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Low occurrence of occult hepatitis B virus infection and high frequency of hepatitis C virus genotype 3 in hepatocellular carcinoma in Brazil

ALENCAR, R.S.M.; GOMES, M.M.S.; SITNIK, R.; PINHO, J.R.R.; MALTA, F.M.; MELLO, I.M.V.G.C.; MELLO, E.S.; BACCHELLA, T.; MACHADO, M.C.C.; ALVES, V.A.F.; CARRILHO, F.J.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.52%
Occult hepatitis B virus (HBV) infection has been reported among patients with hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC). Our aim was to evaluate the presence of occult HBV infection in patients with HCV-related liver cirrhosis (LC) with or without HCC in São Paulo, Brazil. Serum and liver tissue samples from 50 hepatitis B surface antigen-negative patients with HCV-related LC who underwent liver transplantation at the University of São Paulo School of Medicine Hospital from 1993 to 2004 were divided into groups with LC only (N = 33) and with LC plus HCC (N = 17). HBV DNA was assayed for serum and paraffin-embedded liver tissue (tumoral and non-tumoral) using real time PCR and only 1 case with HCC had HBV DNA-positive serum. All liver samples were negative. HCV genotype 3 was detected in 17/39 (43.7%) cases. In conclusion, using a sensitive real time PCR directed to detect HBV variants circulating in Brazil, occult hepatitis B infection was not found among HCV-positive cirrhotic patients and was rarely found among HCV-positive HCC patients. These results are probably related to the low prevalence of HBV infection in our population. Furthermore, we have also shown that HCV genotype 3 is frequently found in Brazilian cirrhotic patients...

Infecção oculta pelo virus da hepatite B em pacientes hemodialisados e em pacientes infectados pelo virus da imunodeficiencia humana; Occult hepatitis B infection in dialysis patients and in HIV infected patients

Ruth Nogueira Cordeiro de Moraes Jardim
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/08/2006 Português
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46.65%
A infecção oculta pelo VHB é caracterizada pela presença do DNA-VHB em indivíduos com o antígeno de superfície (HBsAg) indetectável. A prevalência e significado clínico desta infecção ainda não são totalmente conhecidos. Este trabalho teve por objetivo determinar a prevalência de infecção oculta pelo VHB em dois grupos de pacientes imunossuprimidos (pacientes em tratamento por hemodiálise e pacientes HIV positivos) com anti-HBc positivo co-infectados ou não pelo vírus da hepatite C (VHC). Foi investigada uma possível correlação entre prevalência do DNA-VHB e carga viral, níveis de CD4, fatores de risco e administração de lamivudina no grupo de HIV positivos. O primeiro grupo (G1) foi formado por 34 pacientes hemodialisados que eram HBsAg negativo/anti-HIV negativo. O segundo grupo (G2) formado por 159 pacientes infectados pelo vírus da imunodeficiência humana (anti-HIV positivo) e HBsAg negativo. Foi utilizado como grupo controle (G3), 150 doadores de sangue com marcadores sorológicos negativos para o HBsAg e para o HIV, mas reagentes para o anti-HBc. A pesquisa do DNA do VHB foi realizada pela PCR ?in house? , segundo a técnica de Kaneko et al. (1989), utilizando-se ?primers? específicos da região do core do VHB (limite de detecção 100 cópias/ml). Entre os pacientes hemodialisados...

Occult hepatitis B virus infection in patients with chronic liver disease due to hepatitis C virus and hepatocellular carcinoma in Brazil

