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Biomedical subjects

Gilles Peytavin

Publications and source records attributed to Gilles Peytavin.

At least 19 recordsLinked to original sources
PubMed2007

Hair versus plasma concentrations as indicator of indinavir exposure in HIV-1-infected patients treated with indinavir/ritonavir combination.

Large intra-individual variability in plasma levels may limit the interest of therapeutic drug monitoring based on a single determination. Indinavir concentrations were determined both in plasma and hair samples, and correlated with concomitant plasma HIV-RNA in 43 HIV-infected patients. In multivariate analysis, significant association was found between HIV-RNA below 50 copies/ml and indinavir concentrations in hair but not in plasma, suggesting that hair concentrations gave more extensive information on drug exposure than a single plasma sample.

Antiretroviral Therapy, Highly Active↗
PubMed2007

Efficacy and safety of tenofovir double-dose in treatment-experienced HIV-infected patients: the TENOPLUS study.

Drug resistance is an increasing problem in the treatment of HIV infection. Tenofovir has been shown to inhibit HIV replication even with thymidine-associated resistance mutations (TAMs) if they are limited to two or less. Double-dose of tenofovir disoproxil fumarate (TDF) (600 mg QD) was used to determine weather the drug could be virologically effective in patients harbouring HIV-strains resistant to nucleoside analogues (NRTI). A pilot, open, non-comparative add-on study, where patients failing a current antiretroviral regimen, with at least two TAMs, and naive for tenofovir, were given tenofovir 600 mg once-daily for 4 weeks, in addition to their current failing antiretroviral regimen. The primary end-point was the percentage of patients with plasma viral load (VL) reduction of at least 0.8 log(10) between baseline and week 4 (W4). Ten patients were enrolled. At baseline, the median viral load was 3.66 log(10) copies/ml (range 3.13-4.03) and the median CD4 cell count was 407/mm(3) (range 136-1102). The percentage of patients with reduction the viral load > or =0.8 log(10) was 40% at W4. After 4 weeks of treatment with tenofovir 600 mg, the median decrease in the viral load was -0.61 log(10) (range -0.05; -0.88) and the median gain of CD4 was +109/mm(3). Despite a twofold increase tenofovir plasma concentrations, no serious drug-related adverse event were recorded except for one patient experiencing an de Fanconi syndrome at week 2. This add-on pilot study supports the concept of double dose tenofovir to virologically overcome the decreased sensitivity of NRTI-resistant viruses. However, the safety of this regimen needs to be considered carefully.

Adenine↗
PubMed2006

Impact of nevirapine (NVP) plasma concentration on selection of resistant virus in mothers who received single-dose NVP to prevent perinatal human immunodeficiency virus type 1 transmission and persistence of resistant virus in their infected children.

Nonnucleoside reverse transcriptase inhibitor resistance following the use of single-dose nevirapine (sdNVP) for the prevention of mother-to-child transmission (PMTCT) remains a concern. In the ANRS-1201/1202 Ditrame study, conducted in Abidjan, Côte d'Ivoire, a short-course regimen of zidovudine was associated with sdNVP for PMTCT. In this study, we estimate the frequency of NVP resistance and its relationship with NVP concentration in mothers. Genotypic resistance analysis was performed on mothers' plasma samples at week 4 postpartum (PP) and on human immunodeficiency virus (HIV) DNA in peripheral blood mononuclear cells (PBMC) when an NVP resistance mutation was detected. The same tests were performed for the infected children at week 4, month 3, and month 12. Mothers' NVP plasma concentrations were measured at 48 h PP. Twenty-one (33%) of the 63 women selected had NVP-resistant (NVP-R) virus at week 4 PP. The median plasma NVP concentration was 598 ng/ml for the mothers without NVP-R virus compared to 851 ng/ml for the mothers harboring NVP-R virus (P = 0.014). NVP-R mutations were detected in the HIV DNA of 15/20 women. Plasma NVP-R mutations were detectable in 6 of 26 infected children at week 4. All 6 children had detectable NVP-R mutations in HIV DNA of PBMC. Blood samples taken at month 3 (1 child) and month 12 (1 child) revealed the persistence of NVP-R mutations in plasma and cells. Emergence of NVP-R virus in mothers is strongly correlated with a high level of plasma NVP concentration, owing to a prolonged postpartum period of viral replication under NVP selective pressure. The follow-up of the cohort demonstrates the prolonged archive of resistant virus.

Adult↗
PubMed2006

Presence of numerous stop codons in HIV-1 reverse transcriptase proviral DNA sequences from patients with virological response to HAART.

