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1.
J Clin Microbiol ; 50(4): 1384-9, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22238432

RESUMO

The automation of DNA extraction and the use of commercial quantitative real-time PCR assays could help obtain more reliable results for the quantification of Epstein-Barr virus DNA loads (EBV VL). This study compared two automated extraction platforms and two commercial PCRs for measurement of EBV VL in 10 EBV specimens from Quality Control for Molecular Diagnostics (QCMD) and in 200 whole-blood (WB) specimens from transplant (n = 137) and nontransplant (n = 63) patients. The WB specimens were extracted using the QIAcube or MagNA Pure instrument; VL were quantified with the EBV R-gene quantification kit (Argene) or the artus EBV RG PCR kit (Qiagen) on the Rotor-Gene 6000 real-time analyzer; and the results were compared with those of a laboratory-developed PCR. DNA was extracted from the QCMD specimens by use of the QIAamp DNA minikit and was quantified by the three PCR assays. The extraction platforms and the PCR assays showed good correlation (R, >0.9; P, <0.0001), but as many as 10% discordant results were observed, mostly for low viral loads (<3 log(10) copies/ml), and standard deviations reached as high as 0.49 log(10) copy/ml. In WB but not in QCMD samples, Argene PCR tended to give higher VL values than artus PCR or the laboratory-developed PCR (mean difference for the 200 WB VL, -0.42 or -0.36, respectively). In conclusion, the two automated extraction platforms and the two PCRs provided reliable and comparable VL results, but differences greater than 0.5 log(10) copy/ml remained between the two commercial PCRs after common DNA extraction.


Assuntos
DNA Viral/sangue , DNA Viral/isolamento & purificação , Infecções por Vírus Epstein-Barr/sangue , Herpesvirus Humano 4/genética , Reação em Cadeia da Polimerase em Tempo Real , Carga Viral/métodos , Automação Laboratorial , Infecções por Vírus Epstein-Barr/diagnóstico , Infecções por Vírus Epstein-Barr/virologia , Transplante de Células-Tronco Hematopoéticas , Herpesvirus Humano 4/fisiologia , Humanos , Transplante de Órgãos , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/normas , Padrões de Referência , Estatísticas não Paramétricas
2.
Eur Arch Otorhinolaryngol ; 269(3): 1005-11, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21805179

RESUMO

Because nasopharyngeal carcinoma (NPC) has a close association with Epstein-Barr virus (EBV), measuring serum EBV DNA and anti-EBV serum marker concentrations could be a feasible method for NPC diagnosis, monitoring and probably screening especially in a community at risk. The aim of this study was to determine the EBV pattern in sporadic NPC and in high risk NPC Tunisian families in order to evaluate their risk factors and help for NPC screening. The rates of anti-EBV antibodies and EBV DNA were determined in the serum of 47 healthy members randomly selected from 23 NPC multiplex families with two or more affected members, 93 healthy Tunisian community controls chosen with the same age, sex and geographic origin as unaffected individuals and 66 EBV positive sporadic NPC patients whose serum was available before and after treatment. Unexpectedly, significant lower concentrations of anti-EA (Early Antigen) IgG and anti-VCA (Viral Capsid Antigen) IgG were found in unaffected members from NPC families than in healthy controls while viral loads were negative in all the tested sera. For sporadic NPC patients, anti-EA IgG and anti-VCA IgA concentrations were significantly higher than in healthy controls and these rates decreased after treatment. The level of EBV DNA load varied according to the condition of the tumour. This study suggests that in the Tunisian NPC families, screening for malignancy is based on serum concentrations but not on EBV DNA load while in the sporadic NPC group, serologic markers and EBV DNA load are complementary for diagnosis and follow-up.


Assuntos
Anticorpos Antivirais/sangue , DNA Viral/análise , Diagnóstico Precoce , Infecções por Vírus Epstein-Barr/diagnóstico , Herpesvirus Humano 4/genética , Programas de Rastreamento/métodos , Neoplasias Nasofaríngeas/diagnóstico , Adolescente , Adulto , Idoso , Biomarcadores Tumorais/sangue , Carcinoma , Criança , Diagnóstico Diferencial , Ensaio de Imunoadsorção Enzimática , Infecções por Vírus Epstein-Barr/sangue , Infecções por Vírus Epstein-Barr/epidemiologia , Feminino , Seguimentos , Herpesvirus Humano 4/imunologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/sangue , Neoplasias Nasofaríngeas/epidemiologia , Reação em Cadeia da Polimerase , Prognóstico , Fatores de Risco , Tunísia/epidemiologia , Carga Viral , Adulto Jovem
3.
J Infect ; 63(6): 457-67, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21867729

