Hepatitis C virus quantification in serum and saliva of HCV-infected patients.

The hepatitis C virus (HCV) can be detected in blood and other bodily fluids, such as saliva, semen and gastric juices. The aim of this study was to compare the HCV viral loads in the serum and saliva of infected patients. Twenty-nine patients with detectable HCV RNA in their serum and saliva were included in this study. The HCV viral loads were determined through quantitative real-time polymerase chain reactions. The median viral RNA levels were 5.78 log10 copies in the serum and 3.32 log10 copies in the saliva. We observed that the salivary HCV viral load was significantly lower than the viral load in the serum. Further studies are required to understand the role of saliva in the diagnosis, management and potential transmission of HCV.

Increased frequency of CD56Bright NK-cells, CD3-CD16+CD56- NK-cells and activated CD4+T-cells or B-cells in parallel with CD4+CDC25High T-cells control potentially viremia in blood donors with HCV.

A detailed phenotypic analysis of major and minor circulating lymphocyte subsets is described in potential blood donors with markers of hepatitis C virus (HCV), including non-viremic and viremic groups. Although there were no changes in the hematological profile of either group, increased the levels of pre-NK cells (CD3-CD16+CD56-) and a lower frequency of mature NK cells (CD3-CD16+CD56+) characterized innate immunity in the non-viremic group. Both non-viremic and viremic groups displayed significantly increased levels of CD56(Bright) NK cells. Furthermore, this subset was significantly elevated in the viremic subgroup with a low viral load. In addition, an increase in the NKT2 subset was observed only in this subgroup. An enhanced frequency of activated CD4+ T-cells (CD4+HLA-DR+) was a characteristic feature of the non-viremic group, whereas elevated CD19+ B-cells and CD19+CD86+ cell populations were the major phenotypic features of the viremic group, particularly in individuals with a low viral load. Although CD4+CD25High T-cells were significantly elevated in both the viremic and non-viremic groups, it was particularly evident in the viremic low viral load subgroup. A parallel increase in CD4+CD25High T-cells, pre-NK, and activated CD4+ T-cells was observed in the non-viremic group, whereas a parallel increase in CD4+CD25High T-cells and CD19+ B-cells was characteristic of the low viral load subgroup. These findings suggest that CD56Bright NK cells, together with pre-NK cells and activated CD4+ T-cells in combination with CD4+CD25High T-cells, might play an important role in controlling viremia. Elevated CD56(Bright) NK cells, B-cell responses and a T-regulated immunological profile appeared to be associated with a low viral load.

Domestic swine in a visceral leishmaniasis endemic area produce antibodies against multiple Leishmania infantum antigens but apparently resist to L. infantum infection.

In order to investigate whether pigs can be infected by Leishmania infantum, a serological and parasitological study was carried out on swine in the Jequié municipality, Northeast of Brazil. Anti-Leishmania infantum antibodies were detected in 37 out of 92 swine (40.2%), by two different assays: an anti-L. infantum lysate and an anti-K39 recombinant protein ELISA. An experimental study was also carried out to verify the susceptibility of domestic pigs to L. infantum infection. Three sows inoculated with 10(8) stationary-phase infective L. infantum promastigotes (26% metacyclic promastigotes) per kilogram of body weight produced anti-Leishmania antibodies until the end of the experiment, 11 months later. No parasites, however, could be visualized through optical microscopy of spleen, liver and bone marrow or by in vitro culture of these organs. Homogenates of these organs were also inoculated in hamsters, without producing infection. No Leishmania DNA was detected by polymerase chain reaction (PCR) in sand flies fed on these animals. The results indicate that domestic pigs bitten by L. infantum-infected vectors in the endemic area do not display a full infection pattern, and the positive association in endemic areas between the presence of swine and infection in canines may not be ascribable to the former acting as a parasite reservoir.

Indeterminate RIBA results were associated with the absence of hepatitis C virus RNA (HCV-RNA) in blood donors.

