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Vincent Thibault

Publications and source records attributed to Vincent Thibault.

At least 37 records · Page 2Linked to original sources
PubMed2004

Long-term therapy with lamivudine in renal transplant recipients with chronic hepatitis B.

BACKGROUND: Lamivudine is a potent inhibitor of hepatitis B virus (HBV) replication. As other available HBV therapies, its efficacy is hampered by relapse after discontinuation and by the risk of viral breakthrough. A recent study suggests that pre-emptive lamivudine therapy improves survival in HBV renal transplants, but few data are available regarding its long-term use in this population. The clinical features, course and viral mutations associated with the emergence of viral resistance in this population have not been well studied. METHODS: We followed 14 consecutive renal transplant patients treated with lamivudine for chronic hepatitis B. Breakthrough was defined as the reappearance of HBV DNA by hybridization. In patients with breakthrough, lamivudine was always continued and patients were followed up monthly. Mutations associated with viral resistance were determined by sequencing the polymerase encoding gene at the beginning of treatment and at the time of breakthrough. RESULTS: The median duration of treatment was 64.5 months. Resistance to lamivudine appeared in eight patients (57%) after a median duration of treatment of 15 (9-24) months. During a 51 month follow-up after breakthrough, only three of eight patients had a flare-up with alanine aminotransferase levels more than 5 ULN, and no hepatic decompensation was observed. Analysis of HBV sequencing after breakthrough revealed specific resistance mutations in both the B and C domains of the polymerase (rtL180M/M204V, n = 5; rtM204I, n = 2). CONCLUSION: Lamivudine is a safe and effective treatment of active hepatitis B in renal transplant patients. Resistance to treatment is frequent but seems to have little clinical impact over the considered period. In our experience, the YMDD mutation accounts for most cases of virological escape in patients with good compliance.

Adult↗
PubMed2004

Expertise of French laboratories in detection, genotyping, and quantification of hepatitis C virus RNA in serum.

Before initiating new large-scale therapeutic trials for hepatitis C virus (HCV)-infected patients, the French Health Authorities for HCV research decided to organize an evaluation of the expertise of laboratories that could be engaged to undertake molecular biology assays in such trials; 21 experienced laboratories participated in this national evaluation of laboratory expertise, which was performed in two successive rounds. The first round evaluated the laboratories for their abilities to detect HCV RNA in serum, determine genotypes, and quantify HCV RNA loads. The results observed by qualitative assays for HCV RNA detection were 100% sensitivity and 100% specificity for all laboratories. The genotyping results were 100% concordant for 9 laboratories and greater than 90% for 10 laboratories. By contrast, large coefficients of variation were observed for quantitative determination of HCV RNA loads, leading to a second round with standardized quantitative assays only. The dispersion of the results was larger by the AMPLICOR HCV Monitor assay than by the branched-DNA assay (mean coefficients of variation, 57.4 and 16.9%, respectively). In the majority of cases, discrepancies between the results of the two tests were found for samples with high viral loads. These results indicate the usefulness of validating, by controlling for expertise, both the reliabilities of laboratories involved in multicenter work and the standardized assays chosen for use in the evaluation of the biological impacts of new therapies.

Analysis of Variance↗
PubMed2004

Intra-laboratory analytical variability of biochemical markers of fibrosis (Fibrotest) and activity (Actitest) and reference ranges in healthy blood donors.

