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Biomedical subjects

Thierry Poynard

Publications and source records attributed to Thierry Poynard.

At least 55 records · Page 3Linked to original sources
PubMed2004

Decreased frequencies of virus-specific T helper type 1 cells during interferon alpha plus ribavirin treatment in HIV-hepatitis C virus co-infection.

Anti-hepatitis C virus (HCV) treatment combining IFN-alpha and ribavirin (IFN+R) has still poorly defined effects on immune responses. Frequencies of T helper (Th) type 1 cells specific for HCV, cytomegalovirus (CMV) and HIV were measured in chronically HCV-infected patients with or without HIV co-infection during IFN+R treatment. Although scarce, peripheral blood HCV-specific Th1 cells did not change significantly, while frequencies of HIV and CMV-specific Th1 cells decreased in co-infected patients independently of CD4 cell count changes. This suggests that IFN+R therapy might compromise virus-specific immune defenses in immunosuppressed patients.

Antiviral Agents↗
PubMed2004

Clonal B cell populations in the blood and liver of patients with chronic hepatitis C virus infection.

OBJECTIVE: The association of hepatitis C virus (HCV) infection with type II mixed cryoglobulinemia is well established, but the role of HCV in B cell lymphoma remains controversial. The objective of this study was to determine the frequency of circulating and liver-infiltrating monoclonal B cells in patients with HCV infection. METHODS: One hundred sixty patients were studied prospectively, including 115 HCV-positive patients and 45 HCV-negative patients with other nonimmune chronic liver disease(s). B cell clonality was determined by DNA amplification of the IgH rearrangements, followed by polyacrylamide gel electrophoresis. RESULTS: A clonal B cell population was detected in the blood of 21 (26%) of 81 HCV-positive patients whose cryoglobulin status was known, including 12 of 25 patients with type II cryoglobulinemia, 2 of 12 patients with type III cryoglobulinemia, and 7 of 44 patients without cryoglobulins. A clonal IgH rearrangement was detected in 26 (32%) of 81 liver biopsy specimens from HCV- infected patients, including 16 patients with a circulating clonal population. A clonal B cell population was not observed in the blood of 40 patients with non-HCV liver diseases and was present in only 1 (3%) of 30 liver biopsy specimens. Logistic regression analysis showed that HCV-infected patients with clonal B cell proliferation in both the blood and liver were older (P = 0.004) and had longer duration of HCV infection (P = 0.009), higher serum cryoglobulin levels (P = 0.001) that were more frequently symptomatic (P < 0.03), and liver disease that was more severe than that in patients without a clonal B cell population in the blood or liver (P = 0.05). In 4 of 16 patients with a clonal B cell population in both the blood and liver, a definite B cell malignancy was finally diagnosed. CONCLUSION: Clonal B lymphocytes are frequently detected in the blood and liver of patients with chronic HCV infection, in the absence of overt B cell malignancy. These clones are usually, but not always, associated with the presence of type II cryoglobulins. A high percentage of patients with B cell clonality in both the blood and liver were finally diagnosed as having a definite B cell malignancy.

Adult↗
PubMed2004

Progression of liver fibrosis in women infected with hepatitis C: long-term benefit of estrogen exposure.

Female sex is a protective factor for the progression of fibrosis in patients with chronic hepatitis C virus (HCV) infection. Experimental data suggest that estrogens may have an antifibrotic effect. The objective of this study was to evaluate the influence of past pregnancies, oral contraceptives, menopause, and hormone replacement therapy (HRT) on liver fibrosis progression in HCV-infected women. Four hundred seventy-two HCV-infected women received a survey regarding prior pregnancies, menopause, and the use of oral contraceptives and HRT. The impact of these variables on liver fibrosis and its progression were evaluated using multivariate analyses considering all putative confounding factors. Two hundred one women completed the survey (43% response rate), 157 of whom had an estimated date of HCV infection (96 postmenopausal women, 96 women with previous pregnancies, and 105 women with past use of oral contraceptives). Through multivariate analyses, the estimated rate of fibrosis progression was higher in postmenopausal (P < .05) and nulliparous (P = .02) women and was associated with greater histological activity (P < .001). Prior use of oral contraceptives had no significant influence. Among postmenopausal women, the estimated rate of fibrosis progression (+/-SE) was lower in women who received HRT compared with untreated patients (0.099 +/- 0.016 vs. 0.133 +/- 0.006 METAVIR units/yr; P = .02) and was similar to that of premenopausal women (0.093 +/- 0.012 METAVIR units/yr; P value not significant). In conclusion, menopause appears to be associated with accelerated liver fibrosis progression in HCV-infected women, an effect that may be prevented by HRT. Pregnancies may have a beneficial impact on the long-term progression of liver fibrosis.

