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Biomedical subjects

C Trepo

Publications and source records attributed to C Trepo.

At least 109 records · Page 6Linked to original sources
PubMed1996

Predictive value of HIV-1 RNA detection in plasma by branched DNA assay during long-term zidovudine therapy.

The predictive value of human immunodeficiency virus type 1 (HIV-1) RNA detection in plasma using branched DNA assay was studied in a subgroup of 36 asymptomatic HIV-1-infected patients enrolled in a multicenter, double-blind, randomized study. Patients were randomized to receive either zidovudine (AZT) 1 g/day or placebo and were monitored for a mean time of 61 months. HIV-1 RNA was detected in plasma using branched DNA assay at months 0, 6, 12, 24, and 36. HIV-1 RNA was detected at levels of > or = 10(4) RNA eq/ml (eq/ml) in 8.3% of the patients at baseline, and this percentage increased during the first two years in the placebo group only. The detection rate of HIV-1 RNA at three years was 50% in both the AZT and the placebo groups. HIV-1 RNA levels ranged from 10(4) to 478 x 10(3) RNA eq/ml. HIV-1 RNA was detected at levels of > or = 10(4) eq/ml a mean time of 19 +/- 13 months before progression to AIDS in 76.5% of progressing patients. In a multivariate analysis including baseline CD4+ count, the initial randomization group, HIV-1 RNA detection in plasma, and detection of p24 antigenemia during the first three years of follow-up, the best independent predictors of progression to AIDS at five years and the best independent predictors of death at five years were HIV-1 RNA detection in plasma and p24 antigenemia.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Heterogeneity of hepatitis B virus (HBV) core gene in a patient with HBV-associated cirrhosis and serum negativity for anti-HBc.

AIMS: We describe here the case of a patient suffering from severe chronic hepatitis B associated with an unusual hepatitis B virus serology: HBsAg and HBeAg were both positive while anti-HBc was negative by radioimmunoassay. METHODS: A very sensitive anti-HBc ELISA (IMx CORE) was performed and was able to detect anti-HBc sporadically throughout the clinical course. Molecular characterization of hepatitis B virus strains in this patient enabled us to explain this particular serological and clinical pattern of hepatitis B virus infection. RESULTS: Hepatitis B virus genotype determined by size polymorphism of the core gene and the pre-S region was found to be D/E and consistent with the results of serological subtyping (HBV ayw2-4). DNA sequence analysis of the pre-C/C region showed the presence of significant nucleotide changes. In association with a wild type hepatitis B virus strain, we could detect at least four hepatitis B virus variants with nucleotide deletions leading to a frameshift in the core gene. According to the position of the mutations, these hepatitis B virus core variants are expected to be defective for B-cell epitopes and TH-cell epitopes. CONCLUSIONS: These mutations explain the low level production of anti-HBc antibody. It is noteworthy that the absence of detectable anti-HBc in serum was associated with severe liver damage, suggesting that the deficient humoral response to HBcAg was not accompanied by a cellular immune tolerance to HBc/eAg, the supposed target for cytotoxic T-cell lysis.

Adult↗
PubMed1996

Clinical evaluation of a single reaction, diagnostic polymerase chain reaction assay for the detection of hepatitis C virus RNA.

