PubMed Health⌕ Search

Biomedical subjects

Christophe Pasquier

Publications and source records attributed to Christophe Pasquier.

34 records · Page 2Linked to original sources
PubMed2004

HIV therapy after treatment interruption in patients with multiple failure and more than 200 CD4+ T lymphocyte count.

The aim of the study was to investigate the safety and efficacy of a salvage therapy initiated after interrupting treatment in patients with virological failure and more than 200 CD4(+) T lymphocyte count. In this prospective study, 77 patients who received failing regimens had stopped completely all medication for 3 months before starting an optimised regimen consisting of 3-5 drugs. Patients were tested for HIV resistance before and after treatment interruption. Discontinuation of therapy for 3 months was associated with a median increase in HIV RNA of 1.1 log(10), a median decrease in CD4(+) T cell count of 136 x 10(6)/L and five clinical events related to HIV, but no AIDS-defining event. Eighty-seven percent of patients showed a shift from a drug resistant genotype to a wild-type genotype based on the major resistance mutations. Forty-seven percent of patients with a genotype shift reached fewer than 200 HIV RNA copies/ml of plasma 6 and 12 months after treatment resumption whereas none of those without a genotype shift did so (P = 0.03). However, the genotypic shift was not associated with a sustained virological response by multivariate analysis. The use of a new therapeutic class of compound in the salvage regimen was the only predictor of the sustained virological response. Salvage therapy with 3-5 drugs after interrupting treatment for 3 months can be a safe and effective strategy provided the HIV disease is not too advanced. Randomised trials in this population are needed to assess the clinical benefit of this strategy.

AIDS-Related Opportunistic Infections↗
PubMed2004

Insemination with isolated and virologically tested spermatozoa is a safe way for human immunodeficiency type 1 virus-serodiscordant couples with an infected male partner to have a child.

OBJECTIVE: To enable serodiscordant couples to reproduce while minimizing the risk of infecting the female partner and to demonstrate the feasibility of including these couples in an insemination program. DESIGN: Prospective follow-up study. SETTING: Ambulatory IUIs. PATIENT(S): Fifty-six HIV-1-serodiscordant couples with a male infected partner. INTERVENTION(S): Sperm cell separation by the gradient density method followed by the swim-up method, virological detection, and IUI after ovarian stimulation. MAIN OUTCOME MEASURE(S): Pregnancy rate, HIV-1 test, and p24 antigenemia in women. RESULT(S): Two hundred thirteen IUIs were performed, and 37 pregnancies occurred, resulting in 33 births and 2 ongoing pregnancies. Fifty percent of couples have a child. No women were infected. CONCLUSION(S): Our study demonstrates the efficiency of an IUI program with prepared and virologically tested spermatozoa in serodiscordant couples with an HIV-1-infected male partner, allowing the couples to have children without transmission of the virus to the female partner.

Adult↗
PubMed2003

Genetic heterogeneity of the NS5A gene of hepatitis C virus and early response to interferon-alpha.

The double-stranded RNA-activated protein kinase-binding domain (PKRbd) of the NS5A gene of hepatitis C virus (HCV) was studied by the cloning and sequencing method, in HCV-infected patients who had a primary resistance to treatment with interferon (IFN)-alpha (early nonresponders). Patients whose virus load decreased by >or=0.5 log (early responders) were similarly analyzed. In the 2 groups, the PKRbd evolved similarly over the first 24 h. Selection of resistant HCV variants is unlikely to explain primary resistance to IFN-alpha.

Antiviral Agents↗
PubMed2003

Assessment of HIV-1 subtyping for Cameroon strains using phylogenetic analysis of pol gene sequences.

Phylogenetic analysis of human immunodeficiency virus type 1 (HIV-1) pol gene is a useful method for subtyping European strains of HIV-1. The suitability of this method for genetically diverse African strains was evaluated by comparing HIV-1 subtyping of Cameroon strains using a long fragment of the pol gene sequence to the findings obtained using env gene sequences. When the pol gene could not be amplified, the reverse transcriptase (RT) or the protease (PR) genes were used. Phylogenetic analysis of the env C2/V3 gene sequences of 60 HIV-1 isolates showed 52 to be subtype A, 2 subtype G, plus one each of subtypes C, F2 and H, with 3 subtypes not determined. A long fragment of the pol gene was amplified successfully and sequenced in 23% of cases. The RT region was amplified for 42% of the samples that could not be typed by analysing the long fragment, and the PR gene was amplified for 40% of them. Thus, 63% of samples were typable. Env and pol gene subtypings were in agreement in 86% of cases. It is concluded that the phylogenetic analysis of pol gene sequences is not a practical method for HIV-1 subtyping in areas of high subtype diversity, despite the good agreement between the env and pol gene subtypings. However, it can be a useful method for HIV-1 subtyping, provided that the gene is amplifiable.

