Desempeño de métodos moleculares para la identificación de subtipos poco comunes del virus de la hepatitis C, genotipo 2 / Performance of molecular methods for identification of unusual subtypes of hepatitis C virus genotype 2

Resumen Introducción. El virus de la hepatitis C (HCV) presenta una gran variabilidad genética, con siete genotipos y numerosos subtipos. La determinación del tipo viral ha sido fundamental para la escogencia y la duración del tratamiento antiviral adecuado. En Venezuela, el genotipo 2 del HCV es relativamente diverso, siendo particularmente prevalente el subtipo 2j. Objetivo. Evaluar el desempeño de las metodologías para la determinación del genotipo del HCV, particularmente para la identificación del subtipo 2j. Materiales y métodos. Se determinaron el genotipo y el subtipo del HCV mediante la técnica de hibridación inversa LiPA (Line Probe Assay) y secuenciación de las regiones genómicas 5'NC y NS5B del virus. Resultados. En 65 muestras analizadas, la metodología basada en la amplificación de la región 5'NC mostró mayor sensibilidad (100 %), en comparación con la técnica LiPA (91 %) y la secuenciación de la región NS5B (77 %). La determinación de genotipo, tomando como método de referencia la secuenciación de NS5B, mostró un alto grado de concordancia para la secuenciación de la región 5´NC y la hibridación inversa LiPA, con 100 % en la asignación de genotipos, comparado con 70 % y 66 % para los subtipos, respectivamente. La secuenciación de la región NS5B permitió identificar los subtipos 2j y 2s, los cuales no fueron detectados por las otras metodologías. No se observó un patrón característico para las muestras subtipo 2j en la hibridación inversa LiPA. Conclusión. Aunque es la metodología con menor sensibilidad, la secuenciación de la región NS5B es una herramienta poderosa para la correcta discriminación de los distintos subtipos circulantes del HCV, lo cual reviste importancia epidemiológica.

Abstract Introduction: Hepatitis C virus (HCV) displays high genetic variability, with seven genotypes and numerous subtypes. The determination of the viral type has been essential for the selection and timing of antiviral treatment. In Venezuela, HCV genotype 2 is relatively diverse, being particularly prevalent subtype 2j. Objective: To evaluate the performance of methodologies for genotyping HCV, particularly for identification of subtype 2j. Materials and methods: HCV genotype and subtype were determined by reverse hybridization technique (LiPA) and sequencing of the HCV 5'UTR and NS5B regions. Results: A total of 65 samples from HCV-infected patients were analyzed. PCR amplifications of the 5'UTR region exhibited the highest sensitivity (100% vs 91% for LiPA and 77% for NS5B). Genotype determination, taking as reference test NS5B, showed 100% concordance with the other methods, and 67% and 59% for subtypes with 5´NC and LiPA, respectively. NS5B sequencing allowed the identification of subtypes 2j and 2s, which were not detected by the other methods. A specific LiPA pattern was not observed for HCV subtype 2j. Conclusion: Although being the methodology with lowest sensitivity for amplification of HCV RNA, sequencing NS5B region remains a powerful tool for correct discrimination of the different HCV subtypes, which is of epidemiological relevance.

Genotipos circulantes del virus de la hepatitis C en Colombia / Hepatitis C virus genotypes circulating in Colombia