Branco,Fernanda; Mattos,Angelo Alves de; Coral,Gabriela Perdomo; Vanderborght,Bart; Santos,Diogo Edele; França,Paulo; Alexander,Cláudio
Fonte: Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia - IBEPEGE ; Colégio Brasileiro de Cirurgia Digestiva - CBCD ; Sociedade Brasileira de Motilidade Digestiva - SBMD ; Federação Brasileira de Gastroenterologia - FBG; Sociedade Brasileira de Hepatologia - SBH; Sociedade Brasileira de Endoscopia Digestiva - SOBED Publicador: Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia - IBEPEGE ; Colégio Brasileiro de Cirurgia Digestiva - CBCD ; Sociedade Brasileira de Motilidade Digestiva - SBMD ; Federação Brasileira de Gastroenterologia - FBG; Sociedade Brasileira de Hepatologia - SBH; Sociedade Brasileira de Endoscopia Digestiva - SOBED
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2007 Português
Relevância na Pesquisa
36.58%
BACKGROUND: The prevalence and consequences of occult HBV infection in patients with chronic liver disease by HCV remain unknown. AIMS: To evaluate the prevalence of occult HBV infection in a population of HCV-infected patients with hepatocellular carcinoma. METHODS: The serum samples were tested for HBV DNA by nested PCR and liver tissue analysis was carried out using the immunohistochemical technique of 66 HBsAg-negative patients: 26 patients with chronic hepatitis by HCV (group 1), 20 with hepatocellular carcinoma related to chronic infection by HCV (group 2) and 20 with negative viral markers for hepatitis B and C (control group). RESULTS: Occult HBV infection was diagnosed in the liver tissue of 9/46 (19.5%) HCV-infected patients. Prevalence of occult B infection was evaluated in the HCV-infected patients with and without hepatocellular carcinoma, and there were seven (77.7%) of whom from group 2, conferring a 35% prevalence of this group. No serum sample was positive for HBV DNA in the three groups. CONCLUSION: Occult infection B is frequently detected in liver tissue of HCV-infected patients, especially in cases of hepatocellular carcinoma. However large studies are needed to confirm that co-infection could determine a worse progress of chronic liver disease in this population.

Occult hepatitis B virus infection in hemodialysis patients in Recife, State of Pernambuco, Brazil

Albuquerque,Ana Cecília Cavalcanti de; Coelho,Maria Rosângela Cunha Duarte; Lemos,Marcílio Figueiredo; Moreira,Regina Célia
Fonte: Sociedade Brasileira de Medicina Tropical - SBMT Publicador: Sociedade Brasileira de Medicina Tropical - SBMT
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2012 Português
Relevância na Pesquisa
56.55%
INTRODUCTION: Persistence of the hepatitis B virus (HBV) genome in individuals negative for the HBV surface antigen (HBsAg) reflects occult infection. The aim of this study was to identify occult HBV infection among hemodialysis patients at 5 clinics in Recife, State of Pernambuco, Brazil, between August 2006 and August 2007. METHODS: Serum samples underwent enzyme-linked immunosorbent assay to investigate total antibodies against HBcAg (anti-HBc), HBsAg, and antibodies against HBsAg (anti-HBs). Samples that were HBsAg-negative were tested for total anti-HBc, and those that were positive for total anti-HBc were tested for anti-HBs. HBV DNA was investigated with an in-house PCR technique to identify samples positive for total anti-HBc. Subsequently, the samples positive for HBV DNA were sequenced to identify the genotype and mutations. RESULTS: The study population (n = 752) had a mean age of 50 15.1 years and included both sexes. All samples analyzed were negative for HBsAg. The seroprevalence of total anti-HBc was 26.7% (201/752), while that of anti-HBs was 67.2% (135/201). Total anti-HBc alone was detected in 5.7% of the patients. Occult infection was found in 1.5%, comprising genotypes A (33.3%, 1/3) and D (66.7%, 2/3). No mutations were found. CONCLUSIONS: The study detected occult hepatitis B virus infection in hemodialysis patients. Molecular studies on HBV are of fundamental importance because they identify patients that had been considered virus-negative but who...

Patterns of hepatitis B virus infection in Brazilian human immunodeficiency virus infected patients: high prevalence of occult infection and low frequency of lamivudine resistant mutations

Sucupira,Michel VF; Mello,Francisco CA; Santos,Eneida A; Niel,Christian; Rolla,Valeria C; Arabe,Juçara; Gomes,Selma A
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2006 Português
Relevância na Pesquisa
46.36%
Hepatitis B virus (HBV) molecular profiles were determined for 44 patients who were infected with human immunodeficiency virus (HIV) type 1 and had antibodies to the hepatitis B core antigen (anti-HBc), with and without other HBV serological markers. In this population, 70% of the patients were under lamivudine treatment as a component of antiretroviral therapy. HBV DNA was detected in 14 (32%) patients. Eight out of 12 (67%) HBsAg positive samples, 3/10 (30%) anti-HBc only samples, and 3/22 (14%) anti-HBs positive samples were HBV DNA positive. HBV DNA loads, measured by real time polymerase chain reaction, were much higher in the HBsAg positive patients (mean, 2.5 × 10(9) copies/ml) than in the negative ones (HBV occult infection; mean, 2.7 × 10(5) copies/ml). Nine out of the 14 HBV DNA positive patients were under lamivudine treatment. Lamivudine resistant mutations in the polymerase gene were detected in only three patients, all of them belonging to the subgroup of five HBsAg positive, HBV DNA positive patients. A low mean HBV load (2.7 × 10(5) copies/ml) and an absence of lamivudine resistant mutations were observed among the cases of HBV occult infection.

