[Human Pegivirus: Pathogenic potential and non-Hodgkin lymphoma development risk]. / Pegivirus humano: Potencial patogénico y riesgo de desarrollo de linfoma no Hodgkin.

The human pegivirus (HPgV), classified in the Flaviviridae family - Pegivirus genus, is an RNA virus identified in 1995. HPgV is a lymphotrophic virus, with replication sites in bone marrow and lymphoid tissue, as well as in peripheral blood mononuclear cells (PBMCs). Transmission is through sexual and parenteral routes, and recent estimations suggest nearly 750 million people are infected with HPgV worldwide. Almost 25% of infected individuals can develop persistent infection. Until now, HPgV has been considered a non-pathogenic virus; however, epidemiological studies suggest a potential role in lymphoproliferative diseases, particularly in the development of non-Hodgkin lymphoma (NHL). The evidence of this is controversial and the role of HPgV in lymphomagenesis has not yet been demonstrated. Several studies report a high prevalence of HPgV infection in patients with NHL compared to controls and patients with other hematological diseases. Therefore, analytic studies show that HPgV could be related to an increased risk of NHL development. Conversely, other studies indicate no association between HPgV and NHL, so the role of HPgV in lymphomagenesis is not clear. This review summarizes the main findings related to HPgV's pathogenic potential and association with NHL.

Pegivirus humano: potencial patogénico y riesgo de desarrollo de linfoma no Hodgkin / Human Pegivirus: pathogenic potential and non-Hodgkin lymphoma development risk

Resumen El pegivirus humano (HPgV) es un virus ARN que fue identificado en el año 1995. Actualmente se encuentra clasificado dentro de la familia Flaviviridae, género Pegivirus, relacionado filogenéticamente con el virus de la hepatitis C (VHC). El HPgV es un virus linfotrópico, con replicación en médula ósea, tejidos linfoides, y en células mononucleares de sangre periférica. Este virus se transmite por vía parenteral y sexual. Según estimaciones realizadas, en el mundo existen alrededor de 750 millones de personas infectadas por este agente. Se ha evidenciado que hasta en 25% de los casos se presenta una infección persistente, y aunque se considera que el HPgV es un virus no patogénico, existen evidencias epidemiológicas que sugieren una relación con el desarrollo de desórdenes linfoproliferativos, particularmente linfoma no Hodgkin (LNH). Algunos estudios han reportado una alta prevalencia de HPgV en pacientes con LNH comparado con donantes de sangre y/o pacientes con enfermedades hematológicas no malignas, lo que se asocia a un incremento en el riesgo relativo para el desarrollo de LNH en personas infectadas. De otra parte, existen estudios epidemiológicos que contradicen esta asociación, por lo que el rol de HPgV en la aparición de desórdenes lifoproliferativos es un tema actual de debate. En el presente manuscrito se discute el potencial patogénico derivado de los mecanismos de infección persistente del HPgV, así como las principales evidencias sobre la relación entre el HPgV y el riesgo de desarrollo de LNH.

The human pegivirus (HPgV), classified in the Flaviviridae family - Pegivirus genus, is an RNA virus identified in 1995. HPgV is a lymphotrophic virus, with replication sites in bone marrow and lymphoid tissue, as well as in peripheral blood mononuclear cells (PBMCs). Transmission is through sexual and parenteral routes, and recent estimations suggest nearly 750 million people are infected with HPgV worldwide. Almost 25% of infected individuals can develop persistent infection. Until now, HPgV has been considered a non-pathogenic virus; however, epidemiological studies suggest a potential role in lymphoproliferative diseases, particularly in the development of non-Hodgkin lymphoma (NHL). The evidence of this is controversial and the role of HPgV in lymphomagenesis has not yet been demonstrated. Several studies report a high prevalence of HPgV infection in patients with NHL compared to controls and patients with other hematological diseases. Therefore, analytic studies show that HPgV could be related to an increased risk of NHL development. Conversely, other studies indicate no association between HPgV and NHL, so the role of HPgV in lymphomagenesis is not clear. This review summarizes the main findings related to HPgV's pathogenic potential and association with NHL.

Chimeric viruses between Rocio and West Nile: the role for Rocio prM-E proteins in virulence and inhibition of interferon-α/ß signaling.

