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P Halfon

Publications and source records attributed to P Halfon.

At least 19 recordsLinked to original sources
PubMed1999

Prevalence of GBV C/HGV RNA and GBV C/HGV antibodies in French volunteer blood donors: results of a collaborative study.

BACKGROUND AND OBJECTIVES: Posttransfusion hepatitis still occurs at an incidence of about 1 in 118,000 for HBV and 1 in 220,000 for HCV. This collaborative study aimed to determine the prevalence of a novel flavivirus, GBV-C/HGV, even though its role in transfusion-associated hepatitis is uncertain. MATERIALS AND METHODS: GBV-C/HGV RNA was detected by PCR using either the Boehringer detection kit or by primers previously described. HGV antibodies were detected by a serological assay from Boehringer. RESULTS: The observed GBV-C/HGV RNA frequency was 3.4%. HGV antibodies occurred in 9.5% of donors. CONCLUSION: In our study, 12. 9% of the donors had been in contact with the GBV-C/HGV virus.

Adolescent↗
PubMed1998

Prospective virological follow-up of hepatitis C infection in a haemodialysis unit.

Hepatitis C virus (HCV) is of major concern in the management of patients on maintenance haemodialysis. Many studies have reported a high prevalence of HCV infection in dialysis centres. The objective of our study was first, to perform a prospective follow-up of the evolution of HCV infection in a haemodialysis centre, and second, to assess the rate of viral clearance in patients on dialysis. For this, genotypes, HCV antibodies (anti-HCV) and HCV RNA were evaluated initially and 9 months later. HCV RNA quantification was also performed. Of 136 patients, 62 (45.6%) were anti-HCV positive by third-generation enzyme immunoassay (EIA 3) in the first survey and 64 of 136 (47.1%) were anti-HCV positive by EIA 3 in the second survey. The rate of new HCV infection, estimated from the two seroconversions between the surveys, was 1.9% per year. One of the two patients was initially HCV RNA positive, with a titre of 0.6 x 10(6) eq ml-1. The viral load measured in the dialysis patients was low and does not seem to be influenced by dialysis. No significant difference was observed in viral load between the two periods nor were there any gender-related differences in viral load. In conclusion, detection of antibodies to HCV, together with HCV RNA, seems to be relevant in haemodialysis patients, but this strategy is not suitable for use in all haemodialysis centres because of its high cost.

Adolescent↗
PubMed1998

Assessment of spontaneous fluctuations of viral load in untreated patients with chronic hepatitis C by two standardized quantitation methods: branched DNA and Amplicor Monitor.

Quantitation of hepatitis C virus (HCV) RNA in serum has been used to predict and monitor the efficacy of interferon therapy in chronic HCV infection. We prospectively studied the fluctuation of viremia by a longitudinal follow-up of HCV RNA levels for 2 months in six untreated patients. Spontaneous fluctuations of HCV RNA ranged from 2.8- to 5.7-fold with branched DNA assay and from 2.9- to 5.6-fold with Monitor. These large spontaneous fluctuations (up to 0.75 log), observed daily, weekly, and monthly, raise doubt about the clinical value of a single assessment of pretherapeutic viremia.

Adult↗
PubMed1997

Serotyping and genotyping of hepatitis C virus (HCV) strains in chronic HCV infection. Commission Hepatologie du CREGG. Club de Reflexion des Cabinets de Groupes en GastroEnterologie.

Hepatitis C virus (HCV) genotypes can be established by methods based on PCR typing and serological typing. The accuracy of these methods depends on their sensitivity and specificity. These should be compared with the reference method, direct sequencing, and analysis of viral genomes. Among the serologic methods recently developed, the performance of a new serotyping assay (RIBA HCV 3.0 SIA, Chiron corporation, Emeryville) was assessed using a panel of 147 well-characterized French isolates from chronic hepatitis C patients. Definitive genotypes of the isolates were established by direct sequencing in 5' NC and in some cases in NS-5B. HCV serotypes 1, 2, and 3 were determined by measuring type specific antibodies to core and NS-4 derived peptide antigens. Of the 147 sera, serotypic-specific antibodies were detected in 136 (sensitivity, 92.5%). The specificity of the RIBA SIA HCV serotyping assay was 92.6% (including samples with mixed results); without these, the specificity was 80.1%. Analysis of the 28 discrepant samples showed that (1) a different serotype was found in 18 samples including five for genotype 1, three for genotype 2, two for genotype 3, five for genotype 4, and three for genotype 5, and that (2) ten patients showed a reactivity with mixed serotypes, one had circulating antibodies to type 1 or 2, and nine had circulating antibodies to type 1 or 3. In summary, except for genotypes 4 and 5, the results of the test were well correlated (85.7%) with those of direct sequence genotyping. The former test is rapid and does not require the strict HCV RNA storage and preservation conditions of the latter. This new method may thus be considered as an alternative for HCV typing. However, although it is convenient, its lower sensitivity compared to the molecular typing method and the discrepant results limit its routine use in a clinical context.

