Infliximab: Use in Inflammatory Bowel Disease

Patient-derived organoids for therapy personalization in inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders of the intestinal tract that have emerged as a growing problem in industrialized countries. Knowledge of IBD pathogenesis is still incomplete, and the most widely-accepted interpretation considers genetic factors, environmental stimuli, uncontrolled immune responses and altered intestinal microbiota composition as determinants of IBD, leading to dysfunction of the intestinal epithelial functions. In vitro models commonly used to study the intestinal barrier do not fully reflect the proper intestinal architecture. An important innovation is represented by organoids, 3D in vitro cell structures derived from stem cells that can self-organize into functional organ-specific structures. Organoids may be generated from induced pluripotent stem cells or adult intestinal stem cells of IBD patients and therefore retain their genetic and transcriptomic profile. These models are powerful pharmacological tools to better understand IBD pathogenesis, to study the mechanisms of action on the epithelial barrier of drugs already used in the treatment of IBD, and to evaluate novel target-directed molecules which could improve therapeutic strategies. The aim of this review is to illustrate the potential use of organoids for therapy personalization by focusing on the most significant advances in IBD research achieved through the use of adult stem cells-derived intestinal organoids.

Infliximab-Associated Xanthogranulomatous Pyelonephritis: A Rare Complication

Xanthogranulomatous pyelonephritis (XGP) is one of the rare diseases characterized by chronic inflammation and destruction of the renal parenchyma, and it is usually associated with renal infection, and nephrolithiasis. Infliximab is an anti-tumor necrosis factor-alpha (anti-TNF-α) monoclonal antibody, which is widely used for treating inflammatory bowel disease, and it is known to increase the risk of rare and opportunistic infections. In this study, we report a case of XGP presenting after the initiation of infliximab treatment. We highlight one of the possible complications associated with immunosuppression due to infliximab. Furthermore, the importance of increasing the awareness among physicians for early recognition of this rare complication.

Effect of Originator Infliximab Treatment on Disease-Related Hospitalizations, Work Productivity and Activity Impairment, and Health Resource Utilization in Patients with Crohn's Disease in a Real-Life Setting: Results of a Prospective Multicenter Study in Germany

Introduction

Infliximab (IFX) therapy is efficacious for inducing and maintaining symptomatic remission in patients with Crohn's disease (CD), but whether this benefit results in reduced hospitalization rates and therefore may improve patients' quality of life in an economically sensible way is conflicting so far.

Methods

We conducted a noninterventional, multicenter, open-label, prospective study to evaluate the effect of originator IFX treatment on patient-reported outcomes and disease-related hospitalizations in adult CD patients in Germany treated for the first time with IFX according to label.

Results

Two hundred and ninety-four patients were included in the study. We observed a statistically significant reduction in the number of CD-related hospitalizations from the year before baseline (mean 1.00 per patient, SD ± 0.93) to the mean value of the 1st (0.62, SD ± 0.95) and 2nd year (0.32, SD ± 0.75) of the observation period (p < 0.0001). After 3 months of IFX therapy, work productivity and activity increased by an average of 12.6 and 17.1%, respectively. Patient's clinical outcome was markedly improved as the total CD activity index (CDAI) sum score continuously decreased from baseline to month 24 and the mean score of the total inflammatory bowel disease questionnaire (IBDQ) changed substantially from 141 at baseline to 172 after 24 months of IFX treatment. Additionally, the number of work incapacity days declined. Recently, no new safety issues of IFX have been identified.

Conclusion

In this large, prospective, multicenter study on disease-related hospitalization rates, work productivity, capacity for daily activities, and HRQoL in patients with CD, IFX significantly reduces their hospitalization rates and improves work productivity, daily activity, and quality of life over 24 months.