BACKGROUND/AIMS: In the past few years the detection of HCV-RNA by polymerase chain reaction has become a well-established diagnostic tool for patients with chronic hepatitis C. However, the lack of reproducible results between laboratories and the relatively high proportion of false-positive results, has indicated the need for a standardized and reliable polymerase chain reaction assay. In the present study we have analyzed the performance of a commercial, HCV-RNA polymerase chain reaction assay based on a single, combined reverse transcription and amplification reaction and on the use of Uracil-N-glycosilase to prevent carry-over contamination (Amplicor HCV, Roche Molecular Systems). METHODS: In this assay the amplification products are detected in microwell plates using biotinylated primer and the HRP avidin colorimetric system. Serum samples collected from 446 patients, including 181 with chronic active hepatitis C, 50 with autoimmune chronic hepatitis, 117 in hemodialysis, 30 asymptomatic carriers of anti-HCV and 68 with indeterminate serology (RIBA indeterminate results), as well as from 121 controls were tested with the commercial, single-step assay and with nested polymerase chain reaction. Both techniques use primers located within the 5' non-coding region of the HCV genome. RESULTS: In all cases a good concordance was observed between the commercial, single-step assay and nested polymerase chain reaction which, for patients with chronic active hepatitis, showed a sensitivity and specificity of 100% and 99.3% for the former and of 98.8% and 100% for the latter, when compared to clinical diagnosis taken as the gold standard. Most of the 11 discordant samples were seen in the group of RIBA-indeterminate cases and in patients with chronic active hepatitis C. Further analysis of these cases, based on repeat testing and clinical data showed that 64% and 36% of the discrepancies were due, respectively, to nested polymerase chain reaction and Amplicor inconsistent reactions. In hemodialyzed patients, patients with autoimmune hepatitis and asymptomatic carriers of anti-HCV, both assays produced results which were consistent with the clinical diagnosis. In the former group, polymerase chain reaction was able to identify the presence of active viral replication in some antibody negative samples. CONCLUSIONS: Taken together, these results indicate that the commercial, single-step polymerase chain reaction assay has the same clinical sensitivity and specificity as nested polymerase chain reaction and that, because of its simplified procedures and fast turn-around time, it may be a valuable test for routine diagnostic applications.

Hepacivirus↗
PubMed1996

Prednisolone withdrawal therapy enhances the effect of human lymphoblastoid interferon in chronic hepatitis B. INTERPRED Trial Group.

BACKGROUND/AIMS: The aim of this multicentre, randomised, controlled, clinical trial was to evaluate the effect of prednisolone followed by lymphoblastoid interferon treatment in chronic hepatitis B. METHODS: Two hundred and thirteen patients with chronic hepatitis B were randomised to either prednisolone (2 weeks of 0.6 mg/kg/day, 1 week of 0.45 mg/kg/day and 1 week of 0.25 mg/kg/day) or matching placebo followed by a 2-week rest phase and then human lymphoblastoid interferon 10 MU daily for 5 days followed by 10 MU thrice weekly for 11 weeks. Of 200 evaluable patients, 33 (16.5%) were females, and 50 (25%) were male homosexuals. Thirty three patients (16.5%) had chronic persistent hepatitis, 145 (72.5%) had chronic active hepatitis and 22 (11%) had active cirrhosis. RESULTS: Survival analysis disclosed statistically significant effects of prednisolone pre-treatment on both HBeAg disappearance and HBeAg to anti-HBe seroconversion (log-rank test statistics 5.43; p = 0.02 and 4.75; p = 0.03). Observed HBeAg disappearance and HBeAg to anti-HBe seroconversion rates (placebo vs. prednisolone patients) were 28% vs. 44% and 23% vs. 38%. Six months after stopping interferon, HBV DNA was negative in 51% of prednisolone patients vs. 28% of placebo patients (Chi-square test statistic 6.13; p = 0.013). Prednisolone pre-treatment tended to be more effective in patients with higher transaminase levels and in patients with low levels of HBV DNA. Fifteen patients (7.5%) (13 within 1 year of follow-up) eventually lost HBsAg; 14 of these subsequently developed anti-HBs. Interferon treatment was modified in 102 patients (51%). Three out of 22 patients with cirrhosis (14%), one of whom received prednisolone pre-treatment, developed hepatic decompensation with a fatal outcome while on interferon treatment. CONCLUSIONS: Prednisolone pre-treatment significantly enhanced the treatment effect of lymphoblastoid interferon in terms of HBeAg clearance and seroconversion to anti-HBe. Treatment should be used with caution in patients with cirrhosis and avoided in patients showing signs, or with a history, of decompensated cirrhosis.

Adult↗
PubMed1996

Inhibition of the expression of hepatitis A and B viruses (HAV and HBV) proteins by interferon in a human hepatocarcinoma cell line (PLC/PRF/5).