Cameroon↗
PubMed2003

Quantitation of human cytomegalovirus in recipients of solid organ transplants by real-time quantitative PCR and pp65 antigenemia.

Human cytomegalovirus (HCMV) infections and anti-HCMV treatment are usually monitored by measuring pp65 antigenemia. This method is time-consuming, labour-intensive and requires skilled operators. We have compared results obtained using real-time Light Cycler quantitative PCR (QPCR) and the pp65 antigen assay on serial samples collected from recipients of solid organ transplants. We collected 198 blood samples from 14 solid organ transplant recipients and assayed them for pp65 antigen and with Light Cycler PCR. HCMV DNA was extracted from leukocytes and measured using primers and probe located in the UL83 region. The quantity of HCMV DNA was calculated using a standard curve prepared from a plasmid containing the target sequence. There was a good correlation between the number of pp65-positive cells and the DNA copy number (r = 0.57, P < 0.0001). A clinical threshold of 50 positive polymorphonuclear leukocytes/200,000 cells was equivalent to two log10 genome copies per capillary by Light Cycler PCR. HCMV DNA was detected before pp65 antigen in three patients at a mean time of 10 days, whereas the two tests were positive simultaneously for eight patients. Both the pp65 antigen data and DNA copy number decreased over time during antiviral treatment, although the QPCR was positive 28.2 days after the pp65 antigen assay had become negative. The real-time Light Cycler quantitative PCR assay is a rapid and labour-saving technique. This molecular method could be useful for monitoring infections and antiviral treatment in recipients of solid organ transplants.

Adult↗
PubMed2003

Intermittent detection of hepatitis C virus (HCV) in semen from men with human immunodeficiency virus type 1 (HIV-1) and HCV.

HCV is usually transmitted via the blood, but HCV RNA has been detected recently in seminal fluid. This study was done to study HCV seminal shedding and factors that could influence the presence of HCV in the seminal fluid of men coinfected with HCV and HIV-1. HCV and HIV-1 genomes were assayed in multiple paired blood and semen samples obtained from 35 men enrolled in an assisted medical procreation protocol. HCV RNA was found intermittently in semen samples from 9 patients (25.7%). Samples from 9 men with HCV RNA in their semen and 26 men without were compared to further analyze these parameters. No correlation was found between HCV RNA in the seminal fluid and age, HCV virus load, the duration of HIV-1 infection, HIV treatment, the CD4(+) cell count, HIV-1 virus load or HIV-1 detection in the semen. The intermittent detection of HCV RNA in semen samples support the systematic search for HCV RNA in semen and the use of processed spermatozoa in assisted medical procreation of infertile HCV serodiscordant couples.

Adult↗
PubMed2003

Hepatitis C virus infection among pregnant women in Yaounde, Cameroon: prevalence, viremia, and genotypes.

Central Africa is considered to be an area of high endemic hepatitis C infection. To determine the prevalence of anti-HCV antibodies, HCV RNA, and the genotype distribution in Cameroon, 1,494 pregnant women attending antenatal care units in Yaounde, Cameroon were screened for HCV infection. Anti-HCV antibodies were detected with a 3rd generation ELISA (Monolisa anti-HCV plus version 2, BioRad, Richmond, CA). All anti-HCV antibody-positive sera were then tested with another 3rd generation ELISA (AxSYM) HCV version 3, Abbott Laboratories, Abbott Park, IL) and subsequently for HCV RNA (Amplicor HCV, Roche Diagnostics, Basel, Switzerland). Genotype was determined by phylogenetic analysis of the NS5b gene. Seventy-three pregnant women were found to be anti-HCV antibody positive by the first ELISA, but only 28 were anti-HCV positive by both ELISA. The prevalence of anti-HCV antibodies was thus 1.9% (28/1,494) (95% CI: 1.3-2.7%). 21/28 (75%) of the positive samples by both ELISA were HCV RNA positive. The 45 samples that were HCV antibody negative by the second ELISA were also HCV RNA negative. The HCV subtypes identified were 1a (24%), 2f (38%) and 4f (38%). In contrast to previous studies, anti-HCV antibodies were rare among pregnant women in Cameroon. The percentage of HCV seropositive pregnant women who had circulating HCV RNA was similar to that observed in Europe. Several HCV genotypes were found in Cameroon.