Dermal Lesions and Skin Cancer in Patients with Inflammatory Bowel Disease Receiving Immunosuppressive Therapy

Background: Anti-TNFa medications represent the first effective biologic therapy for IBD that has largely revolutionized treatment. The aim of this study was to quantify the risk of MM and other skin cancers among patients from Northern Greece area with IBD who take immunosuppressive or biologic anti-TNF medications. Methods: The current study was conducted during a 3-year period (2014-2016). Clinical history and metabolic data of all patients were extracted from the IBD database that is kept since 1980. 101 patients with IBD from Northwestern Greece, were studied. Results: The mean age of enrolled patients was 44.2±15.9 years old ranging from 17 years to 77 years old. No sun burn was reported from the 44.6% of the patients, 53.5% presented mild reticular veins in the face, and lack of any elastosis was noticed in 60.4%. The occurrence of two cases with squamous and basal cell carcinoma is an important finding. The absence of any case with MM should not quiet down but should strengthen our efforts for further implementation of preventive measures. Conclusions: Furthermore, education of patients to avoid deleterious sun exposure may help decrease MM incidence.

Therapeutic drug monitoring was helpful in guiding the decision-making process for children receiving infliximab for inflammatory bowel disease

AIM

This study examined the impact of therapeutic drug monitoring (TDM) on clinical decision-making for children receiving infliximab for inflammatory bowel disease (IBD).

METHODS

The medical records of children with IBD who had infliximab trough levels (ITLs) measured between January 2013 and December 2015 at two Canadian tertiary-care centres were examined. The indications for TDM, clinical and laboratory disease activity indices and TDM-driven treatment changes to infliximab therapy were documented.

RESULTS

We included 107 consecutive serum measurements of ITLs in 73 children (40 boys), with a median age of 16.1 years, including 52 with Crohn's disease. TDM was performed due to concerns about clinical disease activity in 24/107 (22.4%) measurements and 83 (77.6%) were ordered as routine tests. Of these, 38 (35.5%) ITLs were suboptimal (<3.5 μg/mL) and 36 (34.0%) resulted in more frequent doses of infliximab, with subsequent improvements in disease biomarkers. Interval changes were implemented as a result of 34 (32.0%) ITLs, with shorter intervals in 19 (17.0%) cases, and seven (6.5%) ITLs resulted in adding or increasing doses of immunomodulators. In addition, four children were switched to adalimumab.

CONCLUSION

Therapeutic drug monitoring was helpful in guiding the decision-making process for children with IBD on infliximab.

Molecular design and structural optimization of potent peptide hydroxamate inhibitors to selectively target human ADAM metallopeptidase domain 17

Human ADAMs (a disintegrin and metalloproteinases) have been established as an attractive therapeutic target of inflammatory disorders such as inflammatory bowel disease (IBD). The ADAM metallopeptidase domain 17 (ADAM17 or TACE) and its close relative ADAM10 are two of the most important ADAM members that share high conservation in sequence, structure and function, but exhibit subtle difference in regulation of downstream cell signaling events. Here, we described a systematic protocol that combined computational modeling and experimental assay to discover novel peptide hydroxamate derivatives as potent and selective inhibitors for ADAM17 over ADAM10. In the procedure, a virtual combinatorial library of peptide hydroxamate compounds was generated by exploiting intermolecular interactions involved in crystal and modeled structures. The library was examined in detail to identify few promising candidates with both high affinity to ADAM17 and low affinity to ADAM10, which were then tested in vitro with enzyme inhibition assay. Consequently, two peptide hydroxamates Hxm-Phe-Ser-Asn and Hxm-Phe-Arg-Gln were found to exhibit potent inhibition against ADAM17 (Ki=92 and 47nM, respectively) and strong selectivity for ADAM17 over ADAM10 (∼7-fold and ∼5-fold, S=0.86 and 0.71, respectively). The structural basis and energetic property of ADAM17 and ADAM10 interactions with the designed inhibitors were also investigated systematically. It is found that the exquisite network of nonbonded interactions involving the side chains of peptide hydroxamates is primarily responsible for inhibitor selectivity, while the coordination interactions and hydrogen bonds formed by the hydroxamate moiety and backbone of peptide hydroxamates confer high affinity to inhibitor binding.

