Human platelet antigen-3 polymorphism as a risk factor for rheumatological manifestations in hepatitis C

Abstract INTRODUCTION: Hepatitis C virus (HCV) infection is involved in the pathogenesis of autoimmune and rheumatic disorders. Although the human platelet antigens (HPA) polymorphism are associated with HCV persistence, they have not been investigated in rheumatological manifestations (RM). This study focused on verifying associations between allele and genotype HPA and RM in patients with chronic hepatitis C. METHODS: Patients (159) with chronic hepatitis C of both genders were analyzed. RESULTS: Women showed association between HPA-3 polymorphisms and RM. CONCLUSIONS: An unprecedented strong association between rheumatological manifestations and HPA-3 polymorphism, possibly predisposing women to complications during the disease course, was observed.

HPA-1a/1b could be considered a molecular predictor of poor prognosis in chronic hepatitis C

Abstract INTRODUCTION: HPA polymorphism has been associated with HCV presence and fibrosis progression in chronic hepatitis C. However, it is unknown if there is an association between HPA-1 polymorphism and hepatocellular carcinoma (HCC). Therefore, this study aimed to evaluate HPA-1 polymorphism in the presence of HCC. METHODS: PCR-SSP was used to perform HPA genotyping on 76 HCV-infected patients. RESULTS: There was no association between patients with and without HCC. There was significant difference in HPA-1 genotypic frequency distribution between HCC and F1/F2 fibrosis degree. CONCLUSIONS: The HPA-1a/1b polymorphism appears to be more associated with liver damage progression than with HCC presence.

Platelet-derived growth factor A mRNA in platelets is associated with the degree of hepatic fibrosis in chronic hepatitis C

Abstract: INTRODUCTION: Transforming growth factor beta 1 (TGFB1) and platelet-derived growth factor (PDGF) are the main cytokines related to hepatic fibrogenesis. METHODS: RNA isolated from the platelets and hepatic tissue of 43 HCV carriers was used for quantitative polymerase chain reaction to determine TGFB1, PDGFA, and PDGFB RNA expression. RESULTS: The mRNA expression of PDGFA in platelets was significantly lower in the group with advanced fibrosis than in the group with early-stage fibrosis. TGFB1 was more frequently expressed in platelets than in hepatic tissue, which was different from PDGFB. CONCLUSIONS: A pathway mediated by overexpression of TGFB1 via PDGFA in megakaryocytes could be involved in the development of fibrosis.

The absence of the human platelet antigen polymorphism effect on fibrosis progression in human immunodeficiency virus-1/hepatitis C virus coinfected patients

Hepatic fibrosis progression in patients with chronic hepatitis C virus infections has been associated with viral and host factors, including genetic polymorphisms. Human platelet antigen polymorphisms are associated with the rapid development of fibrosis in HCV-monoinfected patients. This study aimed to determine whether such an association exists in human immunodeficiency virus-1/hepatitis C virus-coinfected patients.

Platelets can be a biological compartment for the Hepatitis C Virus

Although HCV has hepatic tropism, the presence of the virus in extra-hepatic compartments has been well documented. Platelets have been described as carriers of the virus in the circulation and may be a natural reservoir for the virus. However, few studies have been performed to evaluate the levels of HCV RNA in plasma and platelets are equal or differ in some way. Therefore, the aim of this study was to perform a comparative evaluation of the stability of HCV RNA in plasma and isolated platelets. Four aliquots of whole plasma obtained from patients infected with HCV were incubated at 37 °C for 0, 48, 96 and 144 h. After incubation, the plasma and platelet pellet was obtained from each aliquot. Viral RNA in plasma and platelets was quantified by q-PCR. The results showed a decrease in HCV RNA levels in plasma with incubation time. However, platelet HCV RNA levels were stable up to 144 h incubation. The results of this study showed that HCV RNA in platelets, although at lower concentrations than in plasma, is preserved from degradation over time, suggesting that the virus may persist longer in the body when associated with platelets, which could have an impact on the efficiency of antiviral therapy.

In vitro detection of hepatitis C virus in platelets from uninfected individuals exposed to the virus

Introduction Despite hepatocytes being the target cells of hepatitis C virus (HCV), viral ribonucleic acid RNA has been detected in other cells, including platelets, which have been described as carriers of the virus in the circulation of infected patients. Platelets do not express cluster differentiation 81 CD81, the main receptor for the virus in hepatocytes, although this receptor protein has been found in megakaryocytes. Still, it is not clear if HCV interacts with platelets directly or if this interaction is a consequence of its association with megakaryocytes. The aim of this study was to evaluate the interaction of HCV with platelets from non-infected individuals, after in vitro exposure to the virus. Methods Platelets obtained from 50 blood donors not infected by HCV were incubated in vitro at 37°C for 48h with serum containing 100,000IU∕mL of genotype 1 HCV. After incubation, RNA extracted from the platelets was assayed for the presence of HCV by reverse transcription – polymerase chain reaction RT-PCR. Results After incubation in the presence of virus, all samples of platelets showed HCV RNA. Conclusions The results demonstrate that, in vitro, the virus interacts with platelets despite the absence of the receptor CD81, suggesting that other molecules could be involved in this association. .