Combinations of tests comprising alpha2-macroglobulin, haptoglobin, apolipoprotein Al, gamma-glutamyltransferase, total bilirubin (Fibrotest) and alanine aminotransferase (Actitest) are being developed as alternatives to liver biopsy in patients with chronic hepatitis C. The aim of this study was to assess in the same laboratory the impact of parameter assay variations on Fibrotest and Actitest results and intra-patient reproducibility of the two tests. The stability of the samples for each test was studied after storage at -80 degrees C and -20 degrees C. Within-run, between-run and total imprecision for each parameter assay, and for Fibrotest and Actitest results, were determined. Transferability of assay results between different analyzers was studied. Intra-patient reproducibility was assessed in 55 hospitalized patients. Fibrotest and Actitest reference ranges were determined in 300 blood donors (reference group). The stability of the parameters was affected by serum storage at -20 degrees C only. The impact of parameter analytical variability on Fibrotest and Actitest results was less than 10% and intra-patient reproducibility was acceptable (p > 0.05). The transferability between different analyzers of results of assays performed under the same standardized and calibration conditions was excellent. Fibrotest and Actitest reference ranges in blood donors were (mean+/-SE) 0.075+/-0.004 and 0.068+/-0.004, respectively. The low intra-laboratory and intra-patient variability in Fibrotest and Actitest results confirm Fibrotest and Actitest reliability.

Age Factors↗
PubMed2004

In vitro susceptibility of lamivudine-resistant hepatitis B virus to adefovir and tenofovir.

Emergence of lamivudine-resistant hepatitis B virus (HBV) is a major concern in human immunodeficiency virus (HIV) and HBV coinfected patients. Following selection of resistant mutants, hepatitis flare or rapid progression to cirrhosis may occur. Treatment of patients with new nucleotide analogues such as adefovir dipivoxil (ADV) or tenofovir disoproxil fumarate (TDF) has shown good efficacy in controlling wild-type or lamivudine-resistant HBV replication. The purpose of this study was to assess the in vitro efficacy of new nucleotide analogues on HBV strains isolated from lamivudine-treated patients. After purification of HBV DNA from patient sera, the whole HBV genome was PCR-amplified and cloned. Drug sensitivity was measured after transfection of the isolated full genomes into HepG2 cells and measurement of HBeAg, HBsAg and viral replication in the culture media under increasing drug concentrations. A wild-type strain isolated from an untreated patient served as control. In a clinical study of ADV (Gilead 460i study), seven of the 35 patients carried HBV strains with the triple lamivudine resistance-associated amino-acid changes rtV173L/L180M/M204V at baseline. Although all patients responded to ADV in this clinical study, the serum HBV reduction was lower in the seven patients with the triple mutation (median -3.3 log copies/ml) compared to the patients who had only the rtL180M/M204V mutations (median -4.1 log copies/ml) at week 48 (P=0.04, Mann-Whitney test). In our in vitro system, lamivudine IC50 on lamivudine-resistant HBV carrying amino-acid substitutions rtL180M and rtM204V within the polymerase encoding region increased by more than 16,000-fold (from 6 nM to over 100 microM) when compared to wild-type HBV. For ADV and TDF, comparison of wild-type and lamivudine-resistant HBV IC50 (rtL180M-M204V) showed, respectively, 2.85-fold (from 0.07 to 0.2 microM) and 3.3-fold (from 0.06 to 0.2 microM) increases, indicating a mild decrease of both drug activities, in vitro. At the ADV concentration of 0.1 microM, presence of the V173L mutation reduced the inhibition of HBsAg production from 50 to 30% (P<0.01) and the viral replication from 45 to 32% (P<0.01, Mann-Whitney). Conversely, tenofovir had similar potency on both HBV mutation profiles with 60% inhibition of HBsAg production and 45% inhibition of viral replication at 0.1 microM. Our study supports the high efficacy of ADV and TDF seen in patients after lamivudine breakthrough. The excellent activity of TDF on lamivudine-resistant virus independently of the resistance mutation profile offers an interesting treatment alternative to HIV-HBV coinfected patients.

Adenine↗
PubMed2004

Longterm course of mixed cryoglobulinemia in patients infected with hepatitis C virus.