An orally administrated nucleotide-delivery vehicle targeting colonic macrophages for the treatment of inflammatory bowel disease

Tumor necrosis factor-alpha (TNF-α) plays a central role in the pathogenesis of inflammatory bowel disease (IBD). Anti-TNF-α therapies have shown protective effects against colitis, but an efficient tool for target suppression of its secretion - ideally via oral administration - remains in urgent demand. In the colon tissue, TNF-α is mainly secreted by the colonic macrophages. Here, we report an orally-administrated microspheric vehicle that can target the colonic macrophages and suppress the local expression of TNF-α for IBD treatment. This vehicle is formed by cationic konjac glucomannan (cKGM), phytagel and an antisense oligonucleotide against TNF-α. It was given to dextran sodium sulfate (DSS) colitic mice via gastric perfusion. The unique swelling properties of cKGM enabled the spontaneous release of cKGM& antisense nucleotide (ASO) nano-complex from the phytagel scaffold into the colon lumen, where the ASO was transferred into colonic macrophages via receptor-mediated phagocytosis. The treatment significantly decreased the local level of TNF-α and alleviated the symptoms of colitis in the mice. In summary, our study demonstrates a convenient, orally-administrated drug delivery system that effectively targets colonic macrophages for suppression of TNF-α expression. It may represent a promising therapeutic approach in the treatment of IBD.

Inflammation, DNA methylation and colitis-associated cancer

Inflammation can result from a range of sources including microbial infections, exposure to allergens and toxic chemicals, autoimmune disease and obesity. A well-balanced immune response can be anti-tumorigenic; however, a sustained or chronic inflammatory response is generally harmful as the immune response becomes distorted. A causal link between chronic inflammation and cancer is now well accepted and many chronically inflamed organs of the gastrointestinal tract show this association. For example, patients with inflammatory bowel disease (IBD), including both ulcerative colitis and Crohn's disease, have a 2- to 3-fold greater lifetime risk of developing colorectal cancer compared with the general population. The development of colitis-associated cancer (CAC) is thought to be multifaceted and is probably due to a combination of genetic factors, epigenetic factors and the duration, extent and severity of disease. Recently, epigenetic alterations, in particular alterations in DNA methylation, have been observed during inflammation and inflammation-associated carcinogenesis. The mediators of this, the significance of these changes in DNA methylation and the effect this has on gene expression and the malignant transformation of the epithelial cells during IBD and CAC are discussed in this review. The recent advances in technologies to study genome-wide DNA methylation and the therapeutic potential of understanding these molecular mechanisms are also highlighted.

The role of tumour necrosis factor-α and tumour necrosis factor receptor signalling in inflammation-associated systemic genotoxicity

Chronic inflammatory diseases are characterised by systemically elevated levels of tumour necrosis factor (TNF)-α, a proinflammatory cytokine with pleiotropic downstream effects. We have previously demonstrated increased genotoxicity in peripheral leukocytes and various tissues in models of intestinal inflammation. In the present study, we asked whether TNF-α is sufficient to induce DNA damage systemically, as observed in intestinal inflammation, and whether tumour necrosis factor receptor (TNFR) signalling would be necessary for the resultant genotoxicity. In the wild-type mice, 500 ng per mouse of TNF-α was sufficient to induce DNA damage to multiple cell types and organs 1-h post-administration. Primary splenic T cells manifested TNF-α-induced DNA damage in the absence of other cell types. Furthermore, TNFR1(-/-)TNFR2(-/-) mice demonstrated decreased systemic DNA damage in a model of intestinal inflammation and after TNF-α injection versus wild-type mice, indicating the necessity of TNFR signalling. Nuclear factor (NF)-κB inhibitors were also able to decrease damage induced by TNF-α injection in wild-type mice. When TNF-α administration was combined with interleukin (IL)-1β, another proinflammatory cytokine, DNA damage persisted for up to 24 h. When combined with IL-10, an anti-inflammatory cytokine, decreased genotoxicity was observed in vivo and in vitro. TNF-α/TNFR-mediated signalling is therefore sufficient and plays a large role in mediating DNA damage to various cell types, subject to modulation by other cytokines and their mediators.