Adult↗
PubMed2004

Fat, diabetes, and liver injury in chronic hepatitis C.

It is increasingly recognized that host factors can modulate the fibrogenic response in patients with chronic hepatitis C. Obesity, because of its prevalence, and diabetes, which seems to occur more frequently in patients infected by the hepatitis C virus (HCV), are often present in patients with chronic hepatitis C. Both conditions result in fatty liver, which in turn is associated with more severe liver damage, especially fibrosis or inflammation. Steatosis can either originate from associated metabolic alterations (insulin resistance resulting in metabolic steatosis) or from a direct cytopathic effect of the virus (genotype 3, resulting in viral steatosis). Metabolic steatosis seems to be a factor in resistance to antiviral therapy, whereas viral steatosis is reduced in sustained responders. Whether metabolic steatosis has a direct role in liver fibrosis progression or is only a surrogate marker of an underlying defect triggering fibrogenesis, such as insulin resistance, is a subject of debate. High serum glucose levels and diabetes have a strong and independent profibrogenic impact. Exciting new data are expanding our understanding of the mechanisms of steatogenesis in HCV infection and providing potential links between insulin resistance or hyperglycemic states and liver fibrogenesis.

Comorbidity↗
PubMed2004

Comparing the public health burden of chronic hepatitis C and HIV infection in France.

BACKGROUND/AIMS: In France, the prevalence of hepatitis C virus (HCV) exceeds that of HIV, but in the absence of treatment, HIV infection progresses more rapidly than HCV. More HIV-infected patients, however, have received treatment. Using reported public health data in France and natural history models, we applied the back-calculation method to project future mortality from HCV and HIV incorporating current therapies. METHODS: The HCV model was based on literature data for the natural history of HCV and reports of hepatocellular carcinoma mortality. The HIV model used estimates from the French Hospital Database on HIV and reported AIDS cases and deaths. RESULTS: Peak annual mortality from HIV at 5000 occurred in 1994 and was 1000 in 1998, but HCV mortality likely increased through the 1990s and reached 3000 in 1998. Considering only HCV infections occurring until 1998 and currently available therapy, our model suggested that annual HCV-related mortality would continue to rise and would reach 4500 deaths in 2022. In contrast, AIDS-related deaths began to decrease in 1997. CONCLUSIONS: The public health burden of HCV is likely on the rise, while the burden of HIV, given the fairly widespread use of effective medications, may be on the decline. These results may help health policymakers in planning their responses to these epidemics.

Acquired Immunodeficiency Syndrome↗
PubMed2004

Treatment of cirrhotic patients in the pegylated interferon era.

Chronic hepatitis C is a leading cause of cirrhosis, hepatocellular carcinoma, digestive tract haemorrhage and hepatic insufficiency. The present best strategy to prevent severe complications of chronic hepatitis C is the decrease of fibrosis progression. Recently, pegylated interferon combination treatments of chronic hepatitis C have made it possibly to obtain 60% sustained virological responses. Pooled individual data from 3,010 naïve patients with pre-treatment and post-treatment biopsies from 4 randomised trials have shown that all regimens significantly reduced the fibrosis progression rates in comparison to the pre-treatment ones. Six factors were independently associated with the absence of significant fibrosis after treatment: baseline fibrosis stage, sustained viral response, age <40 years, body mass index <27 kg/m2, no or minimal baseline activity, and viral load <3.5 x 10(6) copies/ml. In virological non-responders after the combination of ribavirin and pegylated interferon, the best strategy is still unknown. From a scientific point of view these patients should be included in randomised trials of maintenance therapy. From a pragmatic point of view, if inclusion in a trial is not possible, treatment with low-dose pegylated interferon can be considered in patients with rapid fibrosis progression rates or high risk factors. Non-invasive biochemical markers of liver fibrosis should facilitate the management.

