Role of meprins to protect ileal mucosa of Crohn's disease patients from colonization by adherent-invasive E. coli

Ileal lesions in Crohn's disease (CD) patients are colonized by pathogenic adherent-invasive Escherichia coli (AIEC) able to adhere to and invade intestinal epithelial cells (IEC), and to survive within macrophages. The interaction of AIEC with IEC depends on bacterial factors mainly type 1 pili, flagella, and outer membrane proteins. In humans, proteases can act as host defence mechanisms to counteract bacterial colonization. The protease meprin, composed of multimeric complexes of the two subunits alpha and beta, is abundantly expressed in IECs. Decreased levels of this protease correlate with the severity of the inflammation in patients with inflammatory bowel disease. The aim of the present study was to analyze the ability of meprin to modulate the interaction of AIEC with IECs. In patients with ileal CD we observed decreased levels of meprins, in particular that of meprin β. Dose-dependent inhibition of the abilities of AIEC strain LF82 to adhere to and invade intestinal epithelial T84 cells was observed when bacteria were pre-treated with both exogenous meprin α and meprin β. Dose-dependent proteolytic degradation of type 1 pili was observed in the presence of active meprins, but not with heat-inactivated meprins, and pretreatment of AIEC bacteria with meprins impaired their ability to bind mannosylated host receptors and led to decreased secretion of the pro-inflammatory cytokine IL-8 by infected T84 cells. Thus, decreased levels of protective meprins as observed in CD patients may contribute to increased AIEC colonization.

Circulating DNA and myeloperoxidase indicate disease activity in patients with thrombotic microangiopathies

Thrombotic microangiopathies (TMAs) are a group of life-threatening disorders characterized by thrombocytopenia, fragmentation of erythrocytes, and ischemic organ damage. Genetic disorders, autoimmune disease, and cancer are risk factors for TMAs, but an additional, unknown trigger is needed to bring about acute disease. Recent studies suggest that DNA and histones are released during inflammation or infection and stimulate coagulation, thrombosis, thrombocytopenia, and organ damage in mice. We show that extracellular DNA and histones as well as markers of neutrophils are present in acute TMAs. Analysis of plasma from TMA patients of different clinical categories revealed elevated levels of DNA-histone complexes and myeloperoxidase (MPO) from neutrophil granules as well as S100A8/A9, a heterocomplex abundant in neutrophil cytosol. During therapy of thrombotic thrombocytopenic purpura, a subtype of TMAs often associated with severe ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motifs, member 13) deficiency, plasma DNA and MPO were inversely correlated with platelet counts, and their levels indicated amelioration or exacerbation of the disease. ADAMTS13 deficiency together with increased levels of plasma DNA and MPO were characteristic for acute thrombotic thrombocytopenic purpura. A minor infection often precedes acute TMA and extracellular DNA and histones released during the inflammatory response could provide the second hit, which precipitates acute TMA in patients with pre-existing risk factors.

Life cycle complexity, environmental change and the emerging status of salmonid proliferative kidney disease

P>1. Proliferative kidney disease (PKD) is a disease of salmonid fish caused by the endoparasitic myxozoan, Tetracapsuloides bryosalmonae, which uses freshwater bryozoans as primary hosts. Clinical PKD is characterised by a temperature-dependent proliferative and inflammatory response to parasite stages in the kidney.;2. Evidence that PKD is an emerging disease includes outbreaks in new regions, declines in Swiss brown trout populations and the adoption of expensive practices by fish farms to reduce heavy losses. Disease-related mortality in wild fish populations is almost certainly underestimated because of e.g. oversight, scavenging by wild animals, misdiagnosis and fish stocking.;3. PKD prevalences are spatially and temporally variable, range from 0 to 90-100% and are typically highest in juvenile fish.;4. Laboratory and field studies demonstrate that (i) increasing temperatures enhance disease prevalence, severity and distribution and PKD-related mortality; (ii) eutrophication may promote outbreaks. Both bryozoans and T. bryosalmonae stages in bryozoans undergo temperature- and nutrient-driven proliferation.;5. Tetracapsuloides bryosalmonae is likely to achieve persistent infection of highly clonal bryozoan hosts through vertical transmission, low virulence and host condition-dependent cycling between covert and overt infections. Exploitation of fish hosts entails massive proliferation and spore production by stages that escape the immune response. Many aspects of the parasite's life cycle remain obscure. If infectious stages are produced in all hosts then the complex life cycle includes multiple transmission routes.;6. Patterns of disease outbreaks suggest that background, subclinical infections exist under normal environmental conditions. When conditions change, outbreaks may then occur in regions where infection was hitherto unsuspected.;7. Environmental change is likely to cause PKD outbreaks in more northerly regions as warmer temperatures promote disease development, enhance bryozoan biomass and increase spore production, but may also reduce the geographical range of this unique multihost-parasite system. Coevolutionary dynamics resulting from host-parasite interactions that maximise fitness in previous environments may pose problems for sustainability, particularly in view of extensive declines in salmonid populations and degradation of many freshwater habitats.