The impact of proviral DNA reverse transcriptase mutations on virological failure was evaluated in 50 HIV-1 HAART-treated patients switching from a protease inhibitor to a non-nucleoside reverse transcriptase inhibitor. Neither the M184I/V mutation detected in 12 patients nor stop codons at tryptophane positions detected in 13 patients were associated with virological failure. Stop codons appeared under successful therapy in 12 patients. Their presence should be assessed in studies with higher statistical power.

Antiretroviral Therapy, Highly Active↗
PubMed2006

Placental transfer of lopinavir/ritonavir in the ex vivo human cotyledon perfusion model.

OBJECTIVE: This study was done to determine the placental transfer of the human immunodeficiency virus protease inhibitor lopinavir with ritonavir. STUDY DESIGN: Twenty-five human cotyledons that were obtained after uneventful pregnancies and deliveries were perfused in an open double circuit with lopinavir (1099-10,606 microg/L) and ritonavir (254-1147 microg/L) at various albumin concentrations (2, 10, and 40 g/L). RESULTS: The fetal transfer rate of lopinavir, when combined with ritonavir, was 23.6% +/- 6.9% at an albumin concentration of 2 g/L. The fetal transfer rate decreased to 20.7% +/- 10% at an albumin concentration of 10 g/L and to 3.3% +/- 0.5% at an albumin concentration of 40 g/L. CONCLUSION: The placental transfer of lopinavir, a highly protein-bound molecule, was compatible with passive diffusion of the unbound fraction. Even at physiologic maternal albumin concentrations, the amount of drug transferred into the fetal compartment was well above the 50% inhibitory concentration.

Albumins↗
PubMed2006

CD4 cell recovery in treated HIV-2-infected adults is lower than expected: results from the French ANRS CO5 HIV-2 cohort.

In 61 antiretroviral-naive HIV-2-infected patients starting triple therapy at a median CD4 cell count of 136 cells/microl, the median increase was 41 cells/microl at month 12, which was no different among those on protease inhibitors or triple nucleoside analogues. Despite virological response, as the median plasma load was under the detectable threshold from month 3, CD4 cell recovery remained poor in treated HIV-2 infection. Our results raise the question of the optimal regimen to recommend in HIV-2-infected patients.

AIDS-Related Opportunistic Infections↗
PubMed2006

Low risk of nevirapine resistance mutations in the prevention of mother-to-child transmission of HIV-1: Agence Nationale de Recherches sur le SIDA Ditrame Plus, Abidjan, Cote d'Ivoire.

The frequency of resistance mutations was estimated in the cohort of Agence Nationale de Recherches sur le SIDA Ditrame Plus, a study that evaluated the combination of short-course zidovudine (ZDV) plus lamivudine (3TC) and single-dose nevirapine (SD-NVP) followed by 3 days of postpartum ZDV plus 3TC for the prevention of mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1). The frequency with which resistance mutations were detected in mothers at week 4 postpartum was 1.14% (95% confidence interval [CI], 0.03%-6.17%) for NVP and 8.33% (95% CI, 3.66%-15.76%) for 3TC. In multivariate analysis, 3TC resistance was associated with a longer duration of ZDV plus 3TC prepartum prophylaxis (P=.009). This regimen, which is feasible in resource-limited settings, prevents most peripartum HIV-1 transmission and minimizes the development of NVP resistance.

Cote d'Ivoire↗
PubMed2006

Role of HIV-1 minority populations on resistance mutational pattern evolution and susceptibility to protease inhibitors.

We investigated, in the protease and GAG cleavage sites, the role of minority populations on the evolution of resistance to a subsequent boosted protease inhibitor (PI) regimen after a first failure to nelfinavir. Two pathways were observed: the addition of mutations to a currently dominant genotype when minority variants are not shown, or the emergence of a minority variant as a dominant strain. These minor species, not detected by standard genotype, may influence PI susceptibility.

Drug Resistance, Multiple, Viral↗
PubMed2006

Clinical validation of atazanavir/ritonavir genotypic resistance score in protease inhibitor-experienced patients.

