301 research outputs found
Intestinal barrier dysfunction in inflammatory bowel diseases
The etiology of human inflammatory bowel diseases (IBDs) is believed to involve inappropriate host responses to the complex commensal microbial flora in the gut, although an altered commensal flora is not completely excluded. A multifunctional cellular and secreted barrier separates the microbial flora from host tissues. Altered function of this barrier remains a major largely unexplored pathway to IBD. Although there is evidence of barrier dysfunction in IBD, it remains unclear whether this is a primary contributor to disease or a consequence of mucosal inflammation. Recent evidence from animal models demonstrating that genetic defects restricted to the epithelium can initiate intestinal inflammation in the presence of normal underlying immunity has refocused attention on epithelial dysfunction in IBD. We review the components of the secreted and cellular barrier, their regulation, including interactions with underlying innate and adaptive immunity, evidence from animal models of the barrier's role in preventing intestinal inflammation, and evidence of barrier dysfunction in both Crohn's disease and ulcerative colitis. (Inflamm Bowel Dis 2008
Efficacy of rectal tacrolimus for induction therapy in patients with resistant ulcerative proctitis
Background & Aims Resistant ulcerative proctitis can be extremely difficult to manage. Topically administered tacrolimus, however, may be effective in difficult-to-treat proctitis. This was a randomized, double-blind, placebo-controlled induction trial of rectal tacrolimus in patients with active ulcerative colitis. Methods Eleven patients received rectal tacrolimus (0.5 mg/mL), and 10 placebo, for 8 weeks. The primary endpoint was clinical response by using the Mayo Clinic score. Results A planned interim analysis after 20 patients had completed the study demonstrated highly significant differences between the groups and the study was closed because of ethical considerations with patients already recruited allowed to complete the study. The primary endpoint was met in 8 of 11 patients receiving rectal tacrolimus and 1 of 10 patients receiving placebo (73% vs 10%; P = .004). Of the secondary endpoints, 5 patients with rectal tacrolimus achieved clinical remission compared with none receiving placebo (45% vs 0%; P = .015). Mucosal healing at Week 8 was achieved in 8 patients receiving rectal tacrolimus compared with 1 (73% vs 10%) receiving placebo (P = .004). The Inflammatory Bowel Disease Questionnaire increased ≥16 points over baseline in 5 of the tacrolimus and 2 (45% vs 20%) of the placebo patients (P = .36). Finally, the average partial Mayo score was numerically lower in the tacrolimus-treated group compared with placebo at Week 2 (4.3 ± 0.74 vs 5.8 ± 0.64; P = .15) and Week 4 (3.7 ± 0.96 vs 5.8 ± 0.6; P = .08) but was significantly lower at Week 8 (3.3 ± 1.2 vs 6.7 ± 0.62; P = .01). There were no safety issues identified with rectal tacrolimus use. Conclusions Rectal tacrolimus was more effective than placebo for induction of a clinical response, clinical remission, and mucosal healing in resistant ulcerative proctitis (Clinicaltrials.gov registration: NCT01418131)
Randomized, placebo controlled trial of experimental hookworm infection for improving gluten tolerance in Celiac disease
INTRODUCTION:
Celiac disease is an autoimmune disorder where intestinal immunopathology arises after gluten consumption. Previous studies suggested that hookworm infection restores gluten tolerance; however, these studies were small (n = 12) and not placebo controlled.
METHODS:
We undertook a randomized, placebo-controlled trial of hookworm infection in 54 people with celiac disease. The 94-week study involved treatment with either 20 or 40 Necator americanus third-stage larvae (L3-20 or L3-40) or placebo, followed by escalating gluten consumption (50 mg/d for 12 weeks, 1 g intermittent twice weekly for 12 weeks, 2 g/d sustained for 6 weeks, liberal diet for 1 year).
RESULTS:
Successful study completion rates at week 42 (primary outcome) were similar in each group (placebo: 57%, L3-20: 37%, and L3-40: 44%; P = 0.61), however gluten-related adverse events were significantly reduced in hookworm-treated participants: Median (range) adverse events/participant were as follows: placebo, 4 (1–9); L3-20, 1 (0–9); and L3-40, 0 (0–3) (P = 0.019). Duodenal villous height:crypt depth deteriorated similarly compared with their enrolment values in each group (mean change [95% confidence interval]: placebo, −0.6 [−1.3 to 0.2]; L3-20, −0.5 [−0.8 to 0.2]; and L3-40, −1.1 [−1.8 to 0.4]; P = 0.12). A retrospective analysis revealed that 9 of the 40 L3-treated participants failed to establish hookworm infections. Although week 42 completion rates were similar in hookworm-positive vs hookworm-negative participants (48% vs 44%, P = 0.43), quality of life symptom scores were lower in hookworm-positive participants after intermittent gluten challenge (mean [95% confidence interval]: 38.9 [33.9–44] vs 45.9 [39.2–52.6]).