Resumen Introducción: La infección crónica por el virus de la hepatitis C es un problema de salud pública y se estima que hay más de 180 millones de personas infectadas en el mundo. En Colombia no se conoce la epidemiología de la infección ni los genotipos virales más frecuentes. Objetivo. Describir los genotipos y subtipos del virus de la hepatitis C en pacientes colombianos infectados. Materiales y métodos: Se hizo un estudio descriptivo y retrospectivo de pruebas realizadas en dos laboratorios de referencia nacional, entre el 2003 y el 2015, mediante electroforesis en geles de poliacrilamida (Polyacrylamide Gel Electrophoresis, PAGE) o reacción en cadena de la polimerasa en tiempo real (quantitative PCR, qPCR). Resultados. Se estudiaron 1.538 aislamientos del virus de la hepatitis C de 1.527 pacientes con una edad promedio de 53 años, de los cuales 70 % tenía entre 40 y 70 años y 52 % eran mujeres. El 57 % de las pruebas se ordenaron en la ciudad de Bogotá, y el 80 % de los casos provenía de los departamentos de Cundinamarca, Valle y Atlántico. Se encontró el genotipo 1 en 88,6 % de los casos, distribuido así: subtipo 1b, 70 %, subtipo 1a, 13,5 %, y no determinado, 5,1 % de los casos; el genotipo 2 se encontró en el 5,4 % de los casos, el 3, en el 2 %, y el 4, en el 4 %. Se encontraron genotipos mixtos en 0,8 % de la muestra. Conclusión: El genotipo 1 del virus de la hepatitis C es el que circula con mayor frecuencia en el país, con predominio del subtipo 1b.

Abstract Introduction: Chronic hepatitis C virus infection is a worldwide public health problem; it has been estimated that over 180 million people are infected with this virus worldwide. Its precise incidence and prevalence (i.e., epidemiology) and the most frequent circulating genotypes in Colombia are unknown. Objective: To describe the hepatitis C virus (HCV) genotypes and subtypes in infected Colombian patients. Materials and methods: We recovered the data on 1,538 HCV isolates from 1,527 patients in two Colombian reference laboratories typed by PAGE or qPCR. Results: Patients' mean age was 53 years; 70% of them were 40 to 70 years old, and 52%, females; 57% of all tests were ordered in Bogotá and 80% of cases were from Cundinamarca, Valle and Atlántico departments. Genotype 1 was detected in 88.6% of cases, distributed as follows: 70% subtype 1b, 13.5% subtype 1a and 5.1%, undetermined subtypes. Genotype 2 was found in 5.4% of the patients, genotype 3 in 2% and genotype 4 in 4%. Mixed genotypes were found in 0.8% of the samples. Conclusion: Genotype 1 is the most common HCV genotype circulating in Colombia, and subtype 1b the most frequent.

Relationship of the total atrial conduction time to subclinical atherosclerosis, inflammation and echocardiographic parameters in patients with type 2 diabetes mellitus

OBJECTIVES: The aim of our study was to evaluate the total atrial conduction time and its relationship to subclinical atherosclerosis, inflammation and echocardiographic parameters in patients with type 2 diabetes mellitus. METHODS: A total of 132 patients with type 2 diabetes mellitus (mean age 54.5±9.6 years; 57.6% male) and 80 age- and gender-matched controls were evaluated. The total atrial conduction time was measured by tissue-Doppler imaging and the carotid intima-media thickness was measured by B-mode ultrasonography. RESULTS: The total atrial conduction time was significantly longer in the patients with type 2 diabetes mellitus than in the control group (131.7±23.6 vs. 113.1±21.3, p<0.001). The patients with type 2 diabetes mellitus had significantly increased carotid intima-media thicknesses, neutrophil to lymphocyte ratios and high-sensitivity C-reactive protein levels than those of the controls. The total atrial conduction time was positively correlated with the high-sensitivity C-reactive protein level, neutrophil to lymphocyte ratio, carotid intima-media thickness and left atrial volume index and negatively correlated with the early diastolic velocity (Em), Em/late diastolic velocity (Am) ratio and global peak left atrial longitudinal strain. A multiple logistic regression analysis demonstrated that the neutrophil to lymphocyte ratio, carotid intima-media thickness and global peak left atrial longitudinal strain were independent predictors of the total atrial conduction time. CONCLUSIONS: We suggest that subclinical atherosclerosis and inflammation may represent a mechanism related to prolonged total atrial conduction time and that prolonged total atrial conduction time and impaired left atrial myocardial deformation may be represent early subclinical cardiac involvement in patients with type 2 diabetes mellitus. .

