Safety and efficacy of intravenous cyclophosphamide pulse therapy in therapy refractory Crohn's disease patients.

A major challenge in the management of persistently active Crohn's disease patient's refractory to treatment regimen following the current guidelines is the induction of remission, which is a prerequisite for subsequent maintenance therapy. The aim of this study was to evaluate both the clinical and endoscopic benefit of intravenous cyclophosphamide pulse therapy in patients with active and therapy refractory Crohn's disease. Nine patients with acute moderate to severe Crohn's disease, not responding to conventional as well as biological therapy regimen received 3 - 9 cycles of monthly treatments with intravenous cyclophosphamide (680 - 1000 mg) in an uncontrolled setting and were retrospectively analyzed. Eight of nine patients (88.9%) had a clinical response (measured by a decrease in the Harvey-Bradshaw index, HBI ≥ 3) and two of nine patients (22.2%) achieved clinical remission (HBI ≤ 4) at week 8 after two applications of intravenous cyclophosphamide therapy. These response and remission rates remained unchanged after individual completion of cyclophosphamide therapy. Median HBI decreased from 18 (7 - 25) at the beginning of therapy to 7 (3 - 18) at week 8. 5 of 9 patients (56%) showed endoscopic response (defined by a reduction of ulcers) and one patient (11%) reached endoscopic remission (defined by the absence of ulcers) after the last application of cyclophosphamide. Arthralgia, which was present in 4 of 9 (44%) patients, was unchanged in most patients after cyclophosphamide therapy, although one patient described a marked reduction in joint pain. Cyclophosphamide pulse therapy was well tolerated during the whole treatment course in all subjects. One patient with long-standing Crohn's disease was diagnosed with a high-grade intraepithelial neoplasia in the rectum and underwent surgical intervention, where the diagnosis of an early stage adenocarcinoma was made. We concluded that intravenous cyclophosphamide pulse therapy was well tolerated by most patients and effective for inducing clinical and endoscopic response and remission in patients with therapy refractory Crohn's disease. In patients who are unresponsive to available therapies, including available biological treatment options, cyclophosphamide therefore represents a potential option to induce therapeutic response, which must then be maintained by other treatment modalities.

[Biosimilars in inflammatory bowel disease]. / Biosimilars in der Behandlung chronisch entzündlicher Darmerkrankungen.

After the expiry date of the patent protection for Infliximab in 2013, the biosimilar CT­P13 was approved for indications in Crohn's disease and ulcerative colitis in adults as well as in children. The approval has been based on two randomized clinical studies indicating equivalence for the biosimilar with regard to pharmacokinetics, efficacy, as well as side-effects. The clinical experience since, in addition to multiple non-randomized studies, indicate a comparable efficacy and immunogenicity of the Infliximab biosimilar CT-P13 in inflammatory bowel disease. Thus, the introduction of the biosimilar as primary therapy seems to be justified. Tight monitoring of the safety of biosimilars with regard to efficacy and side effects has to be ensured.

Vedolizumab provides clinical benefit over 1 year in patients with active inflammatory bowel disease - a prospective multicenter observational study.

