Anna Andreasson

Association of TNFSF15 polymorphism with irritable bowel syndrome

Background Irritable bowel syndrome (IBS) is the most common gastrointestinal disorder, affecting more than 10% of the general population worldwide. Although a genetic component is suspected, unambiguous susceptibility genes have so far not been identified. This study tested the hypothesis that genes contributing to epithelial barrier integrity, control of mucosal immune responses and interactions with bacteria in the gut are associated with IBS. Methods Single nucleotide polymorphisms (SNPs) corresponding to top signals of association with Crohns disease at 30 known susceptibility loci were tested for their effect on IBS risk in 1992 individuals from two independent case–control cohorts from Sweden and the USA. Association tests included a conservative Bonferroni correction for multiple comparisons, and were also performed on specific subgroups of patients characterised by constipation (IBS-C), diarrhoea (IBS-D) or alternating constipation and diarrhoea (IBS-A). Results The Crohns disease risk allele rs4263839 G in the TNFSF15 gene was significantly associated with an increased risk of both IBS (p=2.2×10−5; OR 1.37) and more pronouncedly, IBS-C (p=8.7×10−7; OR 1.79) in the entire sample. Similar associations and risk effects of the same magnitude were observed in the two cohorts analysed separately. A correlation between rs4263839 genotype and TNFSF15 mRNA expression was detected both in peripheral blood and in rectal mucosal biopsies from healthy individuals (combined p=0.0033). Conclusions TNFSF15 is a susceptibility gene for IBS and IBS constipation. As TL1A, the protein encoded by TNFSF15, contributes to the modulation of inflammatory responses, the results support a role of immune activation in IBS.

Gender Differences in Self-Rated Health, Quality of Life, Quality of Care, and Metabolic Control in Patients with Diabetes

BACKGROUND Because the projected increase in the number of diabetic patients is expected to strain the capabilities of health care providers worldwide, we are challenged to find ways of reducing the burden of diabetes. Maintaining and improving health-related quality of life (QoL) for diabetic patients may be viewed as public health goals. OBJECTIVE The aim of this cross-sectional study was to compare different aspects of health, QoL, and quality of care (QoC) between men and women with diabetes as a basis for planning and managing diabees care. METHODS All patients in 2 age groups (aged 20-30 years [younger age group] and aged 50-60 years [middle-aged group]) who were registered with the Department of Endocrinology, Metabolism, and Diabetes at Karolinska University Hospital, Stockholm, Sweden, in October 2004, were recruited for a survey. Questions were included about self-rated health (SRH), QoL, QoC, diabetes-related worries, occupational status, physical activity level, living arrangements, and educational background. Glycosylated hemoglobin (HbA1c) values were obtained from medical records. RESULTS Of the 223 eligible patients (109 men, 114 women) in the younger age group, 49 men and 74 women responded to the questionnaire; of the 300 eligible patients (170 men, 130 women) in the middle-aged group, 120 men and 93 women responded. Middle-aged women rated their mental well-being and QoL as worse compared with men (P < 0.001 and P < 0.05, respectively). In both age groups, women reported more diabetes-related worries and less ability to cope (P < 0.05 for the younger age group and P < 0.001 for the middle-aged group for both variables), thus the differences were more marked for middleaged women. Although there were no gender differences in metabolic control, middle-aged women reported less satisfaction with diabetes care (P < 0.001). Higher HbA1c was related to worse SRH in both men and women when analyzing the age groups together (P < 0.05). This association was most prominent in young women, in whom having more diabetes-related worries was also related to higher HbA1c (P < 0.01). CONCLUSION In this study, women with diabetes appeared to have worse QoL and mental well-being compared with men with diabetes. Therefore, identifying strategies to improve SRH and QoL among diabetic patients, especially among women, is of great importance.

A putative role for cytokines in the impaired appetite in depression

Impaired appetite and weight changes are commonly seen in patients with depression, but the pathophysiology behind this imbalance between energy intake and energy expenditure remains largely unknown. The aim of this paper is to review the literature regarding a possible role for cytokines in the regulation of appetite and body weight, with special emphasis on depression. There now exists a substantial amount of evidence that depressed patients show signs of immune activation including increased levels of proinflammatory cytokines. Cytokines, which by themselves have anorectic properties, stimulate the release of the cytokine-like anorexogenic peptide leptin. In addition to their anorectic properties, both proinflammatory cytokines and leptin interact with the hypothalamic-pituitary-adrenal (HPA) axis, the sympathetic nervous system (SNS) and the immune system. In turn, these systems regulate energy balance as well as they are dysfunctional in depression. Furthermore, both proinflammatory cytokines and leptin can induce anhedonia, one of the cardinal symptoms of depression. In view of the different effects on appetite and/or body weight observed in melancholic versus atypical depression, we suggest that cytokines are differentially altered in these subtypes of depression, and that this may explain some of the inconsistency in the reported findings of cytokine as well as leptin levels in depressed patients. Finally, we propose that the immune system uses the interoceptive pathway projecting to the insular cortex, a brain region where cytokine-induced changes in appetite could be partly mediated, and that this pathway is activated in depression.