Avaliação de citocinas no desfecho da infecção aguda pelo HCV / Evaluation of citokynes on acute HCV infection outcome

Citocinas são proteínas imunomodulatórias que regulam e amplificam a resposta imune do hospedeiro. Na infecção pelo HCV as citocinas podem influenciar o desfecho da infecção aguda e a progressão da hepatite C crônica. No entanto, em virtude do grande número de casos assintomáticos, pouco se sabe sobre o papel, produção e progressão das citocinas durante a fase inicial da infecção. O objetivo desde estudo foi investigar a possível relação dos níveis de citocinas plasmáticas com à resolução espontânea ou com à persistência da infecção pelo HCV em indivíduos sintomáticos. Para análise das concentrações das citocinas TNFalfa, INFgama, IL-2, IL-4,IL-6, IL-10, IL-7, IL-21 e IL-17A foi utilizado imunoensaio multiplex pela metodologia Luminex. Para tanto, foram selecionados 14 pacientes ictéricos, na fase aguda da infecção pelo HCV,distribuídos em dois grupos, de acordo com o desfecho da infecção: eliminação viral espontânea(9) e persistência viral (5). Para a comparação dos níveis das citocinas entre os grupos, dois períodos da fase aguda foram selecionados a partir da provável data da infecção de cada paciente: T1= 8,0-10,5 semanas (compreende o início da resposta imune celular); T2= 16,0-18,5 semanas (diferença na qualidade da resposta das células T em relação ao desfecho da infecção). Nove controles saudáveis também foram selecionados e utilizados como padrão de normalidade para cada citocina estudada. Os resultados demonstraram que os níveis plasmáticos das citocinas IL-6 e IL-10 apresentaram-se mais elevados no grupo correspondente à persistência viral em ambos os períodos da fase aguda analisados ((IL-6 T1 p=0,03/ T2p=0,01), (IL-10 T1 p=0,04/ T2 p=0,04)), quando comparados ao grupo correspondente àeliminação viral espontânea. Com relação aos níveis de IFNgama, estes não apresentaram diferença significativa entre os dois grupos no tempo 1...

Cytokines are immunomodulatory proteins which regulate and amplify the host’s immuneresponse. In hepatitis C virus (HCV) infection, cytokines can influence the outcome of acuteinfection and the progression of chronic hepatitis C infection. However, due to the large numberof asymptomatic cases, little is known about the role, production and progression of cytokinesduring the initial phase of the infection. The aim of this study was to investigate the possibleassociation of plasma cytokine levels with spontaneous resolution or persistence HCV infection insymptomatic individuals. For analysis of concentrations of TNFalpha, INFgama, IL-2, IL-4, IL-6, IL-10, IL-7,IL-21 and IL-17A were used a multiplex immunoassay for the Luminex methodology. Therefore,14 jaundiced pacients were selected in the acute phase of HCV infection, distributed in twogroups according to the outcome of infection: spontaneous viral clearance (9) and viralpersistence (5). To compare the levels of cytokines between the groups, based on the probabledate of infection of each patient, two periods of the acute phase were selected: T1 = 8.0 to 10.5 weeks (the start of the cellular immune response); T2 = 16.0 to 18.5 weeks (difference in T cellresponse quality in relation to the outcome of the infection). Nine healthy controls were alsoselected and used to establish the normal range for each cytokine studied. The results showedthat IL-6 and IL-10 plasma cytokine levels were more elevated in both of the periods of the acutephase analyzed among patients with viral persistence ((IL-6 p = 0.03 T1 / T2 w = 0.01) (IL-10 p =0.04 T1 / T2 p = 0.04)) when compared to patients in the spontaneous viral clearance group.Regarding the INFgama levels, these did not differ significantly between the two groups at T1. However, at T2 higher levels of this cytokine were identified in the spontaneous viral clearancegroup (T2 p = 0.03)...

Hope for Cirrhosis Patients with Genotype 1 Hepatitis C Virus Who Failed the Previous Treatment / 대한소화기학회지

No abstract available.

