Prospective multicentre clinical study on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori.

OBJECTIVES: We report on a large prospective, multicentre clinical investigation on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori. METHODS: Therapy-naive patients (n = 2004) who had undergone routine diagnostic gastroscopy were prospectively included from all geographic regions of Austria. Gastric biopsy samples were collected separately from antrum and corpus. Samples were analysed by histopathology and real-time PCR for genotypic resistance to clarithromycin and quinolones. Clinical and demographic information was analysed in relation to resistance patterns. RESULTS: H. pylori infection was detected in 514 (26%) of 2004 patients by histopathology and confirmed in 465 (90%) of 514 patients by real-time PCR. PCR results were discordant for antrum and corpus in 27 (5%) of 514 patients, indicating inhomogeneous infections. Clarithromycin resistance rates were 17% (77/448) and 19% (84/455), and quinolone resistance rates were 12% (37/310) and 10% (32/334) in antrum and corpus samples, respectively. Combination of test results per patient yielded resistance rates of 21% (98/465) and 13% (50/383) for clarithromycin and quinolones, respectively. Overall, infection with both sensitive and resistant H. pylori was detected in 65 (14%) of 465 patients. CONCLUSIONS: Anatomically inhomogeneous infection with different, multiple H. pylori strains is common. Prospective clinical study design, collection of samples from multiple sites and microbiologic methods that allow the detection of coinfections are mandatory for collection of reliable data on antimicrobial resistance patterns in representative patient populations. (ClinicalTrials.gov identifier: NCT02925091).

The impact of prolonged strenuous endurance exercise on interleukin 18 and interleukin 18 binding protein in recreational cyclists.

Interleukin 18 (IL-18) is an important pro-inflammatory cytokine in the early phase of human immune response to microbial infections. The influence of strenuous exercise on the intrinsic balance of IL-18 and its endogenous antagonist IL-18 binding protein (IL-18 BP) is unknown, but could be of major relevance for the athlete's immune function empirically and epidemiologically proven to be altered after exhaustive exertion. To study the effect of strenuous marathon cycling on the interaction of IL-18 and IL-18 BP we investigated 37 male, healthy, and well-trained amateur cyclists participating in the Otztaler Radmarathon in Tyrol (distance: 230 km; cumulative altitude difference: 5500 m). IL-18 was measured by a commercially available ELISA-Kit and IL-18 BP by a novel IL-18 BP ELISA method. Free, unbound IL-18 was calculated according to a standard equation. The mean plasma level of IL-18 was 142.27 +/- 21.85 pg/ml pre-race, remained nearly unchanged (124.35 +/- 13.16 pg/ml; p = 1.0) immediately after competition (mean race time 9 h 38 min), but declined significantly 24 h afterward (62.92 +/- 6.80 pg/ml; p = 0.002). The plasma levels of IL-18 BP increased considerably immediately after and kept on rising for the following 24 h (pre-race: 1.51 +/- 0.20 ng/ml; immediately post-race: 3.84 +/- 0.26 ng/ml, p < 0.001; 24 h post-race: 4.33 +/- 0.42 ng/ml, p < 0.001). Therefore, the calculated free IL-18 was 122.06 +/- 16.79 pg/ml pre-race, declined to 82.86 +/- 8.59 (p = 0.05) immediately post-race and to 39.17 +/- 3.76 pg/ml 24 h post-race (p < 0.001). The respective percentages of this post-exercise reduction in free IL-18 plasma levels were 32 % and 68 %. The present study reveals an exercise-induced significant decline in free IL-18 accompanied by an immediate up-regulation of IL-18 BP and decreased IL-18 in marathon cyclists. This down-regulation of free IL-18 may (i) limit the magnitude and duration of a too excessive inflammatory response to the exercise-induced tissue damage and (ii) on the other hand contribute to the elevated susceptibility to infection in athletes undergoing exhaustive exercise.

Circulating adiponectin reflects severity of liver disease but not insulin sensitivity in liver cirrhosis.