DISCUSSION:
Hookworm infection does not restore tolerance to sustained moderate consumption of gluten (2 g/d) but was associated with improved symptom scores after intermittent consumption of lower, intermittent gluten doses
The effectiveness, acceptability and cost-effectiveness of psychosocial interventions for maltreated children and adolescents: an evidence synthesis.
BACKGROUND: Child maltreatment is a substantial social problem that affects large numbers of children and young people in the UK, resulting in a range of significant short- and long-term psychosocial problems. OBJECTIVES: To synthesise evidence of the effectiveness, cost-effectiveness and acceptability of interventions addressing the adverse consequences of child maltreatment. STUDY DESIGN: For effectiveness, we included any controlled study. Other study designs were considered for economic decision modelling. For acceptability, we included any study that asked participants for their views. PARTICIPANTS: Children and young people up to 24 years 11 months, who had experienced maltreatment before the age of 17 years 11 months. INTERVENTIONS: Any psychosocial intervention provided in any setting aiming to address the consequences of maltreatment. MAIN OUTCOME MEASURES: Psychological distress [particularly post-traumatic stress disorder (PTSD), depression and anxiety, and self-harm], behaviour, social functioning, quality of life and acceptability. METHODS: Young Persons and Professional Advisory Groups guided the project, which was conducted in accordance with Cochrane Collaboration and NHS Centre for Reviews and Dissemination guidance. Departures from the published protocol were recorded and explained. Meta-analyses and cost-effectiveness analyses of available data were undertaken where possible. RESULTS: We identified 198 effectiveness studies (including 62 randomised trials); six economic evaluations (five using trial data and one decision-analytic model); and 73 studies investigating treatment acceptability. Pooled data on cognitive-behavioural therapy (CBT) for sexual abuse suggested post-treatment reductions in PTSD [standardised mean difference (SMD) -0.44 (95% CI -4.43 to -1.53)], depression [mean difference -2.83 (95% CI -4.53 to -1.13)] and anxiety [SMD -0.23 (95% CI -0.03 to -0.42)]. No differences were observed for post-treatment sexualised behaviour, externalising behaviour, behaviour management skills of parents, or parental support to the child. Findings from attachment-focused interventions suggested improvements in secure attachment [odds ratio 0.14 (95% CI 0.03 to 0.70)] and reductions in disorganised behaviour [SMD 0.23 (95% CI 0.13 to 0.42)], but no differences in avoidant attachment or externalising behaviour. Few studies addressed the role of caregivers, or the impact of the therapist-child relationship. Economic evaluations suffered methodological limitations and provided conflicting results. As a result, decision-analytic modelling was not possible, but cost-effectiveness analysis using effectiveness data from meta-analyses was undertaken for the most promising intervention: CBT for sexual abuse. Analyses of the cost-effectiveness of CBT were limited by the lack of cost data beyond the cost of CBT itself. CONCLUSIONS: It is not possible to draw firm conclusions about which interventions are effective for children with different maltreatment profiles, which are of no benefit or are harmful, and which factors encourage people to seek therapy, accept the offer of therapy and actively engage with therapy. Little is known about the cost-effectiveness of alternative interventions. LIMITATIONS: Studies were largely conducted outside the UK. The heterogeneity of outcomes and measures seriously impacted on the ability to conduct meta-analyses. FUTURE WORK: Studies are needed that assess the effectiveness of interventions within a UK context, which address the wider effects of maltreatment, as well as specific clinical outcomes. STUDY REGISTRATION: This study is registered as PROSPERO CRD42013003889. FUNDING: The National Institute for Health Research Health Technology Assessment programme
A pleiotropic missense variant in SLC39A8 is associated with Crohn's disease and human gut microbiome composition
Genome-wide association studies have identified 200 inflammatory bowel disease (IBD) loci, but the genetic architecture of Crohn's disease (CD) and ulcerative colitis remain incompletely defined. Here, we aimed to identify novel associations between IBD and functional genetic variants using the Illumina ExomeChip (San Diego, CA)
IMPRoving Outcomes for children exposed to domestic ViolencE (IMPROVE): an evidence synthesis
BackgroundExposure to domestic violence and abuse (DVA) during childhood and adolescence increases the risk of negative outcomes across the lifespan.ObjectivesTo synthesise evidence on the clinical effectiveness, cost-effectiveness and acceptability of interventions for children exposed to DVA, with the aim of making recommendations for further research.Design(1) A systematic review of controlled trials of interventions; (2) a systematic review of qualitative studies of participant and professional experience of interventions; (3) a network meta-analysis (NMA) of controlled trials and cost-effectiveness analysis; (4) an overview of current UK provision of interventions; and (5) consultations with young people, parents, service providers and commissioners.SettingsNorth America (11), the Netherlands (1) and Israel (1) for the systematic review of controlled trials of interventions; the USA (4) and the UK (1) for the systematic review of qualitative studies of participant and professional experience of