RESUMO

BACKGROUND: Studies assessing the risk of cytomegalovirus (CMV), parvovirus B19 (B19V), rubella and varicella infections in female child-care personnel may help define appropriate preventive strategies during pregnancy. METHODS: Serologic testing for all four viruses and a self-administered questionnaire to identify risk factors were conducted on child-care staff aged 20-50 years old and on a reference group of women. RESULTS: In 395 exposed and 382 reference women, CMV, B19V, rubella and varicella seroprevalence were 69.4, 79.4, 98.7, 100% for exposed women, and 41.1, 68.0, 98.2, 99.7% for reference women, respectively. For CMV, the adjusted seroprevalence ratio (PR) of exposed versus reference workers, (PR, 1.43 [95% IC, 1.22-1.69]) was observed as of the first year of exposure. The risk attributed to occupation was 30.1%. Identified risk factors included exposure duration, past employment in maternity hospital, and participation in cleaning tasks. The risk attributable to personal factors ranged from 14.5% to 32.4%. The adjusted B19V PR was not significant (PR, 1.05 [95% IC, 0.94-1.16]). CONCLUSIONS: French female child-care staff runs an occupational risk for CMV infection, but not for B19V infection. The fraction attributable to this CMV occupational risk was not higher than the risk associated with personal factors.


Assuntos
Cuidado da Criança , Infecções por Citomegalovirus/epidemiologia , Pessoal de Saúde , Exposição Ocupacional , Infecções por Parvoviridae/epidemiologia , Adulto , Varicela/epidemiologia , Pré-Escolar , Feminino , França/epidemiologia , Humanos , Lactente , Pessoa de Meia-Idade , Infecções por Parvoviridae/virologia , Parvovirus B19 Humano/isolamento & purificação , Risco , Medição de Risco , Rubéola (Sarampo Alemão)/epidemiologia , Estudos Soroepidemiológicos
4.
J Med Virol ; 82(5): 747-54, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20336715

RESUMO

The prevalence of occult hepatitis B, defined by absence of HBsAg and HBV DNA, ranges widely in patients with hepatitis C. This may influence the treatment of hepatitis C and the severity of liver disease. Sensitive and specific real-time PCR techniques are available commercially and can detect more reliably low HBV DNA levels. The aim of this study was to determine the prevalence of occult hepatitis B virus infection using the COBAS Taqman assay (Roche Diagnostics, Meylan, France) in the serum and liver of HBsAg negative patients with chronic hepatitis C and to evaluate its clinical consequences on liver pathology and its impact on the response to treatment with peg-IFNalpha and Ribavirin. HBV DNA detection was assessed retrospectively on 140 sera and 113 liver biopsies of HCV positive/HBsAg negative patients before treatment. A 4.4% (5/113) prevalence of occult hepatitis B was recorded in liver samples and in none of the sera. Anti-HBc was not detected in one, three of whom were sustained virological responders to treatment, one was relapsed responder and one was non-responder. Furthermore, in this cohort composed of 12% anti-HBs negative/anti-HBc positive and 20% anti-HBs positive/anti-HBc positive patients, anti-HBc was not associated with pre-therapeutic viral load, ALT serum levels, and histological activity or fibrosis. Using a commercial real-time PCR assay, we observed a low prevalence of occult B hepatitis. This, just as anti-HBC status, had no clinical impact in a large cohort of hepatitis C patients. It therefore does not appear useful to screen for occult hepatitis B in these patients with this test before beginning HCV treatment.


Assuntos
Antivirais/uso terapêutico , DNA Viral/isolamento & purificação , Vírus da Hepatite B/isolamento & purificação , Hepatite B/epidemiologia , Hepatite C Crônica/complicações , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Adulto , Sangue/virologia , DNA Viral/análise , DNA Viral/sangue , Feminino , França , Hepatite B/virologia , Antígenos de Superfície da Hepatite B/sangue , Hepatite C Crônica/tratamento farmacológico , Humanos , Interferon alfa-2 , Fígado/virologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Prevalência , Kit de Reagentes para Diagnóstico , Proteínas Recombinantes
5.
Blood ; 115(6): 1145-55, 2010 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-20007541