AIMS/METHODS: PLC/PRF/5 is a continuous human hepatocarcinoma cell line whose genome contains integrated HBV DNA and which secretes two of the hepatitis B virus envelope proteins (HBs and PreS2). This line is also susceptible to infection by hepatitis A virus and was therefore used to compare the effects of interferon on protein synthesis of these two viruses and to assess the interactions which occur between them during infection. RESULTS: Results showed that recombinant interferon alpha 2-a inhibited the expression of the two hepatitis B virus envelope antigens (HBs and PreS2) and of the only hepatitis A virus antigen in a dose-dependent fashion. Comparison of the effect of interferon on antigenic protein production of these two viruses, showed stronger inhibition of hepatitis A virus capsid antigen than of hepatitis B virus envelope antigens. Infection with hepatitis A virus also downregulates the expression of the two hepatitis B virus proteins. CONCLUSIONS: Considering the absence of cytotoxic effects from the doses used, this study confirms the relevance of this cellular model for the study of antiviral cytokines in vitro. It also provides a further rationale for the clinical evaluation of the therapeutic potential of interferons in severe hepatitis cases due either to hepatitis A virus alone or to superinfection of hepatitis B virus carriers by hepatitis A virus.

Antigens, Viral↗
PubMed1996

Cytomegalovirus DNA level on biopsy specimens during treatment of cytomegalovirus gastrointestinal disease.

BACKGROUND & AIMS: There is no clear and point for the response to treatment of gastrointestinal human cytomegalovirus (HCMV) disease. HCMV-DNA quantitation on gastrointestinal biopsy specimens has proven its value for the diagnosis of gastrointestinal HCMV disease in patients with acquired immunodeficiency syndrome (AIDS). The aim was to study HCMV-DNA levels on gastrointestinal biopsy specimens during the treatment of gastrointestinal HCMV disease. METHODS: HCMV-DATA quantitation was performed using two different polymerase chain reaction assays on 90 biopsy specimens obtained before anti-HCMV therapy, during the induction phase, or during maintenance therapy for gastrointestinal HCMV disease in 21 patients with AIDS. RESULTS: HCMV-DNA was detected on all the biopsy specimens ranging from 9 to > or = 80,000 Eq/0.1 microgram DNA. Pretherapeutic mean level was 69,000 +/- 27,000 Eq/0.1 microgram DNA. Induction therapy was followed by a mean decrease of 1.7 +/- 1.3 log10 Eq/0.1 microgram DNA. HCMV-DNA levels decreased during induction therapy to < 1000 Eq/0.1 microgram DNA in 60% of patients but remained > 80,000 Eq/0.1 microgram DNA in 20% of patients. Relapse occurred in all the patients in a mean time of 100 days. HCMV-DNA level at the end of the induction phase seems to influence the time to relapse. CONCLUSIONS: Quantitation of HCMV-DNA on gastrointestinal biopsy specimens seems to be useful for monitoring gastrointestinal HCMV disease in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Treatment of HCV liver disease by recombinant interferon alpha.

Interferon alpha has confirmed its efficacy for the therapy of chronic hepatitis C. Half of the patients treated will normalize their plasma ALT at the end of a 6-month course of 3 MU thrice a week. This biochemical response is associated with a reduction of HCV RNA (viraemia) from serum and with significant improvement of liver histology. Despite those beneficial effects, 50% of treatment responders generally relapse after treatment arrest. Increasing doses to 6 MU and/or the duration of interferon therapy increases the proportion of long-term sustained responders. Combining therapy with ribavirin, a nucleoside analogue, also appears to have a similar effect.

Alanine Transaminase↗
PubMed1996

Treatment of chronic hepatitis C: another therapeutic option.

