PubMed Health⌕ Search

Biomedical subjects

Evelyne Schvoerer

Publications and source records attributed to Evelyne Schvoerer.

10 recordsLinked to original sources
PubMed2006

Early decrease in circulating dendritic cells number after liver transplantation could favor hepatitis C virus recurrence.

Cirrhosis and hepatocarcinoma related to hepatitis C virus (HCV) lead to more than 30% of liver transplantations. Host- and virus-related mechanisms, involved in the recurrence of HCV infection of the liver graft, are not yet well known. A weak CD4+ T-cell response was shown to be involved in the outcome of re-infection but whether dendritic cell numbers are modified in patients transplanted for HCV-related disease has never been evaluated. Eight transplanted patients for HCV-related disease and eight non-HCV-infected transplanted controls were included. Blood plasmacytoid dendritic cells and myeloid dendritic cells were quantified before transplantation, at day 7 and 1 month after transplantation. Plasma interferon (IFN)-alpha and interleukin (IL)-12 were concomitantly measured. The results showed a significant decrease in the relative (P < 0.0001) and absolute (P = 0.0002) values of blood plasmacytoid dendritic cells at day 7 after transplantation when compared to the values obtained before transplantation, increasing again 1 month later, in both HCV-infected patients and controls. The same tendency was observed for myeloid dendritic cell relative values (P = 0.0004) and plasma IL-12 (P < 0.05). IFN-alpha appeared to be less often detectable for HCV-infected patients. These results obtained on dendritic cell numbers could explain partially the early and systematic recurrence of HCV infection on the liver graft and contribute to better adapted therapeutic strategies.

Cell Count↗
PubMed2005

Evaluation of three commercially available hepatitis C virus antibody detection assays under the conditions of a clinical virology laboratory.

BACKGROUND: Most studies evaluating antibody detection assays are conducted on samples from healthy blood donors but not on samples of hospitalized patients which can show non-specific reactions. OBJECTIVES: To compare the performance of three commercial automated assays for the detection of hepatitis C virus (HCV) antibodies, Monolisa anti-HCV Plus version 2, Axsym anti-HCV 3.0 and Vitros anti-HCV, on a population of hospitalized patients. STUDY DESIGN: The specificity of the assays was prospectively evaluated in 2020 routine serum samples. In order to assign the serostatus of each sample, those giving positive or discordant results were further tested by three immunoblots and by RT-PCR (Roche). Moreover, the sensitivity was evaluated on eight commercial HCV seroconversion panels. RESULTS: The Monolisa, Axsym and Vitros assays showed specificities of 99.64%, 99.12% and 99.33%, respectively. Concerning the sensitivity, among 49 samples, the number of positive results was 21, 24 and 24 for the Monolisa, Axsym and Vitros kits, respectively. The differences were not statistically significant at an alpha risk of 5%. CONCLUSIONS: All assays appeared to be reliable for routine screening, but there were a surprising number of indeterminate samples that could not be resolved by confirmatory tests.

Algorithms↗
PubMed2005

Monitoring low cytomegalovirus viremia in transplanted patients by a real-time PCR on plasma.

Until recently, human cytomegalovirus (hCMV) infection and anti-CMV treatment in transplanted patients have been monitored essentially by pp65 antigenemia, which is time-consuming and requires experienced operators. For the last two years, pp65 antigenemia levels have tended to be lower than previously in our laboratory, which could be due to better monitoring of CMV-related risk. Results obtained by real-time PCR with a LightCycler instrument or by pp65 antigen assay were compared on 145 serial samples from bone marrow or kidney transplant recipients under the usual conditions of our laboratory. CMV DNA was extracted from plasma and quantified by using primers and probes directed to HXFL4 gene. The plasma CMV DNA load was measured by using a standard curve constructed with a commercially available quantified CMV DNA suspension. Among the 145 samples, 139 showed a pp65 antigen which was negative or lower than 20 positively stained cells per 200,000 leukocytes. In the patients with positive pp65 antigenemia, the corresponding values of CMV DNA copy number/ml were significantly higher than those observed in patients without antigenemia (P < 0.001). CMV DNA was detected from 4 up to 52 days before pp65 antigen. Elsewhere, between two dates at which pp65 antigen was positive, intermediate PCR results could be positive while the pp65 antigen was negative. This real-time quantitative PCR assay is a rapid technique adapted to monitor plasma CMV DNA in transplant setting, even for low viremia.

Adult↗
PubMed2003

Persistent multiple pulmonary nodules in a nonimmunocompromised woman after varicella-related myelitis treated with acyclovir.

Persistent multiple pulmonary nodules were observed on the chest X ray of a nonimmunocompromised woman 6 months after she was treated with acyclovir for a varicella-related myelitis without respiratory symptoms. Early antiviral therapy given for varicella infections might decrease the intensity of clinical symptoms without actually preventing the occurrence of varicella-zoster virus-related lesions such as the persistent pulmonary nodules reported here.

