BACKGROUND & AIMS:The lectin pathway of complement activation is a crucial effector cascade of the innate immune response to pathogens. Cytomegalovirus (CMV) infection occurs frequently in... Show moreBACKGROUND & AIMS:The lectin pathway of complement activation is a crucial effector cascade of the innate immune response to pathogens. Cytomegalovirus (CMV) infection occurs frequently in immunocompromised patients after orthotopic liver transplantation (OLT). Single-nucleotide polymorphisms (SNPs) in the lectin pathway genes determine their liver-derived protein level and functional activity. We examined the association between these SNPs and the risk for CMV infection in OLT. METHODS:OLT patients (n = 295) were genotyped for recipient and donor SNPs in mannose-binding lectin (MBL2), Ficolin-2 (FCN2) and MBL-associated serine protease (MASP2) genes. RESULTS:Combined analysis of independently associated variant MBL2 [HR 1.65, p<0.02] and wild-type FCN2 [1.85; p<0.02] SNPs in the donor liver showed an increased risk of CMV infection for either and both risk genotypes [HR 2.02 and HR 3.26, respectively, p = 0.004], especially in CMV Donor-/Recipient+ (D-/R+) patients [HR 4.7 and HR 10.0, respectively, p = 0.01]. A genetic donor-recipient mismatch for MBL2 and FCN2 increased the CMV risk independently, also combined [HR 5.35; p<0.001], particularly in CMV D-/R+ patients [HR 16.6; p = 0.009]. Multivariate Cox analysis showed a consistent stepwise increase in CMV infection risk with the gene profile of the donor [up to HR 2.77; p<0.005] and the combined MBL2 and FCN2 donor-recipient mismatch profile [up to HR 4.57; p<0.001], independent from donor-recipient CMV serostatus, also at higher CMV (re)infection cut-off values. CONCLUSIONS:MBL2 and FCN2 risk alleles of donor liver and recipient constitute independent risk factors for CMV infection after OLT. Patients with these risk genes probably need intensified CMV monitoring and anti-viral therapy. Show less
Inflammatory bowel diseases, Crohn's disease and ulcerative colitis, are associated with a variety of extraintestinal manifestations. The most common extraintestinal manifestation, articular... Show moreInflammatory bowel diseases, Crohn's disease and ulcerative colitis, are associated with a variety of extraintestinal manifestations. The most common extraintestinal manifestation, articular involvement, occurs in 16% to 33% of inflammatory bowel disease patients. These arthropathies may increase morbidity, resulting in a worse quality of life compared with inflammatory bowel disease patients without arthropathies. Thus, arthropathies in inflammatory bowel diseases represent a major medical problem in these patients. Arthritis associated with inflammatory bowel diseases is one of the diseases captured under the umbrella of spondyloarthritis. Spondyloarthritis is a group of inflammatory diseases with overlapping features and is linked to Human Leukocyte Antigen-B27. Arthropathy in inflammatory bowel diseases is clinically divided into peripheral and axial involvement. Peripheral arthritis often flares with relapses of bowel disease resulting in a different treatment approach than axial arthritis in which the course is independent of inflammatory bowel disease activity. Definitions, prevalence, pathophysiology and treatment of the arthropathies commonly seen in inflammatory bowel diseases such as peripheral arthritis, dactylitis, enthesitis, arthralgia, sacroiliitis, inflammatory back pain and ankylosing spondylitis are summarized. Show less
Inflammatory bowel diseases, Crohn's disease and ulcerative colitis, are associated with a variety of extraintestinal manifestations. The most common extraintestinal manifestation, articular... Show moreInflammatory bowel diseases, Crohn's disease and ulcerative colitis, are associated with a variety of extraintestinal manifestations. The most common extraintestinal manifestation, articular involvement, occurs in 16% to 33% of inflammatory bowel disease patients. These arthropathies may increase morbidity, resulting in a worse quality of life compared with inflammatory bowel disease patients without arthropathies. Thus, arthropathies in inflammatory bowel diseases represent a major medical problem in these