INTRODUCTION: Hepatitis C virus (HCV) infection is diagnosed by the presence of antibodies and is supplemented by confirmatory testing methods, such as recombinant immunoblot assay (RIBA) and HCV-RNA detection. This study aimed to evaluate the efficacy of RIBA testing to diagnose HCV infection in blood donors positive for anti-HCV antibodies. METHODS: A total of 102 subjects positive for anti-HCV determined by enzyme-linked immunosorbent assay (ELISA) at the Hematology and Hemotherapy Foundation of Bahia (HEMOBA) were later assessed with new samples using the Abbott Architect anti-HCV test (Abbott Diagnostics, Wiesbaden, Germany), the RIBA III test (Chiron RIBA HCV 3.0 SIA, Chiron Corp., Emeryville, CA, USA), the polymerase chain reaction (PCR; COBAS® AMPLICOR HCV Roche Diagnostics Corp., Indianapolis, IN, USA) and line probe assay (LiPA - Siemens, Tarrytown, NY, USA) genotyping for HCV diagnosis. RESULTS: Of these new samples, 38.2% (39/102) were positive, 57.8% (59/102) were negative and 3.9% (4/102) were indeterminate for anti-HCV; HCV-RNA was detected in 22.5% (23/102) of the samples. RIBA results were positive in 58.1% (25/43), negative in 9.3% (4/43) and indeterminate in 32.6% (14/43) of the samples. The prevailing genotypes were 1 (78.3%, 18/23), 3 (17.4%, 4/23) and 2 (4.3%, 1/23). All 14 samples with indeterminate RIBA results had undetectable viral loads (detection limit ≤50 IU/mL). Of these samples, 71.4% (10/14) were reevaluated six months later. Eighty percent (8/10) of these samples remained indeterminate by RIBA, and 20% (2/10) were negative. CONCLUSIONS: In this study, individuals with indeterminate RIBA results had no detectable HCV-RNA.

Indeterminate RIBA results were associated with the absence of hepatitis C virus RNA (HCV-RNA) in blood donors

Introduction: Hepatitis C virus (HCV) infection is diagnosed by the presence of antibodies and is supplemented by confirmatory testing methods, such as recombinant immunoblot assay (RIBA) and HCV-RNA detection. This study aimed to evaluate the efficacy of RIBA testing to diagnose HCV infection in blood donors positive for anti-HCV antibodies. Methods: A total of 102 subjects positive for anti-HCV determined by enzyme-linked immunosorbent assay (ELISA) at the Hematology and Hemotherapy Foundation of Bahia (HEMOBA) were later assessed with new samples using the Abbott Architect anti-HCV test (Abbott Diagnostics, Wiesbaden, Germany), the RIBA III test (Chiron RIBA HCV 3.0 SIA, Chiron Corp., Emeryville, CA, USA), the polymerase chain reaction (PCR; COBAS® AMPLICOR HCV Roche Diagnostics Corp., Indianapolis, IN, USA) and line probe assay (LiPA - Siemens, Tarrytown, NY, USA) genotyping for HCV diagnosis. Results: Of these new samples, 38.2% (39/102) were positive, 57.8% (59/102) were negative and 3.9% (4/102) were indeterminate for anti-HCV; HCV-RNA was detected in 22.5% (23/102) of the samples. RIBA results were positive in 58.1% (25/43), negative in 9.3% (4/43) and indeterminate in 32.6% (14/43) of the samples. The prevailing genotypes were 1 (78.3%, 18/23), 3 (17.4%, 4/23) and 2 (4.3%, 1/23). All 14 samples with indeterminate RIBA results had undetectable viral loads (detection limit ≤50 IU/mL). Of these samples, 71.4% (10/14) were reevaluated six months later. Eighty percent (8/10) of these samples remained indeterminate by RIBA, and 20% (2/10) were negative. Conclusions: In this study, individuals with indeterminate RIBA results had no detectable HCV-RNA. .

The dynamics of dengue virus serotype 3 introduction and dispersion in the state of Bahia, Brazil.

By 2002, dengue virus serotype 1 (DENV-1) and DENV-2 had circulated for more than a decade in Brazil. In 2002, the introduction of DENV-3 in the state of Bahia produced a massive epidemic and the first cases of dengue hemorrhagic fever. Based on the standardized frequency, timing and location of viral isolations by the state's Central Laboratory, DENV-3 probably entered Bahia through its capital, Salvador, and then rapidly disseminated to other cities, following the main roads. A linear regression model that included traffic flow, distance from the capital and DENV-1 circulation (r2 = 0.24, p = 0.001) supported this hypothesis. This pattern was not seen for serotypes already in circulation and was not seen for DENV-3 in the following year. Human population density was another important factor in the intensity of viral circulation. Neither DENV-1 nor DENV-2 fit this model for 2001 or 2003. Since the vector has limited flight range and vector densities fail to correlate with intensity of viral circulation, this distribution represents the movement of infected people and to some extent mosquitoes. This pattern may mimic person-to-person spread of a new infection.