GLP-2 receptors in human disease: high expression in gastrointestinal stromal tumors and Crohn's disease

Peptide hormones of the glucagon-like peptide (GLP) family play an increasing clinical role, as reported for GLP-1 in diabetes therapy and insulinoma diagnostics. GLP-2, despite its known trophic and anti-inflammatory intestinal actions translated into preliminary clinical studies using the GLP-2 analogue teduglutide for treatment of short bowel syndrome and Crohn's disease, remains poorly characterized in terms of expression of its receptor in tissues of interest. Therefore, the GLP-2 receptor expression was assessed in 237 tumor and 148 non-neoplastic tissue samples with in vitro receptor autoradiography. A GLP-2 receptor expression was present in 68% of gastrointestinal stromal tumors (GIST). Furthermore, GLP-2 receptors were identified in the intestinal myenteric plexus, with significant up-regulation in active Crohn's disease. The GLP-2 receptors in GIST may be used for clinical applications like in vivo targeting with radiolabelled GLP-2 analogues for imaging and therapy. Moreover, the over-expressed GLP-2 receptor in the myenteric plexus may represent the morphological correlate of the clinical target of teduglutide in Crohn's disease.

Crohn's disease-associated polymorphism within the PTPN2 gene affects muramyl-dipeptide-induced cytokine secretion and autophagy

The single nucleotide polymorphism (SNP) rs2542151 within the gene locus region encoding protein tyrosine phosphatase non-receptor type 2 (PTPN2) has been associated with Crohn's disease (CD), ulcerative colitis (UC), type-I diabetes, and rheumatoid arthritis. We have previously shown that PTPN2 regulates mitogen-activated protein kinase (MAPK) signaling and cytokine secretion in human THP-1 monocytes and intestinal epithelial cells (IEC). Here, we studied whether intronic PTPN2 SNP rs1893217 regulates immune responses to the nucleotide-oligomerization domain 2 (NOD2) ligand, muramyl-dipeptide (MDP).

β-glucan triggers spondylarthritis and Crohn's disease-like ileitis in SKG mice

The spondylarthritides (SpA), including ankylosing spondylitis (AS), psoriatic arthritis (PsA), reactive arthritis, and arthritis associated with inflammatory bowel disease, cause chronic inflammation of the large peripheral and axial joints, eyes, skin, ileum, and colon. Genetic studies reveal common candidate genes for AS, PsA, and Crohn's disease, including IL23R, IL12B, STAT3, and CARD9, all of which are associated with interleukin-23 (IL-23) signaling downstream of the dectin 1 β-glucan receptor. In autoimmune-prone SKG mice with mutated ZAP-70, which attenuates T cell receptor signaling and increases the autoreactivity of T cells in the peripheral repertoire, IL-17-dependent inflammatory arthritis developed after dectin 1-mediated fungal infection. This study was undertaken to determine whether SKG mice injected with 1,3-β-glucan (curdlan) develop evidence of SpA, and the relationship of innate and adaptive autoimmunity to this process.

Imaging appearances of Buerger's disease complications in the upper and lower limbs

Thromboangiitis obliterans (Buerger's disease) is a rare, non-atherosclerotic, segmental, inflammatory vasculitis that most commonly involves small and medium-sized arteries, veins and nerves of the extremities and affects tobacco smokers between the ages of 25 and 45 years. The manifestations of Buerger's disease can be extremely variable and, therefore, awareness of the condition is important for both general and musculoskeletal radiologists. This paper presents the radiological appearance of the sequelae of Buerger's disease involving the upper and lower limbs.

Small-bowel MRI in children and young adults with Crohn disease: retrospective head-to-head comparison of contrast-enhanced and diffusion-weighted MRI

Small-bowel MRI based on contrast-enhanced T1-weighted sequences has been challenged by diffusion-weighted imaging (DWI) for detection of inflammatory bowel lesions and complications in patients with Crohn disease.

