Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic inflammation in inflammatory bowel disease (IBD; Crohn's disease and ulcerative colitis) may be attributed partly to increased secretion of inflammatory cytokines. The aim of this study was to investigate simultaneously the spontaneous release patterns of tumor necrosis factor-alpha (TNF-alpha), interleukin-1-beta (IL-1 beta), and interleukin-6 (IL-6) by organ cultures of inflamed mucosa from IBD patients. Organ cultures of involved IBD mucosa spontaneously produced increased amounts of TNF-alpha, IL-1 beta, and IL-6 compared to normal mucosa. The patterns of cytokine release between Crohn's disease and ulcerative colitis organ cultures were not significantly different. Increased inflammatory cytokine production by lamina propria mononuclear cells (LPMCs) and mucosa treated with EDTA suggests that these cytokines originate mainly from LPMCs. These results confirm the role of inflammatory cytokines in IBD and shed a new light on the role of TNF-alpha in IBD.
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PMID:Mucosal inflammatory cytokine production by intestinal biopsies in patients with ulcerative colitis and Crohn's disease. 873 57

Several theories have already been postulated in connection with the pathogenesis of inflammatory bowel diseases, yet none of them has been approved. Recently increasing attention has been payed to different cytokines, playing central role in the development of inflammatory processes. In the intestinal mucosa of patients suffering from inflammatory bowel diseases increasing amounts of interleukin-1 (IL-1), tumor necrosis factor (TNF) and platelet activating factor (PAF) could be measured. On the other hand, antiinflammatory cytokines seem to be ineffective, or being present in insufficient amount (IL-4 and IL-10 respectively). It is therefore probable, that altered ratios of cytokines, or pathologic regulation of their production lead to progression of inflammation in IBD. Influence of cytokine production may open new therapeutic approach, e.g. IL-10 enema proved to be effective in the treatment of some cases of steroid-resistant ulcerative colitis, while intravenous administration was useful in Crohn's disease. A brief, comprehensive review of our present knowledge about cytokines in IBD is given.
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PMID:[The role and significance of the most important known cytokines in inflammatory bowel diseases]. 963 23

Proinflammatory cytokines released from monocytes/macrophages, in particular tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, IL-6, and IL-8 seem to play an important role in Inflammatory Bowel Disease (ulcerative colitis and Crohn's disease). Endotoxins or lipopolysaccharides, derived from the outer membrane of Gram-negative bacteria interact with CD14 on surface membrane of macrophages, thus triggering a signal cascade, which leads to the production and release of proinflammatory cytokines, particularly TNF-alpha. Therefore, in IBD, lipopolysaccharides could play a pathogenic role. In this respect, plasma endotoxins have been demonstrated in a not negligible percentage of patients with ulcerative colitis and in their unaffected relatives. The presence of circulating endotoxins could be due, at least in part, to the impaired natural immunity in either patients with ulcerative colitis or in their first degree unaffected relatives. Lactoferrin is an iron-binding glycoprotein, which binds to the lipid A region of lipopolysaccharide with a high affinity and this interaction prevents the binding of lipopolysaccharide to CD14, thus inhibiting the release of proinflammatory cytokines. Therefore, based on the possible pathogenic role exerted by endotoxins in ulcerative colitis, lactoferrin may deserve attention as a possible therapeutical agent in experimental models of Inflammatory Bowel Disease.
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PMID:Immune abnormalities and endotoxemia in patients with ulcerative colitis and in their first degree relatives: attempts at neutralizing endotoxin-mediated effects. 1287 Nov 78