Hepatitis C virus quantification in serum and saliva of HCV-infected patients

The hepatitis C virus (HCV) can be detected in blood and other bodily fluids, such as saliva, semen and gastric juices. The aim of this study was to compare the HCV viral loads in the serum and saliva of infected patients. Twenty-nine patients with detectable HCV RNA in their serum and saliva were included in this study. The HCV viral loads were determined through quantitative real-time polymerase chain reactions. The median viral RNA levels were 5.78 log10 copies in the serum and 3.32 log10 copies in the saliva. We observed that the salivary HCV viral load was significantly lower than the viral load in the serum. Further studies are required to understand the role of saliva in the diagnosis, management and potential transmission of HCV.

The dynamics of dengue virus serotype 3 introduction and dispersion in the state of Bahia, Brazil

By 2002, dengue virus serotype 1 (DENV-1) and DENV-2 had circulated for more than a decade in Brazil. In 2002, the introduction of DENV-3 in the state of Bahia produced a massive epidemic and the first cases of dengue hemorrhagic fever. Based on the standardized frequency, timing and location of viral isolations by the state's Central Laboratory, DENV-3 probably entered Bahia through its capital, Salvador, and then rapidly disseminated to other cities, following the main roads. A linear regression model that included traffic flow, distance from the capital and DENV-1 circulation (r² = 0.24, p = 0.001) supported this hypothesis. This pattern was not seen for serotypes already in circulation and was not seen for DENV-3 in the following year. Human population density was another important factor in the intensity of viral circulation. Neither DENV-1 nor DENV-2 fit this model for 2001 or 2003. Since the vector has limited flight range and vector densities fail to correlate with intensity of viral circulation, this distribution represents the movement of infected people and to some extent mosquitoes. This pattern may mimic person-to-person spread of a new infection.

Células de doadores normais primadas in vitro respondem ao antígeno ovular solúvel e ao peptídeo sintético MAP4 derivado da triose fosfato isomerase do Schistosoma mansoni / Cells of normal primed givers in vitro answer to the antigen to ovular soluble and synthetic peptíde MAP4 derived from triose-phosphate isomerase of the Schistosoma mansoni

Dados da literatura demonstram que os antígenos do Schistosoma mansoni induzem uma resposta imune de células T auxiliadora (Th) CD4. Os eventos inciais da resposta imune na esquistossomose são bem caracterizados no modelo murino. Entretanto, ainda são poucos os estudos que avaliam a resposta imune inicial desenvolvida em humanos, especialmente aquelas contra os antígenos mais relevantes do parasito. Para estudar esses eventos iniciais que ocorrem na resposta imune humana após a oviposição na esquistossomose mansoni, foi realizado o priming a estimulação primaria in vitro (PIV), um sistema que simula as condições in vivo. Este sistema pode ser usado para estudar os eventos iniciais in vitro à semelhança de uma infecção natural. No estudo in vitro, foram utilizadas células dendríticas profissionais como células apresentadoras de antígeno. Células mononucleares do sangue periférico (PBMCs) de doze doadores normais saudáveis sem historia prévia de contacto com S. mansoni ou com qualquer de seus antígenos, foram primadas com antígeno ovular solúvel (SEA) do S. mansoni ou múltiplos peptídeos antigênico (MAP4), contendo epitopos de células T e B derivado da triose fosfato isomerase. As células dendríticas foram previamente geradas, caracterizadas e em seguida incubadas na presença ou ausência de antígenos, posteriormente cultivadas na presença de PBMCs total por um período de sete dias para simular a infecção in vivo. As células primadas foram coletadas, lavadas e reestimuladas duas vezes. Em cada etapa do PIV foram determinadas as concentrações de citocinas nos sobrenadantes de culturas e a expressão dos marcadores de superfície das subpopulações de linfócitos, durante o prime e após as reestimulações da primeira e segunda chamada. As PBMCs primadas com antígenos SEA apresentaram um perfil de células semelhante do tipo Th2, exceto 2/12 doadores que apresentaram uma resposta semelhante do tipo Th1. Diferente do observado para PBMCs primadas com SEA...linfócitos.