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)

We conducted a case-control study to assess the roles of tumor necrosis factor (TNF)-alpha polymorphisms, substance use habits, and chronic hepatitis B virus (HBV)/hepatitis C virus (HCV) infection on the risk for hepatocellular carcinoma (HCC). We enrolled 200 pairs of sex- and age-matched patients with HCC and unrelated healthy controls. TNF-alpha polymorphisms were detected with polymerase chain reaction and direct sequencing. Serum hepatitis B surface antigen (HBsAg) and antibodies to HCV (anti-HCV) were detected. We used a structured questionnaire to obtain information about substance use habits.Multivariate analysis indicated that TNF308.2 allele (odds ratio [OR], 3.23; p = 0.011), habitual betel quid chewing (OR, 3.70; p = 0.011), HBsAg (OR, 23.62; p = 0.0001), and anti-HCV (OR, 38.73; p = 0.0001) were independent risk factors for HCC. Having at least 2 substance use habits was associated with risk for HCC. The more substance use habits, the higher the OR for HCC (p(for trend) = 0.0001). There were additive interactions among TNF308.2 allele, substance use habits, and chronic HBV/HCV infection. Multivariate analysis indicated that TNF308.2 allele (p = 0.001), cigarette smoking (p = 0.0001), and alcohol drinking (p = 0.0001) were independent risk factors for habitual betel quid chewing. Moreover, patients harboring the TNF308.2 allele and/or those with habits of substance use had low serum albumin concentration and platelet count (each p = 0.0001). In conclusion, there are independent and additive interactive effects among the TNF308.2 allele, substance use habits, and chronic HBV/HCV infection on the risk for HCC. Substance use habits or carrying the TNF308.2 allele correlates with disease severity and hepatic fibrosis, which may contribute to higher risks for HCC.
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PMID:Independent and additive interactive effects among tumor necrosis factor-alpha polymorphisms, substance use habits, and chronic hepatitis B and hepatitis C virus infection on risk for hepatocellular carcinoma. 1991 Jul 49

The role of liver NK cells in virus-induced severe viral hepatitis and, subsequently, hepatic failure is not well defined. In this study, we investigated the role of liver NK cells in the development of hepatocyte necrosis in fulminant hepatic failure (FHF) and acute-on-chronic liver failure (ACLF) because of viral infection. A mouse model of FHF induced by murine hepatitis virus strain 3 (MHV-3) was used to study the role of liver NK cells. Samples from patients with hepatitis B virus-related ACLF (HBV-ACLF) were examined. After MHV-3 infection, the number of NK cells in livers of BALB/cJ mice increased markedly, peaked at 48 h postinfection, and remained at a high level until sacrifice. In peripheral blood, spleen, and bone marrow, this number decreased significantly. Expression of CD69, cytotoxic activity, and intracellular IFN-gamma and TNF-alpha production by liver NK cells at 48 h postinfection were all significantly upregulated. Depletion of NK cells 24 h post-MHV-3 infection increased the mice survival from 0 of 18 (0%) to 4 of 18 (22.2%). Highly activated liver NK cells were cytotoxic to MHV-3-infected hepatocytes and this effect was markedly inhibited by anti-Fas ligand (FasL) plus anti-NKG2D mAbs. Furthermore, the accumulation of hepatic NK cells and increased expression of FasL and natural cytotoxicity receptors (NKp30 and NKp46) on the peripheral NK cells from patients with HBV-ACLF were correlated with disease progression. These results indicate NK cells play a pivotal role in the pathogenesis of FHF and HBV-ACLF, in which process Fas/FasL and NKG2D/NKG2D ligand pathway contribute to the liver NK cell-mediated hepatocyte injury.
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PMID:Increased killing of liver NK cells by Fas/Fas ligand and NKG2D/NKG2D ligand contributes to hepatocyte necrosis in virus-induced liver failure. 1994 88