Seroprevalence of HBV and HCV markers among young adult males in the Air Force in Florianópolis, South Brazil

We investigated the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) serological markers of infection in young adults from the metropolitan region of Florianópolis who were conscripts of the Air Base of Florianópolis in the state of Santa Catarina, Brazil. A population-based cross-sectional seroprevalence study was conducted with 371 young males during a one year period starting in June 2009. Demographic characteristics, socio-economic characteristics and possible risk factors to HBV and HCV were assessed. Blood samples were analyzed for HBsAg, anti-HBc, anti-HCV and anti-HBs through automated microparticle enzymatic immunoassays (Abbott®, AxSYM System, Wiesbaden, Germany). None of the participants showed positivity to HBsAg or anti-HCV. The prevalence of anti-HBc was 1.6% (95% CI 0.6 - 3.5), and the prevalence of anti-HBs was 40.7% (95% CI 35.7 - 45.9). Unsafe sex was associated with positive anti-HBc in a bivariate analysis. There was a very low prevalence of past HBV infection and no cases of past HCV infection in a young adult population in the metropolitan region of Florianópolis. The very low prevalence of markers of infection and risk factors indicates a very optimistic future with respect to HBV and HCV infection in this population.

Este estudo teve como objetivo investigar a prevalência dos marcadores sorológicos de infecção pelo HBV e HCV em adultos jovens na Região Metropolitana de Florianópolis, conscritos da Base Aérea de Florianópolis, Santa Catarina, Brasil. Trata-se de um estudo soroepidemiológico transversal de base populacional com 371 adultos jovens, no período de um ano a partir de junho de 2009. Foram pesquisadas características sócio-econômicas e possíveis fatores de risco para HBV e HCV. As amostras de sangue foram analisadas quanto à presença de HBsAg, anti-HBc, anti-HCV e anti-HBs pelo método imunoensaio enzimático automatizado de micropartículas (Abbott®, Sistema AxSYM, Wiesbaden, Alemanha). Nenhum dos participantes demonstrou positividade para HBsAg ou anti-HCV. A prevalência do anti-HBc foi de 1,6% (IC 95% 0,6 - 3,5) e do anti-HBs foi 40,7% (IC 95% 35,7 - 45,9). Relação sexual desprotegida associou-se com a positividade do anti-HBc na análise bivariada. Demonstrou-se prevalência muito baixa de infecção passada pelo HBV e ausência de HCV nesta população de adultos jovens na Região Metropolitana de Florianópolis. A particularidade desta prevalência muito baixa de marcadores de infecção e fatores de risco aponta para um quadro otimista em relação ao HBV e HCV no futuro para esta população.

Hibridização reversa e sequenciamento na genotipagem do vírus da hepatite C / Reverse hybridization and sequencing for genotyping the hepatitis C virus

INTRODUÇÃO: Os métodos de genotipagem do vírus da hepatite C têm sido muito discutidos. O objetivo deste trabalho foi comparar as metodologias de hibridização reversa e sequenciamento direto para a genotipagem do vírus da hepatite C. MÉTODOS: Noventa e uma amostras de plasma de pacientes assistidos na Faculdade de Medicina de Botucatu da Universidade Estadual Paulista foram utilizadas. A genotipagem por hibridização reversa foi realizada utilizando o kit comercial INNO-LiPA® v.1.0. O sequenciamento direto foi efetuado em sequenciador automático utilizando protocolos in house. RESULTADOS: A genotipagem por sequenciamento direto mostrou-se eficiente na resolução dos resultados inconclusivos pelo kit comercial. O kit mostrou resultados errôneos em relação à subtipagem viral. Além disso, a genotipagem por sequenciamento direto revelou um erro do kit com relação à determinação genotípica questionando a eficiência do método também para a identificação do genótipo viral. CONCLUSÕES: A genotipagem realizada por meio de sequenciamento direto permite uma maior acurácia na classificação viral quando comparada à hibridização reversa.