Variability and resistance mutations in the hepatitis C virus NS3 protease in patients not treated with protease inhibitors

The goal of treatment of chronic hepatitis C is to achieve a sustained virological response, which is defined as exhibiting undetectable hepatitis C virus (HCV) RNA levels in serum following therapy for at least six months. However, the current treatment is only effective in 50% of patients infected with HCV genotype 1, the most prevalent genotype in Brazil. Inhibitors of the serine protease non-structural protein 3 (NS3) have therefore been developed to improve the responses of HCV-infected patients. However, the emergence of drug-resistant variants has been the major obstacle to therapeutic success. The goal of this study was to evaluate the presence of resistance mutations and genetic polymorphisms in the NS3 genomic region of HCV from 37 patients infected with HCV genotype 1 had not been treated with protease inhibitors. Plasma viral RNA was used to amplify and sequence the HCV NS3 gene. The results indicate that the catalytic triad is conserved. A large number of substitutions were observed in codons 153, 40 and 91; the resistant variants T54A, T54S, V55A, R155K and A156T were also detected. This study shows that resistance mutations and genetic polymorphisms are present in the NS3 region of HCV in patients who have not been treated with protease inhibitors, data that are important in determining the efficiency of this new class of drugs in Brazil.

Epstein-Barr virus-associated gastric carcinoma in Brazil: comparison between in situ hybridization and polymerase chain reaction detection

Epstein-Barr virus (EBV) has been associated with 10% of gastric carcinomas. The aim of this study was to determine the frequency of EBV in gastric carcinomas in Brazil assessed by in situ hybridization (ISH) and PCR, which would contribute to the characterization of the clinical and pathological aspects of EBV-associated gastric carcinomas. One hundred and ninety-two gastric carcinoma cases were collected at hospitals in two Brazilian states. Seventy-three out of 151 cases were PCR(+), while 11/160 cases were ISH(+). Nine out of eleven ISH(+) cases displayed a diffuse staining pattern and 2 out of 11 a focal pattern. Both techniques showed that the EBV(+) cases were characterized by their association with males, older patients, lower gastric region, intestinal type, advanced stage and poorly to moderately differentiated tumors. The concordance between the two techniques was 55.8% (Cohen's kappa index = 0.034). Four cases were ISH(+)/PCR(-), while 49 cases were PCR(+)/ISH(-). Only two cases showed stained lymphocytes by ISH and one of them was PCR(-). The observed discrepancy between the two techniques could not be explained just by the elevated accuracy of PCR. ISH(+)/PCR(-) carcinomas may be encountered if EBV is not present in the whole tumor tissue or if there are polymorphisms in the sequences of the viral genome amplified. On the other hand, the high frequency of PCR(+) results associated with the absence of ISH staining in lymphocytes and/or tumors cells suggests that the virus may be present in tumor cells or other cell types without expressing EBER1, the target of the ISH technique.

A first case of protease codon 35 amino acid insertion in a HIV-1 subtype B sequence detected in the Bauru region, state of São Paulo, Brazil: case report / Primeiro caso de inserção de aminoácidos no codon 35 da protease em uma sequência de HIV-1 do subtipo B detectada na região de Bauru, estado de São Paulo, Brasil: relato de caso

Amino acid insertions in the protease have rarely been described in HIVinfected patients. One of these insertions has recently been described in codon 35, although its impact on resistance remains unknown. This study presents a case of an HIV variant with an insertion in codon 35 of the protease, described for the first time in Bauru, State of Sao Paulo, Brazil, circulating in a 38-year-old caucasian male with asymptomatic HIV infection since 1997. The variant isolated showed a codon 35 insertion of two amino acids in the protease: a threonine and an aspartic acid, resulting in the amino acid sequence E35E_TD.

Inserções de aminoácidos na protease têm sido raramente descritas em pacientes infectados pelo HIV. Uma destas inserções foi, recentemente, descrita no codon 35, embora seu impacto na resistência mantém-se pouco conhecido. Este trabalho apresenta um caso de uma variante viral com inserção no codon 35 da protease, descrita pela primeira vez em Bauru, São Paulo, Brasil, circulante em um homem, caucasiano, com 38 anos, o qual apresenta infecção assintomática pelo HIV desde 1997. A variante isolada mostrou uma inserção no codon 35 da protease de dois aminoácidos: uma treonina e um ácido aspártico, resultando na sequência de aminoácidos E35E_TD.

