The mast cell stabiliser ketotifen decreases visceral hypersensitivity and improves intestinal symptoms in patients with irritable bowel syndrome Klooker, T.K.; Braak, B.; Koopman, K.E.; Welting, O.; Wouters, M.M.; van der Heide, S.; Schemann, M.; Bischoff, S.C.; van den Wijngaard, R.M.; Boeckxstaens, G.E. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Download date: 10 May 2018The mast cell stabiliser ketotifen decreases visceral hypersensitivity and improves intestinal symptoms in patients with irritable bowel syndrome

BackgroundObesity is a result of a relative excess in energy intake over energy expenditure. These processes are controlled by genetic, environmental, psychological and biological factors. One of the factors involved in the regulation of food intake and satiety is dopaminergic signalling. A small number of studies have reported that striatal dopamine D2/D3 receptor [D2/3R] availability is lower in morbidly obese subjects.MethodsTo confirm the role of D2/3R in obesity, we measured striatal D2/3R availability, using [123I]IBZM SPECT, in 15 obese women and 15 non-obese controls.ResultsStriatal D2/3R availability was 23% (p = 0.028) lower in obese compared with non-obese women.ConclusionThis study is an independent replication of the finding that severely obese subjects have lower striatal D2/3R availability. Our findings invigorate the evidence for lower striatal D2/3R availability in obesity and confirm the role of the striatal dopaminergic reward system in obesity.

Although the number of mast cells, macrophages, T cells, and λFLC-positive mast cells is decreased in IBS compared with HV, this is not associated with the presence of visceral hypersensitivity or abnormal stress response. Our data question the role of microscopic inflammation as an underlying mechanism of visceral hypersensitivity, but rather suggest dysregulation of the mucosal immune system in IBS.

SUMMARY BackgroundFunctional dyspepsia is one of the most prevalent (15-40%) functional gastrointestinal disorders. Antidepressants such as amitriptyline are often used in these patients, but clinical studies are currently lacking.

Our data indicate that exposure to severe wartime conditions in early life is associated with an increased risk of developing IBS. To what extent this is attributable to the stressful environment of war, to severe undernutrition, or to the increased prevalence of infectious diseases is, however, unclear.

Background & aimsThe causes of gastrointestinal complaints in irritable bowel syndrome (IBS) remain poorly understood. Altered nerve function has emerged as an important pathogenic factor as IBS mucosal biopsy supernatants consistently activate enteric and sensory neurons. We investigated the neurally active molecular components of such supernatants from patients with IBS and quiescent ulcerative colitis (UC).MethodEffects of supernatants from 7 healthy controls (HC), 20 IBS and 12 UC patients on human and guinea pig submucous neurons were studied with neuroimaging techniques. We identify differentially expressed proteins with proteome analysis.ResultsNerve activation by IBS supernatants was prevented by the protease activated receptor 1 (PAR1) antagonist SCHE79797. UC supernatants also activated enteric neurons through protease dependent mechanisms but without PAR1 involvement. Proteome analysis of the supernatants identified 204 proteins, among them 17 proteases as differentially expressed between IBS, UC and HC. Of those the four proteases elastase 3a, chymotrypsin C, proteasome subunit type beta-2 and an unspecified isoform of complement C3 were significantly more abundant in IBS compared to HC and UC supernatants. Of eight proteases, which were upregulated in IBS, the combination of elastase 3a, cathepsin L and proteasome alpha subunit-4 showed the highest prediction accuracy of 98% to discriminate between IBS and HC groups. Elastase synergistically potentiated the effects of histamine and serotonin–the two other main neuroactive substances in the IBS supernatants. A serine protease inhibitor isolated from the probiotic Bifidobacterium longum NCC2705 (SERPINBL), known to inhibit elastase-like proteases, prevented nerve activation by IBS supernatants.ConclusionProteases in IBS and UC supernatants were responsible for nerve activation. Our data demonstrate that proteases, particularly those signalling through neuronal PAR1, are biomarker candidates for IBS, and protease profiling may be used to characterise IBS.

New Findings r What is the central question of this study?Supernatants from colonic mucosal biopsies from patients with irritable bowel syndrome (IBS) activate enteric and dorsal root ganglion (DRG) neurons. Based on the discomfort/pain threshold during rectal distension, IBS patients may be subtyped as normo-or hypersensitive. However, the link between neuronal activation and visceral sensitivity remains unknown. r What is the main finding and its importance?We found that supernatants from hypersensitive IBS patients caused stronger activation of enteric and DRG neurons than supernatants from normosensitive IBS patients. The level of activation correlated with the individual discomfort/pain threshold pressure values. We therefore conclude that mucosal biopsy supernatants have biomarker potential and may, in the future, help to personalize treatment of IBS patients with different visceral sensitivities.Based on the discomfort/pain threshold during rectal distension, irritable bowel syndrome (IBS) patients may be subtyped as normo-or hypersensitive. We previously showed that mucosal biopsy supernatants from IBS patients activated enteric and visceral afferent neurons. We tested the hypothesis that visceral sensitivity is linked to the degree of neuronal activation. Normo-and hypersensitive IBS patients were distinguished by their discomfort/pain threshold to rectal balloon distension with a barostat. Using potentiometric and Ca 2+ dye imaging, we recorded the response of guinea-pig enteric submucous and mouse dorsal root ganglion (DRG) neurons, respectively, to mucosal biopsy supernatants from normosensitive (n = 12 tested in enteric neurons, n = 9 tested in DRG) and hypersensitive IBS patients (n = 9, tested in both

ObjectivesTo examine general practitioners’ (GP) management of cholecystolithiasis and to evaluate persisting abdominal complaints in the years after the diagnosis.DesignRetrospective analysis of registry data and a subset of individual medical records.SettingSeventeen primary care practices affiliated with the Radboudumc Practice Based Research Network in the Netherlands.Participants633 patients with cholecystolithiasis diagnosed between 2012 and 2016.Primary and secondary outcome measuresThe primary outcome of this study was the healthcare utilisation of patients with cholecystolithiasis diagnosed by the GP in terms of referrals to secondary care, laboratory diagnostics, prescribed medication and the prevalence of concomitant abdominal-related diagnoses in a time interval of 3 years before and 3 years after diagnosis of cholecystolithiasis. For secondary outcomes, electronic medical records were studied from seven practices to assess emergency department visits, operation rates and repeat visits for persistent abdominal symptoms. We compared the non-referred group with the referred group.ResultsIn 57% of patients, concomitant abdominal-related diagnoses were recorded besides the diagnosis cholecystolithiasis. In-depth analyses of 294 patients showed a referral rate of 79.3% (n=233); 62.9% (n=185) underwent cholecystectomy. After referral, 55.4% (129/233) returned to the GP for persistent abdominal symptoms. Patients returning after referral were more often treated for another abdominal-related diagnosis before cholecystolithiasis was recorded (51.9% vs 28.8%, p<0.001).ConclusionsThe majority of patients in general practice with gallstones are referred and undergo cholecystectomy. Patients with concomitant abdominal-related diagnoses are likely to return to their physician. GPs should inform patients about these outcomes to improve the shared decision-making process before gallbladder surgery.