24 research outputs found
B Lymphocyte intestinal homing in inflammatory bowel disease
<p>Abstract</p> <p>Background</p> <p>Inflammatory bowel disease (IBD) is thought to be due to an abnormal interaction between the host immune system and commensal microflora. Within the intestinal immune system, B cells produce physiologically natural antibodies but pathologically atypical anti-neutrophil antibodies (xANCAs) are frequently observed in patients with IBD. The objective is to investigate the localisation of immunoglobulin-producing cells (IPCs) in samples of inflamed intestinal tissue taken from patients with IBD, and their possible relationship with clinical features.</p> <p>Methods</p> <p>The IPCs in small intestinal, colonic and rectal biopsy specimens of patients with IBD were analysed by means of immunofluorescence using polyclonal rabbit anti-human Ig and goat anti-human IgM. The B cell phenotype of the IPC-positive samples was assessed using monoclonal antibodies specific for CD79, CD20, CD23, CD21, CD5, λ and κ chains. Statistical correlations were sought between the histological findings and clinical expression.</p> <p>Results</p> <p>The study involved 96 patients (64 with ulcerative colitis and 32 with Crohn's disease). Two different patterns of B lymphocyte infiltrates were found in the intestinal tissue: one was characterised by a strong to moderate stromal localisation of small IgM<sup>+</sup>/CD79<sup>+</sup>/CD20<sup>-</sup>/CD21<sup>-</sup>/CD23<sup>-</sup>/CD5<sup>± </sup>IPCs (42.7% of cases); in the other (57.3%) no such small IPCs were detected in stromal or epithelial tissues. <it>IPCs </it>were significantly less frequent in the patients with Crohn's disease than in those with ulcerative colitis (p = 0.004).</p> <p>Conclusion</p> <p>Our findings suggest that different immunopathogenetic pathways underlie chronic intestinal inflammation with different clinical expressions. The presence of small B lymphocytes resembling B-1 cells also seemed to be negatively associated with Crohn's disease. It can therefore be inferred that the gut contains an alternative population of B cells that have a regulatory function.</p
Management of hepatitis C virus genotype 4: recommendations of an international expert panel.
HCV has been classified into no fewer than six major genotypes and a series of subtypes. Each HCV genotype is unique with respect to its nucleotide sequence, geographic distribution, and response to therapy. Genotypes 1, 2, and 3 are common throughout North America and Europe. HCV genotype 4 (HCV-4) is common in the Middle East and in Africa, where it is responsible for more than 80% of HCV infections. It has recently spread to several European countries. HCV-4 is considered a major cause of chronic hepatitis, cirrhosis, hepatocellular carcinoma, and liver transplantation in these regions. Although HCV-4 is the cause of approximately 20% of the 170 million cases of chronic hepatitis C in the world, it has not been the subject of widespread research. Therefore, this document, drafted by a panel of international experts, aimed to review current knowledge on the epidemiology, natural history, clinical, histological features, and treatment of HCV-4 infections
International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.
Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist
Recommendations for the prevention, diagnosis, and treatment of chronic hepatitis B and C in special population groups (migrants, intravenous drug users and prison inmates)
The global spread of hepatitis B virus (HBV) and hepatitis C virus (HCV), their high chronicity rates and their progression to cirrhosis and hepatocellular carcinoma, are major public health problems. Research and intervention programmes for special population groups are needed in order to assess their infection risk and set up suitable prevention and control strategies. Aim of this paper is to give health care professionals information on HBV and HCV infections amongst migrants, drug users and prison inmates. The manuscript is an official Position Paper on behalf of the following Scientific Societies: Italian Association for the Study of the Liver (A.I.S.F.), Italian Society of Infectious and Tropical Diseases (S.I.M.I.T.), Italian Federation Department's Operators and Addiction Services (FederSerD), Italian Prison Medicine and Healthcare Society (S.I.M.S.Pe.). The considered population groups, having a high prevalence HBV and HCV infections, require specific interventions. In this context, the expression "special population" refers to specific vulnerable groups at risk of social exclusion, such as migrants, prison inmates, and intravenous drug users. When dealing with special population groups, social, environmental and clinical factors should be considered when selecting candidates for therapy as indicated by national and international guidelines. (C) 2010 Editrice Gastroenterologica ltaliana S.r.l. Published by Elsevier Ltd. All rights reserved