Ileal or Anastomotic Location of Lesions Does Not Impact Rate of Postoperative Recurrence in Crohn's Disease Patients Classified i2 on the Rutgeerts Score.

BACKGROUND: The Rutgeerts score with 5 grades of severity (i0-i4) is a suitable endoscopic model to predict clinical recurrence following ileocolonic resection in Crohn's disease (CD). Definition of grade i2 includes lesions confined to the ileocolonic anastomosis (i2a) or moderate lesions on the neo-terminal ileum (i2b). The aim of the present study was to evaluate the probability of clinical recurrence in i2a and i2b patients. METHODS: This multicenter retrospective study included all CD patients classified i2 at the first postoperative ileocolonoscopy. The primary outcome was to evaluate the probability of clinical recurrence in patients classified i2a and i2b. The secondary outcome was to compare the rate of global recurrence of CD. RESULTS: Fifty patients were included: 23 were classified i2a and 27 were classified i2b. The median duration of follow-up was 40 (18.0-80.4) months in the i2a group and 53.5 (25.0-69.0) months in the i2b group (p = 0.9). The probability of clinical recurrence was not significantly different between patients classified i2a and i2b (p = 0.64). Median time to clinical recurrence after the first ileocolonoscopy and probability of global CD recurrence were not different between the two groups (p ≥ 0.19). CONCLUSIONS: The rate of clinical postoperative recurrence is not different in i2a and i2b patients. These results suggest that the same therapeutic strategy should be used in all patients classified i2 on the Rutgeerts score whatever the location of postoperative CD recurrence.

Gut: An underestimated target organ for Aluminum.

Since World War II, several factors such as an impressive industrial growth, an enhanced environmental bioavailability and intensified food consumption have contributed to a significant amplification of human exposure to aluminum. Aluminum is particularly present in food, beverages, some drugs and airbone dust. In our food, aluminum is superimposed via additives and cooking utensils. Therefore, the tolerable intake of aluminum is exceeded for a significant part of the world population, especially in children who are more vulnerable to toxic effects of pollutants than adults. Faced with this oral aluminum influx, intestinal tract is an essential barrier, especially as 38% of ingested aluminum accumulates at the intestinal mucosa. Although still poorly documented to date, the impact of oral exposure to aluminum in conditions relevant to real human exposure appears to be deleterious for gut homeostasis. Aluminum ingestion affects the regulation of the permeability, the microflora and the immune function of intestine. Nowadays, several arguments are consistent with an involvement of aluminum as an environmental risk factor for inflammatory bowel diseases.

[Autologous stem cell transplantation for autoimmune diseases: recommendations from the SFGM-TC]. / Autogreffe des cellules souches hématopoïétiques dans les maladies auto-immunes : recommandations de la SFGM-TC.

Autologous hematopoietic stem cell transplantation is a valid alternative to immunosuppressive treatment in patients with auto-immune disease; however, the role of this approach remains subject to debate. In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) set up its fourth annual series of workshops which brought together practitioners from all of its member centers. These workshops took place in September 2013 in Lille. In this article we give an overview regarding the indications of autologous stem cell transplantation in auto-immune diseases as well as recommendations regarding post-transplant follow-up of patients.

Activation of the peroxisome proliferator-activated receptor gamma promotes the development of colon tumors in C57BL/6J-APCMin/+ mice.