BACKGROUND: The adipocytokine adiponectin has been proposed to play important roles in the regulation of energy homeostasis, insulin sensitivity and shows anti-inflammatory properties. AIM: In this study we investigated the role of circulating adiponectin in different chronic liver diseases, its regulation by systemic anti-tumour necrosis factor (TNF)-alpha treatment and its hepatic metabolism. PATIENTS AND METHODS: Plasma adiponectin levels were determined in 87 patients with liver cirrhosis of different aetiologies, seven patients with alcoholic steatohepatitis undergoing systemic anti-TNF-alpha treatment, in 11 patients with liver cirrhosis receiving transjugular intrahepatic portosystemic shunt implantation and in 21 healthy controls. RESULTS: Adiponectin levels were significantly higher in all subjects with liver cirrhosis of different aetiologies when compared with healthy controls and increased dependent on Child-Pugh classification. In subjects with alcoholic steatohepatitis, systemic anti-TNF-alpha treatment caused a significant decrease in circulating adiponectin. Adiponectin concentrations were similar in portal, hepatic and peripheral veins. No correlation between adiponectin levels and insulin resistance was found in any patient group. CONCLUSIONS: Our data suggest that circulating adiponectin is increased in liver cirrhosis independent of the aetiology of liver disease. We suggest that high adiponectin levels in chronic liver disease might reflect one of the body's anti-inflammatory mechanisms in chronic liver diseases.

The RANKL/OPG system is activated in inflammatory bowel disease and relates to the state of bone loss.

BACKGROUND AND AIMS: A substantial proportion of patients with inflammatory bowel disease (IBD) develops osteopenia and osteoporosis in the course of disease. Recent data from a mouse model of colitis suggest that the receptor activator of nuclear factor kappa B (RANKL)/osteoprotegerin (OPG) system may be responsible for bone loss. METHODS: We investigated the activation state of the RANKL/OPG system and its association with bone loss in human IBD. Plasma levels of OPG and RANKL were correlated with bone mineral density and current IBD therapy. Colonic secretion of OPG and RANKL and cell types responsible for such secretion were determined. RESULTS: OPG plasma levels were elevated 2.4-fold in Crohn's disease (CD) and 1.9-fold in ulcerative colitis (UC) whereas soluble RANKL (sRANKL) levels were not significantly different in IBD patients compared with healthy controls. High levels of OPG were released from colonic explant cultures (CEC) derived from inflamed IBD specimens, and colonic macrophages and dendritic cells costained for OPG. sRANKL levels from CEC were low both in IBD patients and healthy controls. Interestingly, increased expression of RANKL was mainly confined to cells in the lamina muscularis. A significant negative correlation was found between OPG plasma levels and femoral neck/lumbar spine bone mineral density. CONCLUSIONS: We have demonstrated that IBD is associated with alterations in the RANKL/OPG system. Applying results from a murine model of colitis associated bone loss, the constellation of OPG and sRANKL regulation observed in our study raises the possibility that RANKL/OPG may contribute to the development of bone loss in IBD.

Imbalance between interleukin-1 agonists and antagonists: relationship to severity of inflammatory bowel disease.