patients. Arthritis associated with inflammatory bowel diseases is one of the diseases captured under the umbrella of spondyloarthritis. Spondyloarthritis is a group of inflammatory diseases with overlapping features and is linked to Human Leukocyte Antigen-B27. Arthropathy in inflammatory bowel diseases is clinically divided into peripheral and axial involvement. Peripheral arthritis often flares with relapses of bowel disease resulting in a different treatment approach than axial arthritis in which the course is independent of inflammatory bowel disease activity. Definitions, prevalence, pathophysiology and treatment of the arthropathies commonly seen in inflammatory bowel diseases such as peripheral arthritis, dactylitis, enthesitis, arthralgia, sacroiliitis, inflammatory back pain and ankylosing spondylitis are summarized. (C) 2009 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved. Show less
In gastric cancer, a new epigenetic mechanism of tumour suppressor loss has been suggested where the histone methyltransferase enhancer of zeste homolog 2 (EZH2) is responsible for loss of... Show moreIn gastric cancer, a new epigenetic mechanism of tumour suppressor loss has been suggested where the histone methyltransferase enhancer of zeste homolog 2 (EZH2) is responsible for loss of expression of RUNX3. This is consistent with EZH2 upregulation in multiple cancer types being associated with poor prognosis. We investigated whether EZH2 influences the expression of RUNX3 in colorectal cancer (CRC) and whether this is independent of methylation. We determined protein and messenger RNA (mRNA) levels of EZH2 and RUNX3 and assessed RUNX3 methylation with methylation-specific polymerase chain reaction using 72 human CRCs and 8 CRC cell lines. We assessed the effect of efficient RNA interference-mediated knockdown of EZH2 on RUNX3 levels, cell viability and H3K27 trimethylation of the RUNX3 promoter using chromatin immunoprecipitation. Despite higher levels of EZH2 and lower levels of RUNX3 in CRC specimens in general, no inverse correlation between EZH2 and RUNX3 in paired samples was found arguing against a major role for histone methylation in silencing RUNX3 in CRC. Conversely, downregulation of RUNX3 mRNA in the same tumours was associated with RUNX3 DNA methylation (P < 0.05). In cell lines, knockdown of EZH2 removed the repressive chromatin marks from RUNX3 but did not result in RUNX3 re-expression. However, it prevented the re-silencing of RUNX3 after the removal of demethylating agents. In conclusion, DNA methylation is primarily responsible for the transcriptional silencing of RUNX3 in CRC, but EZH2 and histone methylation are necessary for its methylation-dependent re-silencing after the removal of demethylating agents. These results would predict that inhibitors of EZH2 and histone methylation would enhance the effects of demethylating agents in cancer therapy. Show less
Infectious complications after orthotopic liver transplantation (OLT) are a major clinical problem. The lectin pathway of complement activation is liver-derived and a crucial effector of the innate... Show moreInfectious complications after orthotopic liver transplantation (OLT) are a major clinical problem. The lectin pathway of complement activation is liver-derived and a crucial effector of the innate immune defense against pathogens. Polymorphisms in lectin pathway genes determine their functional activity. We assessed the relationship between these polymorphic genes and clinically significant bacterial infections, i.e., sepsis, pneumonia, and intra-abdominal infection, and mortality within the first year after OLT, in relation to major risk factors in two cohorts from different transplant centers. Single-nucleotide polymorphisms in the mannose-binding lectin gene (MBL2), the ficolin-2 gene (FCN2), and the MBL-associated serine protease gene (MASP2) of recipients and donors were determined. Recipients receiving a donor liver in the principal cohort with polymorphisms in all three components i.e., MBL2 (XAJO; O/O), FCN2+6359T, and MASP2+371A, had a cumulative risk of an infection of 75% as compared to 18% with wild-type donor livers (P = 0.002), an observation confirmed in the second cohort (P = 0.04). In