Detecção do vírus Epstein-Barr (EBV) em adenocarcinomas gástricos procedentes dos estados do Ceará e de São Paulo / Epstein-Barr virus (EBV) detection in gastric carcinomas from Ceará and São Paulo states, in Brazil

INTRODUÇÃO: O vírus Epstein-Barr (EBV) está associado a cerca de 10 por cento dos adenocarcinomas gástricos, representando mais de 50 mil casos por ano no mundo. Apesar dos estudos realizados em várias partes do mundo, alguns aspectos clinicopatológicos permanecem controversos. OBJETIVOS: O presente estudo teve como objetivo analisar as características clinicopatológicas de casos de adenocarcinomas gástricos procedentes dos estados de São Paulo e Ceará, correlacionando-os com a detecção de EBV. MATERIAIS E MÉTODOS: Foram obtidos 192 casos de adenocarcinomas gástricos de hospitais dos estados de São Paulo e do Ceará, dos quais 160 foram submetidos à técnica de RNA-hibridização in situ para detecção de EBV. RESULTADOS: Dos 160 casos, 11 (6,9 por cento) foram EBV-positivo, exibindo intensa marcação nuclear em células tumorais. Destes, dois casos também apresentaram linfócitos infiltrados marcados. Não encontramos marcação em tecido normal ou pré-neoplásico. São Paulo e Ceará apresentaram as frequências 3/60 (5 por cento) e 8/100 (8 por cento), respectivamente, e maior relação do EBV com indivíduos do sexo masculino, de idade avançada, com tumores do tipo intestinal, de estadiamento elevado e grau pouco a moderadamente diferenciado. Os casos do Ceará exibiram aumento relativo de tumores EBV(+) localizados na cárdia, enquanto os casos de São Paulo demonstraram aumento naqueles localizados no corpo gástrico. CONCLUSÃO: A frequência de tumores EBV(+) do presente estudo situa-se nos valores descritos na literatura mundial. Entre os achados, um deles não encontra paralelo na literatura mundial e refere-se ao elevado percentual de tumores EBV(+) no corpo gástrico observado nos casos de São Paulo.

INTRODUCTION: The Epstein-Barr virus (EBV) has been associated with approximately 10 percent of gastric adenocarcinomas, which represents more than 50,000 cases/year worldwide. Despite the studies undertaken in several countries, some clinical-pathological aspects remain contentious. OBJECTIVE: The objective of this study was to analyze clinical-pathological features of gastric adenocarcinomas from two Brazilian states, São Paulo and Ceará, by correlating them with EBV detection. MATERIALS AND METHODS: One hundred ninety-two gastric adenocarcinoma cases were selected from hospitals in São Paulo and Ceará, of which 160 were submitted to RNA in situ hybridization for EBV detection. RESULTS: Eleven (6.9 percent) out of 160 cases were EBV-positive with intense nuclear staining in tumor cells. Among these, two cases also showed stained infiltrating lymphocytes. There was no staining in normal or preneoplastic tissue. São Paulo and Ceará yielded the respective results: 3/60 (5 percent) and 8/100 (8 percent). In both states, EBV was more prevalent among elder male patients with little to moderately differentiated intestinal tumors in advanced stage. Ceará cases substantiated a relative increase in EBV(+) tumors located in the cardia, whereas São Paulo cases presented an increase in the gastric corpus. CONCLUSION: The frequency of EBV(+) tumors is similarly described in the literature. Among our findings, the elevated percentage of EBV(+) tumors in the gastric corpus, which was observed in São Paulo cases, is unprecedented in the literature.

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.

Detecçäo de mutaçäo do fator V (Fator V Leiden) em pacientes com trombose venosa / Detection of mutation in factor V gene (Factor V Leiden) in patients with venous thrombosis

