Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5-6
pubmed:dateCreated
1999-5-13
pubmed:abstractText
Hepatitis C virus (HCV) is a single-stranded RNA agent which expresses its genetic informations in the form of a single, large polyprotein encoded by an open reading frame (ORF) that extends through most of its genomic RNA. Proteolytic cleavage of the ORF product is essential for the virogenesis and the production of viral progeny. HCV is responsible for chronic liver disease, cirrhosis and possibly hepatocellular carcinoma. Viral persistence is considered the greatest problem in the management of HCV infection. It may result from several mechanisms, two of which are established. In the first, the high rate of genetic variations during viral replication results in the production of mutants capable of escaping the immune attack. In the second, the virus infects cells of the immune system itself, which represent a privileged site that cannot be reached by virus-specific T cell response. Involvement of lymphoid cells in the early stages of HCV infection may provide insight into the pathobiologic patterns of extrahepatic dissemination (lymph nodes, major salivary glands, kidneys, blood vessels). Dissemination of HCV-infected lymphoid cells throughout the organism is likely to maintain a mobile and extensive reservoir of the virus. In this respect, extrahepatic sites may act as a source of continuous reinfection of hepatocytes. Studies of intrahepatic B lymphocytes indicate that they are infected with HCV, clonally expanded and activated to secrete IgM molecules with rheumatoid factor activity. This strongly suggests that HCV directly stimulates B cell expansion, which may result in an indolent stage of lymphoproliferation (i.e., mixed cryoglobulinemia) or in frank B cell non-Hodgkin's lymphoma (NHL). The frequency of NHL, however, is much lower than that of HCV infection, suggesting that HCV alone is not able to induce tumors and that cellular events, in addition to the presence of virus and virus-encoded products, are necessary in order to obtain a malignant B cell phenotype. The demonstration of HCV productive infection in bone marrow-recruited and circulating pluripotent hematopoietic CD34+ stem cells indicates that HCV replication occurs in the early differentiation stages of hematopoietic progenitors. These are stable cell populations and are likely to represent the initial site of infection and a continuous source of virus production.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1042-8194
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
463-76
pubmed:dateRevised
2005-11-16
pubmed:meshHeading
pubmed-meshheading:9922037-B-Lymphocytes, pubmed-meshheading:9922037-Clone Cells, pubmed-meshheading:9922037-Cryoglobulinemia, pubmed-meshheading:9922037-Gene Rearrangement, B-Lymphocyte, pubmed-meshheading:9922037-Genes, Viral, pubmed-meshheading:9922037-Germinal Center, pubmed-meshheading:9922037-Hematopoietic Stem Cells, pubmed-meshheading:9922037-Hepacivirus, pubmed-meshheading:9922037-Hepatitis C, Chronic, pubmed-meshheading:9922037-Hepatitis C Antigens, pubmed-meshheading:9922037-Humans, pubmed-meshheading:9922037-Immunoglobulin M, pubmed-meshheading:9922037-Liver, pubmed-meshheading:9922037-Lymphoid Tissue, pubmed-meshheading:9922037-Lymphoma, Non-Hodgkin, pubmed-meshheading:9922037-Polymerase Chain Reaction, pubmed-meshheading:9922037-Prevalence, pubmed-meshheading:9922037-RNA, Viral, pubmed-meshheading:9922037-Rheumatoid Factor, pubmed-meshheading:9922037-Viral Proteins, pubmed-meshheading:9922037-Virus Replication
pubmed:year
1998
pubmed:articleTitle
Hepatitis C virus infection, mixed cryoglobulinemia, and non-Hodgkin's lymphoma: an emerging picture.
pubmed:affiliation
Department of Biomedical Sciences, University of Bari Medical School, Italy.
pubmed:publicationType
Journal Article, Review