OBJECTIVE: To describe epidemiological, clinical, and immunological characteristics and the longterm course of persistent mixed cryoglobulinemia (MC) in patients infected with hepatitis C virus (HCV). METHODS: Retrospective study of HCV infected patients (HCV RNA positive) who had persistent positive MC, with 2 immunochemical typings of MC carried out after 24-month minimum interval. RESULTS: In total, 125 patients were studied, aged 52 +/- 13 years at diagnosis of MC, with duration of HCV infection of 18 +/- 10 years. At entry, 60 patients had type II MC, 53 patients had type III, and 12 patients had the oligoclonal type. At the second immunochemical typing, after a mean interval of 45 +/- 20 months, MC was type II in 72 patients, type III in 39 patients, and the oligoclonal type in 14 patients. The proportion of cases of MC with the same immunochemical type was higher among patients with type II (78%) than type III (59%) or oligoclonal MC (17%) (p < 0.01). The MC that changed turned more to type II (55.5%) than type III (29%) or the oligoclonal type (15.5%) (p = 0.0002). MC vasculitis (purpura, arthralgia, peripheral neuropathy, renal involvement) and other extrahepatic manifestations (polyarteritis nodosa, lymphoma) in 60/125 patients was associated with advanced age (p < 0.01), a longer duration of infection (p < 0.05), type II MC (odds ratio = 5, p < 0.01), and a higher MC serum level (p < 0.01). CONCLUSION: During chronic active HCV infection, type II MC is more stable over time than type III and oligoclonal MC. The oligoclonal type appears to be an intermediate stage in the course of type III changing to type II MC. Symptomatic persistent HCV MC was associated with advanced age, longer duration of HCV infection, type II MC, and a higher MC serum level.

Adult↗
PubMed2003

Serum biochemical markers accurately predict liver fibrosis in HIV and hepatitis C virus co-infected patients.

OBJECTIVE: Liver biopsy, the gold standard for assessing hepatitis C virus (HCV)-related fibrosis, is invasive and prone to complications. Our aim was to determine the operating characteristics of a non-invasive index of biochemical markers for the prediction of fibrosis in patients with HIV/HCV co-infection. DESIGN: In a cross-sectional, cohort study in a French tertiary-care hospital 130 HIV/HCV-co-infected patients with a liver biopsy and serum were tested for markers of liver fibrosis. METHODS: An index incorporating age, sex, alpha(2)-macroglobulin, apolipoprotein A1, haptoglobin, bilirubin, and gamma-glutamyl-transpeptidase (GGT), derived using multivariate logistic regression, was compared with liver histology. HIV-specific indices including the CD4 cell count and HIV-RNA load were also constructed. The diagnostic values of the indices were compared using receiver operating characteristic (ROC) curves. MAIN OUTCOME MEASURE: Septal fibrosis (F2-F4) by the METAVIR classification. RESULTS: By multivariate analysis, the most informative markers were alpha(2)-macroglobulin, apolipoprotein A1, GGT, and sex. The area under the ROC curve of the five-marker index was 0.856 +/- 0.035; not significantly different from the HIV-specific indices. On a scale from zero to 1.00, the five-marker index had a positive predictive value of 86% for scores greater than 0.60, and a negative predictive value of 93% for scores of 0.20 or less. These thresholds could reduce the necessity for liver biopsy by 55% while maintaining an accuracy of 89%. CONCLUSION: An index including five biochemical markers accurately predicts significant fibrosis in patients with HIV/HCV co-infection, and may substantially reduce the necessity for liver biopsy.

Adult↗
PubMed2003

Prediction of liver histological lesions with biochemical markers in patients with chronic hepatitis B.