Adolescent↗
PubMed2003

High rate of hepatitis C virus infection and predominance of genotype 4 among elderly inhabitants of a remote village of the rain forest of South Cameroon.

To determine the prevalence of hepatitis C virus (HCV) infection and genotype distribution in a rural isolated area of Central Africa, plasma of 409 Bantous (mean age, 32 years; range, 2-78 years) living in a remote village of the rain forest of Southern Cameroon was screened for anti-HCV antibodies. HCV seropositive samples were also subjected to qualitative detection of viral RNA. HCV antibodies were detected in 70 (17.1%) individuals, 48 (68.8%) of whom had detectable viremia. The seroprevalence did not differ by gender (P = 0.37), but increased significantly with age (P < 0.05), with a strong increase in the oldest age groups. Indeed, nearly one-half (48%) of the adults >50 years old were HCV seropositive. The characterization of the viral genotypes indicated that most of the HCV strains were of genotype 4 (76%), while genotype 2 (16%), and 1 (8%) were marginally represented. The results suggest a cohort effect with an old, possibly iatrogenic, group exposure rather than a continuous exposure. A more in-depth population-based epidemiological study is needed to address this issue further.

Adolescent↗
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↗
PubMed2002

Evolution of total and integrated HIV-1 DNA and change in DNA sequences in patients with sustained plasma virus suppression.

Blood samples from patients with plasma HIV-1 RNA <20 copies/ml for more than 2 years were studied. Significant decreases in total and integrated HIV-1 DNA were observed during the first 15 months of suppressive therapy before the concentrations became stable. Clonal analysis of HIV-1 pol demonstrated that the proportions of resistance mutations in DNA sequences after 2 years were lower than those in baseline DNA and RNA sequences. The changes in the clonal composition of HIV-1 env populations in three patients with evidence of changes in HIV-1 pol populations indicated a shift from predominantly R5-like viruses to predominantly X4-like viruses in two patients and the persistence of predominantly X4-like viruses in the third. Our analyses indicate the reemergence of ancestral sequences from long-lived cells or the residual production of wild-type virus from anatomic sites with limited access to antiretroviral drugs and the preferential infection of cells expressing CXCR4.

Amino Acid Sequence↗
PubMed2002

Evolution of human immunodeficiency virus type 1 populations after resumption of therapy following treatment interruption and shift in resistance genotype.

Conventional genotyping of human immunodeficiency virus type 1 often reveals a shift from a drug-resistant genotype to a wild-type genotype after treatment interruption. A real-time polymerase chain reaction-based technique was used to detect minority resistant populations in 13 patients who showed genotype reversion after interruption of treatment for 3 months. Sixty-two percent of patients in whom the V82A and L90M protease mutations were no longer detectable by conventional genotyping still harbored minority resistant variants, in proportions ranging from 0.1% to 21%. None of the patients with these minority resistant variants who received a protease-inhibitor regimen on resumption of therapy had a response to treatment. However, population sequencing and clonal analysis of plasma samples obtained 1-2 months after resumption of treatment revealed the presence of wild-type virus during the initial decline in plasma virus load, which indicates that minority resistant variants were not rapidly selected.

Amino Acid Sequence↗
PubMed2002

Genetic heterogeneity of the envelope 2 gene and eradication of hepatitis C virus after a second course of interferon-alpha.

The heterogeneity of the envelope 2 (E2) gene of the hepatitis C virus (HCV) was involved in the sensitivity of HCV to interferon-alpha (IFN-alpha). To assess the factors leading to virus eradication by IFN-alpha, patients whose first treatment by IFN-alpha failed and who had virus eradication after a second treatment were studied. These patients were paired with subjects in whom both treatments failed. The phosphorylation homology domain of the E2 gene (E2-PHD) had no sequence variation between the two stages in both groups of patients. Therefore, this region has no clinical predictive value within a specific genotype. The hypervariable region 1 (HVR1) was analyzed by cloning and sequencing 20 clones per sample. Comparison of samples showed that the change in quasispecies induced by the first IFN-alpha therapy could be associated with virus elimination obtained after a second treatment. The greater proportion of nonsynonymous mutations that was noted before the second treatment in responders suggest that pretherapeutic immune response is a major factor determining virus elimination and that the immune status of these patients changed between the first and the second treatment.

Adult↗
PubMed2002

Virological and immunological effects of salvage therapy following treatment interruption and a shift in HIV-1 resistance genotype.

