Immune activation in patients with irritable bowel syndrome.
ABSTRACT We set out to test the hypothesis that irritable bowel syndrome (IBS) is characterized by an augmented cellular immune response with enhanced production of proinflammatory cytokines. We further aimed to explore whether symptoms and psychiatric comorbidity in IBS are linked to the release of proinflammatory cytokines.
We characterized basal and Escherichia coli lipopolysaccharide (LPS)-induced cytokine production in peripheral blood mononuclear cells (PBMCs) from 55 IBS patients (18 mixed-, 17 constipation-, 20 diarrhea-predominant) and 36 healthy controls (HCs). PBMCs were isolated by density gradient centrifugation and cultured for 24 hours with or without (1 ng/mL) LPS. Cytokine production (tumor necrosis factor [TNF]-alpha, interleukin [IL]-1beta, and IL-6) was measured by enzyme-linked immunosorbent assay. Abdominal symptoms and psychiatric comorbidities were assessed by using the validated Bowel Disease Questionnaire and the Hospital Anxiety and Depression Scale.
IBS patients showed significantly (P < .017) higher baseline TNF-alpha, IL-1beta, IL-6, and LPS-induced IL-6 levels compared with HCs. Analyzing IBS subgroups, all cytokine levels were significantly (P < .05) higher in diarrhea-predominant IBS (D-IBS) patients, whereas constipation-predominant IBS patients showed increased LPS-induced IL-1beta levels compared with HCs. Baseline TNF-alpha and LPS-induced TNF-alpha and IL-6 levels were significantly higher in patients reporting more than 3 bowel movements per day, urgency, watery stools, and pain associated with diarrhea compared with patients without these symptoms (all P < .05). LPS-induced TNF-alpha production was associated significantly (r = 0.59, P < .001) with anxiety in patients with IBS.
Patients with D-IBS display enhanced proinflammatory cytokine release, and this may be associated with symptoms and anxiety.
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ABSTRACT: Acute phase proteins, synovial fluid (SF) cellular infiltrates, pro-inflammatory (TNF-alpha, IL-1alpha, IL-6) and Th1 (IL-2) and Th2 (IL-4) derived cytokine levels both in plasma and SF were examined in pauciarticular and polyarticular juvenile chronic arthritis (JCA) patients during the active (n = 22) and inactive (n = 14) period in order to determine pathogenic mechanisms and correlations between cytokines and laboratory parameters showing disease activity. The erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP) and IgG concentrations were found to be significantly elevated in the active period of JCA. In pauciarticular JCA patients, when compared with their peripheral blood lymphocyte subpopulations, SF CD3+ cells (73.1%) and HLA-DR+ active T cells (22.5%) were found to be significantly increased. In the active period of JCA, plasma TNF-alpha and IL-6 concentrations were significantly elevated. Plasma IL-2 and IL-4 levels were not elevated and were found to be similar to those in the inactive phase and in healthy controls. SF IL-6, TNF-alpha and IL-1alpha levels were extremely high in all the patients. SF IL-4 and IL-2 levels were all undetectable. There was a significant correlation between ESR values and plasma IL-6 levels and between serum CRP levels and plasma IL-6 and TNF-alpha concentrations. In conclusion, increased local production of pro-inflammatory cytokines appears to account for the articular manifestations of JCA. The impaired production of anti-inflammatory Th2-derived cytokines (IL-4) seems to cause increased production of inflammatory cytokines acting on the balance between them. The deficit in IL-2 production was not suggested to be primarily involved in the pathogenesis. In addition, not only CRP and ESR values, but also plasma IL-6 and TNF-alpha concentrations may be used as markers of disease activity.Clinical Rheumatology 02/1998; 17(4):288-92. · 2.04 Impact Factor
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ABSTRACT: Background and aims: Chronic bowel disturbances resembling irritable bowel syndrome (IBS) develop in approximately 25% of patients after an episode of infectious diarrhoea. Although we have previously shown that psychosocial factors operating at the time of, or prior to, the acute illness appear to predict the development of post-infectious IBS (PI-IBS), our finding of an increased inflammatory cell number in the rectum persisting for at least three months after the acute infection suggested that there is also an organic component involved in the development of PI-IBS. To evaluate this further, we measured expressions of interleukin 1beta (IL-1beta) and its receptor antagonist (IL-1ra) in these patients to provide additional evidence that the pathogenesis of PI-IBS is underpinned by an inflammatory process. Sequential rectal biopsy samples were prospectively obtained during and three months after acute gastroenteritis, from eight patients who developed post-infectious IBS (INF-IBS) and seven patients who returned to normal bowel habits after acute gastroenteritis (infection controls, INF-CON). Eighteen healthy volunteers who had not suffered from gastroenteritis in the preceding two years served as normal controls (NOR-CON). IL-1beta and IL-1ra gene expressions were assayed by reverse transcriptase-polymerase chain reaction, and their levels of expression were quantitated by optical densitometry after electrophoresis on agarose gel. INF-IBS patients exhibited significantly greater expression of IL-1beta mRNA in rectal biopsies than INF-CON patients both during and three months after acute gastroenteritis. Moreover, IL-1beta mRNA expression had increased in biopsies taken from INF-IBS patients at three months after the acute infection but no consistent change was observed in INF-CON patients. IL-1beta mRNA expression of INF-IBS patients at three months post gastroenteritis was significantly greater than NOR-CON whereas that of INF-CON patients was not significantly different from NOR-CON. Despite these differential changes in IL-1beta mRNA expression, no significant changes were observed in IL-1ra mRNA expression among the three groups. These findings indicate that those patients who develop IBS post infection exhibit greater IL-1beta mRNA expression, both during and after the infection, compared with individuals who do not develop PI-IBS. We conclude that such patients may be susceptible to inflammatory stimuli, and that inflammation may play a role in the pathogenesis of PI-IBS.Gut 05/2003; 52(4):523-6. · 10.73 Impact Factor
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ABSTRACT: Interleukin-6 (IL-6) has a major function in the regulation of the inflammatory process. We aimed to define its role as a parameter of disease activity and extent in inflammatory bowel disease. Serum concentrations of IL-6 were measured in 28 patients with Crohn's disease (CD) and in 15 with ulcerative colitis (UC) before starting corticosteroid treatment. Disease activity was measured by standard activity indexes. Serum IL-6 levels were increased in patients with CD (36 +/- 8 pg/ml; p < 0.001) and UC (10 +/- 4 pg/ml; p < 0.05) as compared with 25 control patients. A significant correlation between serum IL-6 concentrations and disease activity was found in patients with CD as well as in patients with UC (active CD: 73 +/- 14 pg/ml, inactive disease: < 10 pg/ml, p = 0.003; active UC: 26 +/- 10 pg/ml, inactive disease: < 10 pg/ml, p = 0.004). IL-6 serum levels were related to the acute-phase reactant c-reactive protein (r = 0.51, p < 0.01) in CD patients. The serum IL-6 concentrations were more pronounced in CD of the colon than in disease limited to the small bowel (p < 0.05). In patients with CD as well as in patients with UC, IL-6 serum concentrations showed a higher sensitivity for disease activity (94 and 83%) than serum c-reactive protein levels. In patients without corticosteroid treatment, the IL-6 serum concentration is related to disease activity in CD as well as UC. Serum IL-6 levels show a higher correlation with disease activity than c-reactive protein levels.Journal of Clinical Gastroenterology 03/1995; 20(2):123-6. · 3.20 Impact Factor