Resolution of hepatitis B virus (HBV) infection was believed to be attributed to the cytotoxic T cell-mediated killing of infected hepatocytes. However, studies in HBV transgenic mice and HBV-infected chimpanzees revealed that T cell control of HBV replication also involves cytokine-mediated noncytolytic mechanisms. The relative role of cytolytic and noncytolytic functions of virus-specific CD8(+) T cells during interaction with HBV-producing hepatocytes is not well understood. By using HLA-A2 matched effector cells (CD8(+) T cell line or clone) and target cells supporting full HBV replication, we demonstrate that virus-specific CD8(+) T cells can inhibit HBV replication in HBV-producing hepatocytes with minimal cell lysis. Although CD8(+) T cells kill a fraction of infected cells, this effect is minimal, and most of the viral inhibition is mediated by noncytolytic mechanisms. CD8(+) T cells produce an array of cytokines, among which IFN-gamma and TNF-alpha are responsible for HBV inactivation in the target cells. Blockade of IFN-gamma and TNF-alpha abrogated the noncytolytic inhibition of HBV, indicating that these two cytokines mediate the control of HBV by noncytolytic mechanisms. Furthermore, treatment of the HBV-producing hepatocytes with rIFN-gamma and rTNF-alpha resulted in an efficient suppression of viral replication without cytotoxicity. In contrast, coculture of the same target cells with activated HLA-mismatched mitogen-activated lymphomononuclear cells caused a marked cytolytic effect and was less effective in HBV control. These results provide direct evidence that virus-specific CD8(+) T cells efficiently control HBV replication by noncytolytic mechanisms, and this effect is mediated by IFN-gamma and TNF-alpha.
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PMID:CD8(+) T cell control of hepatitis B virus replication: direct comparison between cytolytic and noncytolytic functions. 1994 99

We previously identified two HLA-DRB1*0101-restricted epitopes in hepatitis B virus (HBV) X protein (HBx) and in HBV envelope proteins (preS2). To evaluated their help in the development of CD8+ T-cell responses, mice transgenic for human class I and class II HLA molecules were immunized with HBV-T helper constructs. The preS2 epitope favored a well-balanced response with CD4+ and CD8+ T cells producing IFN-gamma, IL-2 and TNF-alpha. The response was focused on CD8+ T cells with the HBx epitope. Fine characterization of helper activities may meet clinical needs in terms of enhancing the potency of preventive or therapeutic polyepitope vaccines.
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PMID:Hepatitis B virus (HBV)-derived DRB1*0101-restricted CD4 T-cell epitopes help in the development of HBV-specific CD8+ T cells in vivo. 2036 6

As a class, tumor necrosis factor (TNF)-alpha inhibitors have provided clinicians significant control over chronic inflammatory diseases. With their widespread use has come the emergence of new side effects such as the reactivation of latent infections. One such infection that may reactivate is the hepatitis B virus (HBV). It is currently unknown if HBV reactivation is a class effect or attributable to a particular TNF-alpha inhibitor. To answer this question, a comprehensive literature review to identify trends in related cases was performed. A systemic literature review was performed using the PubMed and Medline databases (1996 to January 2010) searching for the index term "Hepatitis B" combined with the terms "tumor necrosis factor," "TNF-alpha inhibitors," "etanercept," "adalimumab," "certolizumab," and "golimumab." All relevant articles in English were reviewed, and secondary references of interest were also retrieved. Thirty-five cases with hepatitis B surface antigen (HBsAg) positivity known prior to initiation of TNF-alpha inhibitors were identified. Infliximab was used in 17 cases, etanercept in 12 cases, and adalimumab in 6 cases. All six cases of clinically symptomatic hepatitis were associated with infliximab therapy. Infliximab was associated with the most cases of greater than 2-fold increase in alanine aminotransferase (six of nine cases) and greater than 1,000-fold increase in HBV DNA load (three of four). The two deaths reported occurred with infliximab therapy. Potential mechanisms of action for the reported observations include differences in molecular design, route of administration, and potency in clearing TNF-alpha. In patients with a positive HBsAg prior to starting a TNF-alpha inhibitor, infliximab has the most reported cases associated with HBV reactivation. While such reactivation may be due to a variety of reasons, clinicians prescribing TNF-alpha inhibitors to HBsAg-positive patients should consider prophylactic antiviral therapy and close monitoring for any clinical or serological evidence of hepatitis.
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PMID:Use of tumor necrosis factor alpha inhibitors in hepatitis B surface antigen-positive patients: a literature review and potential mechanisms of action. 2055 50