A review of infliximab use in ulcerative colitis

BACKGROUND

Infliximab is a chimeric immunoglobulin G1kappa monoclonal antibody that binds with high affinity and specificity to the soluble form of tumor necrosis factor (TNF)-alpha, preventing it from binding to cellular receptors. Infliximab also binds to membranebound TNF-alpha found on inflammatory cell surfaces, inducing apoptosis. Currently, infliximab is used for the induction and maintenance of remission in Crohn's disease (CD), with documented success. Infliximab's efficacy in the treatment of ulcerative colitis (UC) is now being investigated due to the similarities in the pathophysiology of CD and UC.

OBJECTIVE

The aim of this study was to review and evaluate the current literature of infliximab use in steroid-refractory UC to assess its role in treatment.

METHODS

A search of MEDLINE was conducted (1950-November 2007). Key terms included, but were not limited to, infliximab, inflammatory bowel disease, ulcerative colitis, cost, and quality of life. Studies included for review were limited to English-language, full-text, randomized, double-blind, placebo-controlled trials. Clinical trials were reviewed and summarized.

RESULTS

Four controlled clinical trials of infliximab in the treatment of steroid-refractory UC were found and assessed. In a double-blind, randomized, controlled trial in 43 patients with moderately severe, glucocorticoid-resistant UC, infliximab and placebo were not significantly different with respect to clinical and sigmoidoscopic remission or quality of life 2 and 6 weeks after infliximab treatment. In a multicenter, randomized, double-blind, placebo-controlled study in 45 patients with moderately severe to severe glucocorticoid-resistant UC, infliximab was associated with a significantly reduced need for colectomy compared with placebo (29% vs 67%; P=0.017). The Active Ulcerative Colitis Trials (ACT) 1 and 2 together included 728 patients with moderate to severe glucocorticoid-resistant UC. The primary outcome, the rate of clinical response at 8 weeks, was significantly higher with infliximab compared with placebo (5 mg/kg: ACT 1, 69.4%, ACT 2, 64.5%; 10 mg/kg: ACT 1, 61.5%, ACT 2, 69.2%; placebo: ACT 1, 37.2%;, ACT 2, 29.3%; all, P < 0.001 vs placebo). Based on the data from ACT 1 and 2, infliximab was associated with improved health-related quality-of-life (HRQOL) scores based on the Inflammatory Bowel Disease Questionnaire and the 36-item Short Form Health Survey.

CONCLUSIONS

Current data suggest that infliximab is an effective alternative treatment option for patients with moderate to severe UC with an inadequate response to conventional glucocorticoid treatment. Further trials are needed to assess infliximab's impact on the treatment and progression of UC, the HRQL of patients with UC, and the economic impact on the health care system.

Tanshinone IIA ameliorates trinitrobenzene sulfonic acid (TNBS)-induced murine colitis

Inflammatory bowel diseases are characterized by proinflammatory cytokines, oxidative stress, and tissue damage. Recently, tanshinone had been shown to act as an antioxidant, and to have anti-inflammatory bioactivity. The study was carried out to investigate the effect of tanshinone IIA on the inflammatory response of experimental colitis. Murine colitis was induced by trinitrobenzene sulfonic acid (TNBS). Ten or 20 mg tanshinone IIA was administrated to mice 4 h before the induction of colitis, and repeated daily until the mice were sacrificed. Colonic inflammation was examined by histological analysis, myeloperoxidase (MPO) activity, and the production of proinflammatory cytokines in colonic tissue. Activation of nuclear factor-kappa B was identified by western blot and immunohistochemistry, and oxidative stress was shown by glutathione (GSH) level in tissue. The mice with colitis treated by tanshinone IIA showed less tissue damage, lower MPO activity, less production of TNF-alpha and IL-1beta, a higher level of GSH in colonic tissue, and downregulated activation of nuclear factor-kappa B in lamina propria mononuclear cells, compared with those of the untreated colitis group. Our data indicates that tanshinone IIA inhibits inflammatory response of colitis by downregulating the production of proinflammatory cytokines, and attenuating oxidative stress, which suggests that tanshinone IIA may be a new potential management for inflammatory bowel diseases.