RESUMO

Here we report a unique situation in which an early and synchronized Epstein-Barr virus (EBV) reactivation was induced by a 6-day course of treatment with a humanized CD3-specific monoclonal antibody in patients with recent onset of type 1 diabetes. The virologic and immunologic analysis demonstrated that this reactivation was transient, self-limited, and isolated, associated with the rapid advent of an EBV-specific T-cell response. The anti-CD3 antibody administration induced short-lasting immunosuppression and minor yet clear-cut signs of T-cell activation that preceded viral reactivation. Early posttransplant monitoring of renal and islet allograft recipients showed that no comparable phenomenon was observed after the administration of full-dose immunosuppressive therapy. This EBV reactivation remains of no apparent clinical concern over the long term and should not preclude further development of therapeutic anti-CD3 antibodies. This phenomenon may also direct new research avenues to understand the still ill-defined nature of stimuli triggering EBV reactivation in vivo.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Complexo CD3/imunologia , Infecções por Vírus Epstein-Barr/terapia , Sobrevivência de Enxerto/imunologia , Herpesvirus Humano 4/fisiologia , Linfócitos B/imunologia , DNA Viral/genética , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 1/virologia , Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/virologia , Citometria de Fluxo , Humanos , Transplante de Rim , Tonsila Palatina/citologia , Fenótipo , Placebos , Reação em Cadeia da Polimerase , Linfócitos T/imunologia , Carga Viral , Ativação Viral
6.
AIDS ; 23(16): 2165-71, 2009 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-19657270

RESUMO

OBJECTIVE: The objectives of this study were to determine whether peripheral blood mononuclear cell (PBMC)-associated HIV-1 DNA level in patients on long-term suppressive antiretroviral therapy (ART) was associated with plasma HIV-1 RNA level, CD4 cell count, and therapeutic factors throughout patient history. DESIGN: Patients receiving triple or dual therapy with plasma HIV-1 RNA below detection limit for more than 3 years were recruited in a multicentric, cross-sectional study within the eight virology laboratories of the Agence Nationale de Recherche sur le SIDA et les Hépatites virales HIV quantification working group, each one in relation with a clinical center. METHODS: PBMC-associated HIV-1 DNA was quantified using a standardized real-time PCR method in all laboratories. RESULTS: A total of 236 patients was included. Median HIV-1 DNA was 2.8 log10 copies/10 PBMCs (interquartile range 2.4-3.0). Univariate analysis showed PBMC HIV-1 DNA level to be related to pre-ART immuno-virologic status (plasma HIV-1 RNA zenith and CD4 cell count nadir) and to current CD4 T-cell count. HIV-1 DNA was lower in patients receiving ART with inferior virologic efficacy, as they also had a higher CD4 nadir and a lower HIV-1 RNA zenith than other patients. PBMC HIV-1 DNA level was not related to therapy duration, to time spent with undetectable HIV-1 RNA or to occurrence of a blip. Plasma HIV-1 RNA zenith and CD4 cell count nadir remained predictive of HIV-1 DNA level in the multivariate model which was associated with 22% of its variability. CONCLUSION: Whatever the duration of treatment, HIV-1 DNA level during ART gives a picture of the intensity of viral replication and immune deficiency reached before starting therapy.


Assuntos
Antirretrovirais/uso terapêutico , DNA Viral/sangue , Infecções por HIV/virologia , HIV-1/genética , Leucócitos Mononucleares/virologia , Adulto , Contagem de Linfócito CD4 , Estudos Transversais , Feminino , Infecções por HIV/sangue , Infecções por HIV/tratamento farmacológico , HIV-1/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , Resultado do Tratamento , Carga Viral
7.
Antivir Ther ; 14(5): 655-62, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19704168

RESUMO

BACKGROUND: The Epstein-Barr virus (EBV) protease (PR), coded by the BVRF2 gene, is essential for the maturation of the viral capsid and viral DNA packaging during the late stage of the EBV lytic cycle. Like the other herpesvirus serine PRs, EBV PR could be a target for the inhibition of EBV replication. To date, no data have been reported on the inhibition of EBV PR messenger RNA (mRNA) by small interfering RNA (siRNA). METHODS: In this study, siRNAs targeting EBV PR were delivered to the epithelial 293 cell line stably transfected with the complete B95-8 EBV episome. EBV DNA and PR mRNA were quantified by real-time PCR in cells and supernatant, protein expression was assessed by immunoblotting, and production of EBV infectious particles in the culture medium was measured by Raji cell superinfection. RESULTS: The EBV PR mRNA within the cells was reduced by 73%, the PR protein by 35% and the amount of virus in the cell supernatant was drastically decreased by 86% or 95%, depending on the method. CONCLUSIONS: The strong effect of the siRNA targeting EBV PR on EBV replication attests to the crucial role played by EBV PR in the production of infectious particles and suggests that targeting this enzyme can be a new strategy against EBV-associated diseases where virus replication occurs.