Antibodies, Viral↗
PubMed1997

Prevalence of hepatitis G virus RNA in a monocentric population of French haemophiliacs.

Hepatitis G virus (HGV) and hepatitis GB virus (GBV-C) have been reported as possible causes of non-A-E transfusional hepatitis. To assess the prevalence of hepatitis G virus infection in haemophiliacs we retrospectively investigated the presence of viral RNA in 92 patients with and without HCV infection. HGV/GBV-C RNA was reverse transcribed and amplified with primers from the 5' non-coding region of the genome. RNA was detected in 16/92 patients (17.4%). Restriction enzyme analysis revealed that the 16 patients belonged to the HGV-like genotype. Serology with E2-specific antibodies demonstrated that HGV viraemia underestimates previous infection by HGV. 33 patients were positive for HGV; all but two have cleared HGV RNA. 47/92 patients had a marker of prior infection by HGV. No difference between HGV RNA positive and negative patients was observed concerning age, diagnosis, HIV and HCV status. Previous HBV infection correlated with the frequency of HGV infection. There was no difference in alanine aminotransferase levels between HGV positive and negative patients. All 18 patients exposed to only virally inactivated plasma-derived concentrates were negative for both HGV RNA and anti E2 antibodies. Prior exposure to untreated concentrates correlated with HGV viraemia (P=0.03), HGV seropositivity (P=0.0002), and markers of HGV infection (P<0.0001). In haemophiliacs with a past exposure to non-inactivated concentrates, persistence of HCV RNA (53/74 patients) was more frequent than HGV RNA persistence (16/74 patients) although HGV viraemia is more frequent than HCV viraemia in blood donors. This may be related to a greater ability of individuals to clear HGV infection and suggests that hepatitis G virus infection in multi-transfused patients has a better outcome than infection with other blood-borne viruses.

Adolescent↗
PubMed1997

GEMHEP multicenter quality control study of PCR detection of GB virus C/hepatitis G virus RNA in serum.

PCR is, to date, the only available tool for the detection of GB virus C (GBV-C) and hepatitis G virus (HGV) RNAs. Twenty-two French laboratories participated in a quality control study to assess the sensitivity and specificity of their procedures. The panel included 13 positive controls and 7 negative controls. The laboratories used either in-house PCR techniques adapted from the literature or partly standardized commercial tests. Three laboratories performed faultlessly with the entire panel. Most laboratories had excellent specificity (100% in 20 of 22 laboratories). Sensitivity was acceptable (85 to 100%) in 15 centers and insufficient (38 to 77%) in 7. As with nonstandardized in-house PCR, the commercial assays gave discrepant performances in different laboratories. These results suggest that laboratories willing to use PCR for detection of GBV-C/HGV RNA for research or diagnostic purposes should participate in multicenter quality control trials.

Flaviviridae↗
PubMed1997

[Clinical significance of detection and quantification of hepatitis C virus RNA in hemodialysis: proposal for a rational diagnostic strategy].

Viral infections due to hepatitis C virus in hemodialysis patients are frequent and have a potential risk of progression towards chronicity. Biochemical and viral markers of infection, are transaminases level, anti-HCV serology and the detection of HCV RNA, respectively. A rational strategy based on routine use of these three diagnostic tools is proposed in order to avoid unnecessary assays and to increase in the case of health cost control, the cost/efficacy ratio. The latter is set up, in the sero-negative hemodialysed, on the early detection of infection by the hepatitis C virus in order to consider of a therapeutic which is able to cure patients and to avoid the ineluctable passage towards chronicity; in hemodialysed with positive HCV serology, the detection of HCV RNA allows to establish the infectiosity status of these hemodialysis patients. It is therefore very important to evaluate prospectively this diagnosis approach in hemodialysis patients.

Genotype↗
PubMed1996

Impact of various handling and storage conditions on quantitative detection of hepatitis C virus RNA.

BACKGROUND/AIMS: Both HCV RNA viral load and HCV genotype have been described as important predicting factors determining the response to interferon in chronic hepatitis C. To investigate whether processing and storage conditions might influence the stability and could alter the concentration of the HCV RNA in serum, quantification of HCV RNA was performed by branched DNA assay. METHODS: We studied serum samples obtained from seven patients with histologically proven chronic hepatitis C. These were subjected to the following physical conditions: (1) immediate quantification, (2) storage at room temperature for 5 days, (3) storage at 4 degrees C for 5 days, (4) storage at -20 degrees C for 5 days, (5) storage at -80 degrees C for 5 days, (6) five freeze-thaw cycles, (7) blood unspun for 4 h at room temperature then centrifuged and stored at -80 degrees C for 5 days, (8) storage at 4 degrees C for 6 months, (9) storage at -20 degrees C for 6 months, (10) storage at -80 degrees C for 6 months. RESULTS: A loss of 100% HCV RNA titers was observed after storage at RT for 5 days and then storage at 4 degrees C for 6 months. A surprising decrease of HCV RNA titer (15.6%) was observed in sera stored for 5 days at -20 degrees C. Five freeze-thaw cycles resulted in a 16% decrease of the HCV RNA level. When centrifugation was performed after a 4 h delay at room temperature, a significant loss of HCV RNA titers of 29.5% was observed. Long-term stability (6 months) was observed at -80 degrees C with a slight loss of about of 10% HCV RNA titers, but a significant decrease in HCV RNA of 23% was observed at -20 degrees C. The reproducibility of the bDNA assay on five patient samples was performed eight times in duplicate and showed an average coefficient of variation of 9.1%. CONCLUSIONS: These data confirm the importance of storage and handling in measuring the amount of HCV RNA in clinical samples.