The development of colorectal cancer, one of the most frequent cancers, is influenced by prostaglandins and fatty acids. Decreased prostaglandin production, seen in mice with mutations in the cyclooxygenase 2 gene or in animals and humans treated with cyclooxygenase inhibitors, prevents or attenuates colon cancer development. There is also a strong correlation between the intake of fatty acids from animal origin and colon cancer. Therefore, the peroxisome proliferator-activated receptor gamma (PPARgamma), a downstream transcriptional mediator for prostaglandins and fatty acids which is highly expressed in the colon may be involved in this process. Activation of PPARgamma by two different synthetic agonists increased the frequency and size of colon tumors in C57BL/6J-APCMin/+ mice, an animal model susceptible to intestinal neoplasia. Tumor frequency was only increased in the colon, and did not change in the small intestine, coinciding with the colon-restricted expression of PPARgamma. Treatment with PPARgamma agonists increased beta-catenin levels both in the colon of C57BL/61-APCMin/+ mice and in HT-29 colon carcinoma cells. Genetic abnormalities in the Wnt/wingless/APC pathway, which enhance the transcriptional activity of the beta-catenin-T-cell factor/lymphoid enhancer factor 1 transcription complex, often underly the development of colon tumors. Our data indicate that PPARgamma activation modifies the development of colon tumors in C57BL/61-APCMin/+ mice.

Post-surgical recurrence of Crohn's disease: Situational analysis and future prospects.

Surgery retains a major role in the treatment of Crohn's disease, and the prevention of post-operative recurrence is an essential issue. In fact, despite the increasing use of biotherapies, almost all of the patients who undergo surgery will present with a recurrence, initially endoscopic and then clinical, eventually leading to a second intervention in 15 to 20% of cases. Certain risk factors for recurrence such as smoking, repeated and/or extensive resections, anoperineal involvement, myenteric plexitis, epithelioid granulomas, penetrating disease behaviour and lack of post-operative prophylactic treatment have been well established. Currently, measures to prevent post-operative recurrence are based mainly on smoking cessation in all patients and the prescription of anti-TNFα medications for patients with a high risk of recurrence (at least two risk factors for recurrence). However, new surgical techniques have recently been described which could modify post-operative prevention strategies. Kono's lateral anti-mesenteric anastomosis could significantly reduce clinical and endoscopic recurrence compared to conventional anastomosis techniques. Long latero-lateral isoperistaltic stricturoplasties have been shown to be feasible and are associated with a low rate of long-term symptomatic recurrence requiring surgery. In a preliminary series, intestinal resections with extensive mesenteric resection reduced the rate of recurrence in comparison with patients operated on conventionally (3% vs. 40% at five years). If the results of these new surgical techniques are confirmed, the indications for post-operative immunomodulatory treatments could be downgraded in patients currently considered to be at high risk of recurrence.

Interleukin 5 synthesis by eosinophils: association with granules and immunoglobulin-dependent secretion.

Interleukin 5 (IL-5) is the main factor that promotes the terminal differentiation of eosinophil progenitors (as indicated by colony formation assays), and enhances the effector capacity of mature eosinophils. IL-5 is produced by T lymphocytes, CD4-/CD8- and mast cells and recently, messenger (m)RNA of this cytokine has been identified in eosinophils from patients with coeliac disease, asthma, or eosinophilic heart diseases. In this study, IL-5 mRNA and immunoreactive IL-5 protein were detected in tissue and blood eosinophils from patients with eosinophilic cystitis or hypereosinophilic syndromes but not in Crohn's disease. By electron microscopy associated to immunogold staining, immunoreactive IL-5 was identified in eosinophilic granules. After stimulation with IgA-, IgE-, or IgG-immune complexes, blood eosinophils were shown, by immunocytochemistry and by enzyme-linked immunosorbent assay, to secrete IL-5. These observations demonstrate that eosinophils, under physiological stimulation, can release significant amounts of IL-5, which may contribute to local eosinophil recruitment and activation.

Immunoreactivity for interleukin 3 and 5 and granulocyte/macrophage colony-stimulating factor of intestinal mucosa in bronchial asthma.