In patients with chronic HBV infection, immunosuppressive therapy leads to the loss of immune control of replication and excessive increase of HBV viremia. Reactivation of HBV is usually characterized by ALT activity elevation but it may also cause acute liver failure. In patients with a past history of HBV infection (anti-HBc positive), the virus persists in liver cells and may lead to HBV recurrence with identical manifestation. Reactivation and recurrence of hepatitis B may be induced not only by immunosuppressive therapy, but also by anti-CD20 or anti-TNFa treatment. In inactive HBsAg carriers, HBV recurrence and reactivation may be prevented by prophylactic antiviral therapy with lamivudine or other synthetic antivirals (tenofovir, entecavir). Patients who underwent HBV infection in the past should be closely monitored and the treatment should be started when viremia increases. In chronic HCV infection, viremia also increases due to immunosuppression, progression of liver fibrosis is accelerated, but fulminant liver failure is rare. In HCV infected patients, preemptive antiviral treatment cannot be used. In immunocompromised patients, therapy with peginterferon alpha should be indicated individually. Kidney transplant candidates should undergo antiviral treatment before kidney transplantation, during the hemodialysis period.
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PMID:[Viral hepatitis in immunosuppressed patients]. 2080 62

Anti-tumor necrosis factor-a (TNF) therapy has been associated with reactivation of hepatitis B virus infection. Case reports have suggested the concomitant need of lamivudine treatment in patients with HBV infection treated with antiTNFa agents. We describe a case of ankylosing spondylitis with positive HBV surface antigen (HBsAg) treated with infliximab and lamivudine. Clinical response was excellent but when lamivudine therapy was stopped, reactivation of replication viral occurred. After the reintroduction of lamivudine, viral replication was controlled and liver function tests were normalized. Preventive long-term lamivudine therapy is mandatory when anti-TNFa therapy is maintained in patients with chronic HBV infection.
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PMID:[Infliximab in ankylosing spondylitis associated with chronic hepatitis B infection. Role of Lamivudine therapy]. 2179 23

The single nucleotide polymorphisms (SNPs) within the tumor necrosis factor-a (TNF-a) gene promoter region have been reported to be associated with susceptibility to various types of cancers. A case-control study (126 hepatocellular carcinoma [HCC] patients and 126 normal controls) was conducted to elucidate their possible association with the risk of hepatitis B virus (HBV)-related HCC in a Han Chinese population. TNF-alpha polymorphisms -1031T/C, -863C/A, -857C/T, -308G/A, and -238G/A were genotyped by polymerase chain reaction (PCR) and direct DNA sequencing. Disease associations were analyzed by the chi-square test or Fisher's exact test. When analyzed by overall groups, no significant differences in genotype and allele distributions were observed between the control and cases. However, stratified analysis according to sex showed that the frequency of the homozygous C allele of the -857 polymorphism was lower in female cases than in female controls (62.9% vs. 88.9%, p=0.026). In addition, further haplotype analysis revealed that the TCCGA (-1031/-863/-857/-308/-238) was more frequent in controls than cases (p=0.018; odds ratio = 0.266; 95% confidence interval, 0.083-0.857). These results indicated that the TNF-alpha-857C/T polymorphism may modify HBV-related HCC risk among women, and the haplotype TCCGA (-1031/-863/-857/-308/-238) may account for a decreased susceptibility to HCC development in the Han Chinese population. Additional studies in patients with different ethnic backgrounds are needed to validate these finding and to further explore the genetic pathogenesis of HBV-related HCC.
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PMID:Association of TNF-alpha genetic polymorphisms with hepatocellular carcinoma susceptibility: a case-control study in a Han Chinese population. 2192 50