Assuntos
Regulação Viral da Expressão Gênica , Herpesvirus Humano 4/fisiologia , Peptídeo Hidrolases/metabolismo , RNA Interferente Pequeno , Replicação Viral/efeitos dos fármacos , Linhagem Celular , Herpesvirus Humano 4/efeitos dos fármacos , Herpesvirus Humano 4/enzimologia , Herpesvirus Humano 4/genética , Humanos , Peptídeo Hidrolases/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Virais/genética , Proteínas Virais/metabolismo
8.
J Virol Methods ; 156(1-2): 52-8, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19041345

RESUMO

A selective real-time PCR (sPCR) assay has been developed to detect the rtM204V/I and rtN236T mutations of hepatitis B virus (HBV) associated with resistance to lamivudine and adefovir. Using mixtures of mutant and wild-type plasmids, this sPCR was able to detect 0.1% of mutated strain in a total plasmid population of 10(5) copies and was more sensitive in detecting resistant strains than the line probe INNO-LiPA-DR-v2 assay and a direct sequencing assay. The comparison of these methods on 20 clinical specimens from treated patients confirmed the plasmid results: the three methods were concordant for the detection of the mutant strains in 72% of the cases and the discrepant results were caused mainly by the sequencing assay's lack of sensitivity. The line probe assay was more sensitive for detecting mutations than sPCR when the viral load was less than 10(4) copies/ml; conversely, the sPCR provided a more sensitive detection when the viral load was greater than 10(4) copies/ml. Although difficult to perform in clinical practice, sPCR appears to be a reliable technique for detecting and quantifying quasi-species resistant to lamivudine (LAM) and adefovir (ADV) and can be useful to gain a better understanding of the natural history of antiviral resistance during the treatment of chronic hepatitis B (CHB).


Assuntos
Farmacorresistência Viral/genética , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/isolamento & purificação , Adenina/análogos & derivados , Adenina/farmacologia , Antivirais/farmacologia , Análise Mutacional de DNA , DNA Viral/análise , Genótipo , Vírus da Hepatite B/genética , Humanos , Lamivudina/farmacologia , Mutação , Organofosfonatos/farmacologia , Plasmídeos , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade
9.
Blood ; 113(3): 604-11, 2009 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-18845794

RESUMO

The Epstein-Barr virus (EBV) causes infectious mononucleosis, establishes latency in resting memory B lymphocytes, and is involved in oncogenesis through poorly understood mechanisms. The EBV lytic cycle is initiated during plasma cell differentiation by mRNAs transcripts encoded by BZLF1, which induce the synthesis of EBV proteins such as the immediate-early antigen ZEBRA and the late membrane antigen gp350. Therefore, we assessed the capacity of circulating EBV-infected B lymphocytes from healthy EBV-seropositive subjects to enter and complete the EBV lytic cycle. Purified B lymphocytes were polyclonally stimulated and BZLF1- or gp350-secreting cells (BZLF1-SCs or gp350-SCs) were enumerated by ELISpot assays. The number of BZLF1-SCs ranged from 50 to 480/107 lymphocytes (median, 80; 25th-75th percentiles, 70-150) and gp350-SCs from 10 to 40/107 lymphocytes (median, 17; 25th-75th percentiles, 10-20). gp350-SCs represented only 7.7% to 28.6% of BZLF1-SCs (median, 15%; 25th-75th percentiles, 10.5%-20%). This EBV functional reservoir was preferentially restricted to plasma cells derived from CD27(+) IgD(-) memory B lymphocytes. In 9 of 13 subjects, EBV DNA quantification in B-cell culture supernatants gave evidence of completion of EBV lytic cycle. These results demonstrate that EBV proteins can be secreted by EBV-infected B lymphocytes from healthy carriers, a majority generating an abortive EBV lytic cycle and a minority completing the cycle.