INTRODUCTION: The methods for genotyping the hepatitis C virus have been much discussed. The aim of this study was to compare the methodologies of reverse hybridization and direct sequencing for genotyping the hepatitis C virus. METHODS: Ninety-one plasma samples from patients attended at the Botucatu Medical School, São Paulo State University, were used. Genotyping by reverse hybridization was performed using the INNO-LiPA® v.1.0 commercial kit. Direct sequencing was performed in an automated sequencer using in-house protocols. RESULTS: Genotyping by direct sequencing was shown to be efficient for resolving cases that had remained inconclusive after using the commercial kit. The kit showed erroneous results in relation to virus subtyping. Moreover, direct sequencing revealed an error of the kit regarding the genotypic determination, thereby raising doubts about the efficiency of reverse hybridization for identifying the virus genotype. CONCLUSIONS: Genotyping by direct sequencing allowed greater accuracy of virus classification than did reverse hybridization.

Hepatitis C virus genotypes in hemodialysis patients in the Federal District, Brazil / Genótipos do vírus da hepatite C em pacientes em hemodiálise no Distrito Federal, Brasil

Hepatitis C virus (HCV) genotypes and subtypes were determined in hemodialysis patients in the Federal District, Brazil, by sequencing of the 5' noncoding (NC) and nonstructural 5B (NS5B) regions. From 761 patients, 66 anti-HCV-positive samples were tested for HCV RNA. All 51 HCV RNA-positive samples by PCR of the 5' NC region were genotyped as genotypes 1 (90.2 percent) and 3 (9.8 percent). Subtype 1a (82.3 percent) was the most prevalent, followed by subtypes 3a (9.8 percent), 1b (5.9 percent) and 1a/1b (2.0 percent). Forty-two samples could be amplified and genotyped in the NS5B region: 38 (90.5 percent) as genotype 1, subtypes 1a, and 8 (9.5 percent) as genotype 3, subtype 3a. For the 42 samples sequenced in both regions, the genotypes and subtypes determined were concordant in 100 percent and 95.2 percent of cases, respectively. Two samples presented discrepant results, with the 5' NC region not distinguishing correctly the subtypes 1a and 1b. These findings indicate that the HCV genotype 1, subtype 1a, is the most prevalent among hemodialysis patients in the Federal District, Brazil.

Os genótipos e subtipos do vírus da hepatite C (HCV) foram determinados em pacientes em hemodiálise no Distrito Federal, Brasil, pelo sequenciamento das regiões 5' não codificante (NC) e não estrutural 5B (NS5B). De 761 pacientes, 66 amostras anti-HCV positivas foram testadas para RNA-HCV. Todas as 51 amostras RNA-HCV positivas por PCR para a região 5' NC foram genotipadas como dos genótipos 1 (90,2 por cento) e 3 (9,8 por cento). O subtipo 1a (82,3 por cento) foi o mais prevalente, seguido pelos subtipos 3a (9,8 por cento), 1b (5,9 por cento) e 1a/1b (2,0 por cento). Quarenta e duas amostras puderam ser amplificadas e genotipadas na região NS5B: 38 (90,5 por cento) como genótipo 1, subtipo 1a, e 8 (9,5 por cento) como genótipo 3, subtipo 3a. Para as 42 amostras sequenciadas nas duas regiões, os genótipos e subtipos determinados foram concordantes em 100 por cento e 95,2 por cento dos casos, respectivamente. Duas amostras apresentaram resultados discrepantes, sendo que a região 5' NC não diferenciou corretamente os subtipos 1a e 1b. Estes achados indicam que o genótipo 1, subtipo 1a, do HCV é o mais prevalente em pacientes em hemodiálise no Distrito Federal, Brasil.

Prevalence of hepatitis C virus (HCV) coinfection in HIV infected individuals in south India and characterization of HCV genotypes.