Infliximab, the chimeric monoclonal immunoglobulin (Ig)G1 antibody to tumor necrosis factor (TNF) has changed our therapy of Crohn's disease. Infliximab is indicated in refractory luminal and fistulizing Crohn's disease. In patients with luminal disease, a single intravenous (i.v.) dose of 5 mg/kg is efficacious; in fistulizing disease, an i.v. loading therapy of 5 mg/kg at weeks 0, 2, and 6 is advocated. Because the majority of patients will relapse if not re-treated, a long-term strategy is necessary. The optimal long-term approach is systematic re-treatment with 5 mg/kg every 8 weeks. Episodic therapy on relapse also is possible but is less efficacious and frequently is associated with problems resulting from the formation of antibodies to infliximab (ATI). If treatment is episodic, maintenance therapy with immunosuppression (azathioprine [AZA]/6-mercaptopurine [6-MP] or methotrexate) is mandatory. Trial data suggest that systematic maintenance with 8 weekly doses of infliximab decreases the rate of complications, hospitalizations, and surgeries. These effects probably are achieved thanks to thorough healing of the bowel. Infliximab also is indicated in treating corticosteroid-dependent Crohn's disease and extraintestinal manifestations of Crohn's disease. There are no data yet that support its use as first-line therapy. The data in ulcerative colitis (UC) are conflicting and we should await the results of 2 large controlled trials (ACT1 and ACT2) to position infliximab in the treatment of UC. Other anti-TNF strategies have been less effective than infliximab in the treatment of IBD until now. The results with thalidomide are promising but much more research into small molecules inhibiting TNF and other proinflammatory cytokines is necessary. Safety problems with antibody treatment mainly concern immunogenicity leading to infusion reactions, loss of response, and serum sickness-like delayed infusion reactions. The rate of opportunistic infections is increased mainly in patients treated concomitantly with immunosuppression. Other adverse events associated with anti-TNF strategies are demyelinating disease and worsening of congestive heart failure. Malignancy rates in patients treated with anti-TNF strategies do not seem to be increased.
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PMID:Optimizing anti-TNF treatment in inflammatory bowel disease. 1516 70

