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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previous retrospective studies of intestinal mucosal mast cells in coeliac disease have given divergent results, and we have recently reported that inappropriate methodology could account for these discrepancies. In this prospective study, mucosal mast cell counts were performed in Carnoy fixed, peroral jejunal biopsy specimens from patients with coeliac disease, both untreated and treated with a gluten-free diet; and from controls (mainly irritable bowel syndrome). Mean mucosal mast cell count in 27 control subjects was 146/mm2, SD 29. Significantly higher values were obtained in untreated coeliac disease (mean 243, SD 41, p less than 0.001) returning to the normal range in coeliacs treated with a gluten-free diet with normal jejunal biopsy morphology. In seven patients mucosal mast cell counts were performed in multiple jejunal biopsies, and these showed that mucosal mast cell distribution was not patchy. There was no evidence of degranulation of intestinal mucosal mast cells under the conditions of routine biopsy (overnight fast). An increase in mucosal mast cells in untreated coeliac disease may be one explanation for the high number of IgE positive stained cells in the intestinal mucosa that has been reported by some authors.
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PMID:Human intestinal mucosal mast cells: expanded population in untreated coeliac disease. 682 6

Despite the progress made in understanding the mechanisms of allergic disease, the pathophysiology and clinical significance of intestinal allergic reactions is largely unclear. The intestinal mucosa is pre-destined for allergic reactions against food proteins and other antigens, and a number of studies indicate that allergic reactions occur in the GI tract. However, only a few epidemiological data are available, and the mechanisms are poorly understood. Intestinal allergic reactions may be different to classical IgE-mediated reactions because patients with intestinal allergy often have negative skin tests and low levels of serum IgE. There is increasing evidence that, as with the findings in the skin and lung, mast cells and eosinophils play a central role in mediating intestinal allergic reactions. Furthermore, both types of cell are found to be activated in a number of other GI inflammatory diseases such as inflammatory bowel disease, celiac disease and eosinophilic gastroenteritis. However, the relationship between these pathologies and intestinal allergy is largely unclear. A major clinical problem is the lack of appropriate means for confirming the diagnosis of intestinal allergy. However, new test systems have been developed--such as the measurement of eosinophil mediators in stool samples or endoscopic provocation tests performed locally at the intestinal mucosa, which may improve the possibility of identifying afflicted patients on an objective basis. Since symptoms of intestinal allergic reactions are variable and non-specific, the diagnosis requires the use of multiple tests and the exclusion of other pathologies such as infectious disease or non-immunological intolerance reactions. The preferred therapeutic option is avoidance of the allergens of relevance; however, this approach can be realized only in some patients, whereas others require additional treatment, for example, with oral cromoglycate or corticosteroids. Although we do not yet know to what extent intestinal allergic reactions may be an aetiological factor in GI diseases, such reactions should be considered in the differential diagnosis of unclear intestinal inflammation and irritable bowel syndrome.
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PMID:Mucosal allergy: role of mast cells and eosinophil granulocytes in the gut. 890 18

The role of allergic reactions in the pathogenesis of inflammatory bowel disease and irritable bowel syndrome has been disputed. This study aimed to determine the prevalence of adverse reactions to food in patients with gastrointestinal disease. A total of 375 adult patients of a gastroenterologic outpatient clinic were examined by history, skin tests, measurements of laboratory parameters, and intestinal provocation with food allergens by colonoscopy. Some 32% complained of adverse reactions to food as a cause of their abdominal symptoms. In 14.4%, the diagnosis of intestinal food allergy could be suspected according to several criteria such as elevated total IgE, specific IgE against food antigens, eosinophilia, responsiveness to cromoglycate, and clinical signs of atopic disease. In 3.2%, the diagnosis could be confirmed by endoscopic allergen provocation and/or elimination diet and rechallenge. In conclusion, the data suggest that allergic reactions to food antigens may be a causative factor in a subgroup of patients with inflammatory and functional gastrointestinal disease.
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PMID:Prevalence of adverse reactions to food in patients with gastrointestinal disease. 894 39