HBV vaccination of HCV-infected patients with occult HBV infection and anti-HBc-positive blood donors

Pereira,J.S.F.; Gonçales,N.S.L.; Silva,C.; Lazarini,M.S.K.; Pavan,M.H.P.; Fais,V.C.; Gonçales Júnior,F.L.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2006 Português
Relevância na Pesquisa
46.59%
Anti-HBc positivity is a frequent cause of donation rejection at blood banks. Hepatitis B virus (HBV) infection may also occur in HBsAg-negative patients, a situation denoted occult infection. Similarly, very low levels of HBV-DNA have also been found in the sera of patients with chronic hepatitis C virus (HCV) infection, even in the absence of serum HBsAg. Initially we searched for HBV-DNA in serum of 100 blood donors and 50 HCV-infected patients who were HBsAg negative/anti-HBc positive by nested-PCR and by an HBV monitor commercial test for HBV-DNA. Anti-HBs seroconversion rates were measured in 100 blood donors and in 22 patients with chronic HCV infection after HBV vaccination to determine if the HBV vaccination could eliminate an occult HBV infection in these individuals. Occult HBV infection was detected in proportionally fewer blood donors (6/100 = 6%) than chronic hepatitis C patients (12/50 = 24%) (P < 0.05). We noted seroconversion in 6/6 (100%) HBV-DNA(+) and in 84/94 (89.4%) HBV-DNA(-) blood donors (P > 0.05). All subjects who were HBV-DNA(+) before the first dose of HBV vaccine (D1), became HBV-DNA(-) after D1, D2, and D3. Among 22 HCV-positive patients, 10 HBV-DNA(+) and 12 HBV-DNA(-), seroconversion was observed in 9/10 (90%) HBV-DNA(+) and in 9/12 (75%) HBV-DNA(-) subjects (P > 0.05). The disappearance of HBV-DNA in the majority of vaccinated patients suggests that residual HBV can be eliminated in patients with occult infection.

Occult hepatitis B virus infection in liver transplant patients in a Brazilian referral center

Ferrari,T.C.A.; Xavier,M.A.P.; Vidigal,P.V.T.; Amaral,N.S.; Diniz,P.A.; Resende,A.P.; Miranda,D.M.; Faria,A.C.; Lima,A.S.; Faria,L.C.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2014 Português
Relevância na Pesquisa
36.63%
Estimates of occult hepatitis B virus (HBV) infection prevalence varies among different studies depending on the prevalence of HBV infection in the study population and on the sensitivity of the assay used to detect HBV DNA. We investigated the prevalence of occult HBV infection in cirrhotic patients undergoing liver transplantation in a Brazilian referral center. Frozen liver samples from 68 adults were analyzed using a nested polymerase chain reaction assay for HBV DNA. The specificity of the amplified HBV sequences was confirmed by direct sequencing of the amplicons. The patient population comprised 49 (72.1%) males and 19 (27.9%) females with a median age of 53 years (range=18-67 years). Occult HBV infection was diagnosed in three (4.4%) patients. The etiologies of the underlying chronic liver disease in these cases were alcohol abuse, HBV infection, and cryptogenic cirrhosis. Two of the patients with cryptic HBV infection also presented hepatocellular carcinoma. Markers of previous HBV infection were available in two patients with occult HBV infection and were negative in both. In conclusion, using a sensitive nested polymerase chain reaction assay to detect HBV DNA in frozen liver tissue, we found a low prevalence of occult HBV infection in cirrhotic patients undergoing liver transplant...