T lymphocytes and eosinophils are important components of the inflammatory cell infiltrate in bronchial mucosa in asthma. Because activated lymphocytes migrate through the thoracic duct and the general circulation to remote glandular and mucosal sites, we initiated this study to evaluate pathological abnormalities and immunoreactivity for interleukin (IL) 3, IL-5, and granulocyte/macrophage colony-stimulating factor (GM-CSF) of intestinal mucosa in bronchial asthma. 15 asthmatic patients, 8 nonasthmatic patients with chronic obstructive pulmonary disease, 6 atopic nonasthmatic healthy controls, and 6 nonatopic healthy controls were studied. Duodenal biopsies were performed by endoscopy. A significantly increased number of intraepithelial lymphocytes and eosinophils and a significant accumulation of mononuclear cells (lymphocytes and mast cells) and eosinophils in the lamina propria were detected in asthmatics and atopic controls. Immunostaining with antibodies directed against IL-3, IL-5, and GM-CSF was positive in asthmatics and atopic controls, whereas no staining was observed in nonatopic controls and chronic obstructive pulmonary disease. Combined ultrastructural study and immunogold labeling demonstrated that IL-3, IL-5, and GM-CSF were localized in eosinophils and mast cells. Although devoid of gastrointestinal symptoms, asthmatics and asymptomatic atopics had duodenal pathological abnormalities mimicking those observed in the bronchial mucosa in asthma, suggesting that the whole mucosal immune system is involved in bronchial asthma.

Role of the high affinity immunoglobulin E receptor in bacterial translocation and intestinal inflammation.

A role for immunoglobulin E and its high affinity receptor (Fc epsilon RI) in the control of bacterial pathogenicity and intestinal inflammation has been suggested, but relevant animal models are lacking. Here we compare transgenic mice expressing a humanized Fc epsilon RI (hFc epsilon RI), with a cell distribution similar to that in humans, to Fc epsilon RI-deficient animals. In hFc epsilon RI transgenic mice, levels of colonic interleukin 4 were higher, the composition of fecal flora was greatly modified, and bacterial translocation towards mesenteric lymph nodes was increased. In hFc epsilon RI transgenic mice, 2,4,6-tri-nitrobenzenesulfonic acid (TNBS)-induced colitis was also more pronounced, whereas Fc epsilon RI-deficient animals were protected from colitis, demonstrating that Fc epsilon RI can affect the onset of intestinal inflammation.

Interleukin 5 messenger RNA expression by eosinophils in the intestinal mucosa of patients with coeliac disease.

Interleukin 5 (IL-5), the major factor involved in eosinophil differentiation, is produced by T cells or mast cells. In the present study, we found that eosinophils infiltrating the mucosa of four patients with active coeliac disease also express the IL-5 mRNA. No positive signal was obtained in normal duodenum tissues and in the cell infiltrate from patients submitted to gluten restriction. The identification of labeled mucosal cells as eosinophils relied on their typical morphology. Moreover, highly purified blood eosinophils from three out of four patients with eosinophilia were also strongly labeled with the IL-5 antisense but not with the corresponding sense probe. Together, these results suggest that eosinophils have the capacity to synthesize IL-5, which could contribute to paracrine interactions with T and B cells and, in autocrine fashion, locally participate, through binding to the IL-5 receptor, to eosinophil differentiation and activation. These data might have implications not only in the pathology of coeliac disease but also in other diseases associated with eosinophil infiltration.

Attenuation of colon inflammation through activators of the retinoid X receptor (RXR)/peroxisome proliferator-activated receptor gamma (PPARgamma) heterodimer. A basis for new therapeutic strategies.

The peroxisome proliferator-activated receptor gamma (PPARgamma) is highly expressed in the colon mucosa and its activation has been reported to protect against colitis. We studied the involvement of PPARgamma and its heterodimeric partner, the retinoid X receptor (RXR) in intestinal inflammatory responses. PPARgamma(1/)- and RXRalpha(1/)- mice both displayed a significantly enhanced susceptibility to 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis compared with their wild-type littermates. A role for the RXR/PPARgamma heterodimer in the protection against colon inflammation was explored by the use of selective RXR and PPARgamma agonists. TNBS-induced colitis was significantly reduced by the administration of both PPARgamma and RXR agonists. This beneficial effect was reflected by increased survival rates, an improvement of macroscopic and histologic scores, a decrease in tumor necrosis factor alpha and interleukin 1beta mRNA levels, a diminished myeloperoxidase concentration, and reduction of nuclear factor kappaB DNA binding activity, c-Jun NH(2)-terminal kinase, and p38 activities in the colon. When coadministered, a significant synergistic effect of PPARgamma and RXR ligands was observed. In combination, these data demonstrate that activation of the RXR/PPARgamma heterodimer protects against colon inflammation and suggest that combination therapy with both RXR and PPARgamma ligands might hold promise in the clinic due to their synergistic effects.