BACKGROUND: Vedolizumab, a monoclonal antibody targeting the α4ß7-integrin, is effective in inducing and maintaining clinical remission in Crohn's disease and ulcerative colitis according to randomised clinical trials. AIM: To determine the long-term effectiveness of vedolizumab in a real-world clinical setting. METHODS: This observational registry assessed the clinical outcome in patients treated with vedolizumab for clinically active Crohn's disease (n = 67) or ulcerative colitis (n = 60). Primary endpoint was clinical remission (HBI ≤ 4/pMayo ≤ 1) at week 54. Secondary endpoints included clinical response rates (HBI/pMayo score drop ≥3) and steroid-free clinical remission at weeks 30 and 54. RESULTS: Vedolizumab was stopped in 69/127 (56%) patients after a median time of 18 weeks (range 2-49) predominantly owing to lack or loss of response. Using nonresponder imputation analysis, clinical remission and steroid-free remission rates were 21% and 15% in Crohn's disease and 25% and 22% in ulcerative colitis, respectively. Lack of clinical remission was associated with prior treatment with anti-TNF or with steroids for more than 3 months in the last 6 months in ulcerative colitis. At week 14, the absence of remission in Crohn's disease or nonresponse in ulcerative colitis indicated a low likelihood of clinical remission at week 54 [2/31 (7%) in Crohn's disease, 4/41 (10%) in ulcerative colitis]. Accordingly, declining C-reactive protein in inflammatory bowel disease and/or lower faecal calprotectin in ulcerative colitis at week 14 predicted remission at week 54. CONCLUSION: Among patients who started vedolizumab for active inflammatory bowel disease, clinical remission rates are 21-25% after 54 weeks.

CD101 inhibits the expansion of colitogenic T cells.

CD101 exerts negative-costimulatory effects in vitro, but its function in vivo remains poorly defined. CD101 is abundantly expressed on lymphoid and myeloid cells in intestinal tissues, but absent from naïve splenic T cells. Here, we assessed the impact of CD101 on the course of inflammatory bowel disease (IBD). Using a T-cell transfer model of chronic colitis, we found that in recipients of naïve T cells from CD101(+/+) donors up to 30% of the recovered lymphocytes expressed CD101, correlating with an increased interleukin (IL)-2-mediated FoxP3 expression. Transfer of CD101(-/-) T cells caused more severe colitis and was associated with an expansion of IL-17-producing T cells and an enhanced expression of IL-2Rα/ß independently of FoxP3. The co-transfer of naïve and regulatory T cells (Treg) protected most effectively from colitis, when both donor and recipient mice expressed CD101. Although the expression of CD101 on T cells was sufficient for Treg-function and the inhibition of T-cell proliferation, sustained IL-10 production required additional CD101 expression by myeloid cells. Finally, in patients with IBD a reduced CD101 expression on peripheral and intestinal monocytes and CD4(+) T cells correlated with enhanced IL-17 production and disease activity. Thus, CD101 deficiency is a novel marker for progressive colitis and potential target for therapeutic intervention.

Review article: in vivo imaging by endocytoscopy.

BACKGROUND: Endocytoscopy (EC) enables in vivo microscopic imaging at 1400-fold magnification, thereby allowing the analysis of mucosal structures at the cellular level. In contrast to fluorescence imaging with confocal laser endomicroscopy which allows analysis of mucosal structures up to 250 µm in depth, EC is based on the principle of contact light microscopy and only allows visualisation of the very superficial mucosal layer. AIM: To systematically review the feasibility and diagnostic yield of EC for in vivo diagnosis of diseases. METHODS: A systematic search of the literature on diagnostic interventions in the gastrointestinal tract using EC was performed by searches in MEDLINE, Current Contents, PubMed, cross-references and references from relevant articles using the search terms 'endocytoscopy', 'endocytoscope', 'magnification endoscopy', 'endocytoscopic imaging', 'virtual histology' and 'optical biopsy'. Only full manuscripts and case reports published in English were included. RESULTS: Overall twenty-nine relevant reports were identified. EC was feasible to detect oesophageal squamous cell cancer with sensitivity, specificity and accuracy of 95%, 84% and 82%, respectively. Moreover, EC reached excellent sensitivity and specificity for in vivo diagnosis of colon polyps (91% and 100%, respectively). Other diagnostic applications of EC included diagnosis of Barrett's oesophagus, Helicobacter pylori, coeliac disease and small cell lung cancer. No serious complications of EC have yet been reported. CONCLUSIONS: Endocytoscopy is a safe and effective new endoscopic imaging technique to obtain in vivo histology and guided biopsies with high diagnostic accuracy. Therefore, endocytoscopy has the potential to facilitate both diagnosis and patient management.