Primary fibromyalgia (PF) has attracted much interest since the 80's. There are many controversies as to whether it is a true disease or not and many studies are carried on. In this study 32 patients which were accepted as PF were examined for some frequent symptoms and allergy and compared with controls. Migraine, irritable bowel syndrome, sleep disturbance and morning stiffness were investigated and found to be 40.6%, 12.5%, 71.9%, 68.8% respectively. Sleep disturbance and morning stiffness showed a positive correlation. Allergy background of PF patients was found frequently when compared with an age and sex matched control group. Though serum IgE levels were found elevated in PF group, they were not statistically significant. Allergic skin tests which could not be performed in the control group, were positive in 10 of 15 PF patients.
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PMID:Primary fibromyalgia and allergy. 913 33

Mast cells are metachromatic cells found widely throughout the body. In gastrointestinal tract they reside particularly in mucosa having close contact with external environment. Their certain role in health and disease remains unclear. Mast cells seem to be involved in lots of allergenic and non-allergenic inflammatory events taking place throughout the gastrointestinal tract including IgE-dependent hypersensitivity reaction, gastritis with or without Helicobacter pylori infection, Crohn's disease, ulcerative colitis, irritable bowel syndrome. Mast cell involvement in certain inflammatory processes in gastrointestinal tract were reviewed.
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PMID:The gastrointestinal mast cell in health and disease. 1069 16

There have frequently been doubts as to the relevance of food allergy, in particular as far as the involvement of the intestinal tract is concerned. Several studies, however, have confirmed the existence of allergic reactions in the gut, with an estimated prevalence of about 1-2% in adults. Clinical symptoms are unspecific and include nausea, vomiting, abdominal pain, cramping and diarrhea. Intestinal mast cells, as well as intestinal eosinophils, have been shown to be involved in the pathogenesis of food-allergy-related enteropathy. In addition to classical IgE-dependent degranulation, further agonists have been demonstrated for mast cell activation, for example IL-4. The methods used to confirm the diagnosis of intestinal allergy are still insufficient. Until now, blinded oral challenge procedures with food antigens have been accepted as the 'gold standard' in diagnosing food allergy, although these tests have practical problems. Therefore, new test systems have been developed, such as endoscopic provocation tests, that may improve diagnostic procedures. Elimination diet still presents the main basis of therapy. Aspects to be focused on in the future are the role fo IgE-independent allergic mechanisms in intestinal allergy, the impact of cross-reactivity with other allergens and the relationship to other inflammatory bowel diseases such as Crohn's disease, ulcerative colitis, celiac disease and irritable bowel syndrome.
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PMID:Allergy and the gut. 1082 17

Irritable bowel syndrome is a common condition but its pathophysiology remains poorly understood. Many irritable bowel syndrome patients give a history of food intolerance, but data from dietary elimination and re-challenge studies are inconclusive. Multiple aetio-pathological mechanisms have been postulated. The gut has an extensive immune system but current understanding of processing of food antigens in health and disease is limited. There is no clinically useful marker available to test for food hypersensitivity in irritable bowel syndrome. Researchers have employed both skin tests and serum immunoglobulins (IgG and IgE) as markers of food hypersensitivity in various disorders including irritable bowel syndrome, but published data are equivocal. In this article, the evidence for the role of food hypersensitivity in irritable bowel syndrome is reviewed and, based on the available data, a possible pathophysiological hypothesis has been formulated.
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PMID:Food hypersensitivity and irritable bowel syndrome. 1128 72