Interleukin (IL)-1 is a key mediator in the pathogenesis of inflammatory bowel disease (IBD). Naturally occurring IL-1 modulators include IL-1 receptor antagonist (IL-1Ra), IL-1 soluble receptor Type I (IL-1sRI), IL-1sRII and IL-1 receptor accessory protein (AcP). Systemic and mucosal levels of IL-1 soluble receptors remain unknown in IBD. Plasma or colonic tissues were obtained from 185 consecutive unselected patients with Crohn's disease (CD) or ulcerative colitis (UC) and from 52 control subjects. Plasma and colonic explant culture supernatants were assessed for IL-1alpha, IL-1beta, IL-1Ra, IL-1sRI and IL-1sRII. Plasma IL-1Ra levels were higher in UC (+93%) than in healthy subjects. IL-1alpha and IL-1beta were not detected. IL-1sRII levels were marginally lower in CD (-10%) and UC (-9%), whereas IL-1sRI levels were elevated in CD (+28%) only. Plasma IL-1sRI levels correlated positively (P < 0.01) with Crohn's disease activity index (r = 0.53), C-reactive protein (r = 0.46) and alpha1-acid glycoprotein (r = 0.42). In colonic explant cultures, IL-1alpha and IL-1Ra levels were elevated in non-lesional (+233% and +185% respectively) and lesional CD (+353% and +1069%), lesional UC (+604% and +1138%), but not in non-lesional UC. IL-1beta was elevated in lesional UC (+152%) and CD (+128%). In contrast, IL-1sRII levels were elevated in non-lesional CD (+65%), but remained unchanged in lesional CD, non-lesional and lesional UC. IL-1sRI levels did not differ between patient and control groups. These results indicate that (i) the proinflammatory moiety IL-1sRI is a systemic marker of inflammation and activity in CD and (ii) local shedding of the functional antagonist IL-1sRII may dampen colonic inflammation in CD, but not in UC.

A randomised placebo controlled trial of pegylated interferon alpha in active ulcerative colitis.

BACKGROUND: Pilot studies of interferon alpha (IFN-alpha) suggest a high remission rate in the treatment of active ulcerative colitis. We evaluated the safety of pegylated interferon alpha (PegIFN) and its role in induction of remission in patients with active ulcerative colitis, in a multicentre placebo controlled trial. METHODS: Sixty patients with a clinical activity score (CAI) of >6 were randomised to receive placebo (n=20), PegIFN 0.5 microg/kg (n=19), or PegIFN 1.0 microg/kg body weight (n=21) once weekly (PegIntron; Schering-Plough, USA) over 12 weeks. Patients receiving 5-aminosalicylates, steroids, and/or azathioprine in stable dosages were included. RESULTS: Serious adverse events were seen in none of the placebo patients, in 3/19 patients in the PegIFN 0.5 microg/kg group (hospitalisation due to disease flare up n=3), and in 3/21 in the PegIFN 1.0 microg/kg group (hospitalisation due to disease flare up n=1; thrombosis n=1; grand mal seizure n=1). Otherwise, we observed only minor IFN-alpha side effects. Clinical remission rates at week 12 (CAI < or =4) were 7/20 (35%) in the placebo, 9/19 (47%) in the PegIFN 0.5 microg/kg group, and 7/21 (33%) in the PegIFN 1.0 microg/kg group (NS). Early withdrawal from the study was observed in 11/20 placebo patients, in 6/19 in the PegIFN 0.5 microg/kg group, and in 10/21 in the PegIFN 1.0 microg/kg group, mainly due to lack of efficacy. The higher PegIFN dose was associated with a significant decrease in levels of C reactive protein (p=0.003, day 0 v 85). CONCLUSIONS: PegIFN is safe but not effective, at the dosages used, in patients with ulcerative colitis.

Plasma levels of soluble CD40 ligand are elevated in inflammatory bowel diseases.

BACKGROUND AND AIMS: CD40/CD40 ligand (CD40L) interaction is important for induction of T cell dependent antibody production and cell-mediated immune responses. Overexpression of CD40/CD40L in the intestinal mucosa is likely to be involved in the pathogenesis of inflammatory bowel disease (IBD). A soluble form of CD40L (sCD40L) exists in the circulation. This study investigated whether plasma levels of sCD40L are higher in patients with IBD than in healthy controls. PATIENTS AND METHODS: Plasma levels of sCD40L were measured in 89 patients with Crohn's disease (CD), 56 patients with ulcerative colitis (UC), 17 patients with infectious diarrhea, and 42 healthy controls, using a specific enzyme-linked immunosorbent assay. RESULTS: In CD patients plasma levels of sCD40L were significantly higher than in healthy controls. Patients with UC and infectious diarrhea had higher sCD40L levels than healthy controls, but the differences were not significant. CD patients with fistulas and/or abscesses (n=38) had significantly higher levels of sCD40L than patients with uncomplicated CD (n=51). Only in patients with uncomplicated CD plasma levels of sCD40L correlated significantly with C-reactive protein and alpha(1)-glycoprotein. In UC patients there was a significant correlation of sCD40L with C-reactive protein. However, there was no significant correlation between plasma sCD40L levels and Crohn's disease activity index or Rachmilewitz score. CONCLUSION: Elevated plasma levels of sCD40L in CD patients supposedly reflect activation of functional CD40L in the intestine and might be a marker of intestinal inflammation.