These national clinical guidelines outlining the screening, prophylaxis and critical information required prior to initiating anti-TNF-alpha treatment have been approved by the Danish Society for Gastroenterology. Anti-TNF-alpha therapy is widely used in gastroenterology (for inflammatory bowel disease), rheumatology (for rheumatoid arthritis, psoriatic arthritis and spondyloarthropathies) and dermatology (for psoriasis). With this background, the Danish Society for Gastroenterology established a group of experts to assess evidence for actions recommended before treatment with anti-TNF-alpha agents. Screening should take place for both active tuberculosis and latent tuberculosis. Screening must evaluate the risk of hepatitis B exposure/infection and that of other viral infections such as human immunodeficiency virus (HIV) and varicella zoster virus (VZV). The assessment should include a history of previous malignancies (cases of malignant disease within 5 years of anti-TNF-alpha treatment should be carefully considered). The physical examination should include lung/heart auscultation and lymph node examination, and the paraclinical investigations should include chest X-rays and laboratory tests, including an interferon gamma release assay, a hepatitis B test, an HIV test and, when prior VZV infection is uncertain, a VZV antibody test. Prophylaxis: Isoniazid should be administered in cases of suspected latent TB infection. Antiviral treatment is recommended in HBsAg-positive patients at the start of anti-TNF-alpha treatment. Before anti-TNF-alpha therapy, vaccination with 23-valent pneumococcal vaccine is recommended, and HBV vaccination may be considered in seronegative patients. Annual vaccination against seasonal influenza is recommended. Human papilloma virus vaccination should be administered in accordance with the guidelines of the National Board of Health of Denmark. In patients without a prior VZV infection, VZV vaccination may be considered. Information for patients: Anti-TNF-alpha treatment results in a generally increased risk of infection and latent tuberculosis flare-up. Women are advised to comply with the national guidelines for screening for cervical cancer, and their HPV immunisation status should be clarified. An increased risk of lymphoma with biological therapy in combination with thiopurines should be mentioned. Patients are advised to seek medical advice in case of herpes zoster infection.
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PMID:Guidelines for screening, prophylaxis and critical information prior to initiating anti-TNF-alpha treatment. 2275 56

Each phase of hepatitis B infection stimulates distinct viral kinetics and host immune responses resulting in liver damage and hepatic fibrosis. Our objective has been to correlate host inflammatory immune response including circulating Th1 and Th2 cytokines in patients with chronic hepatitis B infection with liver histopathology. Sixty-four patients with chronic hepatitis B without previous treatment were recruited. The liver histology and histological activity index were assessed for various degrees of necroinflammation and hepatic fibrosis. We determined circulating levels of the Th1 and Th2 cytokines. Forty-six males and 18 females at a median age of 34.5 years were studied. HBeAg was present in 28/64 (43.75%) of the patients. In patients negative for HBeAg, IL-10 and IFN-gamma were significantly correlated with degrees of necroinflammation (r = 0.34, r = 0.38, resp.; P < 0.05). Moreover, TNF-alpha was significantly correlated with degrees of fibrosis (r = 0.35; P < 0.05), and IL-10 and TNF-alpha were significantly correlated with significant fibrosis (r = 0.39, r = 0.35, resp.; P < 0.05). These correlations were found in the HBeAg negative group as opposed to the HBeAg positive group. In HBeAg negative patients, circulating cytokines IL-10 and IFN-gamma were correlated with degrees of necroinflammation, whereas IL-10 and TNF-alpha were correlated with significant fibrosis.
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PMID:Circulating cytokines and histological liver damage in chronic hepatitis B infection. 2428 3


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