Asthma is a complex disease, with an etiology that includes both genetic and environmental influences that may interact. The moderate heritability of asthma has led researchers to investigate its molecular genetic basis using both exploratory investigations of linkage via genome scans, as well as targeted studies of specific candidate genes. Promising candidate genes include the cytokine genes on chromosome 5q23-31. Both genome scans and association studies of these candidate genes/genomic regions have yielded mixed findings, which raise the possibilities of a true relation that emerges more strongly in certain samples simply due to sampling variability, as well as of genetic heterogeneity. Meta-analytic approaches that combine data across samples and examine how findings may vary as a function of effect modifiers can address both of these possibilities. In this study, we used a meta-analytic approach to examine linkage between the interleukin-9 gene (IL9), one of the cytokine genes located on chromosome 5q31, and asthma diagnoses and serum IgE levels in four samples. We analyzed IBD allele sharing for affected, unaffected, and discordant sib pairs, and as a function of sibling differences in IgE levels. We used a recently developed logistic regression-based method that allows for the inclusion of covariates and/or effect modifiers in the analysis of allele sharing in sib-pairs [Rice et al., Genet Epidemiol 17(Suppl. 1):S691-5, 1999]. Sex of the siblings and transmitting parent were considered both as covariates and effect modifiers in analyses. The results provided little evidence for linkage, or for heterogeneity therein due to sex or transmitting parent, either within or across samples.
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PMID:Meta-analysis of sib pair linkage studies of asthma and the interleukin-9 gene (IL9). 1179 51

Eosinophilic gastroenteritis is a rare gastrointestinal (GI) disorder of undetermined cause characterized by infiltration of eosinophils in the GI tract. Eosinophils accumulate in tissues and may release highly cytotoxic granular proteins, which cause severe tissue damage characteristic of eosinophilic gastroenteritis. Eotaxin may play a role in the recruitment of eosinophils into tissue in combination with chemoattractants and cytokines, including interleukin 3 and 5 and granulocyte-macrophage colony-stimulating factor. Food allergy, especially in children, can be a triggering factor, and an amino acid-based diet may be helpful. Accumulation of eosinophils in the gut is a common feature in food-induced GI disorders that can be regulated through a complex molecular network involving Th2 cells, various cytokines, and chemokines. Eosinophilic gastroenteritis has a wide spectrum of clinical presentation depending on the site of involvement. It may be confused with irritable bowel syndrome or dyspepsia and, rarely, mimics pancreatitis or appendicitis. Diagnosis is important and is usually made by a pathologist. Eosinophilic gastroenteritis is a treatable disease; patients generally respond to steroid therapy, although relapse is common. Non-enteric-coated budesonide, a locally acting corticosteroid with little risk of adrenal suppression, may be substituted, although more experience is needed. Promising new drugs for eosinophilic gastroenteritis include montelukast, a selective leukotriene receptor antagonist, and suplaplast tosilate, a selective Th2 cytokine inhibitor with inhibitory effects on allergy-induced eosinophilic infiltration and IgE production. Although it is likely a separate disease, more experience has accumulated, and an elimination or specific amino acid-based diet appears to be helpful in treatment.
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PMID:Eosinophilic gastroenteritis. 1222 38

A significant proportion of IBS patients attribute their symptoms to adverse food reactions. Dietary elimination and re-challenge studies support the role of diet in the pathogenesis of IBS. The aetiopathogenesis of IBS is thought to be multifactorial involving an interaction between diet, infection, antibiotics and psychosocial factors. Serum IgE and IgG4 antibodies are elevated in food hypersensitivity induced atopic conditions and a similar mechanism has been postulated in IBS. Increased number of mast cells is present in the ileocaecal region of IBS patients. Once sensitized, they are capable of inducing secretory and sensorimotor abnormalities of the gut. The management of IBS is usually aimed at controlling symptoms, however, evaluation of food hypersensitivity may provide a useful adjunct in those with severe symptoms or a clear history of adverse food reaction. There are no well-established tests available but skin prick tests and food specific serum IgG4 and IgE antibodies may help in identifying the offending foods. Other options, which may be explored in individual cases, include sequential dietary exclusion, use of hypoallergenic diets, disodium cromoglycate and novel techniques such as colonoscopic allergen provocation test. Pathophysiology of hypersensitivity induced IBS has been discussed in the light of current data and a management algorithm has been proposed for managing food hypersensitivity in IBS.
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PMID:Role of food hypersensitivity in irritable bowel syndrome. 1241 Jan 72


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