The RAGE signaling pathway is involved in intestinal inflammation and represents a promising therapeutic target for Inflammatory Bowel Diseases.

Inflammatory Bowel Diseases (IBD) are chronic inflammatory conditions of the intestinal tract. IBD are believed to result from an inappropriate immune response against the intestinal flora in genetically predisposed patients. The precise etiology of these diseases is not fully understood, therefore treatments rely on the dampening of symptoms, essentially inflammation, rather than on the cure of the disease. Despite the availability of biologics, such as anti-TNF antibodies, some patients remain in therapeutic failure and new treatments are thus needed. The multiligand receptor for advanced glycation end-products (RAGE) is a pattern recognition receptor implicated in inflammatory reactions and immune system activation. Here, we investigated the role of RAGE in intestinal inflammation and its potential as a therapeutic target in IBD. We showed that RAGE was upregulated in inflamed tissues from IBD patients compared to controls. Rage-/- mice were less susceptible to intestinal and colonic inflammation development than WT mice. WT mice treated with the RAGE-specific inhibitor FPS-ZM1 experienced less severe enteritis and colitis. We demonstrated that RAGE could induce intestinal inflammation by promoting oxidative stress and endothelial activation which were diminished by FPS-ZM1 treatment. Our results revealed the RAGE signaling pathway as a promising therapeutic target for IBD patients.

[Nuclear receptor PPAR and hepatology: pathophysiological and therapeutical aspects]. / Récepteurs nucléaires PPAR et hépatologie: implications physiopathologiques et thérapeutiques.

In last few years, the topic of nuclear receptor has been developed in the field of hepatology allowing envisaging therapeutic strategies for the most frequent chronic liver diseases. Peroxysome proliferator-activated receptors (PPAR) contribute to wide physiological processes within the liver such as lipid/glucid metabolisms, inflammatory response, cell differenciation and cell cycle. In vitro experiments and animal studies showed that PPARalpha discloses anti-inflammatory property and PPARgamma discloses anti-inflammatory, antifibrogenic and antiproliferative properties in the liver. Main available agonists are fibrates (PPARalpha) used for 20 years in cases of lipid metabolism abnormalities and glitazones (PPARgamma) used since 2000 for type 2 diabetes. In terms of therapy, animal studies and human trials have been conducted in steatopathies. However, clinicians have to be aware of potential specific side effects related to glitazones especially on cardiovascular system.

Eosinophils in allergic reactions.

Mainly located in the skin or mucosa of patients with allergic diseases, eosinophils contribute directly to tissue damage and chronic inflammation. The past year has seen significant advances in the study of the factors involved in the specific tissue recruitment of eosinophils, including chemoattractants and their receptors. New data have been obtained on the synthesis by eosinophils of various cytokines mostly released by immune complexes.

Review article: mode of action and delivery of 5-aminosalicylic acid - new evidence.