Blood Preservation↗
PubMed1996

Myasthenia gravis and hepatitis C virus infection.

Chronic hepatitis C virus (HCV) infections are often associated with extrahepatic immunological manifestations, including various autoimmune disorders. The aims of this study were to determine the prevalence of HCV markers in patients with myasthenia gravis (MG) and to determine any relationship with HCV infection. Eighty-three patients with MG. 40 men aged 20-93 years and 43 women aged 13-87 years (mean age 54 years) were studied. The MG patients were positive for antibody to acetylcholine receptor in addition, their sera was analysed for antibody to HCV (HCVAb) and HCV RNA, HCVAb was detected in two of the 83 patients (2.4%). Four patients were repeatedly HCV RNA positive. They were infected by HCV genotype 1 (one patient), HCV genotype 2a (two patients) and an undetermined HCV genotype in one patient. They received plasmapheresis or intravenous immunoglobulin treatment. Among the four patients, one was infected after the onset of MG without receiving a blood transfusion or using intravenous drugs. The other three had chronic hepatitis C which was discovered at the same time as MG and only one patient had been exposed to blood products. The prevalence of HCV markers in patients with MG (4.8%) was higher than that reported for the general French population, about 1%. This prevalence is similar to that occurring in patients exposed to plasmapheresis or intravenous immunoglobulin. In conclusion, HCV appears to play little, if any, role in causing MG. The higher prevalence of infection among MG patients may be related to transmission in the course of therapy.

Adolescent↗
PubMed1995

Persistent hepatitis C virus RNA replication in haemophiliacs: role of co-infection with human immunodeficiency virus.

In order to evaluate the evolution of transfusional hepatitis C in haemophiliacs, we performed a retrospective study of ALT levels and HCV viraemia with a RNA PCR assay in 57 patients. We found that the vast majority of HCV-infected patients remained viraemic (43/57 = 75%) and higher ALT levels correlated with HCV viraemia. Although indicators of the transfusional viral load (age, severity of haemophilia) and HBV co-infection did not correlate with HCV RNA replication, HIV seropositivity was strongly associated with persistence of HCV viraemia (23/25 = 92% in HIV-positive versus 20/32 = 62% in HIV-negative patients), without any correlation with CD4 counts. Genotyping of HCV in the 43 viraemic patients shows more frequent genotype 1 in the HIV-seropositive group (14/23) than in the seronegative group (6/20). Our data emphasize that besides the role of the immunodeficiency status, the genotypes of HCV might be involved in the differences observed in terms of HCV RNA replication between the HIV-seropositive and seronegative haemophiliacs.

AIDS-Related Opportunistic Infections↗
PubMed1995

[Risk of transmission of hepatitis C virus by digestive endoscopy].

OBJECTIVE: In 30 to 50% of cases, the route of transmission of virus C remains unknown. The aim of this study was to investigate the effectiveness of manual cleaning and disinfection procedures after endoscopic examinations in highly infected patients. METHODS: In 39 patients with chronic hepatitis C and a high level of replication, a gastroscopy with biopsy was performed with a fully submersible endoscope. Cleaning and disinfection were carried out with the following protocol: cleaning with detergent solution (Sekulyse), rinsing, 3 to 5 min immersion into a glutaraldehyde disinfectant solution (Sekucid) and final rinsing. One hundred mL of sterile water was flushed through the biopsy channel immediately after removal of the endoscope (T1), after cleaning (T2), and after final disinfection (T3). These 100 mL were collected in aliquots for viral and bacterial screening. Virus C particles were searched for in the effluent of the biopsy channel using two methods of polymerase chain reaction. RESULTS: Virus C particles were found in 2 of 39 patients in T1 aliquots collected before washing. Routine cleaning with a detergent eliminated all viral particles, as tests were negative at T2 and T3. The usual bacteria (Pseudomonas, Streptococcus, Neisseria...) were detected at T1 and had disappeared after total disinfection at T3. CONCLUSION: Virus C hepatitis could be transmitted during endoscopic examination, but cleaning and disinfection procedures effectively eliminated all viral particles.

Disinfection↗
PubMed1995

[Mental representation of drugs: construction of two questionnaires to study patients treated with psychotropic or oral hypoglycemic drugs].

We have built two questionnaires in order to study the representation of drugs. Questionnaires have been established according to the results of an open study involving 78 subjects, whether receiving a treatment or not. These questionnaires were applied on a sample of 126 (psychiatric or diabetic) patients. In the future, we expect the questionnaires to help studying relationships between drugs representation and compliance.

Adult↗