Treatment of Crohn's disease with recombinant human interleukin 10 induces the proinflammatory cytokine interferon gamma.

BACKGROUND: Interleukin 10 (IL-10) exerts anti-inflammatory actions by counteracting many biological effects of interferon gamma (IFN-gamma). AIMS: To investigate this in humans, we studied the effects of human recombinant IL-10 administration on IFN-gamma production by patient leucocytes. Furthermore, we assessed the IFN-gamma inducible molecule neopterin and nitrite/nitrate serum levels, which are indicative of endogenous nitric oxide formation. METHODS: As part of two placebo controlled double blind studies, we analysed patients with chronic active Crohn's disease (CACD) who received either subcutaneous recombinant human IL-10 (n=44) or placebo (n=10) daily for 28 days, and patients with mild to moderate Crohn's disease (MCD) treated with either subcutaneous IL-10 (n=52) or placebo (n=16) daily for 28 days. Neopterin and nitrite/nitrate concentrations were measured in serum, and ex vivo IFN-gamma formation by lipopolysaccharide or phytohaemagglutinin (PHA) stimulated whole blood cells were investigated before, during, and after IL-10 therapy. RESULTS: In patients with CACD, the highest dose of 20 microg/kg IL-10 caused a significant increase in serum neopterin on days +15 and +29 of therapy compared with pretreatment levels. No changes were observed for nitrite/nitrate levels under either condition. In MCD, treatment with 20 microg/kg IL-10 resulted in a significant increase in PHA induced IFN-gamma production. CONCLUSIONS: High doses of IL-10 upregulate the production of IFN-gamma and neopterin. This phenomenon may be responsible for the lack of efficacy of high doses of IL-10 in the treatment of CACD and MCD.

Interleukin-6 stimulates thrombopoiesis through thrombopoietin: role in inflammatory thrombocytosis.

Baseline platelet production is dependent on thrombopoietin (TPO). TPO is constitutively produced and primarily regulated by receptor-mediated uptake by platelets. Inflammatory thrombocytosis is thought to be related to increased interleukin-6 (IL-6) levels. To address whether IL-6 might act through TPO to increase platelet counts, TPO was neutralized in vivo in C57BL/10 mice treated with IL-6, and hepatic TPO mRNA expression and TPO plasma levels were studied. Transcriptional regulation of TPO mRNA was studied in the hepatoblastoma cell line HepG2. Furthermore, TPO plasma levels were determined in IL-6-treated cancer patients. It is shown that IL-6-induced thrombocytosis in C57BL/10 mice is accompanied by enhanced hepatic TPO mRNA expression and elevated TPO plasma levels. Administration of IL-6 to cancer patients results in a corresponding increase in TPO plasma levels. IL-6 enhances TPO mRNA transcription in HepG2 cells. IL-6-induced thrombocytosis can be abrogated by neutralization of TPO, suggesting that IL-6 induces thrombocytosis through TPO. A novel pathway of TPO regulation by the inflammatory mediator IL-6 is proposed, indicating that the number of platelets by themselves might not be the sole determinant of circulating TPO levels and thus of thrombopoiesis. This regulatory pathway might be of relevance for the understanding of reactive thrombocytosis.

Activation of caspase-3 by interferon alpha causes interleukin-16 secretion but fails to modulate activation induced cell death.