The effectiveness of sulfasalazine depends on the splitting of the diazo bond in the molecule by the action of bacteria in the large bowel, releasing the pharmacologically active moiety, 5-aminosalicylic acid. The development of pH-dependent, delayed-release formulations of 5-aminosalicylic acid abolished the toxicity associated with the sulfapyridine part of sulfasalazine. 5-aminosalicylic acid is now believed to act by activating a class of nuclear receptors involved in the control of inflammation, cell proliferation, apoptosis and metabolic function, the gamma form of peroxisome proliferator-activated receptors. These receptors are expressed at particularly high levels in colon epithelial cells, where their expression appears to be at least in part stimulated by gut bacteria. Other drugs known to act via peroxisome proliferator-activated receptor-gamma, such as rosiglitazone and the selective peroxisome proliferator-activated receptor-gamma ligand GW1929, can be displaced from their binding sites on the peroxisome proliferator-activated receptor-gamma molecule by 5-aminosalicylic acid at concentrations of 5-aminosalicylic acid that correspond with the concentrations found in the lumen of ulcerative colitis patients taking oral mesalazine. Genetically engineered heterozygous knockout mice (peroxisome proliferator-activated receptor-gamma+/-) are particularly susceptible to colonic inflammation, and inflammation is more severe in these mice, in response to chemicals that induce experimental colonic ulcers. In these experimental models, 5-aminosalicylic acid is ineffective in peroxisome proliferator-activated receptor-gamma+/- mice. This new insight provides a mechanistic foundation for the possibility that long-term treatment with 5-aminosalicylic acid can reduce the risk of colorectal cancer in patients with ulcerative colitis.

Successful induction of tolerance to infliximab in patients with Crohn's disease and prior severe infusion reactions.

AIM: To appraise the tolerance and efficacy of an induction of tolerance protocol to infliximab permitting the re-administration of the drug to patients with Crohn's disease having had infusion reactions requiring suspension of treatment. METHODS: Fourteen patients were included in the induction of tolerance protocol. Each infusion of infliximab (5 mg/kg) was divided into 11 escalating 15 min increments over a 3-h time period. The induction of tolerance procedure was repeated for subsequent infusions. RESULTS: Ten patients (71.4%) received all the three infusions for the induction treatment. Nine (64.3%) had a significant response and six (48.8%) still benefited from infliximab infusions. Seven patients (50%) achieved a complete remission, after a mean of 2.5 (two to three) infusions. Four patients (28.6%) had no response and the protocol was stopped. Three patients (21.4%) experienced mild immediate hypersensitivity reactions, which were controlled, two patients (14.2%) experienced severe immediate hypersensitivity reactions, leading to interruption of the treatment and one patient developed a delayed hypersensitivity reaction. CONCLUSION: Our induction of tolerance protocol allows some patients who have experienced severe or repetitive infusion reactions to infliximab to be safely retreated with the drug in a hospitalized setting, with a clinical response achieved in a majority of these patients.

[Fatal fulminant Epstein-Barr virus hepatitis]. / Hépatite fulminante fatale à Epstein-Barr virus.

Infectious mononucleosis is a common and benign disease. Although hepatic cytolysis is common during infectious mononucleosis, fulminant hepatitis is rare. We report an observation of a fatal fulminant hepatitis complicating a primary EBV infection in a 15 year-old male.

Toxicological consequences of experimental exposure to aluminum in human intestinal epithelial cells.

Aluminum (Al), a non-essential element, is ubiquitous in industrialized societies. Whereas adult intake is estimated between 3 and 12 mg/day according to dietary aluminum studies conducted in many countries, it is not known if aluminum may have a toxic effect on intestinal epithelium. The aim of this work was to evaluate the cytotoxicity and RNA expression patterns induced in HT-29 cells by aluminum. Both classical toxicological methods and a global transcriptomic approach were used. Cytotoxicity determined by MTT assay showed a time and dose dependent decrease of cell viability in aluminum treated cells compared to control cells. Cell cycle analysis by flow cytometry revealed that aluminum induced accumulation of cells in phase G0/G1, associated with a decrease in the proportion of cells in S and G2/M phases. Aluminum led to apoptosis as evidenced by nuclear morphology changes and mitochondrial membrane perturbations, and induced reactive oxygen species generation. Transcriptomic pattern argued in favor of pro-tumorigenic and pro-inflammatory effects of aluminum in intestinal epithelial cells. These results highlight several pathways by which aluminum has a disturbing impact on intestinal epithelial cells, supporting that the effects of aluminum on intestine warrants further investigation.

The schistosome glutathione S-transferase P28GST, a unique helminth protein, prevents intestinal inflammation in experimental colitis through a Th2-type response with mucosal eosinophils.