Acyclovir↗
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

[Immunomodulating effect of HCV during the development of chronic hepatitis C: toward new therapeutic approaches].

In France, HCV seroprevalence is estimated to be 1%. Most cases are related to illicit parenteral drug use. About 80% of patients infected by HCV will develop chronic infection with HCV RNA detectable in their serum. Factors involved in viral persistence are nor yet clearly identified. Patients who develop a chronic infection show a predominant Th2 response, but a weak Th1 response. This immune response imbalance could result from HCV interaction with dendritic cells functions. Several experimental and clinical studies support this hypothesis. New data on HCV strategy to establish chronic infection suggest that immmunomodulatory molecules could be useful to improve efficacy of therapy.

Adjuvants, Immunologic↗
PubMed2002

CD4 T lymphocyte proliferative responses to hepatitis C virus (HCV) antigens in patients coinfected with HCV and human immunodeficiency virus who responded to anti-HCV treatment.

CD4 T lymphocyte proliferative responses to hepatitis C virus (HCV) antigens were evaluated before and during an anti-HCV regimen (interferon-alpha2a and ribavirin) in 36 patients coinfected with HCV and human immunodeficiency virus (HIV), to determine whether immune responses against HCV antigens are present in such patients, whether these responses are modified by anti-HCV treatment, and whether they are correlated with treatment efficacy. The CD4 responses against HCV antigens (primarily core antigens) detected at study entry in one-half of the patients did not correlate with anti-HCV treatment efficacy. Of 36 patients, 8 had patterns of persistent immune response to infection by genotypes 3 or 4 that were significantly correlated with sustained virologic response. Persistent immunologic reactivity and sustained virologic response coexisted only in patients infected with genotype 3. These findings suggest that HCV genotype may influence specific immune response, which, in turn, is implicated in virologic control.

Adult↗
PubMed2002

Dendritic cell susceptibility to hepatitis C virus genotype 1 infection.

In vitro infection of human monocyte-derived dendritic cells was carried out to study their susceptibility to hepatitis C virus (HCV) infection. Immature dendritic cells and mature dendritic cells were incubated overnight at 37 degrees C with HCV-positive (genotype 1) serum samples; the presence of the viral genome associated with the production of its replicative intermediate was used as evidence of infection. In immature dendritic cells, HCV RNA was detectable from days 1-10 post-infection (p.i.), and de novo synthesis of negative-strand HCV RNA could be demonstrated by a strand-specific rTth reverse transcription-polymerase chain reaction at day 2. In mature dendritic cells, the positive-strand form was detectable from days 1-5 p.i., while the negative-strand HCV RNA appeared at days 1 and 2 p.i. Quasispecies present in the inoculum and 6 days p.i. were analyzed by sequencing hypervariable region 1 of the E2 protein. Only two of seven HVR variants present in the inoculum were found in HCV-infected immature dendritic cells. Another two HVR variants not found in the inoculum were recovered from infected immature dendritic cells, suggesting serum minor variants selection or virus evolution during in vitro replication. Analysis by single-strand conformation polymorphism assay of 5' untranslated region of HCV sequences showed that the patterns obtained from the inoculum and infected immature dendritic cells and mature dendritic cells differed slightly. These findings indicate that both immature dendritic cells and mature dendritic cells are susceptible to HCV genotype 1 infection, supporting at least HCV RNA replication. This model should be a valuable tool for the study of modulation of dendritic cell functions in HCV infection.

Amino Acid Sequence↗
PubMed2002

Lamivudine therapy of chronic hepatitis B in three groups of patients: non transplanted patients, liver recipients, and kidney recipients.

OBJECTIVE: As conflicting results have been observed by some authors in liver recipients, the aim of the study was to evaluate lamivudine therapy in 3 groups of patients with chronic hepatitis B: non-transplanted patients, liver and kidney recipients. METHODS: All patients were studied for clinical symptoms, hepatic enzymes, hepatitis B virus (HBV) serology, serum HBV DNA load, and HBV polymerase genotype (mutations associated with lamivudine resistance). RESULTS: During the 48-144 week-long follow-up (mean: 75 weeks), 23 non-transplanted patients, 5 liver and 6 kidney recipients were studied. A sustained biochemical and virological response was obtained in 19 out of the 23 non-transplanted patients and in 4 of 6 kidney recipients, while the 5 liver recipients did not respond. After the development of lamivudine resistance, mutations rtM204V and rtL180M were detected in all studied patients, mutation rtM207I in one, with similar results from traditional nucleotide sequencing and a commercial line probe assay. CONCLUSION: The poor response to lamivudine in liver recipients requires further studies.

Alanine Transaminase↗