OBJECTIVE: To develop a clinically relevant genotypic resistance score for boosted atazanavir (ATV) in protease inhibitor-experienced patients. METHODS: At baseline, 62 patients with HIV-1 RNA > 1000 copies/ml switched to a boosted ATV regimen (300 mg ATV, 100 mg ritonavir once daily); two were excluded from analysis at 3 months as they had undetectable plasma ATV. The impact of baseline protease mutations on virological response (> 1 log10 copies/ml plasma HIV RNA decrease) at 3 months was analysed using Fisher's exact test. Mutations with prevalence > 8% and P < 0.2 were retained. Cochran-Armitage's test was used to select the combination of mutations most strongly associated with reduced virological response. Robustness of the score was investigated using bootstrap resampling. RESULTS: At 3 months, 82% of patients had a virological response and 56% had RNA < 50 copies/ml. Eight mutations (10F/I/V, 16E, 33I/F/V, 46I/L, 60E, 84V, 85V and 90M) were retained in the genotypic resistance score (P = 8.67 x 10) and virological response was observed in 100%, 100%, 80%, 42%, and 0% of patients with none, one, two, three, and four/five mutations, respectively. There was 100% response in patients with a score < 2 independently of the number of active drugs, whereas in patients with a score > or = 3 there was a gradient of response according to the number of active drugs (0%, 29% and 60% with none, one and two/three active drugs, respectively). CONCLUSIONS: The occurrence of three of the eight mutations in the ATV/RTV genotypic resistance score predicted a clinically identifiable reduced response in patients.

Antiretroviral Therapy, Highly Active↗
PubMed2006

Cyclosporine monitoring in renal transplant recipients with induction therapy: C2 levels in patients monitored on C0.

The aim of this retrospective study was to compare the cyclosporine C(2) blood levels in renal transplant recipients with induction therapy, monitored on C(0) levels during the early and long-term post-transplantation periods in different French transplantation centres, to the target values recommended by the International Consensus on Neoral and used in the Mo2art study. A retrospective study was conducted by the therapeutic drug monitoring (TDM) committee of the French Pharmacological Society. Cyclosporine C(0) and C(2) concentrations from 168 renal transplant recipients were collected at different post-transplantation periods by six TDM laboratories of transplantation centres from April 2001 to April 2002. Cyclosporine blood levels were determined by fluorescence polarization immunoassay (mFPIA, AxSYM, Abbott) or enzyme immunoassay (EMIT, Dade Behring). Most patients had C(0) values in the recommended target ranges, with C(2) levels below the targets used in the Mo2art study or proposed by the International Consensus Conference, both during the early and long-term post-transplantation periods. Sixty-eight per cent of patients had C(2) below 1,500 microg/L +/- 20% in the first 2 months post-transplantation and 55% had C(2) below 800 microg/L +/- 20% in the late post-transplantation period (>1 year). Cyclosporine dose should be increased by 40% on average during the first week post-transplantation period and by 50% during the maintenance period to achieve the C(2) targets. In France, most renal transplant recipients receiving induction agents monitored on C(0) had C(2) levels below the targets recommended by the International Consensus Conference. In clinical practice, the optimal therapeutic windows for CsA monitoring based on C(2) needs to be more precisely defined, both during the early and long-term post-transplantation periods in renal transplant recipients receiving induction agents.

Antibodies, Monoclonal↗
PubMed2005

Absence of association between MDR1 genetic polymorphisms, indinavir pharmacokinetics and response to highly active antiretroviral therapy.

OBJECTIVE: The relationship between MDR1 single nucleotide polymorphisms (SNP) and the pharmacokinetic or pharmacodynamic responses to protease inhibitors has been recently challenged. AIM: The objective of the present study was to determine whether MDR1 genetic polymorphisms in exons 21 and 26 (G2677T/A and C3435T) are in association with indinavir (IDV) plasma concentrations and/or therapeutic response to highly active antiretroviral therapy (HAART) in HIV-infected patients treated with unboosted IDV containing regimens. METHODS: MDR1 genotyping was performed in a population of 139 HIV-1-positive patients followed during 72 weeks, as part of the previous study called ANRS 081 'Trianon'. The primary study was a randomized trial comparing over 72 weeks the efficacy of two antiretroviral drug combinations in a population of adult HIV-1-infected patients: group 1, [lamivudine (3TC) - stavudine (d4T) - IDV (800 mg three times daily)] and group 2, [Nevirapine (NVP) - d4T - IDV (1000 mg three times daily)]. RESULTS: MDR1 SNPs analyzed separately or combined into haplotypes did not show any significant association with IDV pharmacokinetics nor response to HAART. Mean modelled IDV peak and trough concentrations, as well as clearance modelled from pharmacokinetic model, after 8 weeks of therapy were not significantly different between patients carrying the wild-type haplotype GG-CC (at position 2677 and 3435 respectively) and others. CONCLUSIONS: Our results do not support an association between MDR1 genetic polymorphisms and modelled IDV clearance or clinical response to HAART.