The influence of occult infection with hepatitis B virus on liver histology and response to interferon treatment in chronic hepatitis C patients

Silva,Claudia da; Gonçales,Neiva Sellan Lopes; Pereira,Josiane Silveira Felix; Escanhoela,Cecília Amélia Fazio; Pavan,Maria Helena Postal; Gonçales Junior,Fernando Lopes
Fonte: Brazilian Society of Infectious Diseases Publicador: Brazilian Society of Infectious Diseases
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2004 Português
Relevância na Pesquisa
46.54%
Occult hepatitis B virus (HBV) infections have been identified in patients with chronic hepatitis C virus (HCV) infection, although the clinical relevance of occult HBV infection remains controversial. We searched for serum HBV DNA in 106 HBsAg negative/anti-HBc positive patients with chronic HCV infection and in 150 blood donors HBsAg negative/anti-HBc positive/anti-HCV negative (control group) by nested-PCR. HCV genotyping was done in 98 patients and percutaneous needle liver biopsies were performed in 59 patients. Fifty-two patients were treated for HCV infection with interferon alone (n=4) or combined with ribavirin (n=48) during one year. At the end and 24 weeks after stopping therapy, they were tested for HCV-RNA to evaluate the sustained virological response (SVR). Among the 106 HCV-positive patients, 15 (14%) were HBV-DNA positive and among the 150 HCV-negative blood donors, 6 (4%) were HBV-DNA positive. Liver biopsy gave a diagnosis of liver cirrhosis in 2/10 (20%) of the HBV-DNA positive patients and in 6/49 (12%) of the HBV-DNA negative patients. The degree of liver fibrosis and portal inflammation was similar in HCV-infected patients HBV-DNA, irrespective of HBV-DNA status. SVR was obtained in 37.5% of the HBV-DNA positive patients and in 20.5% of the HBV-DNA negative patients; this difference was not significant. In conclusion...

Occult hepatitis B virus infection in immunocompromised patients

Jardim,Ruth Nogueira Cordeiro Moraes; Gonçales,Neiva Sellan Lopes; Pereira,Josiane Silveira Felix; Fais,Viviane Cristina; Gonçales Junior,Fernando Lopes
Fonte: Brazilian Society of Infectious Diseases Publicador: Brazilian Society of Infectious Diseases
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2008 Português
Relevância na Pesquisa
36.57%
Occult hepatitis B infection is characterized by hepatitis B virus (HBV) DNA in the serum in the absence of hepatitis B surface antigen (HBsAg). We assessed occult HBV infection prevalence in two groups of immunocompromised patients (maintenance hemodialysis patients and HIV-positive patients) presenting HBsAg-negative and anti-HBc positive serological patterns, co-infected or not by HCV. Thirty-four hemodialysis anti-HIV negative patients, 159 HIV-positive patients and 150 blood donors who were anti-HBc positive (control group) were selected. HBV-DNA was detected by nested-PCR. Occult hepatitis B infection was not observed in the hemodialysis patients group but was found in 5% of the HIV-patients and in 4% of the blood donors. Immunosuppression in HIV positive patients was not a determining factor for occult HBV infection. In addition, no significant relationship between HBV-DNA and HCV co-infection in the HIV-positive patient group was found. A lack of significant associations was also observed between positivity for HBV-DNA and CD4 count, viral load and previous lamivudine treatment in these HIV-positive patients.

Occult Hepatitis B Infection and its Possible Impact on Chronic Hepatitis C Virus Infection

Habibollahi, Peiman; Safari, Saeid; Daryani, Nasser E.; Alavian, Seyed M.
Fonte: Medknow Publications Publicador: Medknow Publications
Tipo: Artigo de Revista Científica
Publicado em /10/2009 Português
Relevância na Pesquisa
36.55%
As a well-recognized clinical phenomenon, persistent detectable viral genome in liver or sera in the absence of other serological markers for active hepatitis B virus (HBV) replication is called occult HBV infection. The main mechanism through which occult infection occurs is not completely understood and several possible explanations, such as integration into human genome and maintenance in peripheral mononuclear cells, exist. Occult HBV infection has been reported in different populations, especially among patients with Hepatitis C (HCV) related liver disease. The probable impact of occult HBV in patients with chronic HCV infection has been previously investigated and the evidence suggests a possible correlation with lower response to anti-viral treatment, higher grades of liver histological changes, and also developing hepatocellular carcinoma. However, in the absence of conclusive results, further studies should be conducted to absolutely assess the impact of occult HBV contamination on the HCV related liver disease.

