total parenteral nutrition led to a loss of EBF, and this was almost completely prevented in TNFR1R2DKO mice and partly prevented in TNFR1KO mice but not in TNFR2KO mice. The TPN-associated downregulation of junctional protein expression and junctional assembly was almost completely prevented in the TNFR1R2DKO group. Blockade of TNF-α also prevented dysfunction of the EBF and junctional protein losses in mice undergoing TPN. Administration of TPN upregulated the downstream nuclear factor-B and myosin light-chain kinase (MLCK) signalling, and these changes were almost completely prevented in TNFR1R2DKO mice, as well as with TNF-α blockade, but not in TNFR1KO or TNFR2KO TPN groups. Tumour necrosis factor-α is a critical factor for TPN-associated epithelial barrier dysfunction, and both TNFR1 and TNFR2 are involved in EBF loss. Nuclear factor-B and MLCK signalling appear to be important downstream mediators involved in this TNF-α signalling process.

The efficacy of germinated barley foodstuff (GBF) on tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and -8 (IL-8) in patients with ulcerative colitis (UC) has not yet been examined. The aim of the present study was to determine the effect of administration of GBF on serum TNF-α, IL-6 and -8 levels in UC patients in remission.

Forty-one patients with UC were divided into two groups, namely control and GBF group. Twenty-one patients in the control group received standard treatment while 20 patients in the GBF group received 30 g of GBF daily by oral administration during two months of the study along with standard drug therapy.

Levels of TNF-α, IL-6 and -8 all decreased in the GBF group compared with baseline during the two-month study, while in the control group all values rose. For IL-6 and -8 this effect was significant, P = 0.034 and 0.013, respectively.

The results of the present study showed that the consumption of GBF may reduce the level of serum TNF-α, IL-6 and -8 in patients with UC. This investigation was designed as a pilot study and the results may provide a basis for more future clinical trials.

The impact of anti-TNF therapy on systemic immune responses in patients has not been clearly defined. Here, we examined Th1/Th2/Th17 cytokine expression, activation and proliferation of peripheral T cells from patients with psoriasis and inflammatory bowel disease before and during anti-TNF therapy. In parallel, we calculated the correlation with the clinical response and we monitored cytokine expression in biopsies from inflamed tissues. We evidenced a dual role of TNF-blockade. In peripheral blood, it increased the expression of cytokines such as IL-17, IL-10, and IFN-γ, and enhanced the expression of activation markers and the proliferative response of CD4 T cells to TCR stimulation. By contrast, in biopsies from target tissues, TNF-blockade diminished the expression of Th17/Th1 cytokine and early inflammatory genes. Importantly, the enhanced T cell responses to TCR-stimulation did not impair the clinical response to the therapy and, in responder patients, occurred with the concomitant down-regulation of inflammatory genes in the target tissues.

Vitamin D is the critical hormone for intestinal absorption of calcium. Optimal calcium absorption is important for proper mineralization of bone in the prevention of osteoporosis and osteoporotic fractures, among other important functions. Diseases associated with gut inflammation, such as Crohn's disease (CD), may impair calcium absorption. This pilot study evaluated vitamin D- dependent calcium absorption in subjects with CD. Male subjects with CD (n=4) and healthy age-matched controls (n=5) were studied. All subjects had fractional calcium absorption (FCA; by the dual calcium isotope method), serum 25-hydroxyvitamin D, serum calcium and 24 h urinary calcium excretion measurements at baseline. The FCA in response to vitamin D therapy was re-assessed following administration of oral calcitriol 0.25 mcg twice daily for 1 wk, followed by oral calcitriol 0.50 mcg twice daily for 1 wk. Serum calcium and 24 h urinary calcium determinations were re-assessed after each increasing dose of calcitriol as safety measures. There was no significant difference in calcium FCA at baseline or after increasing doses of calcitriol between the CD and controls. FCA in the control and CD group was approximately 35% at baseline, which increased to 60% after calcitriol therapy. No subject developed hypercalcemia or hypercalciuria. Our results suggest that CD patients have a normal response to vitamin D in enhancing the efficacy of calcium absorption. This suggests that stable CD patients can follow calcium and vitamin D guidelines of non-CD adults. Other factors independent of vitamin D status may impair intestinal calcium absorption in CD, including the degree and location of inflammation, presence of surgical resection and/or use of glucocorticoids.