The circulating human immunodeficiency virus type 1 (HIV-1) population of patients in whom many prior therapy regimens have failed often undergo a shift from a drug-resistant virus to a wild-type virus following interruption of treatment. This study analyses the virological and immunological effects of salvage therapy following treatment interruption and a shift from a drug-resistance genotype. Twenty-one HIV-1 infected patients who had genotype reversion by population-based sequencing after 3 months of treatment interruption were given a new salvage regimen consisting of 3-5 drugs selected according to their treatment history. Seven (33%) of 21 patients who had fewer than 200 HIV-1 RNA copies/ml until month 12 were defined as virological responders. Four patients were transient responders and 10 were nonresponders. The virological responders were more frequently CDC group A and had higher CD4 + T lymphocyte counts at the time of treatment resumption. The peripheral blood T CD4 + and T CD8 + lymphocyte populations of the patients declined significantly during treatment interruption. Only virological responders showed significant increases in their CD4 + T lymphocyte count 12 months after treatment resumption and these counts rapidly returned to pre-interruption baseline values in most of these patients. Treatment interruption could be useful for optimising salvage therapy for patients previously given many failing regimens. However, controlled trials are needed to assess the clinical benefit of this strategy.

Adult↗
PubMed2002

Intermittent human immunodeficiency type 1 virus (HIV-1) shedding in semen and efficiency of sperm processing despite high seminal HIV-1 RNA levels.

To study seminal excretion of human immunodeficiency virus type 1 (HIV-1) during 4 years of follow-up in an HIV-1-infected patient, the relationship between high viral excretion and inflammatory status of semen, and the efficiency of sperm processing methods in obtaining spermatozoa with undetectable RNA and proviral DNA levels. Case report. University hospital and research group on human fertility. One HIV-1-infected patient.Paired blood and semen samples were obtained during 4 years of follow-up.CD4 cell count; blood and seminal plasma viral load; and HIV-1 RNA and proviral DNA in different cell fractions obtained during sperm processing, as measured by the density gradient method and the swim-up method; sperm parameters; and polymorphonuclear granulocyte count. Shedding of HIV-1 in semen was intermittent. The highest seminal viral loads were associated with a markedly increased polymorphonuclear granulocyte count, which reflects inflammation of the genital tract. Spermatozoa with undetectable levels of HIV-1 RNA or DNA were obtained regardless of the viral load in semen. In an HIV-1-infected man with intermittent seminal viral excretion, sperm processing was effective in obtaining spermatozoa without detectable HIV-1 genomes.

Adult↗
PubMed2002

Diversity of beta-lactam resistance-conferring amino acid substitutions in penicillin-binding protein 3 of Haemophilus influenzae.

The sequences of the ftsI gene, encoding the transpeptidase domain of penicillin binding protein (PBP) 3A and/or PBP 3B, which are involved in septal peptidoglycan synthesis, were determined for 108 clinical strains of Haemophilus influenzae with reduced susceptibility to beta-lactam antibiotics with or without beta-lactamase production and were compared to those of the ampicillin-susceptible Rd strain and ampicillin-susceptible clinical isolates. The sequences have 18 different mutation patterns and were classified into two groups on the basis of amino acid substitutions deduced from the nucleotide sequences located between bp 960 and 1618 of the ftsI gene. In group I strains (n = 7), His-517 was substituted for Arg-517. In group II strains (n = 101), Lys-526 was substituted for Asn-526. In subgroup IIa (n = 5; H. influenzae ATCC 49247), the only observed substitution was Lys-526 for Asn-526; in subgroup IIb (n = 56), Val-502 was substituted for Ala-502 (n = 13), along with several other substitutions: Asn-350 for Asp-350 (n = 15), Asn-350 for Asp-350 and Glu-490 for Gly-490 (n = 14), and Asn-350 for Asp-350 and Ser-437 for Ala-437 (n = 5). In subgroup IIc (n = 25), Thr-502 was substituted for Ala-502. In subgroup IId, Val-449 was substituted for Ile-449 (n = 15). The MICs of beta-lactam antibiotics for the 108 strains were to 8 to 16 times the MICs for susceptible strains. The strains, isolated from both adults and children, were analyzed for genetic relationship by pulsed-field gel electrophoresis and by determination of ftsI sequence phylogeny. Both analyses revealed the lack of clonality and the heterogeneity of the strains, but some clusters suggest the spread and/or persistence of a limited number of strains of the same pulsotype and pattern of amino acid substitutions. Reduced susceptibility to beta-lactam, brought about by mutations of the ftsI gene, is becoming a frequent phenomenon, affecting both strains that produce beta-lactamase and those that do not. The level of resistance remains low but opens the way to greater resistance in the future.

Adolescent↗