Mosquito-transmitted flavivirus Rocio (ROCV) was responsible for an outbreak of encephalitis in the Ribeira Valley, located in the south coast of Sao Paulo State, Brazil, in 1975-1976. ROCV also causes fatal encephalitis in adult mice. Seroprevalence studies in humans, horses and water buffaloes in different regions of Brazil have suggested that ROCV is still circulating in the country, indicating the risk of re-emergence of this virus. West Nile virus (WNV) is also a mosquito-transmitted encephalitic flavivirus, however, WNV strains circulating in Australia have not been associated with outbreaks of disease in humans and exhibit low virulence in adult mice. To identify viral determinants of ROCV virulence, we have generated reciprocal chimeric viruses between ROCV and the Australian strain of WNV by swapping structural prM and E genes. Chimeric WNV containing ROCV prM-E genes replicated more efficiently than WNV or chimeric ROCV containing WNV prM-E genes in mammalian cells, was as virulent as ROCV in adult mice, and inhibited type I IFN signaling as efficiently as ROCV. The results show that ROCV prM and E proteins are major virulence determinants and identify unexpected function of these proteins in inhibition of type I interferon response.

Avaliação da Atividade Antiviral de Extratos Vegetais e de Fungos contra Dengue Virus

Produtos naturais são potenciais fontes alternativas para o desenvolvimento de antivirais para o tratamento da dengue, assim como de outras doenças causadas por vírus da família Flaviviridae ou mesmo para um amplo espectro de viroses. Neste estudo foi feita a triagem da atividade in vitro contra o Dengue virus 2 (DENV-2) de 3101 extratos, provenientes de plantas e de fungos da Coleção de Amostras para Bioensaios da Fiocruz. Para tal, células BHK-21 foram infectadas com DENV-2 e tratadas simultaneamente com 25 μg/mL de extrato sendo o resultado analisado por dois métodos: observação do grau de inibição do efeito citopático (ECP) por microscopia óptica e análise da viabilidade celular pelo ensaio colorimétrico do MTT. Dentre os 3101 extratos testados, 115 extratos apresentaram atividade antiviral contra DENV-2 e foram selecionados para a determinação da respectiva concentração efetiva 50 (CE50).

Cinquenta e cinco destes extratos foram obtidos de plantas pertencentes a 20 famílias distintas: Amaryllidaceae (3), Annonaceae (1), Asteraceae (5), Begoniaceae (1), Clusiaceae (1), Combretaceae (1), Erythroxylaceae (1), Fabaceae (4), Lythraceae (2), Malpighiaceae (8), Malvaceae(1), Melastomataceae (2), Melochia (1), Myrtaceae (3), Rubiaceae (8), Sapindaceae(9), Ochnaceae (1), Primulaceae (1) Vitaceae (1), Vochysiaceae (1). Os demais extratos (60) foram obtidos de culturas de fungos endofíticos coletados no Brasil, no continente Antártico e no Deserto do Atacama, ainda não identificados. Até o momento, os extratos vegetais mais promissores foram obtidos de plantas da família Amaryllidaceae (IS = 32,15) e da família Fabaceae (IS = 20,47) e (IS = 24,47). Vinte extratos fúngicos apresentaram valores de CE50 que variaram entre 3,1 a 12,5 μg/mL e sem citotoxicidade aparente até a concentração de 100 μg/mL. Nossos resultados mostram que tais plantas e fungos são fontes promissoras de substâncias com ação antiviral contra DENV.

Fatores prognósticos e associados à efetividade do tratamento da hepatite C crônica / Prognostic and associated factors to the effectiveness of chronic hepatitis C treatment

A hepatite C é uma doença recentemente reconhecida cujo tratamento é de eficácia aquém da desejável. O objetivo deste estudo é conhecer os fatores prognósticos de resposta virológica sustentada (RVS) e de efetividade do tratamento da hepatite C crônica e propor um modelo teórico que contenha as principais relações identificadas. A prevalência do HCV no Brasil é estimada entre 0,94% a1,89%, com tendência a aumentar. Há populações especificamente sob maior risco como detentos, usuários de drogas e renais crônicos em diálise. Devido ao seu caráter crônico e progressivo estima-se que as complicações relacionadas aumentem nas próximas décadas caso não haja tratamento efetivo. O tratamento é caro, com efeitos colaterais importantes e promove RVS apenas em uma parcelados indivíduos, mesmo sob condições ideais. São descritos como fatoresprognósticos para RVS: genótipo, carga viral pré-tratamento, cinética viral,transaminases, estágio de fibrose, sexo, idade, peso, raça, esteatose e aderência ao tratamento. Dispensado de acordo com critérios do Ministério da Saúde, otratamento utiliza interferon peguilado para o genótipo 1 e interferon convencional para os genótipos 2 e 3, associado à ribavirina. Associados a RVS, além do custo, outros fatores concorrem para a efetividade do tratamento: diagnóstico precoce doscasos, implementação de pólos de aplicação, qualidade e disponibilidade damedicação, critérios e interrupção precoce através da cinética viral, redução da necessidade de re-tratamento e de transplante hepático. Para aumentar a efetividade do tratamento concluímos ser necessário melhor rastreamento dos casosde infecção pelo VHC, disseminação de pólos de aplicação dos medicamentos eviabilizar exames para cinética viral.