EF is a rare fibrosing disorder that may involve skin and internal organs. Current therapies include moderate- to high-dose glucocorticoids with or without use of immunosuppressives.

We report three cases of steroid-resistant EF in clinical practice who were treated with 3 mg/kg every 8 weeks infliximab therapy.

All patients noticed an improvement in their symptoms, joint contractures and skin thickening within 8 weeks of starting infliximab therapy, ultimately leading to a drug-free remission (range 1-3 years).

Based on this and other reported cases, infliximab may be beneficial in patients with steroid-resistant EF.

The safety and potential efficacy of a chimaeric anti-tumour necrosis factor alpha monoclonal antibody (infliximab) were examined in diffuse cutaneous systemic sclerosis (dcSSc).

A 26-week open-label pilot study in which 16 cases of dcSSc received five infusions of infliximab (5 mg/kg). Clinical assessment included skin sclerosis score, scleroderma health assessment questionnaire, self-reported functional score and physician global visual analogue scale. Collagen turnover, skin biopsy analysis and full safety evaluation were performed.

There was no significant change in skin score at 26 weeks but a trend for lower modified Rodnan skin score at 22 weeks (OR 17, 95% CI 6 to 46) compared with peak value (OR 29, 95% CI 11 to 44; p = 0.10). Serum aminoterminal propeptide of type III collagen level was significantly lower at week 26 compared with baseline (p = 0.03). Secretion of type I collagen by dermal fibroblasts was reduced at 26 weeks compared with baseline (p = 0.02). There were no deaths during the study and no suspected unexpected serious adverse reactions. 21 serious adverse events (AE) occurred in seven subjects, mostly attributable to dcSSc. 127 distinct AE occurred in 16 subjects. Of these, 19 AE (15%) were probably or definitely related to infliximab treatment. Eight (50%) patients prematurely discontinued infliximab. Anti-infliximab antibodies developed during the study in five subjects and were significantly associated with suspected infusion reactions (p = 0.025).

In dcSSc infliximab did not show clear benefit at 26 weeks but was associated with clinical stabilisation and a fall in two laboratory markers of collagen synthesis. The frequency of suspected infusion reactions may warrant additional immunosuppression in any future studies in systemic sclerosis.

Mast cells are well known as versatile cells capable of releasing and producing a variety of inflammatory mediators upon activation and are often found in close proximity of neurons. In addition, inflammation leads to local activation of neurons resulting in the release neuropeptides, which also play an important immune modulatory role by stimulation of immune cells. In intestinal disorders like inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), the number of mast cells is known to be much higher than in the normal intestine. Moreover, both these disorders are also reported to be associated with alterations in neuropeptide content and in neural innervation. Mutual association between mast cells and enteric nerves has been demonstrated to be increased in pathophysiological conditions and contribute to spreading and amplification of the response in IBD and IBS. In this review the focus lies on studies appointed to the direct interaction between mast cells and nerves in IBD, IBS, and animal models for these disorders so far.

Ulcerative colitis (UC) and Crohn's disease (CD) are idiopathic inflammatory bowel diseases (IBDs) that are characterized by chronic periods of exacerbation and remission. Research into the immunopathogenesis of IBD adds support to the theory that the disease results from a dysfunctional regulation of the immune system that leads to the polarization of intestinal immune cells toward a Th1 (T helper) response. The immunologic factors that mediate alterations in intestinal homeostasis and the development of intestinal mucosal inflammation have been at the forefront of IBD research. Cytokines, which are important regulators of leukocyte trafficking and apoptotic cell death, have emerged as essential immune molecules in the pathogenesis of IBD. In this study, recent advances in the understanding of the dynamism of cytokines and the consequences for mucosal immunity and inflammation in IBD are discussed. Furthermore, this study highlights the potential use of cytokines, anti-cytokine antibodies, and cytokine-related biologic therapies as novel targets for the treatment of IBD.