Genetic variations in IL28B and allergic disease in children

Environmental changes affecting the relationship between the developing immune system and microbial exposure have been implicated in the epidemic rise of allergic disease in developed countries. While early developmental differences in T cell function are well-recognised, there is now emerging evidence that this is related to developmental differences in innate immune function. In this study we sought to examine if differences associated with innate immunity contribute to the altered immune programming recognised in allergic children. Here, we describe for the first time, the association of carriage of the T allele of the tagging single nucleotide polymorphism rs12979860 3 kb upstream of IL28B, encoding the potent innate immune modulator type III interferon lambda (IFN-λ3), and allergy in children (p = 0.004; OR 4.56). Strikingly, the association between rs12979860 genotype and allergic disease is enhanced in girls. Furthermore, carriage of the T allele at rs12979860 correlates with differences in the pro-inflammatory profile during the first five years of life suggesting this contributes to the key differences in subsequent innate immune development in children who develop allergic disease. In the context of rising rates of disease, these immunologic differences already present at birth imply very early interaction between genetic predisposition and prenatal environmental influences.

The Emerging Role of TLR and Innate Immunity in Cardiovascular Disease

Cardiovascular disease is a complex disorder involving multiple pathophysiological processes, several of which involve activation of toll-like receptors (TLRs) of the innate immune system. As sentinels of innate immunity TLRs are nonclonally germline-encoded molecular pattern recognition receptors that recognize exogenous as well as tissue-derived molecular dangers signals promoting inflammation. In addition to their expression in immune cells, TLRs are found in other tissues and cell types including cardiomyocytes, endothelial and vascular smooth muscle cells. TLRs are differentially regulated in various cell types by several cardiovascular risk factors such as hypercholesterolemia, hyperlipidemia, and hyperglycemia and may represent a key mechanism linking chronic inflammation, cardiovascular disease progression, and activation of the immune system. Modulation of TLR signaling by specific TLR agonists or antagonists, alone or in combination, may be a useful therapeutic approach to treat various cardiovascular inflammatory conditions such as atherosclerosis, peripheral arterial disease, secondary microvascular complications of diabetes, autoimmune disease, and ischemia reperfusion injury. In this paper we discuss recent developments and current evidence for the role of TLR in cardiovascular disease as well as the therapeutic potential of various compounds on inhibition of TLR-mediated inflammatory responses.

Sense and nonsense of an extended pelvic lymph node dissection in prostate cancer

Lymph node metastases associated with prostate cancer (PCa) has been shown to be a poor prognostic factor. The role of pelvic lymph node dissection (PLND) itself in relation to survival remains unclear, however. A Medline search was conducted to address this issue. The following conclusions were drawn. Only recently, improved survival due to completion of radical prostatectomy (RP) (compared to abandoning RP) in known or presumed lymph-node-positive patients has been shown. Lymph node sampling can only be considered representative if an adequate number of nodes is removed. While several authors have suggested that a therapeutic benefit in patients undergoing RP is not provided by PLND, the reliability of these studies is uncertain. Contrary to this, several studies have indicated the possibility of long-term survival even in the presence of limited lymph node metastases. The role and timing of initiation of adjuvant androgen deprivation therapy (ADT) in patients who have node-positive disease after RP is controversial. Recent studies suggest that delaying ADT may not adversely impact survival.

MR imaging in Crohn's disease: correlation of MR motility measurement with histopathology in the terminal ileum

BACKGROUND: The objective of the study was to correlate MR-detectable motility alterations of the terminal ileum with biopsy-documented active and chronic changes in Crohn's disease. METHODS: This IRB approved retrospective analysis of 43 patients included magnetic resonance enterography (MRE) and terminal ileum biopsies (<2 weeks apart). Motility was measured at the terminal ileum using coronal 2D trueFISP pulse sequences (1.5T MRI,TR 83.8,TE1.89) and dedicated motility assessment software. Motility grading (hypermotility, normal, hypomotility, complete arrest) was agreed by two experienced readers. Motility was compared and correlated with histopathology using two-tailed Kruskal-Wallis test and paired Spearman Rank-Order Correlation tests. KEY RESULTS: Motility abnormalities were present in 27/43 patients: nine hypomotility and 18 complete arrest. Active disease was diagnosed on 15 biopsies: eight moderate and seven severe inflammatory activity. Chronic changes were diagnosed on 17 biopsies: 13 moderate and four severe cases. In four patients with normal motility alterations on histopathology were diagnosed. Histopathology correlated with presence (P = 0.0056 for hypomotility and P = 0.0119 for complete arrest) and grade (P < 0.0001; P = 0.0004) of motility alterations. A significant difference in the motility was observed in patients with active or chronic CD compared with patients without disease (P < 0.001; P = 0.0024). CONCLUSIONS & INFERENCES: MR-detectable motility changes of the terminal ileum correlate with histopathological findings both in active and chronic CD. Motility changes may indicate the presence pathology, but do not allow differentiation of active and chronic disease.