Because of the wide variations in the clinical presentation of celiac disease and because treatment exists that is effective in most cases, screening of the general population for celiac disease has been considered. There is still no evidence that patients who have symptom-free celiac disease are at increased risk of small intestinal lymphoma or other complications. Prevention of osteoporosis seems to be the strongest indicator for widespread screening today [22]. The major cause of failure to respond to a gluten-free diet is continuing ingestion of gluten, but other underlying diseases must be considered. Many different drugs (eg, anti-tumor necrosis factor [TNF]-alpha) have been used in patients who have RCD [23]. Steroid treatment has been reported to be effective even in patients who have underlying early EATL. Histologic recovery in patients who have celiac disease usually takes several months but can take up to 1 year, even if the patient remains on a strict gluten-free diet. Some patients report celiac-related symptoms for months after a single gluten intake. The definitions for RCD in literature vary. The authors consider the definition give by Daum and colleagues [24] suitable. They defined true RCD as villous atrophy with crypt hyperplasia and increased IELs persisting for more than 12 months in spite of a strict gluten-free diet. If a patient is not responding well to a gluten-free diet, three considerations are necessary: (1) the initial diagnosis of celiac disease must be reassessed;(2) the patient should be sent to a dietician to check for errors in diet or compliance problems, because problems with the gluten-free diet are the most important cause for persisting symptoms; (3) other reasons for persisting symptoms (eg, pancreatic insufficiency, irritable bowel syndrome, bacterial overgrowth, lymphocytic colitis, collagenous colitis, ulcerative jejunitis, protein-losing enteropathy,T-cell lymphoma, fructose intolerance, cavitating lymphadenopathy, and tropical sprue) should be considered. Other causes for villous atrophy are Crohn's disease, collagenous sprue, and autoimmune enteropathy. Abdulkarim and colleagues [25] examined 55 patients who had a diagnosis of nonresponsive celiac disease. He found that 6 did not have celiac disease, and25 still had some gluten ingestion.Tursi and colleagues [26] reported 15 patients who had celiac disease with persisting symptoms. Because histology improved in all patients after several months, RCD was excluded. Of the 15 patients, 10 had small intestinal bacterial overgrowth, 2 showed lactose malabsorption causing the described symptoms, 1 had mistakenly taken an antibiotic containing gluten, and 1 patient each had Giardia lamblia and Ascaris lumbricoides. Thus, other entities must be considered in patients who have celiac disease and ongoing symptoms. In a follow-up clinical trial, 158 patients who had celiac disease underwent follow-up small intestine biopsies within 2 years after starting a gluten-free diet. Eleven patients (7.0%) with persisting (partial) villous atrophy were considered to have RCD; 5 of them developed EATL [27].RCD type I is characterized by normal expression of T-cell antigens and polyclonal TCR gene rearrangement.RCD type II is characterized by an abnormal IEL phenotype with the expression of intracytoplasmic CD3e, surface CD103, and the lack of classic surface T-cell markers such as CD8, CD4, and TCR-alpha/beta. This clonal IEL population can be considered crypt IEL [24]. RCD II has a poor prognosis, which is a problem for therapy. Clonal TCR gene rearrangements and loss of T-cell antigens such as CD8 and TCR-beta in IELs may indicate the development of an EATL in patients who have RCD. The markers for an overt EATL are a positive stool blood test, increased lactate dehydrogenase, or beta2-microglobulin [24]. If an overt lymphoma is suspected, upper and lower endoscopy, an ear, nose, and throat work-up, CT scan, capsule endoscopy, and possibly double-balloon enteroscopy should be performed. Most reports of the difficulties in treating patients who have true RCE are casereports. Turner and colleagues [28] reported on an induction of remission by useof the anti-TNF-alpha antibody infliximab and maintenance with prednisoloneand azathioprine. Olaussen and colleagues [29] and Mandal and colleagues [30]tried a nonimmunogenic elemental diet. Gillet and colleagues [31] reported successful treatment of a patient who hadRCD using anti-TNF-alpha antibodies (infliximab) for induction and azathioprinefor maintenance. Maurino and colleagues [32] studied seven consecutive patients diagnosed ashaving refractory sprue and no response to oral or parenteral steroids. Aftertreatment with azathioprine (2 mg/kg/d) and oral prednisone (1 mg/kg/d), fivepatients had a complete clinical remission. Two patients who did not respond totreatment at any time died. Goerres and colleagues [33] described 18 patients who had RCD, 10 of whomhad type I RCD, and 8 of whom had type II RCD. Treatment consisted ofazathioprine combined with prednisone for 1 year. Consistent with reports byother investigators, the response rates in the two groups differed. Eight of the10 patients who had type I RCD had a histologic response. Seven of the eightpatients who had type II RCD died, and six of the eight developed a lymphoma. At present there is no effective treatment for type II RCD.Fig. 3 presents a proposed algorithm for monitoring patients who have ce-liac disease.
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PMID:Monitoring nonresponsive patients who have celiac disease. 1687 29

The CD40-CD154 pathway is important in the pathogenesis of inflammatory bowel disease. Here we show that injection of an agonistic CD40 mAb to T and B cell-deficient mice was sufficient to induce a pathogenic systemic and intestinal innate inflammatory response that was functionally dependent on tumor necrosis factor-alpha and interferon-gamma as well as interleukin-12 p40 and interleukin-23 p40 secretion. CD40-induced colitis, but not wasting disease or serum proinflammatory cytokine production, depended on interleukin-23 p19 secretion, whereas interleukin-12 p35 secretion controlled wasting disease and serum cytokine production but not mucosal immunopathology. Intestinal inflammation was associated with IL-23 (p19) mRNA-producing intestinal dendritic cells and IL-17A mRNA within the intestine. Our experiments identified IL-23 as an effector cytokine within the innate intestinal immune system. The differential role of IL-23 in local but not systemic inflammation suggests that it may make a more specific target for the treatment of IBD.
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PMID:Differential activity of IL-12 and IL-23 in mucosal and systemic innate immune pathology. 1692 Jun 36