BACKGROUND AIMS: Liver biopsy is the gold standard for assessing hepatitis B virus (HBV)-related histology. The aim was to determine the diagnostic utility of noninvasive serum markers in patients with chronic hepatitis B. METHODS: The aminotransferases and indices including alpha(2)-macroglobulin, apolipoprotein A1, haptoglobin, gamma-glutamyl-transpeptidase (GGT), and total bilirubin (Fibrotest), and ALT (Actitest) were compared with liver histology. The primary outcomes were A2-A3 activity and F2-F4 fibrosis (METAVIR). RESULTS: Two hundred and nine patients were included. Forty-one patients (20%) had A2-A3 activity and 61 (29%) had F2-F4 fibrosis. AST and GGT (P<0.001) were independently associated with A2-A3 activity. AST, ALT, and Actitest accurately predicted activity ((areas under receiver operating characteristic (ROC) curves (AUROC), 0.81-0.82+/-0.04)); an AST or ALT< or =30IU/l excluded significant activity with 96% certainty. Fibrotest accurately predicted F2-F4 fibrosis (AUROC, 0.78+/-0.04). Fibrotest scores (range, 0-1.0) < or =0.20 and >0.80 had negative and positive predictive values of 92%, respectively. Restricting biopsy to patients with intermediate scores (>0.20 and < or =0.80) may prevent liver biopsies in 46% of patients while maintaining 92% accuracy. CONCLUSIONS: The aminotransferases and an index including five biochemical markers are accurate noninvasive markers of HBV-related activity and fibrosis, respectively.

Adult↗
PubMed2003

Potential exposure to hepatitis C virus through accidental blood contact in interventional radiology.

PURPOSE: To quantify the prevalence of accidental blood exposure (ABE) among interventional radiologists and contrast that with the prevalence of patients with hepatitis C virus (HCV) undergoing interventional radiology procedures. MATERIALS AND METHODS: A multicenter epidemiologic study was conducted in radiology wards in France. The risk of ABE to radiologists was assessed based on personal interviews that determined the frequency and type of ABE and the use of standard protective barriers. Patients who underwent invasive procedures underwent prospective sampling for HCV serologic analysis. HCV viremia was measured in patients who tested positive for HCV. RESULTS: Of the 77 radiologists who participated in 11 interventional radiology wards, 44% reported at least one incident of mucous membrane blood exposure and 52% reported at least one percutaneous injury since the beginning of their occupational activity. Compliance with standard precautions was poor, especially for the use of protective clothes and safety material. Overall, 91 of 944 treated patients (9.7%) tested positive for HCV during the study period, of whom 90.1% had positive viremia results, demonstrating a high potential for contamination through blood contacts. CONCLUSIONS: The probability of HCV transmission from contact with contaminated blood after percutaneous injury ranged from 0.013 to 0.030; the high frequency of accidental blood exposure and high percentage of patients with HCV could generate a risk of exposure to HCV for radiologists who perform invasive procedures with frequent blood contact. The need to reinforce compliance with standard hygiene precautions is becoming crucial for medical and technical personnel working in these wards.

Blood-Borne Pathogens↗
PubMed2003

Multicenter quality control for the detection of hepatitis C virus RNA in seminal plasma specimens.

The discrepant results available in the literature about the presence of hepatitis C virus (HCV) RNA in seminal plasma of men chronically infected by this agent are related, at least in part, to the molecular techniques used and particularly to the wide range of protocols dedicated to RNA extraction. In order to evaluate these protocols and to standardize the method of detection of HCV RNA in this fluid, a panel of coded specimens was tested blindly in 12 French laboratories; it included 14 seminal plasma specimens and four water controls spiked with HCV RNA ranging from 10 to 20000 IU/ml and two HCV-negative seminal plasma specimens. The extraction step was performed according to methods using either silica beads (NucliSens [Organon Teknika S.A., Fresnes, France]; RNA viral kit [Qiagen, Courtaboeuf, France]) or guanidinium thiocyanate (Amplicor HCV assay; Roche Diagnostics, Meylan, France), preceded or not by a centrifugation of the seminal plasma. For the amplification step, all the laboratories performed the same reverse transcription-PCR technique (Amplicor HCV Cobas assay). The percentage of correct results ranged from 53.3 to 100, the poorest results being obtained when no centrifugation step preceded the Amplicor extraction protocol. The rate of correct results was significantly higher in laboratories using a preliminary centrifugation of the specimen (P = 0.034 by chi-square test). By contrast, the overall number of correct results was not correlated to the initial volume of sample used for the test. These results allowed us to validate standardized techniques adapted to the performance of this test on a routine basis, especially in men infected with HCV and involved in programs of medically assisted reproduction.