As doenças trombóticas constituem um problema de saúde mundial, de etiologia multifatorial, e säo caracterizadas por formaçäo aguda de trombos em veias e artérias. Nos últimos anos, essas doenças têm sido associadas à resistência à proteína C ativada (RAPC), que está correlacionada com a presença de uma mutaçäo de ponto que ocorre no nucleotídeo 1691 do exon 10 do gene do fator V, em que é substituída a base guanina por adenina, resultando na mudança de um único aminoácido na proteína codificada pelo gene. Essa mutaçäo é designada "Fator V Leiden", estando associada aos genótipos heterozigoto ou homozigoto. Neste estudo foram avaliados 52 pacientes com diagnóstico clínico de trombose venosa, confirmado por mapeamento dúplex, atendidos pela disciplina de Cirurgia Vascular da Faculdade de Medicina de Botucatu. A detecçäo da mutaçäo no exon 10 foi realizada através da reaçäo em cadeia da polimerase (PCR), com amplificaçäo de um fragmento de 220pb, o qual foi submetido à digestäo pela enzima de restriçäo Mn/l. A mutaçäo de ponto (G->A) implica perda de um sítio de restriçäo e alteraçäo do padräo eletroforético. Foi encontrada a mutaçäo Fator V Leiten em seis pacientes (12 por cento), dos quais quatro do sexo feminino (67 por cento) e dois do sexo masculino (33 por cento), todos caucasianos. Cinco portadores da mutaçäo tinham idade entre 21 - 40 anos (23 por cento), e um portador tinha mais de 40 anos. A freqüência encontrada neste trabalho é similar à encontrada em outros estudos nacionais e de outros países ocidentais. A investigaçäo da mutaçäo Fator V Leiden deve ser sempre realizada dentro dos parâmetros da populaçäo local, para se avaliar os reais fatores de risco para o desenvolvimento de trombose venosa

Tipagem HLA-classe II de pacientes portadores de Diabetes mellitus insulino-dependentes / Class-II HLA typing of patients with Diabetes mellitus insulin-dependent

Uma forte associaçäo entre Diabetes Melitus Insulino Dependente (Insulin Dependent Diabetes Mellitus - IDDM) e certos antígenos do complexo HLA (Human Leucocytes Antigens - Antígenos Leucocitários Humanos), tem sido descrita em várias populaçöes. Numerosos trabalhos vêm sendo realizados no sentido de avaliar a susceptibilidade genética ao IDDM, segerindo que o envolvimento do complexo HLA é de suma importância, mesmo que outros genes (ainda desconhecidos) também desempenhem importante papel no desenvolvimento da doença. Progressos na área de Biologia Molecular permitiram análises estabelecendo que em caucasianos a susceptibilidade está associada com os haplótipos DRB1*03 - DQA1*0501 - DQB1*0201 e DRB1*04 - DQA1*0301 - DQB1*0302 enquanto que os haplótipos DRB1*1501 - DQA1*0102 - DQB1*0602 säo altamente protetores. Os objetivos deste trabalho foram realizar a tipagem HLA por métodos de Biologia Molecular dos locos DRB1, DQA1 e DQB1 de 23 pacientes portadores de Diabetes Melitus Insulino-Dependente, para avaliar a presença de alelos que pudessem conferir susceptilidade à doença. A metodologia utilizada foi SSO-PCR, padronizada para o 12th International Histocompatibility Workshop (1996). A tipagem HLA dos alelos DRB1*, DQA1* e DQB1*, permitiu a análise parcial desses locos, visto que a tipagem completa ficou prejudicada em alguns casos por dificuldades na interpretaçäo dos resultados, ou por variaçöes dos sinais emitidos pelas sondas de oligonucleotídeos. Mesmo näo tendo sido possível detectar todos os locos em questäo, os resultados revelaram que os pacientes possuíam locos dos haplótipos que predispöem à IDDM, destacando o papel do Laboratório de Análises Clínicas na definiçäo de susceptibilidades genéticas à certas doenças

Detecçäo de monoclonalidade em linfócitos do sangue periférico de pacientes portadores de leucemia linfocítica crônica pela reaçäo em cadeia da polimerase / Detection of monoclonicity in peripheric blood lymphocytes in patients with chronic lymphocytic leukemia by polymerase chain reaction

O rearranjo gênico da cadeia pesada de imunoglobulina é um fenômeno que ocorre precocemente durante a ontogênese do sistema linfóide B, permitindo a aproximaçäo da regiäo variável (VH) da regiäo juncional (JH, as quais flanqueiam a regiäo de diversidade (DH), de tal modo que o fragmento (VHDHJH, originado desse rearranjo torna-se acessível à amplificaçäo pela reaçäo em cadeia da polimerase (PCR). A partir de linfócitos de sangue periférico de 7 pacientes portadores de LLC, utilizando 2 "primers" complementares a sítios conservados das regiöes VH e JH, foi amplificado um fragmento que após eletroforese em gel de poliacrilamida a 12,5 por cento e coloraçäo pela prata, mostrou ser monoclonal. A presença dessa banda monoclonal foi mantida em diluiçöes sequenciais, as quais envolveram a mistura do DNA tumoral com DNA normal, até inclusive o nível de 1 por cento de DNA tumoral. A técnica da PCR revelada pela prata, mostrou-se sensível na detecçäo de monoclonalidade em pacientes portadores de LLC, sem necessidade do uso de sondas.