addition, a genetic (mis)match between donor and recipient conferred a two-fold higher infection risk for each separate gene. Multivariate Cox analysis revealed a stepwise increase in infection risk with the lectin pathway gene profile of the donor (hazard ratio = 4.52; P = 8.1 x 10(-6)) and the donor-recipient (mis)match genotype (hazard ratio = 6.41; P = 1.9 x 10(-7)), independent from the other risk factors sex and antibiotic prophylaxis (hazard ratio > 1.7 and P < 0.02). Moreover, patients with a lectin pathway gene polymorphism and infection had a six-fold higher mortality (P = 0.9 x 10(-8)), of which 80% was infection-related. Conclusion: Donor and recipient gene polymorphisms in the lectin complement pathway are major determinants of the risk of clinically significant bacterial infection and mortality after OLT. (HEPATOLOGY 2010;52:1100-1110) Show less
Genome-wide association studies (GWAS) for Crohn's disease (CD) have identified loci explaining similar to 20% of the total genetic risk of CD. Part of the other genetic risk loci is probably... Show moreGenome-wide association studies (GWAS) for Crohn's disease (CD) have identified loci explaining similar to 20% of the total genetic risk of CD. Part of the other genetic risk loci is probably partly hidden among signals discarded by the multiple testing correction needed in the analysis of GWAS data. Strategies for finding these hidden loci require large replication cohorts and are costly to perform. We adopted a strategy of selecting SNPs for follow-up that showed a correlation to gene expression [cis-expression quantitative trait loci (eQTLs)] since these have been shown more likely to be trait-associated. First we show that there is an overrepresentation of cis-eQTLs in the known CD-associated loci. Then SNPs were selected for follow-up by screening the top 500 SNP hits from a CD GWAS data set. We identified 10 cis-eQTL SNPs. These 10 SNPs were tested for association with CD in two independent cohorts of Dutch CD patients (1539) and healthy controls (2648). In a combined analysis, we identified two cis-eQTL SNPs that were associated with CD rs2298428 in UBE2L3 (P = 5.22 x 10(-5)) and rs2927488 in BCL3 (P = 2.94 x 10(-4)). After adding additional publicly available data from a previously reported meta-analysis, the association with rs2298428 almost reached genome-wide significance (P = 2.40 x 10(-7)) and the association with rs2927488 was corroborated (P = 6.46 x 10(-4)). We have identified UBE2L3 and BCL3 as likely novel risk genes for CD. UBE2L3 is also associated with other immune-mediated diseases. These results show that eQTL-based pre-selection for follow-up is a useful approach for identifying risk loci from a moderately sized GWAS. Show less
Traditionally, mast cells were regarded as key cells orchestrating type I hypersensitivity responses. However, it is now recognized that mast cells are widely involved in nonallergic (non-IgE)... Show moreTraditionally, mast cells were regarded as key cells orchestrating type I hypersensitivity responses. However, it is now recognized that mast cells are widely involved in nonallergic (non-IgE) chronic diseases. Also, in inflammatory bowel disease (IBD), a disease not associated with increased IgE concentrations, clear signs of activation of mast cells have been found. In this study, we investigated if Ig-free L chain-induced hypersensitivity-like responses through activation of mast cells could contribute to the pathophysiology of IBD. As a mast cell-dependent model for IBD, mice were skin-sensitized with dinitrofluorobenzene followed by intrarectal application of the hapten. In this murine IBD model, F991 prevented mast cell activation and also abrogated the development of diarrhea, cellular infiltration, and colonic lymphoid follicle hyperplasia. Furthermore, passive immunization with Ag-specific Ig-free L chains (IgLCs) and subsequent rectal hapten challenge elicited local mast cell activation and increased vascular permeability in the colon of mice. Clinical support is provided by the observation that serum concentrations of IgLCs of patients suffering from Crohn's disease are greatly increased. Moreover, increased presence of IgLCs was evident in tissue specimens from colon and ileum tissue of patients with IBD. Our data suggest that IgLCs may play a role in the pathogenesis of IBD, which provides novel therapeutic means to prevent or ameliorate the adverse gastrointestinal manifestations of IBD. The Journal of Immunology, 2010, 185: 653-659. Show less