Occult hepatitis B virus infection: A complex entity with relevant clinical implications

Larrubia, Juan-Ramon
Fonte: Baishideng Publishing Group Co., Limited Publicador: Baishideng Publishing Group Co., Limited
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.57%
Occult hepatitis B virus (HBV) infection is a world-wide entity, following the geographical distribution of detectable hepatitis B. This entity is defined as the persistence of viral genomes in the liver tissue and in some instances also in the serum, associated to negative HBV surface antigen serology. The molecular basis of the occult infection is related to the life cycle of HBV, which produces a covalently closed circular DNA that persists in the cell nuclei as an episome, and serves as a template for gene transcription. The mechanism responsible for the HBsAg negative status in occult HBV carriers is a strong suppression of viral replication, probably due to the host’s immune response, co-infection with other infectious agents and epigenetic factors. There is emerging evidence of the potential clinical relevance of occult HBV infection, since this could be involved in occult HBV transmission through orthotopic liver transplant and blood transfusion, reactivation of HBV infection during immunosuppression, impairing chronic liver disease outcome and acting as a risk factor for hepatocellular carcinoma. Therefore it is important to bear in mind this entity in cryptogenetic liver diseases, hepatitis C virus/HIV infected patients and immunosupressed individuals. It is also necessary to increase our knowledge in this fascinating field to define better strategies to diagnose and treat this infection.

New perspectives in occult hepatitis C virus infection

Carreño, Vicente; Bartolomé, Javier; Castillo, Inmaculada; Quiroga, Juan Antonio
Fonte: Baishideng Publishing Group Co., Limited Publicador: Baishideng Publishing Group Co., Limited
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.67%
Occult hepatitis C virus (HCV) infection, defined as the presence of HCV RNA in liver and in peripheral blood mononuclear cells (PBMCs) in the absence of detectable viral RNA in serum by standard assays, can be found in anti-HCV positive patients with normal serum levels of liver enzymes and in anti-HCV negative patients with persistently elevated liver enzymes of unknown etiology. Occult HCV infection is distributed worldwide and all HCV genotypes seem to be involved in this infection. Occult hepatitis C has been found not only in anti-HCV positive subjects with normal values of liver enzymes or in chronic hepatitis of unknown origin but also in several groups at risk for HCV infection such as hemodialysis patients or family members of patients with occult HCV. This occult infection has been reported also in healthy populations without evidence of liver disease. Occult HCV infection seems to be less aggressive than chronic hepatitis C although patients affected by occult HCV may develop liver cirrhosis and even hepatocellular carcinoma. Thus, anti-HCV negative patients with occult HCV may benefit from antiviral therapy with pegylated-interferon plus ribavirin. The persistence of very low levels of HCV RNA in serum and in PBMCs, along with the maintenance of specific T-cell responses against HCV-antigens observed during a long-term follow-up of patients with occult hepatitis C...

Naturally Occurring Mutations in Large Surface Genes Related to Occult Infection of Hepatitis B Virus Genotype C

Kim, Hong; Lee, Seoung-Ae; Kim, Dong-Won; Lee, Sueng-Hyun; Kim, Bum-Joon
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 18/01/2013 Português
Relevância na Pesquisa
46.64%
Molecular mechanisms related to occult hepatitis B virus (HBV) infection, particularly those based on genotype C infection, have rarely been determined thus far in the ongoing efforts to determine infection mechanisms. Therefore, we aim to elucidate the mutation patterns in the surface open reading frame (S ORF) underlying occult infections of HBV genotype C in the present study. Nested PCRs were applied to 624 HBV surface antigen (HBsAg) negative Korean subjects. Cloning and sequencing of the S ORF gene was applied to 41 occult cases and 40 control chronic carriers. Forty-one (6.6%) of the 624 Korean adults with HBsAg-negative serostatus were found to be positive for DNA according to nested PCR tests. Mutation frequencies in the three regions labeled here as preS1, preS2, and S were significantly higher in the occult subjects compared to the carriers in all cases. A total of two types of deletions, preS1 deletions in the start codon and preS2 deletions as well as nine types of point mutations were significantly implicated in the occult infection cases. Mutations within the “a” determinant region in HBsAg were found more frequently in the occult subjects than in the carriers. Mutations leading to premature termination of S ORF were found in 16 occult subjects (39.0%) but only in one subject from among the carriers (2.5%). In conclusion...