Intracerebroventricularly delivered VEGF promotes contralesional corticorubral plasticity after focal cerebral ischemia via mechanisms involving anti-inflammatory actions

Vascular endothelial growth factor (VEGF) has potent angiogenic and neuroprotective effects in the ischemic brain. Its effect on axonal plasticity and neurological recovery in the post-acute stroke phase was unknown. Using behavioral tests combined with anterograde tract tracing studies and with immunohistochemical and molecular biological experiments, we examined effects of a delayed i.c.v. delivery of recombinant human VEGF(165), starting 3 days after stroke, on functional neurological recovery, corticorubral plasticity and inflammatory brain responses in mice submitted to 30 min of middle cerebral artery occlusion. We herein show that the slowly progressive functional improvements of motor grip strength and coordination, which are induced by VEGF, are accompanied by enhanced sprouting of contralesional corticorubral fibres that branched off the pyramidal tract in order to cross the midline and innervate the ipsilesional parvocellular red nucleus. Infiltrates of CD45+ leukocytes were noticed in the ischemic striatum of vehicle-treated mice that closely corresponded to areas exhibiting Iba-1+ activated microglia. VEGF attenuated the CD45+ leukocyte infiltrates at 14 but not 30 days post ischemia and diminished the microglial activation. Notably, the VEGF-induced anti-inflammatory effect of VEGF was associated with a downregulation of a broad set of inflammatory cytokines and chemokines in both brain hemispheres. These data suggest a link between VEGF's immunosuppressive and plasticity-promoting actions that may be important for successful brain remodeling. Accordingly, growth factors with anti-inflammatory action may be promising therapeutics in the post-acute stroke phase.

The Impact of PPARγ Genetic Variants on IBD Susceptibility and IBD Disease Course

PPARγ is a nuclear receptor that regulates numerous pathways including cytokine expression and immune responses and plays an important role in controlling colon inflammation. We aimed at determining the occurring PPARγ SNPs, at predicting the haplotypes, and at determining the frequency outcome in inflammatory bowel disease (IBD) patients in comparison with healthy controls. We determined genetic variants in the coding exons and flanking intronic sequences of the NR1C3 gene in 284 IBD patients and 194 controls and predicted NR1C3 haplotypes via bioinformatic analysis. We investigated whether certain NR1C3 variants are associated with susceptibility to IBD or its disease course. None of the detected 22 NR1C3 variants were associated with IBD. Two variants with allelic frequencies over 1% were included in haplotype/diplotype analyses. None of the NR3C1 haplotypes showed association with IBD development or disease course. We conclude that NR1C3 haplotypes are not related to IBD susceptibility or IBD disease activity.

Isolated Rosai-Dorfman disease of intracranial meninges

Rosai-Dorfman disease (RDD) is a non-neoplastic proliferative histiocytic disorder that primarily affects lymph nodes (sinus histiocytosis with massive lymphadenopathy). Primary RDD of the central nervous system is most uncommon. We report on a 35-year-old man with isolated RDD of the meninges overlying the left cerebral hemisphere. Presenting signs and symptoms included severe progressive ipsilateral headaches of 4 months duration, as well as laboratory evidence of mild non-specific systemic inflammatory reaction. On magnetic resonance imaging, the lesion was seen as a contrast-enhancing, plaque-like thickening of the dura mater over the left convexity,without impinging on adjacent bone or cerebral parenchyma. Meningeal biopsy revealed a mixed mononuclear infiltrate dominated by CD68(+), S100(+), CD1a(-) non-Langerhans type histiocytes on a background of fibrosis. Bacteria, in particular mycobacteria, and fungi were excluded with special stains. Extensive clinical workup, encompassing computed tomography of thoracal and abdominal organs, bone marrow biopsy, and bronchoalveolar lavage failed to reveal any extracranial involvement. Laboratory tests for autoimmunity, including C- and P-antineutrophil cytoplasmic antibodies, antinuclear antibody, and serum rheumatoid factor, were negative. Methylprednisolone therapy induced complete remission of symptoms, with the neuroradiologic status remaining unchanged on follow-up after 2 months. We discuss the complex clinicopathologic differential diagnosis and therapeutic issues of this rare condition. While the correct diagnosis of central nervous system RDD is unlikely to be established without invasive procedures (biopsy), a conservative therapeutic approach may be considered a legitimate option.