interventions; and the UK for the overview of current UK provision of interventions and consultations with young people, parents, service providers and commissioners.ParticipantsA total of 1345 children for the systematic review of controlled trials of interventions; 100 children, 202 parents and 39 professionals for the systematic review of qualitative studies of participant and professional experience of interventions; and 16 young people, six parents and 20 service providers and commissioners for the consultation with young people, parents, service providers and commissioners.InterventionsPsychotherapeutic, advocacy, parenting skills and advocacy, psychoeducation, psychoeducation and advocacy, guided self-help.Main outcome measuresInternalising symptoms and externalising behaviour, mood, depression symptoms and diagnosis, post-traumatic stress disorder symptoms and self-esteem for the systematic review of controlled trials of interventions and NMA; views about and experience of interventions for the systematic review of qualitative studies of participant and professional experience of interventions and consultations.Data sourcesMEDLINE, Cumulative Index to Nursing and Allied Health Literature, PsycINFO, EMBASE, Cochrane Central Register of Controlled Trials, Science Citation Index, Applied Social Sciences Index and Abstracts, International Bibliography of the Social Sciences, Social Services Abstracts, Social Care Online, Sociological Abstracts, Social Science Citation Index, World Health Organization trials portal and clinicaltrials.gov.Review methodsA narrative review; a NMA and incremental cost-effectiveness analysis; and a qualitative synthesis.ResultsThe evidence base on targeted interventions was small, with limited settings and types of interventions; children were mostly < 14 years of age, and there was an absence of comparative studies. The interventions evaluated in trials were mostly psychotherapeutic and psychoeducational interventions delivered to the non-abusive parent and child, usually based on the child’s exposure to DVA (not specific clinical or broader social needs). Qualitative studies largely focused on psychoeducational interventions, some of which included the abusive parent. The evidence for clinical effectiveness was as follows: 11 trials reported improvements in behavioural or mental health outcomes, with modest effect sizes but significant heterogeneity and high or unclear risk of bias. Psychoeducational group-based interventions delivered to the child were found to be more effective for improving mental health outcomes than other types of intervention. Interventions delivered to (non-abusive) parents and to children were most likely to be effective for improving behavioural outcomes. However, there is a large degree of uncertainty around comparisons, particularly with regard to mental health outcomes. In terms of evidence of cost-effectiveness, there were no economic studies of interventions. Cost-effectiveness was modelled on the basis of the NMA, estimating differences between types of interventions. The outcomes measured in trials were largely confined to children’s mental health and behavioural symptoms and disorders, although stakeholders’ concepts of success were broader, suggesting that a broader range of outcomes should be measured in trials. Group-based psychoeducational interventions delivered to children and non-abusive parents in parallel were largely acceptable to all stakeholders. There is limited evidence for the acceptability of other types of intervention. In terms of the UK evidence base and service delivery landscape, there were no UK-based trials, few qualitative studies and little widespread service evaluation. Most programmes are group-based psychoeducational interventions. However, the funding crisis in the DVA sector is significantly undermining programme delivery.ConclusionsThe evidence base regarding the acceptability, clinical effectiveness and cost-effectiveness of interventions to improve outcomes for children exposed to DVA is underdeveloped. There is an urgent need for more high-quality studies, particularly trials, that are designed to produce actionable, generalisable findings that can be implemented in real-world settings and that can inform decisions about which interventions to commission and scale. We suggest that there is a need to pause the development of new interventions and to focus on the systematic evaluation of existing programmes. With regard to the UK, we have identified three types of programme that could be justifiably prioritised for further study: psycho-education delivered to mothers and children, or children alone; parent skills training in combination with advocacy: and interventions involving the abusive parent/caregiver. We also suggest that there is need for key stakeholders to come together to explicitly identify and address the structural, practical and cultural barriers that may have hampered the development of the UK evidence base to date.Future work recommendationsThere is a need for well-designed, well-conducted and well-reported UK-based randomised controlled trials with cost-effectiveness analyses and nested qualitative studies. Development of consensus in the field about core outcome data sets is required. There is a need for further exploration of the acceptability and effectiveness of interventions for specific groups of children and young people (i.e. based on ethnicity, age, trauma exposure and clinical profile). There is also a need for an investigation of the context in which interventions are delivered, including organisational setting and the broader community context, and the evaluation of qualities, qualifications and disciplines of personnel delivering interventions. We recommend prioritisation of psychoeducational interventions and parent skills training delivered in combination with advocacy in the next phase of trials, and exploratory trials of interventions that engage both the abusive and the non-abusive parent.Study registrationThis study is registered as PROSPERO CRD42013004348 and PROSPERO CRD420130043489.FundingThe National Institute for Health Research Public Health Research programme.</jats:sec