Hepacivirus↗
PubMed2003

Hepatitis C virus infection in systemic lupus erythematosus: a case-control study.

OBJECTIVE: Viruses might be one of the elements that trigger systemic lupus erythematosus (SLE). Steroid therapy may influence the natural history of virus infections. The most frequent extrahepatic manifestations of hepatitis C virus (HCV) including arthralgia, myalgia, sicca syndrome, and antinuclear antibodies, may mimic a connective tissue disease, particularly SLE. Reports on the association between SLE and HCV infection are scarce. We investigated the association of HCV infection and SLE. METHODS: Retrospective case-control monocentric study of 19 patients with SLE and anti-HCV antibodies versus 42 randomized SLE patients without anti-HCV antibodies, matched for age and sex, coming from our cohort of 700 patients with SLE. SLE and HCV-infection features were reviewed. RESULTS: Mode of infection was blood product transfusion, drug addiction, or unknown. Prevalence of lupus clinical manifestations, antinuclear, anti-dsDNA, anti-extractable nuclear antigen antibodies, and complement levels was not different between HCV positive and negative SLE patients. Prevalence of cryoglobulin was higher in SLE patients with anti-HCV antibodies (p < 0.04), but none had a mixed cryoglobulinemia syndrome. ALT activity was increased in 11 HCV positive patients and 13 had detectable HCV RNA. Liver biopsy showed cirrhosis in 2 and mild fibrosis and activity in 5. One patient treated with interferon-alpha had a sustained virological response without SLE flare. Steroid therapy did not seem to alter HCV course. CONCLUSION: SLE in HCV positive patients shows higher prevalence of cryoglobulin without mixed cryoglobulinemia syndrome. HCV infection has moderate signs of biochemical and liver pathological severity. SLE by itself or treated with steroids does not seem to worsen HCV infection.

Adolescent↗
PubMed2002

Human leukocyte antigen class II alleles may contribute to the severity of hepatitis C virus-related liver disease.

Whether the host's immune response genes influence the severity of hepatitis C virus (HCV) liver disease is controversial. Human leukocyte antigen (HLA) class II alleles were analyzed in 233 HCV RNA-positive patients with chronic active hepatitis (197 patients with Knodell index of fibrosis F0-F3 and 36 patients with index of F4). The 2 groups did not differ by sex, duration of infection, mode of contamination, alcohol consumption, or HCV genotype. Patients with cirrhosis were older than those without (56+/-12 vs. 46+/-14 years; P<10-4) and had a lower DRB1*11 allele frequency (5.6% vs. 14.5%; P=.037), whereas DRB1*03 and DQB1*0201 frequencies appeared to be higher (DRB1*03, 18.1% vs. 9.6%; DQB1*0201, 37.5% vs. 23.4%; P=.04, corrected P value is not significant). Mean index of fibrosis was higher in DR3-positive than in DR11-positive patients (2.14 vs. 1.58; P=.05). By multivariate analysis, cirrhosis was associated with male sex and age >50 years. HLA class II alleles may weakly contribute to the severity of HCV liver disease. Of persons infected with HCV, only 15%-20% spontaneously clear the virus, and the rest become chronically infected.

Adolescent↗
PubMed2002

Strong CD4 Th1 responses to HIV and hepatitis C virus in HIV-infected long-term non-progressors co-infected with hepatitis C virus.