Chronic C hepatitis is a recently recognized entity which treatment efficacy is not definitely established. The aim of this study is to know the prognostic factors for sustained virologic response and effectiveness of the treatment, as well as propose atheoretical model concerning its main issues. Brazilian prevalence of hepatitis C is around 0,94% to 1,89%, with an increasing tendency. Prisoners, drug addicts and patients in dialysis are at greater risk of infection. Related complications tend to increase in the next decades due to the chronic and progressive disease’s character.Only part of treated patients obtain virologic sustained response even in optimal conditions. VHC genotype, pretreatment viral load, viral kinetic, aminotransferases levels, fibrosis, gender, age, body weight, race, steatosis and treatment adherenceare prognostic factors associated with a sustained virologic response. According to the Brazilian control strategy peguilated interferon is used for treatment of genotype 1 and conventional interferon for genotypes 2 and 3. Other factors act along virologicsustained response for treatment effectiveness, such as related costs, early diagnosis, quality and availability of medication, “pólos de aplicação”, early stop criteria implementation, reduced number of retreatments and liver transplantations. In conclusion, to improve hepatitis C treatment effectiveness is necessary to optimizescreening programs, implement more “pólos de aplicação” and make viral kinetic viable.

New hepatitis viruses.

Three new hepatitis viruses are reviewed; Hepatitis E Virus (HEV), Hepatitis G Virus (HGV), and Transfusion Transmitted Virus (TTV). Only HEV has been clearly associated with liver damage. It is transmitted by the fecal-oral route and tends to occur in poor socio-economic conditions. Acute disease is diagnosed by the presence of anti-HEV IgM antibodies in the serum. Hepatitis G virus and TTV are transmitted parenterally. HGV is the same agent as GBV-C. Although it is hepatotropic, and high levels of viremia may occur, pathogenicity to the liver has not been proven. TTV may also be transmitted by the fecal-oral route. It is abundant in liver tissue but, like HGV, pathogenicity has not been proven.

Nuevos virus de hepatitis / New hepatitis viruses

Desde 1990 se han descrito nuevos virus responsables de hepatitis que hasta ese momento eran catalogadas como No A- No B. El virus de la hepatitis E fue descrito como virus transmisión entérica responsable de brotes epidémicos en Asia y México, documentados retrospectivamente. Es un virus RNA, de la familia Caliciviridae, que produce un cuadro similar al virus de la hepatitis A y no produce infección ni partación crónica. Posterior a 1995 se han identificado por técnicas de genéticas molecular nuevos virus, teóricamente responsables de hepatitis post-transfuncional como el virus de la hepatitis G y el virus TT, pero aún no existe certeza de su verdadero rol patogénico

Hepatitis virales / Viral hepatitis

En esta revisión se describen los virus hepatotropos actualmente conocidos, su epidemiología con referencia especial a los datos nacionales relativos a los virus A, B, C y E; su historia natural y sus aspectos clínicos más relevantes. Se enfatizan, además los diferentes marcadores virales serológicos, para el diagnóstico de infección aguda o crónica. Se incluyen también los diferentes tratamientos y las medidas de prevención (pasivas o activas) recomendadas actualmente

Hepatitis G virus/GB virus C in Brazil. Preliminary report.

Hepatitis G virus/GB virus C is a novel flavivirus recently detected in hepatitis non A-E cases. In this study, the presence of this virus in chronic non-B, non-C hepatitis patients was evaluated using GBV-C specific PCR and this virus was detected in one out of thirteen patients. This patient has presented a severe liver failure, has lived for a long time in the Western Amazon basin and no other cause for this clinical picture was reported. The impact of the discovery of this new agent is still under evaluation throughout the world. The study of the prevalence of this virus among chronic hepatitis patients and healthy individuals (as blood donors) will furnish subside to evaluate its real pathogenicity.