Adult↗
PubMed2005

No benefit of a structured treatment interruption based on genotypic resistance in heavily pretreated HIV-infected patients.

OBJECTIVE: To evaluate the potential benefits of a tailored antiretroviral treatment interruption with duration based on the observed reversion of resistance mutations. METHODS: In this open single-arm pilot study, 23 patients with multiple treatment failure interrupted therapy and underwent longitudinal genotypic resistance testing. Salvage gigatherapy was started when resistance mutations to at least two antiretroviral drug classes reverted. The primary endpoint was a fall in viral load by > 1 log10 copies/ml after 12 weeks of salvage therapy. RESULTS: Baseline median viral load was 5.14 log copies/ml and CD4 cell count 43 x 10 cells/l. Genotypic resistance testing showed a median of six, two and nine resistance mutations to nucleoside analogue reverse transcriptase inhibitors, non-nucleoside analogue reverse transcriptase inhibitors and protease inhibitors, respectively; viral strains were susceptible to no more than one drug in 17/23 patients. The median duration of treatment interruption was 24 weeks (range, 12-37), leading to median changes from baseline of + 0.54 log10 copies/ml and -30 x 10(6) cells/l. At the end of treatment interruption, plasma HIV was susceptible to at least three drugs in 16/23 patients. After 12 weeks of salvage multitherapy, only one patient had a decrease in viral load > 1 log copies/ml. All baseline resistance mutations recurred after treatment resumption. AIDS-defining events occurred in two-thirds of patients during the study period. CONCLUSION: In HIV-infected patients with multiple failures and no therapeutic options at baseline, significant reversion of resistance mutations after prolonged treatment interruption failed to restore antiviral efficacy of a salvage regimen and was clinically deleterious.

Anti-HIV Agents↗
PubMed2005

HIV-1 intermittent viraemia in patients treated by non-nucleoside reverse transcriptase inhibitor-based regimen.

BACKGROUND: It has been demonstrated that, in patients treated by protease-inhibitor-based regimen, intermittent viraemia occurred frequently and was associated with higher concentrations of residual replication but not with virological failure. Risk factors associated with intermittent viraemia and its impact in patients treated by non-nucleoside-reverse-transcriptase-inhibitor-based (NNRTI) regimen need to be evaluated. METHODS: We analyzed the occurrence of blips (one HIV-1 RNA > 50 copies/ml with a subsequent value < 50 copies/ml), the level of these blips (between 3 and 50 copies/ml) and their effect on CD4 cell count and the occurrence of virological failure in 43 patients with stable suppression of HIV-1 plasma viraemia (< 50 copies/ml) under NNRTI-based therapy. RESULTS: Eight out of 43 patients had one episode of blips during the follow-up (median = 350 copies/ml). Comparing patients with and without blips, the median level of HIV-1 RNA at baseline was 7.5 versus 3 copies/ml (P = 0.008), respectively. Patients with blips had a significantly lower CD4 cell count after 12 and 18 months than the others. Plasma concentrations of NNRTI before, during, and after the blips were adequate. In addition, the occurrence of blips was not associated with virological failure. CONCLUSION: These results suggest that blips may reflect ongoing viraemia of below 50 copies/ml and can impair the CD4 cell count recovery under an NNRTI regimen. The impairment of CD4 cell count recovery seems to be affected more by the occurrence of blips than by the level of viraemia (< 50 copies/ml) itself. Nevertheless, despite a tight genetic barrier for resistance with NNRTI drugs, no virologic failure occurred during the follow-up.

Adult↗
PubMed2005

Low trough plasma concentrations of nevirapine associated with virologic rebounds in HIV-infected patients who switched from protease inhibitors.