OBJECTIVES: To compare the T-cell responses to hepatitis C virus (HCV) and HIV in HIV-infected long-term non-progressors (LT-NP) and HIV-positive progressors co-infected with HCV and in HIV-negative HCV-infected patients. METHODS: Three groups were studied: 10 HCV/HIV-infected LT-NP, 26 HCV/HIV-infected progressors and 13 HCV-infected/HIV-negative patients. Virus-specific CD4 and CD8 T-cell responses in peripheral blood were assessed by interferon (IFN)-gamma Elispot assays using recombinant proteins (HIV-p24 and three HCV antigens) and 16 HIV or HCV HLA A3- and/or HLA A2-restricted cytotoxic T lymphocytes peptides. Statistical analysis was performed with non-parametric tests. RESULTS: In addition to high T helper 1 (Th1) cell frequencies directed against HIV-p24, LT-NP had significantly (P < 0.05) higher frequencies of Th1 cells against HCV than the two other groups. No difference was observed between HIV-infected progressors and HIV-negative controls. Furthermore, HCV-specific CD4 and CD8 T cells were correlated in LT-NP (P = 0.006). CONCLUSION: Thus, independently of the HIV-related immune alterations, LT-NP of the HIV-infection might have an intrinsic capacity to develop strong Th1 cell responses to viruses, particularly HIV and HCV.

AIDS-Related Opportunistic Infections↗
PubMed2002

Interferon-alpha and ribavirin treatment in patients with hepatitis C virus-related systemic vasculitis.

OBJECTIVE: Hepatitis C virus (HCV)-related vasculitis may involve multiple organs, including the skin, kidneys, and nervous system, and may be life-threatening. Although HCV is increasingly recognized as a cause of systemic vasculitis, limited data are available regarding the optimal treatment of this potentially serious condition. Therefore, we retrospectively analyzed the response to treatment in patients with chronic hepatitis C complicated by systemic vasculitis who had received antiviral therapy with interferon-alpha (IFNalpha) and ribavirin. METHODS: This retrospective study included 27 patients with systemic vasculitis and chronic HCV infection. Each patient had received treatment with IFNalpha and ribavirin for at least 6 months. The response to antiviral treatment was analyzed by comparing clinical, immunologic, and virologic data at the time of entry and during followup. Clinical response was defined according to the evolution of weight, arthralgia, nervous system, renal system, and cutaneous involvement. The virologic and immunologic responses were defined by the absence of HCV RNA and the absence of cryoglobulinemia, respectively, both 6 months after stopping antiviral therapy and at the end of followup. RESULTS: Patients received IFNalpha for a mean +/- SD of 20 +/- 14 months and ribavirin (at a mean +/- SD dosage of 895 +/- 250 mg/day) for 14 +/- 12 months. Other treatments included low-dose corticosteroids and plasma exchange. After a mean +/- SD followup of 57 +/- 29 months, 25 of 27 patients are alive and are being followed up as outpatients. Because of the heterogeneity of anti-HCV treatments received, the main results were stratified according to patients with 6 months of followup after stopping antiviral treatment (group 1, n = 14) and those who were still undergoing antiviral therapy at the time of analysis (group 2, n = 13). Nine patients in group 1 had a sustained virologic response and were clinical and immunologic complete responders. Four patients in group 1 were virologic nonresponders, and 3 of these patients had partial clinical and immunologic responses. Overall, 10 patients in group 1 had a complete clinical and immunologic response of their vasculitis (all 9 of the sustained virologic responders and 1 of the 5 patients who remained viremic). At the end of followup, 7 patients in group 2 were negative for HCV RNA; 6 were complete clinical responders. Among the other 6 patients in group 2, who had persistent viremia, 4 had a partial clinical response. Among the patients in group 1, HCV RNA was more often undetectable and genotype 1 was less frequent in complete clinical responders compared with partial/nonresponders. Age, sex, clinical vasculitic involvement, mean duration or total cumulative dose of IFNalpha or ribavirin, and use of steroids or plasmapheresis did not differ significantly according to clinical response. CONCLUSION: Treatment with IFNalpha and ribavirin can achieve a complete clinical response in most patients with HCV-related systemic vasculitis. Complete clinical response correlates with the eradication of HCV.

Adult↗