Cytokine regulation of mucin secretion in a human middle ear epithelial model

OBJECTIVES

Middle ear mucins are associated with otitis media (OM), contribute to hearing loss and are regulated by cytokines. This work investigates the regulation of mucin secretion from human middle ear epithelial cells (HMEEC) by inflammatory cytokines interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and cytokine inhibitors interleukin-1 receptor antagonist (IL-1ra) and anti-tumor necrosis factor-alpha antibody (TNFab).

METHODS

HMEEC were exposed to IL-1beta and TNF-alpha in a dose- and time-dependent manner. Cytokine stimulated HMEEC were also exposed to IL-1ra and TNFab in a dose-dependent manner. Mucin secretion was characterized by exclusion chromatography and liquid scintillation.

RESULTS

HMEEC exposed to IL-1beta and TNF-alpha demonstrated significant upregulation of mucin secretion in a dose-dependent fashion. Cultures exposed to IL-1beta at 100ng/ml and TNF-alpha at 200ng/ml showed increased mucin secretion in time-dependent experiments at 16h (P=0.00008) for TNF-alpha and 8 (P=0.028) and 16h (P=0.00001) for IL-1beta. IL-1ra and TNFab inhibited the effects of increased mucin secretion by IL-1beta and TNF-alpha.

CONCLUSIONS

IL-1beta and TNF-alpha upregulate mucin secretion from HMEEC in a dose- and time-dependant manner and these effects can be inhibited by cytokine blockade. Improved understanding of these mechanisms has the potential to alter the approach and management of OM and lead to novel therapeutic interventions.

Altered claudin expression is a feature of chronic plaque psoriasis

Epithelial tight junctions play a central role in cell-cell adhesion and are necessary for the selective paracellular movement of ions. Claudins are key components of tight junctions and their expression is altered in gut epithelia in a variety of inflammatory enteropathies, including ulcerative colitis and Crohn's disease. Psoriasis is a chronic inflammatory skin disease affecting approximately 2% of the western population, with significantly increased occurrence in individuals with Crohn's disease. Initial studies investigated the expression of claudins in skin of healthy volunteers and patients with chronic plaque psoriasis. We report here that claudins-1 and -3 are the major protein species present in the epidermis of healthy skin; they are expressed on the surface of epidermal keratinocytes, consistent with their localization to tight junctions. In plaques of psoriasis, claudin-1 was not identifiable in the epidermis, although typical staining patterns were observed in clinically normal, uninvolved skin of patients with psoriasis. Claudin-3 was present in the epidermal granular cell layer in normal skin, but was only identified within the cytosol of epidermal keratinocytes in both involved and uninvolved skin of psoriasis patients. We examined further whether exposure of keratinocytes in vitro to pro-inflammatory cytokines mimicked the observed changes in claudin expression seen in chronic plaque psoriasis; lipopolysaccharide, interferon-gamma and tumour necrosis factor-alpha had no effect on claudin protein expression or distribution. Addition of interleukin-1beta, however, resulted in down-regulation of claudins-1 and -3. Tumour necrosis factor-alpha and interleukin-1beta were further used in an in vivo model of skin inflammation; interleukin-1beta alone modulated claudin protein expression in this system. These data demonstrate that epidermal claudin expression is altered in chronic plaque psoriasis and that expression is in part modulated by interleukin-1beta.

Anti-inflammatory effects of probiotic yogurt in inflammatory bowel disease patients

Our aim was to assess anti-inflammatory effects on the peripheral blood of subjects with inflammatory bowel disease (IBD) who consumed probiotic yogurt for 1 month. We studied 20 healthy controls and 20 subjects with IBD, 15 of whom had Crohn's disease and five with ulcerative colitis. All the subjects consumed Lactobacillus rhamnosus GR-1 and L. reuteri RC-14 supplemented yogurt for 30 days. The presence of putative regulatory T (T(reg)) cells (CD4(+) CD25(high)) and cytokines in T cells, monocytes and dendritic cells (DC) was determined by flow cytometry from peripheral blood before and after treatment, with or without ex vivo stimulation. Serum and faecal cytokine concentrations were determined by enzyme-linked immunosorbent assays. The proportion of CD4(+) CD25(high) T cells increased significantly (P = 0.007) in IBD patients, mean (95% confidence interval: CI) 0.84% (95% CI 0.55-1.12) before and 1.25% (95% CI 0.97-1.54) after treatment, but non-significantly in controls. The basal proportion of tumour necrosis factor (TNF)-alpha(+)/interleukin (IL)-12(+) monocytes and myeloid DC decreased in both subject groups, but of stimulated cells only in IBD patients. Also serum IL-12 concentrations and proportions of IL-2(+) and CD69(+) T cells from stimulated cells decreased in IBD patients. The increase in CD4(+) CD25(high) T cells correlated with the decrease in the percentage of TNF-alpha- or IL-12-producing monocytes and DC. The effect of the probiotic yogurt was confirmed by a follow-up study in which subjects consumed the yogurt without the probiotic organisms. Probiotic yogurt intake was associated with significant anti-inflammatory effects that paralleled the expansion of peripheral pool of putative T(reg) cells in IBD patients and with few effects in controls.