Inflammatory cytokines, behaviour and age as determinants of self-rated health in women

Self-rated health is a powerful and independent predictor of long-term health, but its biological basis is unknown. We have shown previously that self-rated health is associated with increased levels of circulating cytokines in women. The main aim of the present study was to increase the understanding of the association between markers of wellbeing, such as self-rated health, and cytokines and to investigate the impact of age on these associations. In 174 female consecutive primary health care patients divided into three age groups, we examined subjective ratings of health and aspects of wellbeing and circulating levels of IL (interleukin)-1beta, IL-1ra (IL-1 receptor antagonist), IL-6 and TNF-alpha (tumour necrosis factor-alpha). Poor self-rated health was significantly associated with higher levels of TNF-alpha in all of the age groups. For IL-1beta and IL-1ra, the correlations with self-rated health were significant only in the oldest age group. Lower ratings of other measurements of health and wellbeing were related to higher levels of cytokines, most pronounced for TNF-alpha and IL-1beta, and in the middle and olderst age groups. More symptoms resembling a sickness response induced by inflammation were implicated to be associated with lower self-rated health. The strength of the association between inflammatory cytokines and poor health perception increased with advanced age, indicating an increased vulnerability for inflammatory activity during aging. It is suggested that higher levels of TNF-alpha are connected to a sickness response that, in turn, is connected to self-rated health. The results provide a possible psychobiological basis to understand better diffuse subjective symptoms and poor subjective health in women.

Exploring the genetics of irritable bowel syndrome: a GWA study in the general population and replication in multinational case-control cohorts

Objective IBS shows genetic predisposition, but adequately powered gene-hunting efforts have been scarce so far. We sought to identify true IBS genetic risk factors by means of genome-wide association (GWA) and independent replication studies. Design We conducted a GWA study (GWAS) of IBS in a general population sample of 11 326 Swedish twins. IBS cases (N=534) and asymptomatic controls (N=4932) were identified based on questionnaire data. Suggestive association signals were followed-up in 3511 individuals from six case-control cohorts. We sought genotype-gene expression correlations through single nucleotide polymorphism (SNP)-expression quantitative trait loci interactions testing, and performed in silico prediction of gene function. We compared candidate gene expression by real-time qPCR in rectal mucosal biopsies of patients with IBS and controls. Results One locus at 7p22.1, which includes the genes KDELR2 (KDEL endoplasmic reticulum protein retention receptor 2) and GRID2IP (glutamate receptor, ionotropic, delta 2 (Grid2) interacting protein), showed consistent IBS risk effects in the index GWAS and all replication cohorts and reached p=9.31×10−6 in a meta-analysis of all datasets. Several SNPs in this region are associated with cis effects on KDELR2 expression, and a trend for increased mucosal KDLER2 mRNA expression was observed in IBS cases compared with controls. Conclusions Our results demonstrate that general population-based studies combined with analyses of patient cohorts provide good opportunities for gene discovery in IBS. The 7p22.1 and other risk signals detected in this study constitute a good starting platform for hypothesis testing in future functional investigations.

Anti-inflammatory Treatment of Atopic Asthma Guided by Exhaled Nitric Oxide: A Randomized, Controlled Trial

BACKGROUND Atopic asthma is characterized by Th2 cytokine-driven inflammation of the airway mucosa, which is signaled by the fraction of exhaled nitric oxide (FENO). OBJECTIVE We tested whether an FENO-guided anti-inflammatory treatment algorithm could improve asthma-related quality of life and asthma symptom control, and reduce exacerbations in atopic asthmatics within primary care. METHODS Altogether, 187 patients with asthma and who were nonsmokers (age range, 18-64 years) with perennial allergy and who were on regular inhaled corticosteroid treatment were recruited at 17 primary health care centers, randomly assigned to 2 groups and followed up for 1 year. For the controls (n = 88), FENO measurement was blinded to both operator and patient, and anti-inflammatory treatment was adjusted according to usual care. In the active group (n = 93), treatment was adjusted according to FENO. Questionnaires on asthma-related quality of life (Mini Asthma Quality of Life Questionnaire) and asthma control (Asthma Control Questionnaire) were completed, and asthma events were noted. RESULTS The Asthma Control Questionnaire score change over 1 year improved significantly more in the FENO-guided group (-0.17 [interquartile range {IQR}, -0.67 to 0.17] vs 0 [-0.33 to 0.50]; P = .045), whereas the Mini Asthma Quality of Life Questionnaire score did not (0.23 [IQR, 0.07-0.73] vs 0.07 [IQR, -0.20 to 0.80]; P = .197). The change in Asthma Control Questionnaire was clinically important in subpopulations with poor control at baseline (P = .03). Furthermore, the exacerbation rate (exacerbations/patient/y) was reduced by almost 50% in the FENO-guided group (0.22 [CI, 0.14-0.34] vs 0.41 [CI, 0.29-0.58]; P = .024). Mean overall inhaled corticosteroid use was similar in both groups (P = .95). CONCLUSION Use of FENO to guide anti-inflammatory treatment within primary care significantly reduced the exacerbation rate and improved asthma symptom control without increasing overall inhaled corticosteroid use.