Inflammatory bowel disease (IBD) describes chronic inflammatory conditions of the gastrointestinal tract, and TNF-alpha plays a pivotal role in mediating the response. The proinflammatory cytokine TNF-alpha is rapidly released by mast cells after degranulation. In the present study, we hypothesized TNF-alpha to be an important player in our recently described mast cell-dependent murine model for IBD. The effect of neutralizing anti-TNF-alpha MAb was studied on colonic hypersensitivity in mice induced by a skin application of dinitrofluorobenzene (DNFB) followed by an intrarectal challenge with dinitrobenzene sulfonic acid. Features of the colonic hypersensitivity response included diarrhea, mast cell infiltration and activation, infiltration of inflammatory cells in the colon, colonic patch hypertrophy, and increased mast cell-derived TNF-alpha levels in the colon. Anti-TNF-alpha MAb could effectively abrogate diarrhea in DNFB-sensitized mice 72 h after the challenge. The numbers of colonic patches and total tissue damage scores were reduced by anti-TNF-alpha MAb treatment in DNFB-sensitized mice 72 h after the challenge. Mast cell infiltration and activation remained unaffected by neutralizing anti-TNF-alpha MAb. Treatment with the corticosteroid dexamethasone, a frequently used therapeutic treatment in IBD, resulted in a reduction of diarrhea, cellular infiltration, and total tissue damage scores to the same extent as anti-TNF-alpha MAb. Additionally, dexamethasone treatment could also reduce total TNF-alpha levels in the colon, mast cell numbers, and mast cell activation in both vehicle- and DNFB-sensitized mice 72 h after the challenge. These findings suggest that TNF-alpha can play an instrumental role in causing inflammatory responses in the present murine model for IBD downstream from mast cell activation.

Infliximab is a monoclonal antibody directed against the pro-inflammatory mediator TNF-alpha, which was approved in the US in 1998 for treatment-resistant Crohn's disease. Since that time, the indications have dramatically expanded to include rheumatoid arthritis, ankylosing spondylitis, psoriasis and most recently, active ulcerative colitis. Although the safety profile in the initial studies was quite favourable, subsequent studies have shown that a small percentage of patients reported severe side effects, including pneumonia, tuberculosis, lymphoma, drug-induced lupus and hepatotoxicity. Although these complications are rare, it is important to properly screen patients for predisposing conditions before beginning treatment. Furthermore, concurrent use of other immunosuppresive agents, such as 6-mercaptopurine, may reduce the incidence of less serious side effects, such as arthralgias, myopathies and other antibody-associated diseases. Since its approval, infliximab has revolutionised the treatment of Crohn's disease and has shown benefit in a variety of other inflammatory conditions, but significant toxicities can occur that necessitate thorough screening protocols and periodic clinical evaluation.

The variable regions of antibodies play central roles in the binding with antigens. Based on the model of a tumour necrosis factor-alpha (TNF-alpha) neutralizing monoclonal antibody (named as Z12) with TNF-alpha, heavy chain CDR2 (HCDR2) and light chain CDR3 (LCDR3) of Z12 were found to be the most responsible to bind with TNF-alpha. A mimetic peptide (PT) was designed based on the sequence derived from HCDR2 and LCDR3. Fusion protein PT-Fc was constructed by linking PT with Fc of human IgG1 through a flexible linker (GGGGGS). The primary structural characteristics of Fc and PT-Fc were analyzed, including the flexibility, hydrophilicity and epitopes. It was demonstrated that PT and Fc in the fusion protein possessed bio-function properly and non-interfering with each other. Furthermore, PT-Fc was expressed in Escherichia coli by fusion with thioredoxin (Trx). After trx-PT-Fc was cleaved with recombinant enterokinase, PT-Fc was obtained. The results of in vitro cytotoxic assays showed that both PT and PT-Fc could efficiently inhibit TNF-alpha induced apoptosis on L929 cells. At the same micromole concentration, the inhibition activity of PT-Fc was significantly higher than PT.

The variable regions of antibody molecules bind antigens with high affinity and specificity. The binding sites are imparted largely to the hypervariable portions (i.e., CDRs) of the variable region. Peptides derived from CDRs can bind antigen with similar specificity acting as mimic of antibody and become drug-designing core, although with markedly lower affinity. In order to increase the affinity and bioactivity, in this study, a novel peptide (PT) designed on CDRs of a TNFalpha neutralizing monoclonal antibody Z12 was linked with Fc fragment of human IgG1. The interaction mode of PT-linker-Fc (PLF) with TNFalpha was analyzed with computer-guided molecular modeling method. After expression in Escherichia coli and purification, recombinant PT-linker-Fc could bind directly with the TNFalpha coated on the ELISA plates. Furthermore, PLF could competitively inhibit the binding of Z12 to TNFalpha and also inhibit the TNFalpha-induced cytotoxicity on L929 cells. The TNFalpha antagonizing activity of PLF was significantly higher than that of the free peptide. This study highlights the potential of human Fc to enhance the potency of peptides designed on the CDRs of antibodies and could be useful in developing new TNFalpha antagonists.