R-spondin1, a novel intestinotrophic mitogen, ameliorates experimental colitis in mice

BACKGROUND & AIMS

R-spondin 1 (Rspo1) is a novel epithelial mitogen that stimulates the growth of mucosa in both the small and large intestine.

METHODS

We investigated the therapeutic potential of Rspo1 in ameliorating experimental colitis induced by dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS) as well as nonsteroidal anti-inflammatory drug-induced colitis in interleukin (IL)-10-deficient mice.

RESULTS

Therapeutic administration of recombinant Rspo1 protein reduced the loss of body weight, diarrhea, and rectal bleeding in a mouse model of acute or chronic DSS-induced colitis. Histologic evaluation revealed that Rspo1 improved mucosal integrity in both villus and/or crypt compartments in the small intestine and colon by stimulating crypt cell growth and mucosal regeneration in DSS-treated mice. Moreover, Rspo1 significantly reduced DSS-induced myeloperoxidase activity and inhibited the overproduction of proinflammatory cytokines, including tumor necrosis factor-alpha, IL-1alpha, IL-6, interferon-gamma, and granulocyte-macrophage colony-stimulating factor, in mouse intestinal tissue, indicating that Rspo1 may reduce DSS-induced inflammation by preserving the mucosal barrier function. Likewise, Rspo1 therapy also alleviated TNBS-induced interstitial inflammation and mucosal erosion in the mouse colon. Furthermore, Rspo1 substantially decreased the histopathologic severity of chronic enterocolitis by repairing crypt epithelium and simultaneously suppressing inflammatory infiltration in piroxicam-exposed IL-10(-/-) mice. Endogenous Rspo1 protein was localized to villus epithelium and crypt Paneth cells in mouse small intestine.

CONCLUSIONS

Our results show that Rspo1 may be clinically useful in the therapeutic treatment of inflammatory bowel disease by stimulating crypt cell growth, accelerating mucosal regeneration, and restoring intestinal architecture.

Short- and long-term response to and weaning from infliximab therapy in pediatric ulcerative colitis

OBJECTIVES

We evaluated the response to infliximab in pediatric patients with ulcerative colitis (UC) and their long-term follow-up. We expanded our previous study of 14 patients and furthermore evaluated the success of weaning patients from infliximab.

PATIENTS AND METHODS

We reviewed the charts of 27 pediatric patients with UC who were treated with infliximab instead of undergoing a colectomy. Patients with new-onset UC refractory to intravenous steroids for 5 to 10 days and patients with non-steroid-dependent UC with an acute exacerbation were classified as acutely ill (n = 16); patients with chronic steroid-dependent UC were classified as chronically ill (n = 11). The Lichtiger Colitis Activity Index (LCAI) was measured for all patients at baseline and at 1 and 2 months after treatment with infliximab was initiated. Patients were regarded as successfully treated if they remained off steroids and avoided colectomy.

RESULTS

The acutely ill group had a mean LCAI score of 11.4 at induction and 0.3 after 2 months. The chronically ill group had a mean LCAI score of 11.2 at induction and 5.5 after 2 months. Treatment with infliximab was successful in 75% of acutely ill patients and in 27% of chronically ill patients. Infliximab was discontinued in 80% of successfully treated patients (83% of acutely ill, 67% of chronically ill). These patients had an average of 10 infusions and a mean follow-up time of 10 months from their last infliximab infusion.