[Ultrasound education by simulator training--analysis of the largest simulator-based training in Germany]. / Ausbildung am Ultraschallsimulator--Analyse der größten simulatorbasierten Fortbildung in Deutschland.

Teaching ultrasound (US) has not been sufficiently standardised yet. Most educational devices in US consist of 2-dimensional B-mode images. However, the identification of anatomic structures in the 3-dimensional space can only be learned by practical hands-on education. In US simulators, US images of real pathologies are created by the examination of a dummy with a mock transducer. The resulting US images were previously recorded in a 3-dimensional format and were processed in a way which facilitates the reconstruction and projection of the images on a screen corresponding to the sectional plane of the mock transducer, simulating the conventional B-mode images. This enables standardised, real-time, hands-on training of US pathology detection. In June 2007, a hands-on workshop on US simulators was performed in the 1st Department of Internal Medicine of the Johannes Gutenberg-University in Mainz/Germany. During 15 days, 209 participants from all parts of Germany were trained. The workshop included an evaluation to elucidate the value and acceptance of this kind of US training. 149 evaluation forms could be analysed (72 %). The participants were fairly heterogeneous and belonged to the following subspecialties: internal medicine (50 %), surgery (11 %), others (18 %). 72 % were residents, 22 % consultants. 40 % of the participants worked in university hospitals, 12 % in hospitals of highest clinical level, and 42 % in hospital of basic care. Baseline knowledge in US was quite different, too, reflected in the number of independently performed US examinations prior to this course: 0 - 400 examinations (44 %), 401 - 1000 examinations (14 %), 1001 - 4000 examinations (7 %), and > 4000 examinations (2 %). Of note, 56 % of the participants had not received any kind of formal training in US. In daily practice 77 % were trained by tutors, whose formal qualification in US was unknown. Only a small proportion of the tutors had received training in US according to the standards of the German Association of US in Medicine (DEGUM). This evaluation shows the high level of acceptance of simulator-based training in US despite the heterogeneity of the participants. 95 % rated the teaching value as "high" and 95 % wished an integration of US simulators in training curricula. In summary, this analysis proves the need for standardised training programmes in US teaching in Germany and a high level of acceptance of simulator-based US training.

New therapeutic strategies for treatment of inflammatory bowel disease.

Although the precise etiology of inflammatory bowel disease (IBD) still remains unclear, considerable progress has been made in the identification of cytokine-mediated signaling pathways involved in the inflammatory process. Recent data have clearly shown that these pathways induce augmented intestinal T-cell activation and thus resistance to apoptosis, which is a central process in disease pathogenesis, as it impairs mucosal homeostasis. Therefore, novel therapeutic strategies aim at restoring activated effector T-cell susceptibility to apoptosis in the gut, based on a pathophysiological rationale. This development is best exemplified by the emergence of agents that target the TNF pathway, IL-6 trans-signaling, and the IL-12/IL-23 pathway. These compounds give hope for the development of new strategies aiming at more effective and less toxic therapies for IBD.

NF-kappaB in inflammatory bowel disease.

Apart from genetic and environmental factors, the mucosal immune system of the gut plays a central role in the pathogenesis of inflammatory bowel disease (IBD). In the healthy gut, the mucosal immune system ensures the balance between pro- and anti-inflammatory mediators and thereby allows an effective defence against luminal pathogens but at the same time prevents an overwhelming immune reaction directed against the huge amount of harmless luminal antigens (for example, components of food or nonpathological bacteria). In both entities of IBD (Crohn's disease and ulcerative colitis) this immunological balance is severely impaired and shifted towards the pro-inflammatory side. The chronic mucosal inflammation in IBD is caused by hyperactivation of effector immune cells, which produce high levels of pro-inflammatory cytokines like tumour necrosis factor-alpha, interleukin-6 and interferon-gamma, resulting in colonic tissue damage. The nuclear transcription factor kappaB (NF-kappaB) was identified as one of the key regulators in this immunological setting. Its activation is markedly induced in IBD patients and through its ability to promote the expression of various pro-inflammatory genes, NF-kappaB strongly influences the course of mucosal inflammation. Considering the different cell-type specific effects which are mediated by NF-kappaB, this review aims at describing the complex role of NF-kappaB in IBD and discusses existing pharmacological attempts to block the activation of NF-kappaB to develop new therapeutic strategies in IBD.