Assuntos
Linfócitos B/virologia , Infecções por Vírus Epstein-Barr/virologia , Memória Imunológica , Plasmócitos/virologia , Ativação Viral/fisiologia , Adulto , Linfócitos B/metabolismo , Células Cultivadas , DNA Viral/análise , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/imunologia , Citometria de Fluxo , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/imunologia , Humanos , Plasmócitos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transativadores/metabolismo , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Latência Viral/fisiologia
10.
PLoS One ; 3(9): e3262, 2008 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-18810271

RESUMO

BACKGROUND: Langerhans cell histiocytosis (LCH) is a rare disease that affects mainly young children, and which features granulomas containing Langerhans-type dendritic cells. The role of several human herpesviruses (HHV) in the pathogenesis of LCH was suggested by numerous reports but remains debated. Epstein-barr virus (EBV, HHV-4), & Cytomegalovirus (CMV, HHV-5) can infect Langerhans cells, and EBV, CMV and HHV-6 have been proposed to be associated with LCH based on the detection of these viruses in clinical samples. METHODOLOGY: We have investigated the prevalence of EBV, CMV and HHV-6 infection, the characters of antibody response and the plasma viral load in a cohort of 83 patients and 236 age-matched controls, and the presence and cellular localization of the viruses in LCH tissue samples from 19 patients. PRINCIPAL FINDINGS: The results show that prevalence, serological titers, and viral load for EBV, CMV and HHV-6 did not differ between patients and controls. EBV was found by PCR in tumoral sample from 3/19 patients, however, EBV small RNAs EBERs -when positive-, were detected by in situ double staining in bystander B CD20+ CD79a+ lymphocytes and not in CD1a+ LC. HHV-6 genome was detected in the biopsies of 5/19 patients with low copy number and viral Ag could not be detected in biopsies. CMV was not detected by PCR in this series. CONCLUSIONS/SIGNIFICANCE: Therefore, our findings do not support the hypothesis of a role of EBV, CMV, or HHV-6 in the pathogenesis of LCH, and indicate that the frequent detection of Epstein-barr virus (EBV) in Langerhans cell histiocytosis is accounted for by the infection of bystander B lymphocytes in LCH granuloma. The latter observation can be attributed to the immunosuppressive micro environment found in LCH granuloma.


Assuntos
Infecções por Herpesviridae/complicações , Infecções por Herpesviridae/epidemiologia , Histiocitose de Células de Langerhans/complicações , Histiocitose de Células de Langerhans/epidemiologia , Adolescente , Adulto , Antígenos CD1/biossíntese , Antígenos CD20/biossíntese , Antígenos CD79/biossíntese , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos de Coortes , Citomegalovirus/metabolismo , Infecções por Herpesviridae/diagnóstico , Herpesvirus Humano 4/metabolismo , Herpesvirus Humano 6/metabolismo , Histiocitose de Células de Langerhans/diagnóstico , Histiocitose de Células de Langerhans/virologia , Humanos , Imunossupressores/farmacologia , Lactente
11.
Biochem Biophys Res Commun ; 372(3): 429-33, 2008 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18489903

RESUMO

The use of streptomycin in the PrP(sc) detection procedures represents a new and attractive way to detect more PrP(sc), the best marker for the transmissible spongiform encephalopathies (TSEs). Actually, the streptomycin PrP(sc) aggregating property reported recently was established as beneficial in PrP(sc) detection using immunohistochemistry in diagnostic as well as in experimental conditions. The present study reports in details how to use advantageously this original streptomycin property in PrP(res) biochemical extraction and detection. Using TSE diagnostic brain material, specificity and increased sensitivity using streptomycin-treated samples were substantiated. Then an early sequential brain and spleen sampling (from 7 to 49 days post-inoculation) from C57Bl/6 mice inoculated intra-cerebrally or intra-peritoneally with C506M3 scrapie strain was analysed using streptomycin versus ultracentrifugation PrP(res) extraction. Whatever the inoculation route, streptomycin allowed earlier PrP(res) detection in spleen (7 d.p.i.), then in brain suggesting a stronger affinity of the infectious agent for the lymphoid compartment.