Phosphatidylinositol-3-kinase gamma (PI3K gamma) is the major PI3K that is activated in response to chemoattractants. It is responsible for the migration of leukocytes from the bloodstream to sites... Show morePhosphatidylinositol-3-kinase gamma (PI3K gamma) is the major PI3K that is activated in response to chemoattractants. It is responsible for the migration of leukocytes from the bloodstream to sites of injury or infection. Constant migration of new leukocytes to the intestinal mucosa may be an important factor in maintenance of inflammation and tissue damage in inflammatory bowel disease (IBD). Reducing this influx, for example by inhibition of PI3K gamma, might therefore be a potential goal for therapy. Here we investigated the role of PI3K gamma in the migration of leukocytes to sites of intestinal inflammation. We induced colitis in mice with a point mutation that inactivates PI3K gamma enzymatic activity ('kinase-dead') by oral administration of dextran sodium sulphate (DSS). Mice were treated with 1.5% DSS for 1 week and effects on cytokine production, leukocyte recruitment and disease severity were examined. Both clinical and histological parameters showed that the severity of colitis was significantly reduced in PI3K gamma-kinase-dead mice compared to controls. Although mutant mice had a less severe colitis than controls they produced significantly more pro-inflammatory Th1 cytokines such as Il-12. Tnf alpha and Ifn gamma and more Il-10. PI3K gamma mutant mice showed increased numbers of resident macrophages and T cells in the colonic lamina propria in an unstressed condition but failed to recruit new leukocytes to the mucosa upon treatment with DSS despite the increased cytokine levels. These results suggest that PI3K gamma plays a critical role in lamina propria leukocyte trafficking and that loss of PI3Ky-activity ameliorates DSS-induced colitis in mice. (C) 2010 Elsevier B.V. All rights reserved. Show less
Wassenaar, M.J.E.; Cazemier, M.; Biermasz, N.R.; Pereira, A.M.; Roelfsema, F.; Smit, J.W.A.; ... ; Romijn, J.A. 2010
Objective: In acromegaly, overproduction of GH and IGF-I causes abnormal extracellular matrix regulation. We hypothesized that this may predispose to the development of colonic diverticula. Because... Show moreObjective: In acromegaly, overproduction of GH and IGF-I causes abnormal extracellular matrix regulation. We hypothesized that this may predispose to the development of colonic diverticula. Because the relation between acromegaly and colonic diverticula is unknown, the study aim was to assess the prevalence of colonic diverticula in patients with cured acromegaly. Design: This was a case-control study. Methods: We screened reports of colonoscopies performed for the purpose of screening for polyps in 107 patients with cured or biochemically controlled acromegaly and in 214 age- and sex-matched controls for the presence of diverticula, dolichocolon, and polyps. In patients, the findings were related to GH/IGF-I concentrations at the time of diagnosis of acromegaly and to the duration of GH/IGF-I excess. Results: In acromegaly, colonic diverticula were present in 37% of patients, dolichocolon in 34%, and adenomatous polyps in 34%, which was increased compared with controls (odds ratio 3.6, 95% confidence interval 1.4, 5.7; 12.4, 95% confidence interval 6.8, 18.0; 4.1, 95% confidence interval 1.9, 6.4, respectively). The presence of colonic diverticula was associated with both GH and IGF- I concentrations at the time of diagnosis of acromegaly, when adjusted for the duration of active disease. The presence of dolichocolon and adenomatous polyps was associated with higher IGF-I concentrations at diagnosis. Conclusions: Acromegaly is associated with an increased prevalence of colonic diverticula. In addition to the known irreversible effect of GH excess on collagen of joints and cardiac valves, this observation indicates an irreversible effect of GH and/or IGF-I on the collagen in the colon. (J Clin Endocrinol Metab 95: 2073-2079, 2010) Show less