Genomic technologies offer new approaches to the investigation of the aetiology and pathophysiology of inflammatory bowel disease. An important field relevant to inflammatory bowel disease therapy is the pharmacogenetic investigation of gene variations that may predict responses to certain medications in order to target these therapeutic interventions more precisely. To date, only about 12,000 of the estimated 30,000-50,000 human genes have been characterized. Therefore, the use of techniques for a global analysis of gene expression may allow the identification of new pathways or molecules in the therapeutic mechanisms of drugs. Recently, NOD2 has been identified as the first disease gene in inflammatory bowel disease. DLGS and OCTN-1 have been named as further disease genes. Although the detection of disease-associated variants has greatly advanced our understanding of the primary events that lead to the development of inflammatory bowel disease in a subgroup of patients with Crohn's disease, the implications of the findings for diagnostic and therapeutic algorithms are less clear. However, it appears that there is a clear association between certain subphenotypes of Crohn's disease and the disease-associated variants in the NOD2 gene. It can be anticipated that genomic findings will profoundly influence the future therapy of inflammatory bowel disease.

To report a case of psoriasiform eruption induced by infliximab.

A 46-year-old woman with enterocutaneous fistula secondary to Crohn's disease developed pruriginous, erythematous, desquamative plaques on her elbows, knees, hands, and buttocks after receiving the second and third doses of intravenous infliximab. Histologic examination showed a lichenoid pattern. No new cutaneous lesions appeared after cessation of infliximab therapy.

Several cutaneous reactions secondary to infliximab, a monoclonal antibody against tumor necrosis factor-alfa, have been described. Psoriasiform dermatitis has not been reported as a cutaneous reaction to infliximab, but there have been several previous reports of psoriasiform dermatitis secondary to other drugs. An objective causality assessment revealed that the adverse event was probable.

This is the first report of a clinico-pathologic dissociated pattern of cutaneous reaction showing a histopathologic picture of lichenoid dermatitis resulting from infliximab treatment.

Phage displayed peptide library was used to select tumor necrosis factor alpha (TNFalpha) binding peptides. After three sequential rounds of biopanning, some linear TNFalpha-binding peptides were identified from a 12-mer peptide library. A consensus sequence (L/M)HEL(Y/F)(L/M)X(W/Y/F), where X might be variable residue, was deduced from sequences of these peptides. The phages bearing these peptides showed specific binding to immobilized TNFalpha, with over 80% of phages bound being competitively eluted by free TNFalpha. To confirm the binding activity and to explore further functional properties, three peptides with typical structure were selected and expressed as GST-fused protein. These recombinant peptides effectively competed for [125I]TNFalpha binding to TNFR1 in a dose-dependent manner, with IC(50) from 10 to 160 microM. Furthermore, the GST-fused derivatives showed inhibitory effects on TNFalpha-induced cytotoxicity. Taken together, these data demonstrate that the TNFalpha-binding peptides are effective antagonists of TNFalpha and the deduced motif might be useful in development of novel low molecular weight anti-TNFalpha drugs.

Chronic enterocolitis is the leading cause of morbidity in colonies of captive rhesus macaques (Macaca mulatta). This study's aim was to identify the common enteric pathogens frequently associated with chronic enterocolitis in normal, immunocompetent rhesus monkeys and to elucidate the influence of this clinical syndrome on the host immune system. We analyzed the fecal specimens from 100 rhesus macaques with or without clinical symptoms of chronic diarrhea. Retrospective analysis revealed an increased incidence of Campylobacter spp. (Campylobacter coli and Campylobacter jejuni), Shigella flexneri, Yersinia enterocolitica, adenovirus, and Strongyloides fulleborni in samples collected from animals with chronic diarrhea (P < 0.05). The presence of additional enteric pathogens, such as Escherichia coli, carrying the eaeA intimin or Stx2c Shiga toxin virulence genes, Balantidium coli, Giardia lamblia, Enterocytozoon bieneusi, and Trichuris trichiura was found in all animals regardless of whether diarrhea was present. In addition, the upregulation of interleukin-1 alpha (IL-1 alpha), IL-3, and tumor necrosis factor alpha cytokine genes, accompanied by an increased presence of activated (CD4(+) CD69(+)) T lymphocytes was found in gut-associated lymphoid tissues collected from animals with chronic enterocolitis and diarrhea in comparison with clinically healthy controls (P < 0.05). These data indicate that chronic enterocolitis and diarrhea are associated, in part, with a variety of enteric pathogens and highlight the importance of defining the microbiological status of nonhuman primates used for infectious disease studies. The data also suggest that chronic colitis in rhesus macaques may have potential as a model of inflammatory bowel disease in humans.