Assuntos
Doenças Priônicas/diagnóstico , Príons/análise , Estreptomicina/química , Animais , Química Encefálica , Bovinos , Precipitação Química , Feminino , Cinética , Métodos , Camundongos , Camundongos Endogâmicos C57BL , Príons/química , Baço/química
12.
Comp Hepatol ; 7: 3, 2008 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-18336716

RESUMO

BACKGROUND: Sequential monotherapies of nucleotide analogs used in chronic hepatitis B treatment can lead to the selection of a resistance mutation to each antiviral drug. CASE PRESENTATION: A patient with chronic hepatitis B was successively treated with lamivudine monotherapy, lamivudine-adefovir dual therapy, adefovir monotherapy and again with an adefovir-lamivudine dual therapy. Lamivudine-associated mutations (rtL180M and rtM204V/I) followed by adefovir-associated mutations (rtN236T and rtA181V) emerged during the two monotherapy regimens. Despite the presence of rtM204V/I, rtA181V, and rtN236T mutations at the beginning of the second dual therapy, sustained biochemical and virological responses have been observed thus far after 23 months. CONCLUSION: This case illustrates that rtM204V/I, rtA181V, and rtN236T resistance mutations can coexist in a patient but do not preclude the recycling of lamivudine and adefovir in combination therapy, when no other therapeutic choices are available.

13.
J Mol Diagn ; 10(1): 78-84, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18165270

RESUMO

Reliable real-time quantitative PCR assays to measure Epstein-Barr virus (EBV) DNA load (EBV) are useful for monitoring EBV-associated diseases. We evaluated a new commercial kit, EBV R-gene Quantification kit (Argene, Varilhes, France) to quantify EBV DNA load in whole blood. Assay performance was assessed with two PCR platforms (LightCycler 2.0 and SmartCycler 2.0) and three commercial DNA extraction methods. The assay was compared with our in-house real-time EBV PCR using samples from the Quality Control for Molecular Diagnostics 2006 EBV proficiency program and using 167 whole-blood specimens from individuals with infectious mononucleosis, from transplanted or HIV-infected patients, and from EBV-seropositive healthy carriers. The EBV R-gene assay was sensitive to 500 copies of EBV DNA per milliliter of whole blood with the two PCR platforms and the three extraction methods and was linear across 4 orders of magnitude. Intra- and interassay coefficients of variations were less than 20%. Nine of 10 samples tested with the EBV R-gene were in agreement with the expected qualitative results of the Quality Control for Molecular Diagnostics 2006 EBV proficiency program, and 7 of 10 samples were within +/-0.5 log units of the expected quantitative values, with discrepant results mostly observed for low viral load (ie, <1000 copies/ml). In the clinical specimens, the correlation between the R-gene assay and the in-house PCR was high (r=0.92). In conclusion, the EBV R-gene assay accurately assesses the EBV DNA load in whole blood of patients with various forms of EBV infections.


Assuntos
DNA Viral/sangue , DNA Viral/isolamento & purificação , Genes Virais , Herpesvirus Humano 4/genética , Reação em Cadeia da Polimerase/métodos , Kit de Reagentes para Diagnóstico , DNA Viral/genética , Infecções por Vírus Epstein-Barr/diagnóstico , Herpesvirus Humano 4/isolamento & purificação , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Carga Viral
14.
J Acquir Immune Defic Syndr ; 45(4): 380-8, 2007 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-17468666

RESUMO

The high genetic diversity of HIV-1 has a major impact on the quantification of plasma HIV-1 RNA, representing an increasingly difficult challenge. A total of 898 plasma specimens positive for HIV-1 RNA by commercial assays (Amplicor v1.5; Roche Diagnostic Systems, Alameda, CA or Versant v3.0; Bayer Diagnostics, Emeryville, CA) were tested using the Agence Nationale de Recherches sur le SIDA second-generation (G2) real-time reverse transcriptase polymerase chain reaction (RT-PCR) test: 518 samples containing HIV-1 of known subtype, including 88 from 2 subtype panels and 430 harboring B (n = 266) and non-B (n = 164) group M HIV-1 subtypes from patients followed up in 2002 through 2005 at Necker Hospital (Paris, France), and 380 samples from 10 different countries (Argentina, Cambodia, Cameroon, Central African Republic, France, Ivory Coast, Madagascar, Morocco, Thailand, and Zimbabwe). HIV-1 RNA values obtained by G2 real-time PCR were highly correlated with those obtained by the Amplicor v1.5 for B and non-B subtypes (R = 0.892 and 0.892, respectively) and for samples from diverse countries (R = 0.867 and 0.893 for real-time PCR vs. Amplicor v1.5 and real-time PCR vs. Versant v3.0, respectively). Approximately 30% of specimens harboring non-B subtypes were underquantified by at least -0.51 log10 in Amplicor v1.5 versus 5% underquantified in G2 real-time PCR. Discrepant results were also obtained with subtype B samples (14% underquantified by Amplicor v1.5 vs. 7% by G2 real-time PCR). Similar percentages were observed when comparing results obtained with the G2 real-time PCR assay with those obtained using the Versant assay. Addressing HIV-1 diversity, continual monitoring of HIV-1 RNA assays, together with molecular epidemiology studies, is required to improve the accuracy of all HIV RNA assays.