Background: Visilizumab is a humanized IgG(2) monoclonal anti-CD3 antibody. We evaluated its safety and dose response in severe intravenous steroid-refractory ulcerative colitis (UC). Methods: In... Show moreBackground: Visilizumab is a humanized IgG(2) monoclonal anti-CD3 antibody. We evaluated its safety and dose response in severe intravenous steroid-refractory ulcerative colitis (UC). Methods: In all, 104 patients were treated. In Stage 1, 73 patients were randomly assigned to receive intravenous visilizumab 5, 7.5, 10, or 12.5 mu g/kg/day for 2 consecutive days. In Stage II, 33 patients received visilizumab at the optimal clinical dose (OCD) of 5 mu g/kg/day for 2 days. Symptomatic response and remission were defined by the modified Truelove-Witts severity index. Clinical response and remission were defined by the Mayo score. Results: The rates of symptomatic response at day 15 in the 5, 7.5, 10, or 12.5 mu g/kg dose groups were 71%, 70%, 50%, and 61%. respectively, in Stage I and in 54% in Stage II. The symptomatic remission rates were 3.5%, 5%, 22%, and 11% in Stage I and 18% in Stage II. The rates of clinical response at day 30 in the 5, 7.5, 10, or 12.5 mu g/kg dose groups were 71%, 65%, 50%, and 67%, respectively, in Stage I and 55% in Stage II. The clinical remission rates were 6%, 5%, 0%, and 11% in Stage I and 6% in Stage II. All patients experienced adverse events. Serious adverse events included abdominal abscess, cytomegalovirus infection, atrial fibrillation, herpes zoster, and esophageal candidiasis. Conclusions: Treatment with visilizumab induced symptomatic response and clinical response. Results with 5 mu g/kg/day were similar to those observed with higher doses (NCT00267306 at www.clinicaltrials.gov). Show less
Ulcerative colitis is a chronic, relapsing inflammatory condition of the gastrointestinal tract with a complex genetic and environmental etiology. In an effort to identify genetic variation... Show moreUlcerative colitis is a chronic, relapsing inflammatory condition of the gastrointestinal tract with a complex genetic and environmental etiology. In an effort to identify genetic variation underlying ulcerative colitis risk, we present two distinct genome-wide association studies of ulcerative colitis and their joint analysis with a previously published scan(1), comprising, in aggregate, 2,693 individuals with ulcerative colitis and 6,791 control subjects. Fifty-nine SNPs from 14 independent loci attained an association significance of P < 10(-5). Seven of these loci exceeded genome-wide significance (P < 5 x 10(-8)). After testing an independent cohort of 2,009 cases of ulcerative colitis and 1,580 controls, we identified 13 loci that were significantly associated with ulcerative colitis (P < 5 x 10(-8)), including the immunoglobulin receptor gene FCGR2A, 5p15, 2p16 and ORMDL3 (orosomucoid1-like 3). We confirmed association with 14 previously identified ulcerative colitis susceptibility loci, and an analysis of acknowledged Crohn's disease loci showed that roughly half of the known Crohn's disease associations are shared with ulcerative colitis. These data implicate approximately 30 loci in ulcerative colitis, thereby providing insight into disease pathogenesis. Show less
Introduction: Epidemiological data suggests that 5-aminosalicyclic acid (5-ASA), a nonsteroidal antiinflammatory drug used in the treatment of inflammatory bowel diseases, prevents colorectal... Show moreIntroduction: Epidemiological data suggests that 5-aminosalicyclic acid (5-ASA), a nonsteroidal antiinflammatory drug used in the treatment of inflammatory bowel diseases, prevents colorectal cancer development in these patients, although the mechanisms remain incompletely understood. Methods and Results: Here we report that 5-ASA prevents growth of several colorectal cancer cell lines by interfering in the cell cycle, i.e., an S-phase and G2/M phase arrest, dependent on 5-ASA dosage and concentration, together with an increased mitotic index. In addition, prolonged cell cycle arrest by repeated 5-ASA treatment induced apoptosis and caused abnormal spindle organization leading to mitotic catastrophe, another form of cell death. Conclusion: These observations illustrate that 5-ASA has chemopreventive and chemotherapeutic properties. Show less