Signaling molecules: the pathogenic role of the IL-6/STAT-3 trans signaling pathway in intestinal inflammation and in colonic cancer.

Although the precise etiology of inflammatory bowel diseases (IBD) still remains unclear, considerable progress has been made in the identification of novel signal transduction pathways that elucidate the immunopathogenesis involved in the perpetuation of the inflammatory process. As both ulcerative colitis and Crohn's disease are associated with an increased risk for developing colorectal cancer (CRC) and precancerous dysplastic epithelial changes, further studies have concentrated on finding a common signaling pathway that could serve as a mechanistic link between inflammation and associated colonic cancer in IBD. This review presents the current data concerning the pathogenic role of the IL-6/STAT-3 trans signaling pathway in IBD and colorectal cancer. Furthermore it evaluates the possible therapeutic potential of targeting this pathway for the therapy of IBD and CRC.

Novel signal transduction pathways: analysis of STAT-3 and Rac-1 signaling in inflammatory bowel disease.

Although the precise etiology of inflammatory bowel disease still remains unclear, considerable progress has been made in the identification of novel signal transduction pathways that elucidate the immunopathogenesis involved in the perpetuation of the inflammatory process. Augmented T cell resistance against apoptosis is regarded as a pivotal factor in the pathogenesis, as it impairs mucosal homeostasis and leads to unrestrained accumulation of activated T cells, which subsequently lead to the amplification of the inflammatory response. Therefore novel therapeutic strategies aim at restoring mucosal T cell susceptibility to apoptosis through targeting of signal transduction pathways that are elemental for augmented resistance of T lymphocytes against apoptosis. For example, a newly developed humanized anti-IL-6R monoclonal antibody that induces intestinal T cell apoptosis showed clinical efficacy in patients with active Crohn;s disease. Moreover, recent data that relate the immunosuppressive effects of azathioprine in inflammatory bowel disease to its apoptosis-inducing potential, have important implications for the design of a more specific therapeutic approach. The examination of these novel signal transduction pathways has elucidated the pathogenetic mechanisms involved in inflammatory bowel disease and gives hope for the development of new strategies that may result in a more effective and less toxic therapeutic procedure.

Treatment of allergic airway inflammation and hyperresponsiveness by antisense-induced local blockade of GATA-3 expression.

Recent studies in transgenic mice have revealed that expression of a dominant negative form of the transcription factor GATA-3 in T cells can prevent T helper cell type 2 (Th2)-mediated allergic airway inflammation in mice. However, it remains unclear whether GATA-3 plays a role in the effector phase of allergic airway inflammation and whether antagonizing the expression and/or function of GATA-3 can be used for the therapy of allergic airway inflammation and hyperresponsiveness. Here, we analyzed the effects of locally antagonizing GATA-3 function in a murine model of asthma. We could suppress GATA-3 expression in interleukin (IL)-4-producing T cells in vitro and in vivo by an antisense phosphorothioate oligonucleotide overlapping the translation start site of GATA-3, whereas nonsense control oligonucleotides were virtually inactive. In a murine model of asthma associated with allergic pulmonary inflammation and hyperresponsiveness in ovalbumin (OVA)-sensitized mice, local intranasal administration of fluorescein isothiocyanate-labeled GATA-3 antisense oligonucleotides led to DNA uptake in lung cells associated with a reduction of intracellular GATA-3 expression. Such intrapulmonary blockade of GATA-3 expression caused an abrogation of signs of lung inflammation including infiltration of eosinophils and Th2 cytokine production. Furthermore, treatment with antisense but not nonsense oligonucleotides induced a significant reduction of airway hyperresponsiveness in OVA-sensitized mice to levels comparable to saline-treated control mice, as assessed by both enhanced pause (PenH) responses and pulmonary resistance determined by body plethysmography. These data indicate a critical role for GATA-3 in the effector phase of a murine asthma model and suggest that local delivery of GATA-3 antisense oligonucleotides may be a novel approach for the treatment of airway hyperresponsiveness such as in asthma. This approach has the potential advantage of suppressing the expression of various proinflammatory Th2 cytokines simultaneously rather than suppressing the activity of a single cytokine.