Assuntos
Variação Genética , Infecções por HIV/virologia , Repetição Terminal Longa de HIV/genética , HIV-1/classificação , RNA Viral/sangue , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Infecções por HIV/epidemiologia , HIV-1/genética , Humanos , Epidemiologia Molecular , Carga Viral
15.
J Virol Methods ; 143(1): 38-44, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17368820

RESUMO

This study assesses the ability of quantitative real-time PCR to measure the effects of virus DNA polymerase inhibitors on EBV DNA and late mRNAs syntheses in EBV-producing cell lines. In-house real-time quantitative PCRs were used to measure EBV DNA (thymidine kinase) and mRNAs (BLLF1 gene/gp350/220, BVRF2 gene/protease) in P3HR-1 and B95-8 cells induced for EBV production by PMA and exposed to ganciclovir, cidofovir and foscarnet. The calculated 50% effective concentrations (EC(50)) for viral DNA replication inhibition in P3HR-1 cells after 7 days of drug exposure were 0.28+/-0.06, 0.29+/-0.01 and 13.6+/-0.17 microg/mL for ganciclovir, cidofovir and foscarnet, respectively. The EC(50) for B95-8 cells were 0.44+/-0.02, 0.70+/-0.06 and 46.8+/-0.5 microg/mL, respectively. The quantitation of the late viral mRNAs showed a decrease of 79-89% in the mRNA amount after 4 days of antiviral treatment. Nevertheless, a substantial amount of mRNA still remained detectable after drug exposure. The real-time PCR is an improvement in the attempt to simplify EBV DNA-quantitation for antiviral assays. The quantitation of late mRNA does not appear as more informative than DNA quantitation for the assessment of the DNA polymerase inhibitor activity, but it may be useful to assess the antiviral activity of drugs acting by another mechanism.


Assuntos
Antivirais/farmacologia , Sobrevivência Celular/efeitos dos fármacos , DNA Viral/biossíntese , Herpesvirus Humano 4/efeitos dos fármacos , RNA Mensageiro/biossíntese , Replicação Viral/efeitos dos fármacos , Animais , Linfoma de Burkitt , Linhagem Celular , DNA/biossíntese , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Herpesvirus Humano 4/fisiologia , Humanos , Reação em Cadeia da Polimerase , Carga Viral
16.
J Infect Dis ; 192(12): 2108-11, 2005 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-16288374

RESUMO

To monitor multiple Epstein-Barr virus (EBV) infections during the early and convalescent stages of infectious mononucleosis (IM), a cloning and sequencing study of the LMP1 gene was conducted in saliva and peripheral blood mononuclear cells (PBMCs) from 23 patients with IM at day 0 (D0) and day 180 (D180) after the onset of the disease. Multiple EBV strains were detected in 9 (39%) of the patients during follow-up, with 7 of 9 cases detected as early as D0. Six of the nine patients harbored the same dominant strain in saliva and PBMCs during follow-up, with a trend toward a restriction of the number of EBV strains in saliva but not in PBMCs at D180. Furthermore, transmission of a minor strain was observed between partners in a heterosexual couple. There was no correlation between multiple infections and EBV DNA load in either compartment.


Assuntos
Herpesvirus Humano 4/genética , Herpesvirus Humano 4/isolamento & purificação , Mononucleose Infecciosa/virologia , Leucócitos Mononucleares/virologia , Saliva/virologia , Clonagem Molecular , Feminino , Genótipo , Herpesvirus Humano 4/classificação , Humanos , Mononucleose Infecciosa/transmissão , Masculino , Análise de Sequência de DNA , Carga Viral , Proteínas da Matriz Viral/genética
17.
Structure ; 13(9): 1299-310, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16154087

RESUMO

Deoxyuridine 5'-triphosphate pyrophosphatases (dUTPases) are ubiquitous enzymes cleaving dUTP into dUMP and pyrophosphate. They occur as monomeric, dimeric, or trimeric molecules. The trimeric and monomeric enzymes both contain the same five characteristic sequence motifs but in a different order, whereas the dimeric enzymes are not homologous. Monomeric dUTPases only occur in herpesviruses, such as Epstein-Barr virus (EBV). Here, we describe the crystal structures of EBV dUTPase in complex with the product dUMP and a substrate analog alpha,beta-imino-dUTP. The molecule consists of three domains forming one active site that has a structure extremely similar to one of the three active sites of trimeric dUTPases. The three domains functionally correspond to the subunits of the trimeric form. Domains I and II have the dUTPase fold, but they differ considerably in the regions that are not involved in the formation of the unique active site, whereas domain III has only little secondary structure.


