Ensaio quantitativo em tempo real para o DNA do vírus da hepatite B (HBV) desenvolvido para detectar todos os genótipos do HBV

Hepatitis B virus (HBV) is a major cause of chronic liver disease worldwide. Besides genotype, quantitative analysis of HBV infection is extensively used for monitoring disease progression and treatment. Affordable viral load monitoring is desirable in resource-limited settings and it has been already shown to be useful in developing countries for other viruses such as Hepatitis C virus (HCV) and HIV. In this paper, we describe the validation of a real-time PCR assay for HBV DNA quantification with TaqMan chemistry and MGB probes. Primers and probes were designed using an alignment of sequences from all HBV genotypes in order to equally amplify all of them. The assay is internally controlled and was standardized with an international HBV panel. Its efficacy was evaluated comparing the results with two other methods: Versant HBV DNA Assay 3.0 (bDNA, Siemens, NY, USA) and another real-time PCR from a reference laboratory. Intra-assay and inter-assay reproducibilities were determined and the mean of CV values obtained were 0.12 and 0.09, respectively. The assay was validated with a broad dynamic range and is efficient for amplifying all HBV genotypes, providing a good option to quantify HBV DNA as a routine procedure, with a cheap and reliable protocol.O vírus da Hepatite B (HBV) é uma das principais causas de doença crônica do fígado no mundo. Além do genótipo, a análise quantitativa do HBV é amplamente utilizada para monitorar a progressão da doença e o tratamento. Em locais com recursos escassos, métodos baratos para o monitoramento da carga viral são desejáveis e, em países em desenvolvimento, sua utilidade já foi demonstrada para outros vírus, como o da Hepatite C e HIV. Neste trabalho, descrevemos a validação de um teste de PCR em Tempo Real para a quantificação do DNA do HBV utilizando sondas Taqman/MGB. Os oligos e sondas foram escolhidos usando um alinhamento contendo seqüências de todos os genótipos do HBV para garantir uma amplificação igual de todos eles. O teste possui um controle interno e foi padronizado com um painel internacional de HBV. Sua eficácia foi testada comparando-se os resultados com outros dois métodos: Versant HBV DNA Assay 3.0 (bDNA, Siemens, NY, USA) e outro PCR em tempo real realizado em um laboratório de referência. As reprodutibilidades intra e inter-ensaio foram determinadas e a média dos valores de CV obtidos foram de 0,12 e 0,09, respectivamente. O teste foi validado com uma ampla faixa dinâmica e amplificou com eficiência os diferentes genótipos de HBV, fornecendo uma boa opção para a quantificação de rotina do DNA do HBV, com um protocolo barato e confiável

Fatores preditivos para resposta da Lamivudine na hepatite crônica B

BACKGROUND: Lamivudine has been shown to be an efficient drug for chronic hepatitis B (CHB) treatment. AIM: To investigate predictive factors of response, using a quantitative method with high sensitivity. METHODS: We carried out a prospective trial of lamivudine in 35 patients with CHB and evidence for viral replication, regardless to their HBeAg status. Lamivudine was given for 12 months at 300 mg daily and 150 mg thereafter. Response was considered when DNA was undetectable by PCR after 6 months of treatment. Viral replication was monitored by end-point dilution PCR. Mutation associated with resistance to lamivudine was detected by DNA sequencing in non-responder patients. RESULTS: Response was observed in 23/35 patients (65.7%) but only in 5/15 (33.3%) HBeAg positive patients. Only three pre-treatment variables were associated to low response: HBeAg (p = 0.006), high viral load (DNA-VHB >; 3 x 10(6) copies/ml) (p = 0.004) and liver HBcAg (p = 0.0028). YMDD mutations were detected in 7/11 non-responder patients. CONCLUSIONS: HBeAg positive patients with high viral load show a high risk for developing drug resistance. On the other hand, HBeAg negative patients show a good response to lamivudine even with high viremia.INTRODUÇÃO: A Lamivudina tem-se mostrado útil no tratamento da hepatite crônica pelo vírus B (HC-VHB). OBJETIVO: Investigar os fatores preditivos da resposta à Lamivudina na HC-VHB. MATERIAL E MÉTODOS: Estudo prospectivo com Lamivudina em 35 pacientes com HC-VHB e evidência de multiplicação viral, independentemente do resultado do AgHBe. Administrou-se a Lamivudina na dose diária de 300 mg por 12 meses, seguida de 150 mg diários. Critério de resposta: DNA-VHB negativo (por técnica de PCR) aos 6 meses de tratamento. Nos pacientes não respondedores, pesquisaram-se mutações associadas com resistência à Lamivudina, através do sequenciamento do DNA viral. RESULTADOS: Observou-se resposta em 23/35 pacientes (65,7%). Dos 15 pacientes com AgHBe positivo antes do tratamento, apenas 5 (33,3%) responderam. As variáveis prévias ao tratamento que puderam prever uma má resposta foram: AgHBe positivo (p = 0,006), carga viral elevada (>; 3 x 10(6) genomas/ml) (p = 0,004) e AgHBc no tecido positivo (p = 0,0028). Mutações na região YMDD foram detectadas em 7/11 pacientes não respondedores. CONCLUSÕES: Pacientes com AgHBe positivo e com alta carga viral apresentam um alto risco de desenvolver resistência à Lamivudina. Por outro lado, pacientes com AgHBe negativo, mesmo com alta carga viral, mostraram uma boa resposta à Lamivudina