Interferon alpha (IFN-alpha) is the mainstay in the treatment of chronic hepatitis C virus (HCV) infection. Interleukin-16 (IL-16) attracts CD4+ cells to sites of inflammation and plays a role in the interaction of dendritic cells, T cells and B cells. In this study, we show that IFN-alpha itself induces IL-16 secretion by peripheral blood lymphocytes (PBL) and enhances IL-16 secretion by anti-CD3 stimulated PBL. Pro-IL-16 is cleaved into its active form by caspase-3. IFN-alpha increases caspase-3 mRNA levels in activated T cells (ATC), as shown by Northern blot analysis, whereas IL-16 mRNA levels are not affected by IFN-alpha. IL-16 secretion into culture supernatants correlates tightly with intracellular caspase-3 activity in ATC. In our experiments addition of specific caspase inhibitors did not reduce the proportion of ATC undergoing Fas-mediated cell death, but completely blocked IFN-alpha-induced IL-16 secretion into culture supernatants. In conclusion, our results suggest that IFN-alpha activates caspase-3, thereby increasing secretion of IL-16, whereas IFN-alpha-enhanced Fas-mediated cell death in ATC is not caspase-dependent.

B lymphocyte-derived IL-16 attracts dendritic cells and Th cells.

Interaction of B lymphocytes with Th cells is a fundamental step in the establishment of humoral immunity, and recent evidence suggests that direct interaction between B lymphocytes and dendritic cells (DCs) is also an important prerequisite. Factors involved in the selective recruitment of Th cells and DCs by B lymphocytes are insufficiently defined. We set out to delineate the role of IL-16, the soluble ligand of CD4, which is expressed on Th cells and DCs. B lymphocytes express IL-16 mRNA and synthesize bioactive IL-16 protein, and IL-16 is expressed in lymph node follicles in situ. B lymphocyte supernatant efficiently induces migration of CD4+ Th cells, monocyte-derived DCs, and circulating blood DCs in nitrocellulose filter-based assays. Neutralization of IL-16 bioactivity strongly inhibits this migratory response, suggesting that IL-16 might be a major chemotactic factor derived from B cells. The present data further support the idea that IL-16 might have a role in the initiation of cellular as well as humoral immunity by mediating the cellular cross-talk among T lymphocytes, B cells, and DCs, leading to recruitment of these cell types at common anatomical sites.

Interferon-alpha (IFN-alpha) enhances cytotoxicity in healthy volunteers and chronic hepatitis C infection mainly by the perforin pathway.

Cell-mediated cytotoxicity is exerted via perforin and Fas ligand (FasL). We have recently shown that IFN-alpha up-regulates FasL expression in T cells isolated from healthy volunteers and augments activation-induced T cell death. Since the Fas/FasL system is implicated in the pathogenesis of hepatic failure and both molecules have been shown to be up-regulated in hepatitis C virus (HCV) infection, we studied whether cytotoxicity via the FasL system is enhanced by IFN-alpha and therefore could contribute to hepatic injury. We investigated FasL and perforin expression in peripheral blood mononuclear cells (PBMC) derived from HCV+ donors by Northern analysis and soluble FasL synthesis by ELISA. Natural killer (NK) cell and cytotoxic T lymphocyte (CTL) cytotoxicity was studied by 51Cr-release assays. IFN-alpha up-regulates FasL mRNA and protein synthesis in mitogen-activated PBMC of HCV+ individuals, as previously found in healthy subjects. Stimulation with IFN-alpha increases perforin mRNA levels in PBMC. In NK cytotoxicity assays, the enhancement of cytotoxicity by IFN-alpha is mainly due to the perforin pathway, while the FasL pathway plays only a minor role. In CTL cytotoxicity experiments neither the FasL nor the perforin pathway is further enhanced by IFN-alpha. Our data suggest that up-regulation of perforin by IFN-alpha results in elevated cytotoxicity, suggesting that IFN-alpha might support elimination of virally infected cells via this pathway. In contrast, the major effect of IFN-alpha on the Fas/FasL system might be the enhanced elimination of activated T cells as a means of finally limiting a T cell response.