Intestinal helminth parasites are potent inducers of T helper type 2 (Th2) response and have a regulatory role, notably on intestinal inflammation. As infection with schistosomes is unlikely to provide a reliable treatment of inflammatory bowel diseases, we have investigated the beneficial effect of a schistosome enzymatic protein, the 28-kDa glutathione S-transferase (P28GST), on the modulation of disease activity and immune responses in experimental colitis. Our results showed that immunization with recombinant P28GST is at least as efficient as established schistosome infection to reduce colitis lesions and expression of pro-inflammatory cytokines. Considering underlying mechanisms, the decrease of inflammatory parameters was associated with the polarization of the immune system toward a Th2 profile, with local and systemic increases of interleukin (IL)-13 and IL-5. Dense eosinophil infiltration was observed in the colons of P28GST-immunized rats and mice. Depletion of eosinophils by treatment with an anti-Siglec-F monoclonal antibody and use of IL-5-deficient mice led to the loss of therapeutic effect, suggesting the crucial role for eosinophils in colitis prevention by P28GST. These findings reveal that immunization with P28GST, a unique recombinant schistosome enzyme, ameliorates intestinal inflammation through eosinophil-dependent modulation of harmful type 1 responses, representing a new immuno-regulatory strategy against inflammatory bowel diseases.

Gene transfer of CD154 and IL12 cDNA induces an anti-leukemic immunity in a murine model of acute leukemia.

IL12 is an essential cytokine for the generation of T helper 1 response, natural killer (NK) cells and cytotoxic T lymphocyte (CTL) stimulation. CD154 triggers CD40 on antigen-presenting cells, thus inducing antigen presentation to the immune system and production of IL12. As IL12 and CD154 share several pathways mediating immune response, we investigated in an aggressive murine model of acute leukemia the relative antileukemic efficiency of IL12, CD154 and IL12 + CD154 gene transfer. Live leukemic cells transduced by IL12, CD154, and IL12 + CD154 showed reduced leukemogenicity but CD154 protective effect was reduced when 10(6) leukemic cells were injected. Vaccines with lethally irradiated IL12-transduced cells were able to cure mice previously injected with 10(4) leukemic cells and adoptive transfer of IL12-induced antileukemic immunity protected recipient mice. NK cytotoxicity was enhanced in mice vaccinated with leukemic cells transduced by IL12, CD154, and CD154 + IL12. IL12 transduced cells induced IFN-gamma mRNA in CD4(+) and CD8(+) T cells isolated from the spleen of vaccinated animals, however, in vivo depletion experiments showed that IL12 vaccine effect was CD4(+) but not CD8(+) T cell dependent. We conclude that IL12 gene is a more potent candidate than CD154 for gene therapy of acute leukemia.

[Desensitisation to infliximab in patients with Crohn's disease]. / Accoutumance médicamenteuse a l'infliximab dans la maladie de Crohn.

BACKGROUND: Infliximab is a chimeric monoclonal antibody directed against tumour necrosis factor-alpha that has been shown to improve chronic refractory and fistulating Crohn's disease. Infliximab infusions have been associated both with immediate and delayed reactions. MATERIAL AND METHODS: Desensitisation was performed in four patients who had experienced immediate reactions to infliximab infusions and in one who had developed a delayed reaction. No therapeutic alternatives were available for these patients. Before desensitisation, skin tests were performed. RESULTS: Skin-tests were negative for all patients. Desensitisation was performed with serial dilutions of infliximab with monitoring of vital signs before each increment. After parenteral desensitisation, all five patients were able to tolerate infliximab infusion without complications or any requirement for antihistamines or steroids. However, two patients who had initially presented with an immediate reaction to infliximab experienced arthralgia and myalgia similar to a "serum sickness-type" of reaction 6 to 10 days after desensitisation. CONCLUSION: Even if there is no evidence of an allergic mechanism in infusion reactions to infliximab, successful desensitization can be achieved for patients experiencing acute reactions. The mechanism of desensitisation remains presently unknown. It is not yet possible to say if desensitization will be effective in preventing delayed reactions.