Persistent occult hepatitis B virus infection: Experimental findings and clinical implications

Mulrooney-Cousins, Patricia M; Michalak, Tomasz I
Fonte: Baishideng Publishing Group Inc Publicador: Baishideng Publishing Group Inc
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.57%
Hepatitis B virus (HBV) is a highly pathogenic virus that causes chronic liver diseases in millions of people globally. In addition to a symptomatic, serologically evident infection, occult persistent HBV carriage has been identified since nucleic acid amplification assays of enhanced sensitivity became introduced for detection of hepadnaviral genomes and their replicative intermediates. Current evidence indicates that occult HBV infection is a common and long-term consequence of resolution of acute hepatitis B. This form of residual infection is termed as secondary occult infection (SOI). The data from the woodchuck model of HBV infection indicate that exposure to small amounts of hepadnavirus can also cause primary occult infection (POI) where virus genome, but no serological makers of exposure to virus, are detectable, and the liver may not be involved. However, virus replicates at low levels in the lymphatic system in both these forms. We briefly summarize the current understanding of the nature and characteristics of occult hepadnaviral persistence as well as of its documented and expected pathological consequences.

Occult infection related hepatitis B surface antigen variants showing lowered secretion capacity

Kim, Hong; Lee, Seoung-Ae; Won, You-Sub; Lee, HyunJoo; Kim, Bum-Joon
Fonte: Baishideng Publishing Group Inc Publicador: Baishideng Publishing Group Inc
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
46.16%
AIM: To elucidate the molecular mechanisms underlying hepatitis B virus (HBV) occult infection of genotype C.

Induction of endoplasmic reticulum-derived oxidative stress by an occult infection related S surface antigen variant

Lee, In-Kyung; Lee, Seoung-Ae; Kim, Hong; Won, You-Sub; Kim, Bum-Joon
Fonte: Baishideng Publishing Group Inc Publicador: Baishideng Publishing Group Inc
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
46.16%
AIM: To investigate the mechanism of endoplasmic reticulum (ER) stress induction by an occult infection related hepatitis B virus S surface antigen (HBsAg) variant.

Association of preS/S Mutations with Occult Hepatitis B Virus (HBV) Infection in South Korea: Transmission Potential of Distinct Occult HBV Variants

Kim, Hong; Kim, Bum-Joon
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 15/06/2015 Português
Relevância na Pesquisa
36.61%
Occult hepatitis B virus infection (HBV) is characterized by HBV DNA positivity but HBV surface antigen (HBsAg) negativity. Occult HBV infection is associated with a risk of HBV transmission through blood transfusion, hemodialysis, and liver transplantation. Furthermore, occult HBV infection contributes to the development of cirrhosis and hepatocellular carcinoma. We recently reported the characteristic molecular features of mutations in the preS/S regions among Korean individuals with occult infections caused by HBV genotype C2; the variants of preS and S related to severe liver diseases among chronically infected patients were also responsible for the majority of HBV occult infections. We also reported that HBsAg variants from occult-infected Korean individuals exhibit lower HBsAg secretion capacity but not reduced HBV DNA levels. In addition, these variants exhibit increased ROS-inducing capacity compared with the wild-type strain, linking HBV occult infections to liver cell damage. Taken together, our previous reports suggest the transmission potential of distinct HBV occult infection-related variants in South Korea.