Ribavirin is a nucleoside analogue with anti-viral activity against a number of DNA and RNA viruses. That molecule is administered per os and its most frequent adverse effect is haemolysis, moderate in most cases. Used alone, ribavirin normalized liver enzyme concentrations in 45% of patients while viraemia is not significantly modified. Histological improvement is observed in responder patients. The most interesting results have been obtained by associating ribavirin with interferon. In patients who have never been treated, a six-month course of ribavirin-interferon association produced a lasting and total response in 47% of patients versus 25% in patients treated with interferon alone. In relapsers, this bi-therapy produced total and prolonged response in more than 40% of cases and in 20% of non-responder patients. Lastly, that association appears promising in treating hepatitis C reinfection after liver transplantation.

Antiviral Agents↗
PubMed1996

Stability of hepatitis C virus RNA in serum from samples collected in a closed-tube system for serum separation and transport, as measured by a quantitative competitive PCR assay.

Recovery of hepatitis C virus (HCV) RNA, after variable time intervals from collection, was assessed using a closed-tube system for collection, separation and transport (SST tubes). Blood from four hepatitis C-infected patients was collected in 12 SST tubes and centrifuged within 1 to 3 h of collection. Tubes were then left 0, 8, 12, 24, 48 and 72 h at room temperature and at 4 degrees C before removing serum. Hepatitis C virus RNA levels were measured by quantitative polymerase chain reaction (PCR) using the AMPLICOR HVC MONITOR assay. Hepatitis C virus RNA levels in these samples were stable for at least three days at both temperatures. Polymerase chain reaction signals never decreased by more than 0.5 log. The reproducibility of the assays showed that the quantitative PCR method can be used with the storage conditions tested here. Our data suggests that processing blood in SST tubes may be very useful in following hepatitis C virus RNA titres in infected patients, especially those receiving treatment.

Hepacivirus↗
PubMed1996

[Medical and economic evaluation of donated blood screening for hepatitis C and non-A, non-B, non-C hepatitis].

The aim of this study was to evaluate the cost of hepatitis C and non-A non-B non-C screening strategy in donated blood, currently used in French transfusion centres and to assess the effect in the blood transfusion centres according to the prevalence of the disease and the intrinsec values of tests. This screening strategy was based on alanine aminotransferase assay, and HBc and HCV antibodies detection. In 1993, a survey was conducted in 26 French transfusion centers to estimate the costs of the screening strategy currently used. Average expenditure on diagnostic sets, equipment, staff and administration charges for hepatitis C and non-A non-B non-C screening were calculated. From these results, we estimated the cost of the previous strategy which did not involve HCV antibody testing, so as to determine the incremental cost between the two strategies. We used clinical decision analysis and sensitivity analysis to estimate the incremental cost-effectiveness ratio with data gathered from the literature and examine the impact on blood transfusion centre. Implemented for 100,000 volunteer blood donations, the incremental cost of the new strategy was FF 2,566,111 (1992) and the marginal effectiveness was 180 additional infected donations detected. The sensitivity analysis showed the major influence of infection prevalence in donated blood on the incremental cost-effectiveness ratio: the lower the prevalence, the higher the cost-effectiveness ratio per contaminated blood product avoided.

Adult↗
PubMed1995

A comparison of three interferon alfa-2b regimens for the long-term treatment of chronic non-A, non-B hepatitis. Multicenter Study Group.

