Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Severe malaria is a major cause of childhood mortality in sub-Saharan Africa but the factors predisposing children to severe forms of malaria have not been fully elucidated. In a case-control study of over 1,200 Gambian children hepatitis B virus carriage was significantly increased amongst cases of severe malaria compared to matched controls. We suggest that this association may relate to impaired clearance of liver stage parasites in the presence of the reduced level of HLA class I antigen expression on hepatocytes infected by hepatitis B virus. If this association is causal and viral carriage predisposes to severe malaria, widespread vaccination against hepatitis B virus may reduce mortality from severe malaria.
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PMID:Association of hepatitis B surface antigen carriage with severe malaria in Gambian children. 758 70

To determine the relationship between hepatitis B virus (HBV) replication and HLA antigen display at a cellular level, the hepatic expression of HLA antigens and HBV genome (HBV-DNA)/gene products (HBsAg/HBcAg) was studied in 24 patients with chronic HBV infection using simultaneously immunohistochemistry and nonisotopic in situ hybridization. The effect of interferon-alpha and interferon-gamma on hepatocyte HLA antigen expression was also evaluated using primary hepatocyte culture in eight patients with chronic HBV infection. HLA class I antigens were detected on hepatocyte membrane in 23 patients (95.8%). Hepatocytes positive for HBcAg and HBV-DNA (cytoplasmic +/- nuclear) were either negative or only faintly positive for HLA class I antigens, while hepatocytes positive for HBsAg showed similar levels of HLA class I antigen expression compared with those hepatocytes with no HBsAg expression. In contrast, hepatocytes adjacent to inflammatory infiltrates, whether positive for HBV-DNA or HBV antigens or not, were always strongly positive for HLA class I antigens. Furthermore, active liver histology (N = 12) was associated with a higher overall level of hepatic HLA class I antigen expression as compared with inactive histology (N = 12, P = 0.003). Both interferon-alpha and interferon-gamma treatment in vitro enhanced hepatocyte HLA class I antigen expression. These data indicate that expression of HLA class I antigens is not enhanced on the membrane of hepatocytes with HBV replication, and this may be one factor that permits the development of viral persistence.
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PMID:Hepatic HLA antigen display in chronic hepatitis B virus infection. Relation to hepatic expression of HBV genome/gene products and liver histology. 768 63

The relationship between 2', 5'-oligoadenylate synthetase (2-5AS) and HLA class I antigen in the hepatocyte of patients with type B or type C chronic hepatitis with and without interferon (IFN) therapy was investigated. The expression of HLA class I antigen of hepatocytes of biopsied specimen and PBL HLA class I antigen expression showed relevancy. Then, the HLA antigen expression of peripheral blood lymphocyte (PBL) and the 2-5AS activity of peripheral blood mononuclear cell (PBMC) were analyzed. In patients with type B or type C hepatitis, the mean activity of PBMC 2-5AS was significantly higher than that of healthy controls. Also the HLA class I antigen expression of PBL was significantly intense in patients with type B or type C hepatitis compared with healthy controls. In the acute exacerbated phase of type B chronic hepatitis, the HLA class I antigen expression of PBL and 2-5AS activity of PBMC increased along with elevation of serum GPT and then decreased with the remission of serum GPT. These results suggest that endogenously produced IFN leads the lysis of hepatocyte infected with hepatitis B virus (HBV) by cytotoxic T cells, and the restriction of HBV replication by activation of the 2-5A system simultaneously, and then leads the elimination of HBV. The activity of PBMC 2-5AS and the expression of PBL HLA class I antigen increased significantly during IFN therapy. In type B chronic hepatitis, the effective cases showed relatively high activity of serum 2-5AS compared with the non-effective cases. On the other hand, there were no significant differences in PBL HLA class I antigen expression between effective cases and non-effective cases. In type C chronic hepatitis, most patients with type III and type IV HCV genotype showed disappearance of HCV-RNA regardless of serum 2-5AS activity. In patients with type II HCV genotype, the serum 2-5AS activity was related to the anti-viral effect of IFN therapy.
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PMID:[Mechanisms of the effect of interferon (IFN) therapy in patients with type B and C chronic hepatitis]. 768 26

Cytotoxic T lymphocyte (CTL) activity for hepatitis B virus (HBV) DNA-transfected HepG2 cells (designated HB3-5), which secrete HBsAg, HBeAg and HBV particles, was investigated in 31 patients with chronic HBV infection (18 chronic hepatitis and 13 asymptomatic carriers). 51Cr-labeled HB3-5 with A2 as a major HLA class I antigen served as target cells and T cells from peripheral blood mononuclear cells as effector cells. The CTL activity was measured by a 51Cr release assay. Patients were divided into two groups, the A2 group bearing HLA-A2 and the non-A2 group not bearing HLA-A2. Chronic hepatitis patients in the A2 group showed increased HBV Ag-specific cytotoxicity compared with that seen in the non-A2 group (5.2 +/- 3.1% vs. 0.9 +/- 1.4%; means +/- SD, P < 0.01). In the A2 group with chronic hepatitis, the cytotoxicity was greater in anti-HBe positive patients than in HBeAg positive patients (8.6 +/- 1.9% vs. 3.4 +/- 2.0%, P < 0.01), and asymptomatic carriers showed less cytotoxicity (0.35 +/- 0.31%, P < 0.001) compared with chronic hepatitis patients. In the non-A2 group, HBV Ag-specific CTL activity was negligible in most patients and thus no differences were found among all patient groups. The HBV Ag-specific cytotoxicity was inhibited by antibodies to CD3, HLA class I and hepatitis B nucleocapsid antigens. Removal of CD8+ cells also resulted in marked decrease in the cytotoxicity. These findings indicate that HBV Ag-specific cytotoxicity reflects liver cell damage and HBeAg/anti-HBe status. Furthermore, our assay system appears to be useful to assess CTL response in patients with chronic HBV infection.
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PMID:Cytotoxic T lymphocyte activity to hepatitis B virus DNA-transfected HepG2 cells in patients with chronic hepatitis B. 769 38

Studies were undertaken to examine the effect of recombinant human transforming growth factor beta 1 (rTGF-beta 1) on cellular and humoral immune responses of peripheral blood mononuclear cells (PBMC) from patients with chronic hepatitis B. The addition of TGF-beta 1 caused a significant dose-dependent inhibition of hepatitis B (HB) core Ag-stimulated interferon-gamma and antibody to HB core Ag production and proliferation of PBMC from chronic hepatitis patients and HB-immune donors. TGF-beta 1 also induced a significant reduction in pokeweed mitogen-stimulated IgG and IgM production, as well as phytohemagglutinin p-stimulated proliferative response of PBMC. The degree of inhibition of TGF-beta 1 did not differ between antigen-specific and -nonspecific cellular and humoral immune responses, and between control individuals and patients. Pretreatment study with TGF-beta 1 showed that the activities of T cells, B cells and monocytes were similarly inhibited. Further, TGF-beta 1 inhibited activities of HLA class I antigen-matched cytotoxic T cells from patients with chronic hepatitis B for HBV DNA-transfected HepG2 cells in a 51Cr release assay. The results suggest that TGF-beta 1 may play a role in the regulation of antigen-dependent and -independent immune responses in patients with chronic hepatitis B.
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PMID:Effect of recombinant human transforming growth factor beta 1 on immune responses in patients with chronic hepatitis B. 851 Apr 88