Assuntos
Herpesvirus Humano 4/enzimologia , Pirofosfatases/química , Sequência de Aminoácidos , Sítios de Ligação , Catálise , Cristalografia , Dissulfetos/química , Desenho de Fármacos , Evolução Molecular , Dados de Sequência Molecular , Dobramento de Proteína , Estrutura Terciária de Proteína , Especificidade por Substrato
18.
N Engl J Med ; 352(25): 2598-608, 2005 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-15972866

RESUMO

BACKGROUND: Type 1 diabetes mellitus is a T-cell-mediated autoimmune disease that leads to a major loss of insulin-secreting beta cells. The further decline of beta-cell function after clinical onset might be prevented by treatment with CD3 monoclonal antibodies, as suggested by the results of a phase 1 study. To provide proof of this therapeutic principle at the metabolic level, we initiated a phase 2 placebo-controlled trial with a humanized antibody, an aglycosylated human IgG1 antibody directed against CD3 (ChAglyCD3). METHODS: In a multicenter study, 80 patients with new-onset type 1 diabetes were randomly assigned to receive placebo or ChAglyCD3 for six consecutive days. Patients were followed for 18 months, during which their daily insulin needs and residual beta-cell function were assessed according to glucose-clamp-induced C-peptide release before and after the administration of glucagon. RESULTS: At 6, 12, and 18 months, residual beta-cell function was better maintained with ChAglyCD3 than with placebo. The insulin dose increased in the placebo group but not in the ChAglyCD3 group. This effect of ChAglyCD3 was most pronounced among patients with initial residual beta-cell function at or above the 50th percentile of the 80 patients. In this subgroup, the mean insulin dose at 18 months was 0.22 IU per kilogram of body weight per day with ChAglyCD3, as compared with 0.61 IU per kilogram with placebo (P<0.001). In this subgroup, 12 of 16 patients who received ChAglyCD3 (75 percent) received minimal doses of insulin (< or =0.25 IU per kilogram per day) as compared with none of the 21 patients who received placebo. Administration of ChAglyCD3 was associated with a moderate "flu-like" syndrome and transient symptoms of Epstein-Barr viral mononucleosis. CONCLUSIONS: Short-term treatment with CD3 antibody preserves residual beta-cell function for at least 18 months in patients with recent-onset type 1 diabetes.


Assuntos
Complexo CD3/imunologia , Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Imunoglobulina G/uso terapêutico , Insulina/uso terapêutico , Ilhotas Pancreáticas/efeitos dos fármacos , Adolescente , Adulto , Autoanticorpos/sangue , Glicemia/análise , Peptídeo C/biossíntese , Criança , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/imunologia , Feminino , Técnica Clamp de Glucose , Herpesviridae/isolamento & purificação , Humanos , Imunoglobulina G/efeitos adversos , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/fisiopatologia , Masculino
19.
J Infect Dis ; 191(6): 985-9, 2005 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-15717276

RESUMO

Epstein-Barr virus (EBV) DNA loads in peripheral blood mononuclear cells (PBMCs), plasma, and saliva, as well as infectivity of the virus in saliva, were evaluated in 20 patients for 6 months after the onset of infectious mononucleosis (IM). All patients displayed sustained high EBV DNA loads in the saliva, associated with a persistent infectivity of saliva at day 180. EBV DNA load in PBMCs decreased significantly from day 0 to day 180 (in spite of a viral rebound between day 30 and day 90 in 90% of the patients), and EBV DNA rapidly disappeared from plasma. These data show that patients with IM remain highly infectious during convalescence.


Assuntos
Herpesvirus Humano 4/fisiologia , Mononucleose Infecciosa/virologia , Eliminação de Partículas Virais , Adolescente , Adulto , DNA Viral/sangue , Feminino , Herpesvirus Humano 4/isolamento & purificação , Herpesvirus Humano 4/patogenicidade , Humanos , Leucócitos Mononucleares/virologia , Masculino , Saliva/virologia , Fatores de Tempo , Carga Viral
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