Infliximab, the monoclonal anti-tumor necrosis factor-alpha (TNF-alpha) antibodies preparation, is efficacious in the treatment of inflammatory bowel diseases. However, the optimal therapeutic approach is still under investigation. Reports on side effects and potential complications of infliximab therapy, as well as of other anti-TNF-alpha blocking agents are accumulating. Hence, the Israeli Gastroenterological Association had initiated a conference in order to discuss the frequent clinical issues that have arisen following the use of infliximab for the treatment of inflammatory bowel diseases. The aim was to report on the published clinical experience and problems regarding several practical aspects of the use of Infliximab, to suggest guidelines that are evidence-based and to discuss them with experienced IBD-oriented gastroenterologists. The subjects that were discussed include: (1) treatment protocols; (2) maintenance therapy in Crohn's disease; (3) prevention of infections and (4) therapeutic potential in ulcerative colitis. These topics reflect everyday issues that gastroenterologists deal with while treating inflammatory bowel disease patients. The manuscript summarizes the literature and evidence that were presented in the conference, the points raised at the discussions as well as guidelines suggested by work groups that were established for each subject. These guidelines may assist and direct the gastroenterologist treating inflammatory bowel disease patients with infliximab.
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PMID:[Infliximab in inflammatory bowel diseases--conference summary and suggested guidelines]. 1718 61

The proven involvement of cytokines in the pathophysiology of IBD has led to the development of powerful, selective, anticytokine drugs--so-called biologics--as a therapy for IBD. Although the efficacy of infliximab, a chimeric monoclonal IgG1 antibody directed against tumor necrosis factor, is proven and the use of biologic agents is growing worldwide, there is concern about their long-term safety, which includes the risk of developing cancer. An increased risk of malignancies, particularly lymphoma, has been reported in some studies of infliximab-treated patients with IBD; however, the increased risk could be caused by the underlying chronic disease, severity of the disease, concomitant medications (e.g. conventional immunomodulators), infliximab itself, or all of these variables. At present, the data do not provide clear evidence for a causal association between infliximab and the increased cancer risk. In appropriately selected patients with severe, refractory Crohn's disease, the benefits of biologic therapy seem to outweigh the cancer risk. Multicenter, case-control studies in large populations, with a long-term follow-up are needed to define the outcome of patients with IBD treated with biologic therapies.
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PMID:Treatment with biologic therapies and the risk of cancer in patients with IBD. 1726 43

The pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) plays a central role in mucosal inflammation and is a key mediator in the inflammatory cascade in both Crohn's disease (CD) and ulcerative colitis (UC). Infliximab, a monoclonal antibody against TNF-alpha has been proved highly effective in the clinical management of both forms of IBD. Aim of this paper is to review the mechanisms of action of infliximab in IBD.
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PMID:Mechanisms of action of infliximab in inflammatory bowel disease: an anti-inflammatory multitasker. 1859 93

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder. According to the Rome III criteria, IBS is defined as recurrent abdominal pain or discomfort for at least 3 d per month during the previous 3 mo associated with two or more of the following symptoms: improvement with defecation, onset associated with a change in the frequency of stool and/or onset associated with a change in form or appearance of stool. There is growing evidence regarding the genetic contribution in IBS, however the precise etiology of IBS is still unknown. The evaluation of the genetic influence is based on twin studies, familial aggregation and genetic epidemiological investigations. Most studies showed a concordance for IBS significantly greater in monozygotic than in dizygotic twins. The majority of the studies have shown that familial aggregation may represent exposures to a similar environment, as well as the influence of genetic factors. Whereas no specific gene has been identified in association with IBS, recent studies have noticed the importance of polymorphisms in the promoter region of the serotonin reuptake transporter gene, G-protein beta 3 subunit gene (C825T), cholecystokinin receptor (CCKAR gene 779T>C), and high-producer tumor necrosis factor genotype. Further studies are necessary to determine how genetic factors influence the clinical manifestations and therapeutical response in IBS patients.
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PMID:Genetic determination of irritable bowel syndrome. 1903 65


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