A quantificação simultânea do DNA VHB e do AgHBe séricos podem distinguir entre resposta viral lenta e rápida à terapêutica anti-viral em pacientes com hepatite crônica B

BACKGROUND: The quantitation of serum HBeAg is not commonly used to monitor viral response to therapy in chronic hepatitis B. METHODS: In this study, 21 patients receiving varying therapies were followed and their viral response monitored by concomitant viral load and HBeAg quantitation in order to study the meaning and the kinetics of both parameters. RESULTS: It was possible to distinguish between three different patterns of viral response. The first was characterized by a simultaneous decrease in serum HBV DNA and HBeAg. The second pattern was characterized by a decrease in serum HBeAg but persistent detection of HBV DNA. The third pattern was characterized by undetectable HBV DNA with persistent HBeAg positivity, which points to a non-response (Pattern III-B) except when HBeAg levels showed a slow but steady drop, characterizing a "slow responder" patient (Pattern III-A). CONCLUSIONS: The first pattern is compatible with a viral response. A long-term HBeAg seropositivity with a slow and persistent decrease (Pattern III-A) is also compatible with a viral response and calls for a prolongation of anti-viral treatment.INTRODUÇÃO: A quantificação do AgHBe sérico não é habitualmente utilizada para monitorizar a resposta viral ao tratamento da hepatite crônica B. MÉTODOS: Neste estudo, 21 pacientes sob tratamento com diferentes terapias foram acompanhados e a resposta viral monitorizada pela quantificação concomitante da carga viral e do AgHBe a fim de investigar o significado e a cinética de ambos os parâmetros. RESULTADOS: Distinguiram-se três diferentes padrões de resposta viral. O primeiro caracterizou-se pela redução simultânea do HBV DNA e AgHBe séricos. O segundo padrão caracterizou-se por uma redução do AgHBe porém com detecção persistente do HBV DNA. O terceiro padrão caracterizou-se por HBV DNA indetectável com positividade persistente do AgHBe, sugerindo ausência de resposta (Padrão III-B), exceto quando os níveis de AgHBe mostraram uma queda lenta porém persistente, caracterizando um "respondedor lento" (Padrão III-A). CONCLUSÕES: O primeiro padrão é compatível com resposta viral. Uma seropositividade prolongada do AgHBe porém com uma redução lenta e persistente (Padrão III-A) é também compatível com resposta viral, sugerindo o prolongamento do tratamento anti-viral

Improving the diagnosis of meningitis due to enterovirus and herpes simplex virus I and II in a tertiary care hospital

Background Enterovirus and herpes simplex viruses are common causes of lymphocytic meningitis. The purpose of this study was to analyse the impact of the use molecular testing for Enteroviruses and Herpes simplex viruses I and II in all suspected cases of viral meningitis. Methods From November 18, 2008 to November 17, 2009 (phase II, intervention), all patients admitted with suspected viral meningitis (with pleocytosis) had a CSF sample tested using a nucleic acid amplification test (NAAT). Data collected during this period were compared to those from the previous one-year period, i.e. November 18, 2007 to November 17, 2008 (phase I, observational), when such tests were available but not routinely used. Results In total, 2,536 CSF samples were assessed, of which 1,264 were from phase I, and 1,272 from phase II. Of this total, a NAAT for Enterovirus was ordered in 123 cases during phase I (9.7% of the total phase I sample) and in 221 cases in phase II (17.4% of the total phase II sample). From these, Enterovirus was confirmed in 35 (28.5%, 35/123) patients during phase I and 71 (32.1%, 71/221) patients during phase II (p = 0.107). The rate of diagnosis of meningitis by HSV I and II did not differ between the groups (13 patients, 6.5% in phase I and 13, 4.7% in phase II) (p = 1.0), from 200 cases in phase I and 274 cases in phase II. Conclusions The number of cases diagnosed with enteroviral meningitis increased during the course of this study, leading us to believe that the strategy of performing NAAT for Enterovirus on every CSF sample with pleocytosis is fully justified