PURPOSE: To determine anti-HCV antibodies and genomic subtype of HCV in 1487 confirmed human immunodeficiency virus (HIV) positive samples. METHODS: A total of 1487 confirmed HIV-positive samples were tested for anti-HCV antibodies by using a third generation ELISA kit (Ortho 3.0) and by RT PCR for HCV. HIV and HCV coinfected samples were selected for HCV genotyping by RFLP and subtyping with NS5-type specific primers. RESULTS: A total of 1487 HIV-infected serum samples were screened for HCV infection, of which, a 1443 (97.04%) were negative and 45 (3.02%) were coinfected. HIV-HCV coinfection was predominant in the age group 41-50 years (51.1%). HCV genotyping and subtyping was done for the 45 HCV RNA-positive specimens of which genotype 1 was observed in 31 (68.8%) and genotype 3 was observed in 14 (31.1%) subjects. Further subtyping analysis showed the genotype 1b in 23 (51.1%), 1a in eight (17.7%), 3a in 10 (22.2%) and 3b in four (8.8%) subjects. CONCLUSION: HIV and HCV seroprevalence is higher in South India, and the most prevalent genotype in coinfection was genotype 1b.

An evaluation of saliva as an alternative to plasma for the detection of hepatitis C virus antibodies.

PURPOSE: Seroepidemiological studies on the prevalence of Hepatitis C virus (HCV) in India have been hampered by reluctance of subjects to provide blood samples for testing. We evaluated the use of saliva as an alternate specimen to blood for the detection of antibodies to HCV. METHODS: Chronic liver disease (CLD) patients attending the liver clinic were recruited for this study. A saliva and plasma sample (sample pair) was collected from each patient included in the study. Saliva samples were collected using a commercially available collection device--OmniSal. Sample pairs were tested with an in-use ELISA for the detection of antibodies to HCV (HCV-Ab), with a minor modification in the manufacturer's protocol while testing saliva. The cut-off absorbance value for declaring a sample as positive was determined by receiver operating curve (ROC) analysis. HCV-Ab positivity in saliva was compared with that in plasma as well as with viral load in plasma and infecting genotype of the virus. Sensitivity, specificity, positive and negative predictive values, and correlation coefficients were calculated using Medcalc statistical software. RESULTS: The optimal accuracy indices were: sensitivity-81.6%; specificity-92.5%; PPV-85.1% and NPV-90.5%. No correlation was found between salivary positivity and HCV viral load in plasma or infecting genotype. CONCLUSIONS: The accuracy indices indicate that the assay must be optimized further before it can be recommended for routine use in epidemiological surveys for HCV-Ab.

Distribution of hepatitis C virus genotypes in Jeju Island / 대한간학회지

BACKGROUNDS/AIMS: The hepatitis C virus (HCV) genotype affects clinical outcomes of HCV infection, in terms of the response to antiviral therapy and progression of chronic liver diseases, and shows geographic differences in distribution. The aim of this study was to elucidate the HCV genotypes in patients with chronic HCV infection in Jeju, which is an island off the Korean peninsula. METHODS: The study population consisted of 162 patients with anti-HCV antibodies and HCV-RNA. HCV genotypes were determined using genotype specific primers. RESULTS: HCV genotype 2a predominated (62.3%), followed by genotype 1b (34.0%) and 2b (3.7%). The prevalence of genotypes differed significantly with age, with HCV genotypes 1 and 2 being more frequent in older and younger subjects (P=0.035), respectively. HCV-RNA levels were higher in patients with genotype 1 than in those with genotype 2 (P=0.001). HCV genotype was not significantly related to sex, clinical diagnosis and potential risk factors. CONCLUSIONS: HCV genotype 2a is most common in Jeju, followed by genotype 1b. Our results suggest that the distribution of the HCV genotype differs between regions in Korea.