BACKGROUND: We studied the effects of long-term treatment with interferon on histologic features of the liver and serum alanine aminotransferase concentrations in patients with chronic non-A, non-B hepatitis. METHODS: Consecutive patients who met the inclusion criteria were enrolled in the study. The diagnosis of chronic non-A, non-B hepatitis was established on the basis of the liver-biopsy findings and an abnormal serum alanine aminotransferase value (greater than 1.5 times the normal value) for at least one year. All patients were treated for six months with 3 million units of interferon alfa-2b given subcutaneously three times a week and were then randomly assigned to the same treatment for an additional 12 months (group 1), a regimen of 1 million units three times a week for 12 months (group 2), or no further treatment (group 3). Patients in group 3 who had elevated serum alanine aminotransferase concentrations for three consecutive months underwent the initial regimen once again. Follow-up continued for two years after the discontinuation of treatment. Histologic improvement was defined as a decrease of at least one grade in the score for necroinflammatory activity (0, no activity; 1, mild; 2, moderate; or 3, severe) between the first liver biopsy and a biopsy performed at 18 months. RESULTS: Of the 329 patients initially treated, 303 were randomized: 103 to group 1, 101 to group 2, and 99 to group 3. Of the 286 patients tested, 252 (88.1 percent) had antibodies to hepatitis C virus. In an intention-to-treat analysis, 46 of the patients in group 1 (44.7 percent) had normal serum alanine aminotransferase values at 18 months, as compared with 27 of the patients in group 2 (26.7 percent, P = 0.008) and 30 of those in group 3 (30.3 percent, P = 0.04). Between 19 and 42 months, 23 of the patients in group 1 (22.3 percent) continued to have normal serum alanine aminotransferase values (measured every six months), as compared with 10 of the patients in group 2 (9.9 percent, P = 0.02) and 8 of those in group 3 (8.1 percent, P = 0.005). Among the 176 patients with repeated liver biopsies at 18 months, more patients in group 1 had improved histologic-activity scores (69.6 percent) than in group 2 (47.6 percent, P = 0.02) or group 3 (38.6 percent, P < 0.001). CONCLUSIONS: Among patients with chronic non-A, non-B hepatitis, a regimen of 3 million units of interferon alfa-2b given three times a week for 18 months produced better histologic findings and serum alanine aminotransferase values than regimens involving a lower dose or a shorter duration of treatment.

Alanine Transaminase↗
PubMed1995

[Hepatitis viruses].

Five different hepatitis viruses that cause acute and chronic hepatitis in human beings have been identified. Hepatitis viruses are designated by the letters A, B, C, D and E and abbreviated as HAV, HBV, HCV, HDV, and HEV, respectively. Although each belongs to a distinctly different virologic group, they share the feature of hepatotropism, which remains poorly understood. HAV and HEV are transmitted through a fecal-oral route. HDV, also referred to as the delta agent, is a defective, parenterally transmitted virus that uses the hepatitis B surface antigen (HBsAg) of HBV as its envelope. Thus, HDV infection occurs only in patient with HBV infection. Application of molecular biologic techniques has been instrumental in elucidating the genomic sequences of the individual hepatitis viruses and in understanding viral gene expression and mechanisms of viral replication. Knowledge of the genomic structure of these viruses and perfection of molecular biological techniques have also led to clinical applicability of molecular diagnostic techniques. Indeed, these molecular diagnostic techniques have rapidly become the standards against which serologic tests are compared.

Hepatitis Viruses↗
PubMed1995

Serial transmission of spongiocytic hepatitis to woodchucks (possible association with a specific delta strain).

BACKGROUND/AIMS: Outbreaks of severe hepatitis have been reported from Africa and South America. Description of the cases has shown the histological hallmark to be the presence of ballooning hepatocytes with fat drops surrounding the nucleus (spongiocytes or morula cells). METHODS: Experimental reproduction of this syndrome for the verification of a possible role of a specific HDV strain was performed by the inoculation of serum and liver extracts from African patients (Bangui-Central African Republic), who died with this syndrome, into American woodchuck carriers of WHV (WC 231,144), the results of which were then compared with animals inoculated with a reference wild HDV strain (WC 300,173,154), and those which received material from a European fulminant HDV case (WC 88,93). RESULTS: Following the initial inoculation, the animals receiving African inocula had a delayed anti-HDV seroconversion, high mortality and showed the presence of spongiocytes, while the other animals had a classical evolution of HDV superinfection in woodchucks. Furthermore, the African inocula caused less inhibition of WHV replication, as well as a predominant cytoplasmic expression of HDAg, in contrast to the animals which received the other inocula. The second passage experiments gave similar results. CONCLUSIONS: We conclude that this peculiar form of HDV fulminant hepatitis can be experimentally reproduced and might be specifically related to a more pathogenic strain.

Animals↗