Infliximab is a chimeric monoclonal antibody that binds to tumour necrosis factor-alpha (TNFalpha) and neutralises its effects. TNFalpha plays an important role in the development of both Crohn's disease and rheumatoid arthritis. In a large, double-blind, randomised study involving patients with active, refractory Crohn's disease, significantly more recipients of intravenous infliximab, compared with placebo, achieved a clinical response after 4 weeks' follow-up. Moreover, infliximab administration was associated with a rapid improvement in endoscopic and histological findings in clinical trials involving patients with active, refractory Crohn's disease. The results of the A Crohn's Disease Clinical Trial Evaluating Infliximab in a New Long-Term Treatment Regimen (ACCENT) I study showed that maintenance infliximab therapy prolonged response and remission in patients with moderate to severe Crohn's disease. In patients with enterocutaneous fistulae associated with Crohn's disease who were involved in a double-blind, randomised study, significantly more patients who received multiple infusions of infliximab, compared with placebo, experienced a > or=50% reduction from baseline in the number of draining fistulae at > or =2 consecutive study visits. In patients with active rheumatoid arthritis refractory to treatment with methotrexate who were enrolled in a large, double-blind, randomised study [the Anti-TNF Trial in Rheumatoid Arthritis with Concomitant Therapy (ATTRACT) study], American College of Rheumatology (ACR) 20, 50 and 70% response rates were seen in significantly more patients who received multiple infusions of infliximab plus methotrexate, compared with methotrexate plus placebo, after 30 and 54 weeks' treatment. Moreover, the ACR 20% response rate was maintained after 102 weeks' treatment. In addition, significantly less radiographic progression was seen in infliximab plus methotrexate, compared with methotrexate plus placebo, recipients after 54 weeks' treatment. Infliximab therapy was also associated with improvements in health-related quality of life in patients with Crohn's disease or rheumatoid arthritis. Infliximab was generally well tolerated in clinical trials with the most common adverse events including upper respiratory tract infection, headache, nausea, coughing, sinusitis and diarrhoea. Infliximab therapy may be associated with an increased risk of reactivation of tuberculosis in patients with latent disease. In conclusion, infliximab is an important treatment option in patients with active Crohn's disease who have not responded to conventional therapy and in patients with Crohn's disease who have fistulae. Moreover, infliximab plus methotrexate is effective in patients with active rheumatoid arthritis who have not responded adequately to traditional disease-modifying antirheumatic drugs, in terms of reducing symptoms and signs, improving physical function and delaying the progression of structural damage.

Infusion of anti-tumour necrosis factor-alpha appears to be highly effective in patients with Crohn's disease.

To assess the effect of infliximab on the quality of life in patients with active or fistulizing disease, as measured by the inflammatory bowel disease questionnaire, and to examine the impact on its four dimensions.

An observational study was conducted in 65 patients. An infusion of 5 mg/kg infliximab was given at week 0 in patients with active disease and at week 0, 2 and 6 in fistulizing disease. Changes from baseline in the total and dimensional inflammatory bowel disease questionnaire scores were calculated and compared between the patient groups. Potential predictors of change in the quality of life were identified.

In the active disease group, at week 4, the mean total and dimensional inflammatory bowel disease questionnaire scores improved compared to baseline (P < 0.001). In the fistulizing group, at week 6, all scores changed from baseline (P < 0.05). Improvement in the total inflammatory bowel disease questionnaire score correlated well with the improvement of the Crohn's disease activity index. Systemic and social scores improved more than bowel and emotional scores. Inflammatory Crohn's disease and a young age at diagnosis were predictors for a better response to infliximab therapy.