Soluble gp130 is the natural inhibitor of soluble interleukin-6 receptor transsignaling responses.

Signal transduction in response to interleukin-6 (IL-6) requires binding of the cytokine to its receptor (IL-6R) and subsequent homodimerization of the signal transducer gp130. The complex of IL-6 and soluble IL-6R (sIL-6R) triggers dimerization of gp130 and induces responses on cells that do not express membrane bound IL-6R. Naturally occurring soluble gp130 (sgp130) can be found in a ternary complex with IL-6 and sIL-6R. We created recombinant sgp130 proteins that showed binding to IL-6 in complex with sIL-6R and inhibited IL-6/sIL-6R induced proliferation of BAF/3 cells expressing gp130. Surprisingly, sgp130 proteins did not affect IL-6 stimulated proliferation of BAF/3 cells expressing gp130 and membrane bound IL-6R, indicating that sgp130 did not interfere with IL-6 bound to IL-6R on the cell surface. Additionally, sgp130 partially inhibited proliferation induced by leukemia inhibitory factor (LIF) and oncostatin M (OSM) albeit at higher concentrations. Recombinant sgp130 protein could be used to block the anti-apoptotic effect of sIL-6R on lamina propria cells from Crohn disease patients. We conclude that sgp130 is the natural inhibitor of IL-6 responses dependent on sIL-6R. Furthermore, recombinant sgp130 is expected to be a valuable therapeutic tool to specifically block disease states in which sIL-6R transsignaling responses exist, e.g. in morbus Crohn disease.

Blockade of interleukin 6 trans signaling suppresses T-cell resistance against apoptosis in chronic intestinal inflammation: evidence in crohn disease and experimental colitis in vivo.

The pro-inflammatory cytokine interleukin (IL)-6 (refs. 1-5) can bind to cells lacking the IL-6 receptor (IL-6R) when it forms a complex with the soluble IL-6R (sIL-6R) (trans signaling). Here, we have assessed the contribution of this system to the increased resistance of mucosal T cells against apoptosis in Crohn disease (CD), a chronic inflammatory disease of the gastrointestinal tract. A neutralizing antibody against IL-6R suppressed established experimental colitis in various animal models of CD mediated by type 1 T-helper cells, by inducing apoptosis of lamina propria T cells. Similarly, specific neutralization of sIL-6R in vivo by a newly designed gp130-Fc fusion protein caused suppression of colitis activity and induction of apoptosis, indicating that sIL-6R prevents mucosal T-cell apoptosis. In patients with CD, mucosal T cells showed strong evidence for IL-6 trans signaling, with activation of signal transducer and activator of transcription 3, bcl-2 and bcl-xl. Blockade of IL-6 trans signaling caused T-cell apoptosis, indicating that the IL-6-sIL-6R system mediates the resistance of T cells to apoptosis in CD. These data indicate that a pathway of T-cell activation driven by IL-6-sIL-6R contributes to the perpetuation of chronic intestinal inflammation. Specific targeting of this pathway may be a promising new approach for the treatment of CD.