CONCLUSIONS

Our results suggest that infliximab is more effective in acutely ill UC patients than in patients with chronic steroid-dependent UC. In addition, some patients treated with infliximab can be weaned from infliximab and maintain remission.

IFN-gamma and TNF-alpha decrease serotonin transporter function and expression in Caco2 cells

Recent studies have shown that mucosal serotonin (5-HT) transporter (SERT) expression is decreased in animal models of colitis, as well as in the colonic mucosa of humans with ulcerative colitis and irritable bowel syndrome. Altered SERT function or expression may underlie the altered motility, secretion, and sensation seen in these inflammatory gut disorders. In an effort to elucidate possible mediators of SERT downregulation, we treated cultured colonic epithelial cells (Caco2) with conditioned medium from activated human lymphocytes. Application of the conditioned medium caused a decrease in fluoxetine-sensitive [(3)H]5-HT uptake. Individual proinflammatory agents were then tested for their ability to affect uptake. Cells were treated for 48 or 72 h with PGE(2) (10 microM), IFN-gamma (500 ng/ml), TNF-alpha (50 ng/ml), IL-12 (50 ng/ml), or the nitric oxide-releasing agent S-nitrosoglutathione (GSNO; 100 microM). [(3)H]5-HT uptake was then measured. Neither PGE nor IL-12 had any effect on [(3)H]5-HT uptake, and GSNO increased uptake. However, after 3-day incubation, both TNF-alpha and IFN-gamma elicited significant decreases in SERT function. Neither TNF-alpha nor IFN-gamma were cytotoxic when used for this period of time and at these concentrations. These two cytokines also induced decreases in SERT mRNA and protein levels. By altering SERT expression, TNF-alpha and IFN-gamma could contribute to the altered motility and expression seen in vivo in ulcerative colitis or irritable bowel syndrome.

Practical guidelines for the treatment of inflammatory bowel disease

In recent years, great progress has been made regarding the treatment of inflammatory bowel disease (IBD), particularly in the field of biological therapies. Nevertheless, the ultimate treatment is not in sight. With the development of new medication, it has become clear that we need a new understanding of IBD. Therapy needs to fit the different subtypes of IBD; e.g. mild disease in comparison to severe chronic active disease or Crohn's disease with or without fistulation or stenosis. The following article gives a practical overview of actual treatments for IBD. The intention of this article is not to provide a complete review of all new scientific developments, but to give a practical guideline for therapy of IBD.

Therapeutic effectiveness of orally administered transgenic low-alkaloid tobacco expressing human interleukin-10 in a mouse model of colitis

Inflammatory bowel disease (IBD) represents a spectrum of diseases in which inflammation leads to acute and chronic gut injury. It is a growing health issue for which no cure exists. The pathogenesis is multifactorial with links to infectious and environmental events that trigger disease in genetically predisposed individuals. Treatment of the two major forms of IBD, Crohn's disease and ulcerative colitis, involves the reduction of inflammation with toxic immunosuppressive drugs or blocking of the pro-inflammatory effects of tumour necrosis factor-alpha (TNF-alpha) with antibodies. Here, we show that the oral administration of transgenic low-alkaloid tobacco expressing the contra-inflammatory cytokine human interleukin-10 (hIL-10) reduces the severity of colitis by down-regulating TNF-alpha expression directly at the sites of inflammation in IBD-susceptible IL-10(-/-) mice. hIL-10 expressed in plants is biologically active and displays resistance to gastrointestinal degradation. Dietary supplementation with plant tissue delivering up to 9 microg of hIL-10 daily for 4 weeks was well tolerated by treated mice. Gut histology was significantly improved relative to controls (P = 0.002), and was correlated with a decrease in small bowel TNF-alpha mRNA levels and an increase in IL-2 and IL-1beta mRNA levels. Transgenic plants expressing IL-10 to directly attenuate TNF-alpha expression at sites of inflammation in the gut may become a useful new approach in the luminal therapy of IBD.