Infliximab therapy improves all dimensions of the quality of life in patients with Crohn's disease.

Crohn's disease is not medically (and is rarely surgically) curable. Patients do, however, live a normal life span. The goal of therapy is to optimize the quality of life, minimize disease activity and disease-related complications, and avoid therapeutic toxicity.

A proliferation of animal models has not only improved our understanding of inflammatory bowel disease, it has also formed the basis of new treatment strategies.

A search was conducted using the National Library of Medicine for articles discussing immune therapies for inflammatory bowel disease. This was supplemented by findings from the authors' own laboratory.

An overview of the different animal models is presented. These models are used to highlight the recent human trials of immune therapies. Potential future therapies are also discussed.

Immune therapies have altered the management of patients with inflammatory bowel disease. In future they will influence not only the indications for surgery but also its timing and outcome.

This review focuses on data reported in the last year on medical treatment of Crohn's disease and ulcerative colitis. In Crohn's disease, a broad range of cytokine-based therapies are currently being tested. Although all are very exciting, the anti-tumor-necrosis-factor (TNF) approach remains the most effective, with infliximab (a chimeric monoclonal antibody directed against TNF) being the most active agent. With repeated infusions every 8 weeks, remission is induced and can be maintained even in refractory patients with no major apparent side effects. Thalidomide, an oral agent with anti-TNF effects, shows promise in non-controlled experience. Important new data on azathioprine/6-mercaptopurine (6-MP) and its metabolites are also helpful. Methotrexate can induce remissions in 6-MP-allergic or refractory Crohn's patients and has now shown efficacy as a maintenance agent. Beneficial effects are also reported for a variety of new agents: mycophenolate mofetil, tacrolimus (FK506), growth hormone, and granulocyte colony-stimulating factor (G-CSF). Important observations in ulcerative colitis (UC) over the past year include evidence of a protective effect of 5-aminosalicylic acid (5-ASA) with respect to colorectal cancer, negative results from a study for heparin monotherapy, and results from a comparison of mycophenolate mofetil versus azathioprine as maintenance therapy. Epidemiologically, the negative association between appendectomy and UC was corroborated in a meta-analysis, suggesting an immunologic role for this organ. Finally, in chronic pouchitis, probiotic therapy was found to maintain remissions very significantly.

The recent licensing of anti-TNFalpha antibody treatment offers the potential to radically alter the course of severe Crohn's disease using genetically-engineered drugs directed against a specific inflammatory mediator. Controlled randomized trials have demonstrated clinical benefit associated with tissue healing in patients with active intestinal disease and fistulae, often when conventional therapies were unsuccessful. This therapy is expensive, however, and long-term efficacy and safety data are still awaited. This review considers the nature of this therapy and the current evidence for its clinical benefit and adverse effects. The treatment is also considered in the context of available immunosuppressive agents, with suggestions about its practical application.

The discovery of peroxisome proliferator-activated receptor gamma (PPARgamma) as the molecular target for antidiabetic thiazolidinediones has heralded a new era in the approach to understanding the pathophysiology of insulin resistance and its relationship to cardiovascular disease. However, the subsequent discovery of PPARgamma-dependent modulation of immune function and the cell cycle has led to a new paradigm in the approach to treating proliferative, inflammatory diseases. Moreover, PPARgamma agonists can promote apoptosis, block angiogenesis and inhibit pathological remodelling in a variety of malignant and non-malignant pathological states. These findings imply that the pharmacological modulation of this key nuclear transcription factor and its co-factors could be important tools in understanding the relationships between multigenic diseases, and pave the way to a focused interventional approach in their treatment. With the availability of the PPARgamma protein crystal structure, the ligand binding domain co-ordinates and a better knowledge of the interaction of PPARgamma with co-factor assemblies, libraries of simple synthetic organic PPARgamma ligands can be constructed. High throughput screening can identify the best candidates for targeting cellular phenotypic transition, cell cycle control, inflammation and apoptosis. Instead of single agents for single pathologies, one can envisage the development of multifunctional therapeutic agents that target the multiple cellular processes that contribute to multifactorial diseases such as diabetes, hypertension, atherosclerosis, psoriasis and other inflammatory diseases, and carcinogenesis. The considerable potential of PPARgamma ligands in the treatment of diseases other than diabetes is the subject of this review.