Leptin and adiponectin: Distribution and associations with cardiovascular risk factors in men and women of the general population

In view of the increasing prevalence of obesity worldwide, understanding the role of the recently discovered adipokines leptin and adiponectin is of high clinical relevance. The aim of the present study was to assess the association between levels of leptin and adiponectin with age, known cardiovascular risk factors and to establish whether there are differences between men and women of the general population.

Translational Medicine and Patient Safety in Europe: TRANSFoRm—Architecture for the Learning Health System in Europe

The Learning Health System (LHS) describes linking routine healthcare systems directly with both research translation and knowledge translation as an extension of the evidence-based medicine paradigm, taking advantage of the ubiquitous use of electronic health record (EHR) systems. TRANSFoRm is an EU FP7 project that seeks to develop an infrastructure for the LHS in European primary care. Methods. The project is based on three clinical use cases, a genotype-phenotype study in diabetes, a randomised controlled trial with gastroesophageal reflux disease, and a diagnostic decision support system for chest pain, abdominal pain, and shortness of breath. Results. Four models were developed (clinical research, clinical data, provenance, and diagnosis) that form the basis of the projects approach to interoperability. These models are maintained as ontologies with binding of terms to define precise data elements. CDISC ODM and SDM standards are extended using an archetype approach to enable a two-level model of individual data elements, representing both research content and clinical content. Separate configurations of the TRANSFoRm tools serve each use case. Conclusions. The project has been successful in using ontologies and archetypes to develop a highly flexible solution to the problem of heterogeneity of data sources presented by the LHS.

The impact of Crohn's disease genes on healthy human gut microbiota: a pilot study

We read with interest the paper by Rehman et al 1 reporting the contribution of Nod2 genotype to the composition of gut microbiota in mice and Crohns disease (CD) patients. This was followed by a similar description for another CD-predisposing gene, FUT2.2 To date, 163 CD- and ulcerative colitis-risk loci have been identified, and while most of the known causative genes are involved in immune functions and response to infections, their effects on the composition of the gut microbiota are mostly unknown. Studies like those mentioned above are therefore very important, since the relative abundance of specific enteric bacteria has been clearly shown to be of pathogenetic relevance in mouse models of colitis.3 By studying genotype–microbiota correlations in healthy individuals, key information could also be sought for devoid of potentially confounding effects from disease status and therapeutic treatment. We studied the impact of 30 unequivocal CD-risk loci, each tagged by a single nucleotide polymorphism (SNP), on the mucosa-associated …

Intrinsic functional connectivity of insular cortex and symptoms of sickness during acute experimental inflammation

Task-based fMRI has been used to study the effects of experimental inflammation on the human brain, but it remains unknown whether intrinsic connectivity in the brain at rest changes during a sickness response. Here, we investigated the effect of experimental inflammation on connectivity between areas relevant for monitoring of bodily states, motivation, and subjective symptoms of sickness. In a double-blind randomized controlled experiment, 52 healthy volunteers were injected with 0.6ng/kg LPS (lipopolysaccharide) or placebo, and participated in a resting state fMRI experiment after approximately 2h 45min. Resting state fMRI data were available from 48 participants, of which 28 received LPS and 20 received placebo. Bilateral anterior and bilateral posterior insula sections were used as seed regions and connectivity with bilateral orbitofrontal and cingulate (anterior and middle) cortices was investigated. Back pain, headache and global sickness increased significantly after as compared to before LPS, while a non-significant trend was shown for increased nausea. Compared to placebo, LPS was followed by increased connectivity between left anterior insula and left midcingulate cortex. This connectivity was significantly correlated to increase in back pain after LPS and tended to be related to increased global sickness, but was not related to increased headache or nausea. LPS did not affect the connectivity from other insular seeds. In conclusion, the finding of increased functional connectivity between left anterior insula and middle cingulate cortex suggests a potential neurophysiological mechanism that can be further tested to understand the subjective feeling of malaise and discomfort during a sickness response.