Estudo molecular da infecção pelo vírus da hepatite B em pacientes coinfectados pelo HIV, virgens de tratamento, em Goiânia-Goiás; Molecular study of hepatitis B virus infection in HIV-infected treatment-naive patients in Goiânia-Goiás

Oliveira, Marina Pedroso de
Fonte: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Medicina Tropical e Saúde Publica (IPTSP); Instituto de Patologia Tropical e Saúde Pública - IPTSP (RG) Publicador: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Medicina Tropical e Saúde Publica (IPTSP); Instituto de Patologia Tropical e Saúde Pública - IPTSP (RG)
Tipo: Dissertação Formato: application/pdf
Português
Relevância na Pesquisa
56.58%
It is estimated that about 10% of individuals infected with human immunodeficiency virus (HIV) throughout the world have chronic infection with hepatitis B virus (HBV). The HIV-HBV co-infection increases the risk for developing cirrhosis and hepatocellular carcinoma. Also, co-infected individuals have atypical serological profiles more often than monoinfected patients, many of whom may have occult hepatitis B (presence of HBV-DNA in serum and/or liver in the absence of HBsAg) in addition to mutations in the viral genome that may have implications for the prognosis and therapeutics of hepatitis B. This study aimed to estimate the prevalence of occult HBV infection in HIV-infected treatment-naive patients, in Goiânia, Goiás, to determine the viral load of HBV-DNA positive samples, to identify circulating genotypes/subgenotypes and to investigate the occurrence of mutations in P and S regions of the HBV genome. This is a cross-sectional study conducted in HIV-infected treatment-naive patients attended at a reference hospital for infectious diseases in the Goiania city. After serological screening of the population (n = 505), two groups of patients were selected for this study: (i) 99 anti-HBc positive/HBsAg negative and (ii) 29 HBsAg reactive individuals. HBV-DNA was detected by semi-nested PCR and quantified by real time PCR. The amplicons were genotyped by RFLP and nucleotide sequencing. The identification of mutations in the viral genome was made by deduction of the amino acid sequences from the nucleotides sequences. The search for occult HBV infection performed in 99 anti-HBc positive/HBsAg negative samples (Group 1) showed a prevalence of 16.2% (16/99...

Occult hepatitis B virus infection among injecting drug users in the Central-West Region of Brazil

Matos,Marcia Alves Dias de; Ferreira,Renata Carneiro; Rodrigues,Fabiana Perez; Marinho,Tamiris Augusto; Lopes,Carmen Luci Rodrigues; Novais,Antonia Carlos Magalhaes; Motta-Castro,Ana Rita Coimbra; Teles,Sheila Araujo; Souto,Francisco Jose Dutra; Martins,R
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2013 Português
Relevância na Pesquisa
46.54%
The prevalence of occult hepatitis B virus (HBV) infection was investigated in 149 hepatitis B surface antigen (HBsAg) negative injecting drug users (IDUs) in the Central-West Region of Brazil. Of these individuals, 19 were positive for HBV DNA, resulting in an occult HBV infection prevalence of 12.7% (19/149); six of these 19 individuals had anti-HBV core and/or anti-HBV surface antibodies and 13 were negative for HBV markers. All IDUs with occult hepatitis B reported sexual and/or parenteral risk behaviours. All HBV DNA-positive samples were successfully genotyped. Genotype D was the most common (17/19), followed by genotype A (2/19). These findings reveal a high prevalence of occult HBV infection and the predominance of genotype D among IDUs in Brazil's Central-West Region.

Occult Infection in Aseptic Joint Loosening and the Diagnostic Role of Implant Sonication

Kempthorne, J. T.; Ailabouni, R.; Raniga, S.; Hammer, D.; Hooper, G.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
46.25%
Our aim was to determine the incidence of occult infection and to examine the role of ultrasound sonication of the implants in cases of presumed aseptic loosening in a prospective trial. Joint swabs, aspirates, and deep tissue samples were obtained from around the prosthesis for routine microbiology. Each prosthesis was sonicated and the sonicate examined with Gram staining and extended cultures. There were 106 joints in the study of which 54 were revised for aseptic loosening and 52 were assigned to the control revision group. There were 9 positive cultures with 8/54 positive cultures in the aseptic loosening group and 1/52 in the control revision group (p = 0.017, associated OR 47.7). We found concordant results between sonication fluid culture and conventional samples in 5/9 cultures. Preoperative inflammatory markers were not prognostic for infection. Coagulase-negative Staphylococcus was the most commonly cultured organism (7/9). Previously unrecognised infection was present in 15% of patients undergoing revision for aseptic loosening. Ultrasound sonication of the removed prosthesis was less sensitive than conventional sampling techniques. We recommend routine intraoperative sampling for patients having revision for aseptic loosening...