Induction by activated macrophage-like THP-1 cells of apoptotic and necrotic cell death in intestinal epithelial Caco-2 monolayers via tumor necrosis factor-alpha

Intestinal epithelial cells interact with immune cells located in the intestinal epithelium via soluble factors. An in vitro model system using coculture was constructed to analyze the effect of macrophages on intestinal epithelial cells, and human intestinal epithelial-like Caco-2 monolayers and activated macrophage-like THP-1 cells were used in this study. Coculturing with THP-1 cells resulted in an increase of lactate dehydrogenase release from Caco-2 and a decrease in the transepithelial electrical resistance of the monolayers, showing that coculturing with THP-1 induced cell damage to Caco-2 cells. This disruption was significantly suppressed by adding anti-TNF-alpha antibody and etanercept, strongly suggesting that TNF-alpha secreted from THP-1 had caused cell damage to Caco-2 monolayers. The disrupted Caco-2 monolayers showed both apoptotic and necrotic characteristics by morphological and biochemical analyses. TNFRI and NF-kappaB seem to have been involved in this regulation. It is suggested that this phenomenon is similar in some respects to that observed with IBD and that this in vitro coculture system could be a good model for searching for the drugs or food substances that can be used to treat or prevent IBD.

A possible link between Crohn's disease and ankylosing spondylitis via Klebsiella infections

Crohn's disease (CD) is an immune-mediated gastrointestinal inflammatory disease, which could arise from an interplay between genetic and environmental factors. Klebsiella microbes were suggested to have a vital role in the initiation and perpetuation of the disease through the mechanism of molecular mimicry. This proposition is based on the results of various studies where significantly elevated levels of antibodies against the whole bacteria or preparations from Klebsiella microbes and antibodies to collagen types I, III, IV, and V were detected in patients with CD and patients with ankylosing spondylitis (AS). Molecular similarities were found between Klebsiella nitrogenase and HLA-B27 genetic markers and between Klebsiella pullulanase and collagen fibers types I, III, and IV. Furthermore, significantly positive correlations and cross-reactivity binding activities were observed between anti-Klebsiella and anticollagen antibodies among patients with CD and AS. Early treatment of CD patients with anti-Klebsiella measures is proposed, which may involve the use of antibiotics and low starch diet together with other traditionally used immunomodulatory, immunosuppressive, or biologic agents.

Utility of serological markers in predicting the early occurrence of complications and surgery in pediatric Crohn's disease patients

BACKGROUND AND OBJECTIVES

Many Crohn's disease (CD) patients develop complications (fistulae and abscesses), and require surgery, often repeatedly and at variable instances. Identifying serological markers that determine their early or repeated manifestation can enable implementing more aggressive preventive strategies. Our objective was to study the ability of serological markers for predicting development of early (first) and recurrent complications or requirement for surgery.

METHODS

Serum anti-Saccharomyces cervisiae (ASCA) (IgA & IgG) and perinuclear antineutrophil cytoplasmic antibodies (pANCA) were assayed close to diagnosis in a pediatric cohort of CD patients identified between 1996 and 1998. At diagnosis and follow-up, information was acquired on demographic and clinical features of disease. Relation between ASCA and clinical events was studied using adjusted Cox-proportional hazards modeling. The relative rates of recurrent clinical events according to the marker measures were compared.

RESULTS

The mean age (SD) at diagnosis was 11.2 (3.4) yr. Among 139 patients, 35 (25.9%) and 31 (22.3%) acquired one or more CD related surgery or complication, respectively. Time to occurrence of the first complication was lower among patients ASCA+ (IgA or IgG) (hazards ratio (HR) = 2.33; 95% confidence interval (CI) = 0.99-5.50) and among those with higher ASCA-IgA titers (HR = 1.20; 95% CI = 1.08-1.34). The rates of recurrent complications were higher among those positive or with higher ASCA titers. ASCA did not predict time to undergoing surgery independent of complications, and was unrelated to the occurrence of recurrent surgeries.

CONCLUSIONS

Our study shows that serum ASCA measured close to diagnosis can determine the occurrence of early complications in pediatric CD. Preventive treatment targeted toward these susceptible patients could potentially modify the disease course.