Genotyping hepatitis C virus from hemodialysis patients in Central Brazil by line probe assay and sequence analysis

The present study examined the distribution of hepatitis C virus (HCV) genotypes and subtypes in a hemodialysis population in Goiás State, Central Brazil, and evaluated the efficiency of two genotyping methods: line probe assay (LiPA) based on the 5' noncoding region and nucleotide sequencing of the nonstructural 5B (NS5B) region of the genome. A total of 1095 sera were tested for HCV RNA by RT-nested PCR of the 5' noncoding region. The LiPA assay was able to genotype all 131 HCV RNA-positive samples. Genotypes 1 (92.4 percent) and 3 (7.6 percent) were found. Subtype 1a (65.7 percent) was the most prevalent, followed by subtypes 1b (26.7 percent) and 3a (7.6 percent). Direct nucleotide sequencing of 340 bp from the NS5B region was performed in 106 samples. The phylogenetic tree showed that 98 sequences (92.4 percent) were classified as genotype 1, subtypes 1a (72.6 percent) and 1b (19.8 percent), and 8 sequences (7.6 percent) as subtype 3a. The two genotyping methods gave concordant results within HCV genotypes and subtypes in 100 and 96.2 percent of cases, respectively. Only four samples presented discrepant results, with LiPA not distinguishing subtypes 1a and 1b. Therefore, HCV genotype 1 (subtype 1a) is predominant in hemodialysis patients in Central Brazil. By using sequence analysis of the NS5B region as a reference standard method for HCV genotyping, we found that LiPA was efficient at the genotype level, although some discrepant results were observed at the subtype level (sensitivity of 96.1 percent for subtype 1a and 95.2 percent for subtype 1b). Thus, analysis of the NS5B region permitted better discrimination between HCV subtypes, as required in epidemiological investigations.

Hepatitis C treatment: shorter and better?

Herein, we present a synthesis of two publications that evaluate an abbreviated therapeutic approach to treating chronic hepatitis C virus (HCV) infection. Based on those publications, we discuss the use of the early virologic response (EVR) as a tool for the optimized management of patients under treatment, as well as reviewing concepts of HCV viral kinetics. The fourth-week EVR, characterized by HCV RNA dropping to undetectable levels, allows individuals infected with HCV genotype 1 and presenting low baseline viral loads to be treated with the combination of pegylated interferon and ribavirin for 24 weeks, whereas individuals infected with HCV genotypes 2 or 3 can be treated for only 12 weeks. Therefore, by adopting abbreviated treatment regimens optimized through early prediction of sustained viral response, it is possible to increase the number of patients treated without incurring the excess costs related to high rates of treatment failure and management of adverse outcomes, as well as avoiding the risks of unnecessarily exposing patients to drugs that have the potential to be highly toxic.

A unique seroepidemiological pattern of HBV, HCV and HTLV-I in Nenets and Komi in northwestern Russia.

An epidemiological study of hepatitis viruses type B (HBV) and type C (HCV) and human T-cell leukemia virus type I (HTLV-I) was carried out among 105 residents (male:female=19:86) regarded as Nenets partly mixed with Komi, in the region of Krasnoe, the Nenets Autonomous District of the Arkhangelsk Region, in northwestern Russia in 2004. Blood was drawn from apparently healthy volunteers at ages of 41.6+/-16.5 (range 14-85) years. HBsAg, HBsAb, HBcAb, HBeAb and HCV Ab were measured by microparticle enzyme-immunoassay, and HTLV-I Ab was measured by particle agglutination. Prevalences of HBsAg(+), HBsAb(+), HBcAb(+) and HBeAb(+) were 0.0%, 29.5.%, 20.0% and 7.6%, respectively. The overall HBV infection rate (positive HBsAb or HBcAb) was 34.3%, while no positive HCV or HTLV-I Abs could be detected. A serological subgroup with positive HBsAb and negative HBcAb, consisting of 15(14.3%) females, contrasted sharply to other serological subgroups in sex, age, parent's ethnicity, positive HBeAb rate, and HBcAb inhibition%. We conclude that HBV is prevalent with unique serological patterns among the Nenets, while HCV and HTLV-I infections are negligible.