Multitrait analysis of glaucoma identifies new risk loci and enables polygenic prediction of disease susceptibility and progression
Glaucoma, a disease characterized by progressive optic nerve degeneration, can be prevented through timely diagnosis and treatment. We characterize optic nerve photographs of 67,040 UK Biobank participants and use a multitrait genetic model to identify risk loci for glaucoma. A glaucoma polygenic risk score (PRS) enables effective risk stratification in unselected glaucoma cases and modifies penetrance of the MYOC variant encoding p.Gln368Ter, the most common glaucoma-associated myocilin variant. In the unselected glaucoma population, individuals in the top PRS decile reach an absolute risk for glaucoma 10 years earlier than the bottom decile and are at 15-fold increased risk of developing advanced glaucoma (top 10% versus remaining 90%, odds ratio = 4.20). The PRS predicts glaucoma progression in prospectively monitored, early manifest glaucoma cases (P = 0.004) and surgical intervention in advanced disease (P = 3.6 × 10). This glaucoma PRS will facilitate the development of a personalized approach for earlier treatment of high-risk individuals, with less intensive monitoring and treatment being possible for lower-risk groups
Performance of risk prediction for inflammatory bowel disease based on genotyping platform and genomic risk score method
Background: Predicting risk of disease from genotypes is being increasingly proposed for a variety of diagnostic and prognostic purposes. Genome-wide association studies (GWAS) have identified a large number of genome-wide significant susceptibility loci for Crohn's disease (CD) and ulcerative colitis (UC), two subtypes of inflammatory bowel disease (IBD). Recent studies have demonstrated that including only loci that are significantly associated with disease in the prediction model has low predictive power and that power can substantially be improved using a polygenic approach. Methods: We performed a comprehensive analysis of risk prediction models using large case-control cohorts genotyped for 909,763 GWAS SNPs or 123,437 SNPs on the custom designed Immunochip using four prediction methods (polygenic score, best linear genomic prediction, elastic-net regularization and a Bayesian mixture model). We used the area under the curve (AUC) to assess prediction performance for discovery populations with different sample sizes and number of SNPs within cross-validation. Results: On average, the Bayesian mixture approach had the best prediction performance. Using cross-validation we found little differences in prediction performance between GWAS and Immunochip, despite the GWAS array providing a 10 times larger effective genome-wide coverage. The prediction performance using Immunochip is largely due to the power of the initial GWAS for its marker selection and its low cost that enabled larger sample sizes. The predictive ability of the genomic risk score based on Immunochip was replicated in external data, with AUC of 0.75 for CD and 0.70 for UC. CD patients with higher risk scores demonstrated clinical characteristics typically associated with a more severe disease course including ileal location and earlier age at diagnosis. Conclusions: Our analyses demonstrate that the power of genomic risk prediction for IBD is mainly due to strongly associated SNPs with considerable effect sizes. Additional SNPs that are only tagged by high-density GWAS arrays and low or rare-variants over-represented in the high-density region on the Immunochip contribute little to prediction accuracy. Although a quantitative assessment of IBD risk for an individual is not currently possible, we show sufficient power of genomic risk scores to stratify IBD risk among individuals at diagnosis.Guo-Bo Chen, Sang Hong Lee, Grant W. Montgomery, Naomi R. Wray, Peter M. Visscher, Richard B. Gearry, Ian C. Lawrance, Jane M. Andrews, Peter Bampton, Gillian Mahy, Sally Bell, Alissa Walsh, Susan Connor, Miles Sparrow, Lisa M. Bowdler, Lisa A. Simms, Krupa Krishnaprasad, the International IBD Genetics Consortium, Graham L. Radford-Smith, and Gerhard Moser
Genome-wide meta-analysis identifies five new susceptibility loci for cutaneous malignant melanoma.
Thirteen common susceptibility loci have been reproducibly associated with cutaneous malignant melanoma (CMM). We report the results of an international 2-stage meta-analysis of CMM genome-wide association studies (GWAS). This meta-analysis combines 11 GWAS (5 previously unpublished) and a further three stage 2 data sets, totaling 15,990 CMM cases and 26,409 controls. Five loci not previously associated with CMM risk reached genome-wide significance (P < 5 × 10(-8)), as did 2 previously reported but unreplicated loci and all 13 established loci. Newly associated SNPs fall within putative melanocyte regulatory elements, and bioinformatic and expression quantitative trait locus (eQTL) data highlight candidate genes in the associated regions, including one involved in telomere biology.[Please see the Supplementary Note for acknowledgments.]This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ng.337
- …