Antiviral Agents↗
PubMed2004

Treatment of hepatitis C virus: the first decade.

Interferon alfa therapy emerged as an early treatment option for patients with chronic hepatitis C. This therapy, however, fails to produce a sustained virological response in most patients. Various host and viral baseline characteristics, some of which include hepatitis C virus genotype, viral load, presence of cirrhosis, and patient age, affect the response to interferon therapy. The addition of ribavirin to interferon therapy significantly improves long-term virological response in treatment-naive patients and is also more effective than repeat interferon therapy is in patients who fail to initially achieve sustained virological or biochemical responses. However, ribavirin can induce reversible hemolytic anemia, and combination therapy with a ribavirin/interferon regimen is not tolerated as well as interferon is alone. Pegylated interferons used alone or in combination with ribavirin provide improved treatment options for different patient groups with chronic hepatitis C.

Age Factors↗
PubMed2004

The renal tolerance of low-dose adefovir dipivoxil by lamivudine-resistant individuals co-infected with hepatitis B and HIV.

BACKGROUND: Adefovir (ADV), an orally administered nucleotide analogue active against hepadnaviruses, retroviruses and herpes viruses was shown to be effective in HIV-infected patients, but the prevalence of nephrotoxicity with doses of 60-120 mg/day was considered unacceptable. Recently, lower doses of ADV were shown to be effective for the treatment of HIV-1 patients with chronic lamivudine (LAM)-resistant hepatitis B. METHODS: In a cohort of 35 patients infected with both HIV-1 and LAM-resistant hepatitis B virus, we investigated the renal tolerance of a once-daily dose of ADV 10 mg over 52 weeks. Their mean baseline creatinine clearance was within the normal range (105 +/- 3 ml/min/1.73 m(2)). No patient had significant changes in renal function or electrolyte balance secondary to ADV treatment. RESULTS: Transient increases in serum creatinine, which resolved by the end of the study were noted in two patients and three developed proteinuria, which was felt to be unrelated to ADV treatment. The cohort's mean serum phosphate level, 2.45 +/- 0.09 mg/dl at baseline, did not change significantly under treatment (2.66 +/- 0.12 mg/dl at week 52, P = NS). CONCLUSIONS: Our study shows that ADV dosed at 10 mg/day for the treatment of LAM-resistant chronic hepatitis B in patients co-infected with HIV is not associated with renal tubular dysfunction or a significant change in renal function.

Adenine↗
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

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

Viral hepatitis B.

More than 400 million people worldwide are chronically infected by the hepatitis B virus. The virus is responsible for more than 300000 cases of liver cancer every year and for similar numbers of gastrointestinal haemorrhage and ascites. Major breakthroughs have been achieved in diagnosis and treatment of this virus. Hepatitis B vaccine reduces incidence of liver cancer. As with hepatitis C, advances have been made in molecular virology, especially for naturally occurring and treatment-induced mutant viruses. The clinical significance of low viral load and genotypes are also under investigation. Currently available monotherapies-interferon, lamivudine, and adefovir dipivoxil-very rarely eradicate the virus, but greatly reduce its replication, necroinflammatory histological activity, and progression of fibrosis. Lamivudine, and presumably other nucleoside analogues, can reverse cirrhosis of the liver.

Adenine↗
PubMed2003

Viral hepatitis C.

More than 170 million people worldwide are chronically infected with the hepatitis C virus (HCV), which is responsible for more than 100000 cases of liver cancer per year, with similar numbers of digestive haemorrhage and ascites episodes. Major breakthroughs have been made in diagnosis and treatment, and advances in molecular biology mean that the replicative state of the virus can now be assessed. Genotype and serum viral load are useful predictors of response to treatment. The combination of pegylated interferon and ribavirin can eradicate the virus in more than 50% of patients. These antiviral treatments reduce liver fibrosis progression and can reverse cirrhosis. Unfortunately, even in developed countries, death due to hepatitis C is increasing because of inadequate detection and treatment.

Adult↗