Dignass, A.; Assche, G. van; Lindsay, J.O.; Lemann, M.; Soderholm, J.; Colombel, J.F.; ... ; ECCO 2010
OBJECTIVES: Genetic susceptibility is known to make a major contribution to the pathogenesis of ulcerative colitis (UC). Recently, three studies, including a genome-wide association study (GWAS),... Show moreOBJECTIVES: Genetic susceptibility is known to make a major contribution to the pathogenesis of ulcerative colitis (UC). Recently, three studies, including a genome-wide association study (GWAS), reported novel UC risk loci. METHODS: The top-20 single-nucleotide polymorphisms (SNPs) from the first UC-GWAS were genotyped, as part of the study's replication phase, in 561 UC cases and 728 controls from our Dutch UC study sample. We genotyped eight SNPs identified in two more studies, in these individuals, and replicated all significantly associated SNPs in an additional 894 UC cases and 1,174 controls from our Dutch UC study sample. A combined analysis for all patients (n = 1,455) and controls (n = 1,902) was performed. Dose-response models were constructed with the associated risk alleles. RESULTS: We found 12 SNPs tagging ten loci, including HLA-DRA, IL10, IL23R, JAK2, S100Z, ARPC2, and ECM1, to be associated with UC. We identified 10q26, flagged by the UC-GWAS but not confirmed in its replication phase, as a UC locus and found a trend toward association for GAS7. No association with disease localization or severity was found. The dose-response models show that individuals carrying 11 or more risk alleles have an odds ratio of 8.2 (confidence interval 3.0-22.8) for UC susceptibility. CONCLUSIONS: We confirmed the association of multiple loci with UC in the Dutch population and found evidence for association of 10q26 and a trend suggesting association for GAS7. Genetic models show that multiple risk loci in an individual increase the risk for developing UC. Show less
The natural course of Crohn's disease is characterized by the progression from primarily inflammatory disease to a complicated stricturing or penetrating disease. These irreversible complications... Show moreThe natural course of Crohn's disease is characterized by the progression from primarily inflammatory disease to a complicated stricturing or penetrating disease. These irreversible complications lead to repeated surgery and considerable disability. Therefore it may be argued that a window of opportunity for intensive treatment exists early in the disease course. Healing of the mucosa has been shown to be a strong predictor of improved outcome of Crohn's disease on the long-term, in terms of disease control, hospitalizations, and surgery. Anti-tumor necrosis factor (TNF)-alpha therapy has shown to be a strong inducer of mucosal healing and it may be argued that early treatment with anti-TNF's and/or immunomodulators may be the preferable approach in selected patients. The main concern with such strategies is safety, especially the risk of lymphoma's and infections. This paper aims to review the existing data regarding the benefits and disadvantages of inverting the classic step up therapeutic paradigm. Show less
The transforming growth factor-beta (TGF-beta) pathway is an important pathway in the initiation and progression of colorectal cancer. We aimed to determine the effects of 5-aminosalicylic acid (5... Show moreThe transforming growth factor-beta (TGF-beta) pathway is an important pathway in the initiation and progression of colorectal cancer. We aimed to determine the effects of 5-aminosalicylic acid (5-ASA) on TGF-beta signalling in colorectal cancer cells in vitro. 5-ASA inhibited TGF-beta 1 signalling in HCT1 16 cells and colonic fibroblasts, as judged by a TGF-beta-specific reporter gene assay, plasminogen activator inhibitor-1 mRNA and protein levels, fibroblast trans-differentiation, Smad3 phosphorylation and nuclear translocation. We conclude that 5-ASA inhibits TGF-beta 1 signalling in colorectal cancer cells, and might be a potent adjuvant therapeutic drug, interfering with aberrant TGF-beta signalling in colorectal cancer. (C) 2009 Elsevier Ireland Ltd. All rights reserved. Show less
