Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “IBD”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources

[Chronic inflammatory bowel diseases (IBD): novel pathophysiological concepts and their clinical relevance].

Despite many years of intensive research the pathogenesis of inflammatory bowel diseases is still enigmatic. All efforts to identify the cause of Crohn's disease and ulcerative colitis in a dysregulation of specific immune mechanisms have failed. This review presents a novel pathogenetic concept, based on the expression of natural mucosal antibiotic peptides. These so called defensins are part of innate immunity and defend the mucosa as antimicrobial peptides against intraluminal potentially pathogenic and invasive bacteria. In contrast to ulcerative colitis, Crohn's disease is characterised by a diminished defensin expression. This defect may represent the molecular pathogenesis of this disease.

Bacterial Translocation↗

Linkage analysis of susceptibility to leprosy type using an IBD regression method.

Leprosy is a chronic disease caused by infection with Mycobacterium leprae, which is manifested across a wide clinical spectrum. There is evidence that susceptibility both to leprosy per se and to the clinical type of leprosy is influenced by host genetic factors. This paper describes the application of an identity by descent regression search for genetic determinants of leprosy type among families from Karonga District, Northern Malawi. Suggestive evidence was found for linkage to leprosy type on chr 21q22 (P<0.001). The methodological implications of the approach and the findings are discussed.

Chromosomes, Human, Pair 21↗

Evidence for genetic heterogeneity in inflammatory bowel disease (IBD); HLA genes in the predisposition to suffer from ulcerative colitis (UC) and Crohn's disease (CD).

Family and epidemiological studies support a genetic susceptibility to UC and CD. Conflicting reports regarding associations between UC and HLA-DR2 and between CD and various HLA alleles have been published. The aim of this study was to determine whether molecularly defined HLA-DR genes are associated with these diseases in a Dutch group of patients. Fifty-nine unrelated Dutch UC patients and 89 CD patients were typed using DNA-based methods. A total of 2400 healthy local blood donors served as controls. The phenotype frequency of the HLA-DRB1*15 allele was increased in UC patients compared with controls (42% versus 26% in controls; P = 0.006; odds ratio (OR) = 2.1), and was predominantly found in female patients (53% versus 24%; P = 0.001; OR = 3.5). The DRB1*15 allele was increased in UC patients having a positive family history (P = 0.01; OR = 5.8). Among the 16 patients who showed an increase in extent of disease during follow up, 10 were DRB1*15+ (P = 0.002; OR = 4.8). The frequency of the DRB1*13 allele was decreased in patients with UC (15% versus 28% in controls; P = 0.04; OR = 0.5). In CD, no association was observed between disease or particular clinical subgroups and any allele tested. The present study provides additional evidence for the genetic association between UC and HLA-DRB1*15, and supports recent findings that the susceptibility gene(s) for CD is not located in the HLA class II region.

Adolescent↗

The triangle test statistic (TTS): a test of genetic homogeneity using departure from the triangle constraints in IBD distribution among affected sib-pairs.

The proportions of affected sibs sharing 2, 1 or 0 identical by descent parental marker alleles have been shown to conform to the 'triangle constraints' (Suarez, 1978; Holmans, 1993). It has also been shown (Dudoit & Speed, 1999) that the constraints are verified provided certain assumptions hold. In this study we explore a realistic situation in which the constraints fail due to the presence of a factor in which the sibs differ, a factor on which penetrance depends. This factor may be a characteristic of the trait (severe vs. mild form), or the presence/absence of an associated trait or an environmental factor. We show that under such situations, using the triangle constraints may lead to important loss of power to detect linkage by the MLS test. We propose here an alternative approach in order to detect both linkage and heterogeneity.

Alleles↗

Strategies for targeting tumour necrosis factor in IBD.

Tumour necrosis factor (TNF) plays an important role in mediating the inflammation of inflammatory bowel disease, in particular, Crohn's disease. Strategies aimed at reducing tumour necrosis factor in patients with inflammatory bowel disease include the mouse/human chimeric monoclonal antibody infliximab, the humanized monoclonal antibody CDP571, the human soluble TNF p55 receptor onercept, the human monoclonal antibody D2E7 (adalimumab), the anti-TNF human antibody Fab' fragment-polyethelene glycol (PEG) conjugate CDP870, and the small molecules thalidomide and CNI-1493 (MAP-kinase inhibitor). Infliximab is effective for treating active Crohn's disease, maintaining remission, closing fistulas, maintaining fistula closure, and treating ankylosing spondylitis. Infliximab is also being investigated for the treatment of ulcerative colitis. Side-effects occurring in patients treated with infliximab include human anti-chimeric antibodies, infusion reactions, delayed hypersensitivity reactions, formation of autoantibodies, and, in rare circumstances, drug-induced lupus and serious infections, including tuberculosis. CDP571 is effective for treating active Crohn's disease, steroid sparing, and possibly for closing fistulas and maintaining remission. Side-effects occurring in patients treated with CDP571 include anti-idiotype antibodies, infusion reactions and the formation of autoantibodies. A controlled trial of etanercept in patients with Crohn's disease was negative. Pilot studies with onercept, thalidomide, and CNI-1493 have suggested benefit for Crohn's disease. There are no published data on the efficacy of adalimumab (D2E7) or CDP870 for either Crohn's disease or ulcerative colitis. Anti-tumour necrosis factor therapies are effective for the treatment of Crohn's disease and are being investigated for ulcerative colitis.

Antibodies, Monoclonal↗

"Atypical p-ANCA" in IBD and hepatobiliary disorders react with a 50-kilodalton nuclear envelope protein of neutrophils and myeloid cell lines.

BACKGROUND & AIMS: Atypical "antineutrophil cytoplasmic antibodies" (ANCA) are present in patients with ulcerative colitis (UC), primary sclerosing cholangitis (PSC), and autoimmune hepatitis (AIH). Recently, we showed that atypical p-ANCA react with nuclear envelope proteins of neutrophils. Based on this observation, we aimed to characterize the nuclear antigen recognized by atypical p-ANCA. METHODS: We prepared cytoplasmic and nuclear extracts of human neutrophils, human HL-60, and murine 32D myeloid cells. Proteins were resolved by 1- and 2-dimensional gel electrophoresis. Reactive proteins were detected by immunoblotting with sera from 118 individuals (UC, 25; PSC, 28; AIH, 35; disease and normal controls, 30). Atypical p-ANCA (n = 64) were affinity-purified against the reactive protein and investigated for their immunofluorescence pattern using confocal microscopy. RESULTS: Immunoblotting showed reactivity to a myeloid-specific 50-kilodalton nuclear protein with an isoelectric point of pH 6.0 detected in 92% (59 of 64) of the patients with inflammatory bowel or hepatobiliary diseases and atypical p-ANCA. Affinity-purified antibodies against the 50-kilodalton protein gave a nuclear rim-like fluorescence on myeloid cells examined by immunofluorescence microscopy. Affinity-purified antibodies did not recognize antigens in nonmyeloid cells. CONCLUSIONS: Atypical p-ANCA in UC, PSC, or AIH recognize a 50-kilodalton myeloid-specific nuclear envelope protein.

Adolescent↗