Distribution of hepatitis B virus subgenotype F2a in São Paulo, Brazil

Abstract\ud \ud \ud \ud Background\ud HBV genotype F is primarily found in indigenous populations from South America and is classified in four subgenotypes (F1 to F4). Subgenotype F2a is the most common in Brazil among genotype F cases. The aim of this study was to characterize HBV genotype F2a circulating in 16 patients from São Paulo, Brazil. Samples were collected between 2006 and 2012 and sent to Hospital Israelita Albert Einstein. A fragment of 1306 bp partially comprising HBsAg and DNA polymerase coding regions was amplified and sequenced. Viral sequences were genotyped by phylogenetic analysis using reference sequences from GenBank (n=198), including 80 classified as subgenotype F2a. Bayesian Markov chain Monte Carlo simulation implemented in BEAST v.1.5.4 was applied to obtain the best possible estimates using the model of nucleotide substitutions GTR+G+I.\ud \ud \ud \ud Findings\ud It were identified three groups of sequences of subgenotype F2a: 1) 10 sequences from São Paulo state; 2) 3 sequences from Rio de Janeiro and one from São Paulo states; 3) 8 sequences from the West Amazon Basin.\ud \ud \ud \ud Conclusions\ud These results showing for the first time the distribution of F2a subgenotype in Brazil. The spreading and the dynamic of subgenotype F2a in Brazil requires the study of a higher number of samples from different regions as it is unfold in almost all Brazilian populations studied so far. We cannot infer with certainty the origin of these different groups due to the lack of available sequences. Nevertheless, our data suggest that the common origin of these groups probably occurred a long time ago.This work has been supported by CNPq and by Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP 2011/50562-0 and 2008/50461-6, HCFMUSP, FFM, Alves de Queiroz Family Fund for Research and IIRS-SBIBAE. These supported institutions provided the found to development the DNA amplification, sequencing and phylogenetic analysis

Distribution of hepatitis B virus subgenotype F2a in São Paulo, Brazil

Abstract\ud \ud \ud \ud Background\ud HBV genotype F is primarily found in indigenous populations from South America and is classified in four subgenotypes (F1 to F4). Subgenotype F2a is the most common in Brazil among genotype F cases. The aim of this study was to characterize HBV genotype F2a circulating in 16 patients from São Paulo, Brazil. Samples were collected between 2006 and 2012 and sent to Hospital Israelita Albert Einstein. A fragment of 1306 bp partially comprising HBsAg and DNA polymerase coding regions was amplified and sequenced. Viral sequences were genotyped by phylogenetic analysis using reference sequences from GenBank (n=198), including 80 classified as subgenotype F2a. Bayesian Markov chain Monte Carlo simulation implemented in BEAST v.1.5.4 was applied to obtain the best possible estimates using the model of nucleotide substitutions GTR+G+I.\ud \ud \ud \ud Findings\ud It were identified three groups of sequences of subgenotype F2a: 1) 10 sequences from São Paulo state; 2) 3 sequences from Rio de Janeiro and one from São Paulo states; 3) 8 sequences from the West Amazon Basin.\ud \ud \ud \ud Conclusions\ud These results showing for the first time the distribution of F2a subgenotype in Brazil. The spreading and the dynamic of subgenotype F2a in Brazil requires the study of a higher number of samples from different regions as it is unfold in almost all Brazilian populations studied so far. We cannot infer with certainty the origin of these different groups due to the lack of available sequences. Nevertheless, our data suggest that the common origin of these groups probably occurred a long time ago.This work has been supported by CNPq and by Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP 2011/50562-0 and 2008/50461-6, HCFMUSP, FFM, Alves de Queiroz Family Fund for Research and IIRS-SBIBAE. These supported institutions provided the found to development the DNA amplification, sequencing and phylogenetic analysis

A Novel Assay for the Identification of NOTCH1 PEST Domain Mutations in Chronic Lymphocytic Leukemia

Aims. To develop a fast and robust DNA-based assay to detect insertions and deletions mutations in exon 34 that encodes the PEST domain of NOTCH1 in order to evaluate patients with chronic lymphocytic leukemia (CLL). Methods. We designed a multiplexed allele-specific polymerase chain reaction (PCR) combined with a fragment analysis assay to detect specifically the mutation c.7544 7545delCT and possibly other insertions and deletions in exon 34 of NOTCH1. Results. We evaluated our assay in peripheral blood samples from two cohorts of patients with CLL. The frequency of NOTCH1 mutations was 8.4% in the first cohort of 71 unselected CLL patients. We then evaluated a second cohort of 26 CLL patients with known cytogenetic abnormalities that were enriched for patients with trisomy 12. NOTCH1 mutations were detected in 43.7% of the patients with trisomy 12. Conclusions. We have developed a fast and robust assay combining allele-specific PCR and fragment analysis able to detect NOTCH1 PEST domain insertions and deletions

Quantitation of HIV-1 RNA viral load using NASBA methodology and comparison with other surrogate markers for disease progression

In this study, HIV-1 viral load quantitation determined by Nucleic Acid Sequence Based Amplification (NASBA) was compared with other surrogate disease progression markers (antigen p24, CD4/CD8 cell counts and b-2 microglobulin) in 540 patients followed up at Sao Paulo, SP, Brazil. HIV-1 RNA detection was statistically associated with the presence of antigen p24, but the viral RNA was also detected in 68% of the antigen p24 negative samples, confirming that NASBA is much more sensitive than the determination of antigen p24. Regarding other surrogate markers, no statistically significant association with the detection of viral RNA was found. The reproducibility of this viral load assay was assessed by 14 runs of the same sample, using different reagents batches. Viral load values in this sample ranged from 5.83 to 6.27 log (CV = 36 %), less than the range (0.5 log) established to the determination of significant viral load changes