BACKGROUND: The substitution of a nonnucleoside reverse-transcriptase inhibitor (NNRTI) for protease inhibitors (PIs) has demonstrated its suitability to maintain virologic response. However, the switch from PIs to an NNRTI could fail for a number of reasons, including NNRTI-associated toxicity and emergence of NNRTI-resistant variants. OBJECTIVE: To describe the virologic failures among 74 HIV-infected patients who switched from PIs to nevirapine. METHODS: Virologic failure was defined as any rebound of the plasma HIV-RNA (pVL) levels >1000 copies/mL on one occasion or 2 consecutive intermittent viremia episodes defined as increases of the pVL >20 copies/mL but <1000 copies/mL. Virologic failures were investigated retrospectively by determining nevirapine trough concentrations and performing genotypic resistance analysis. RESULTS: The mean nevirapine concentration was significantly lower in patients with virologic failure in comparison with patients with virologic response (2572 +/- 1642 vs 4550 +/- 2084 ng/mL, respectively; p = 0.003). In multivariate analysis, the mean duration of undetectable pVL before the switch and the mean plasma concentration of nevirapine were significantly associated with virologic success with relative rates of 1.39 (95% CI 1.10 to 1.76, p = 0.006) and 2.7 (95% CI 1.37 to 5.41, p = 0.01), respectively. In patients with pVL >1000 copies/mL, nevirapine mutations and nucleoside reverse-transcriptase inhibitor mutations were found in 80% of the cases. CONCLUSIONS: The risk of virologic failure after the switch from PI to nevirapine is higher in cases of inadequate nevirapine plasma concentrations. Our data support prospective monitoring of nevirapine plasma concentrations to detect low concentrations prior to the emergence of resistance mutations.

Adult↗
PubMed2005

Virological and pharmacological factors associated with virological response to salvage therapy after an 8-week of treatment interruption in a context of very advanced HIV disease (GigHAART ANRS 097).

Both highly potent antiretroviral drug rescue multi therapy and treatment interruption (TI) have been suggested to be effective in HIV-1 infected-patients with multiple treatment failure. GigHAART-ANRS 097 was the only randomized trial during which an 8-week TI was beneficial in heavily pre-treated patients with multi-drug resistant virus on resuming a multiple-drug salvage regimen. The aim of this study was to analyze virological and pharmacological factors associated with a virological response. Clonal resistance analysis showed that although the viral population was highly mutated and nearly monoclonal at baseline, the 8-week interruption therapy allowed the re-emergence of more susceptible quasispecies to the subsequent salvage therapy, which were not detected by classical genotypic resistance testing. The fact that not every viral clone harbored all resistance viral mutations could explain a part of the virological response to a six to eight drug regimen for patients enrolled in the TI group. This phenomenon was associated with a transient virological response after the use of a GigHAART therapy, but was followed by the re-emergence of baseline resistance pattern and acquisition of additional mutations in patients failing this strategy. A combined factor of protease inhibitor (PI) concentration and genotypic score, expressed as a genotypic inhibitory quotient (GIQ), was used to assess the importance of genotypic resistance and plasma drug levels in the rate of response to multiple PI combination. The GIQ of each PI used in the regimen was not associated with virological success. However, the sum of PI GIQs was predictive of a virological response. These results suggest that pharmacological enhancement might overcome viral resistance and that there is some benefit in adding the activity of several boosted-PIs to improve the response to a salvage regimen.

Anti-HIV Agents↗
PubMed2005

Genotypic resistance analyses in nucleoside-pretreated patients failing an indinavir containing regimen: results from a randomized comparative trial: (Novavir ANRS 073).

BACKGROUND: Different studies have shown that most patients failing a first-line treatment containing a protease-inhibitor (PI) had low PI plasma levels and no PI-related resistance mutations. NOVAVIR was a randomized trial comparing stavudine/lamivudine/indinavir (d4T/3TC/IDV) and zidovudine/lamivudine/indinavir (AZT/3TC/IDV) in patients pretreated with AZT, didanosine (ddI) and/or zalcitabine (ddC) but naive for PIs. OBJECTIVE: To study the mechanisms of virological failure in NOVAVIR trial through analyses of genotypic resistance profiles of reverse transcriptase (RT) and protease (PR), and plasma IDV concentrations at time to failure. METHODS: Plasma HIV-RNA PR and RT sequences were determined in 27 failing patients (d4T/3TC/IDV n=11; AZT/3TC/IDV n=16) at baseline and at time to failure. IDV plasma measurements were performed in both samples. RESULTS: At baseline, 20 out of the 27 patients had at least two thymidine analogs associated mutations. At time to failure, mutation M184V in the RT gene was present in 22 out of the 27 failing patients. Thirteen out of the 27 (48%) patients had acquisition of PI mutations compared to baseline sequence. Of the 26 patients with adherence data, 13 (50%) subjects were classified as having difficulty in adherence. The proportion of patients with low adherence was higher in the subgroup of patients failing without acquisition of new PI mutations. CONCLUSIONS: In patients experienced with NRTIs, failure to PI-containing regimen may occur in spite of appropriate adherence to therapy and is associated with emergence of PI mutations in half of the cases. These results suggest that, although PIs have a high genetic barrier, sub-optimal activity of associated drugs may favor the selection of PI resistance mutations.

Amino Acid Substitution↗
PubMed2005

Selection of a rare resistance profile in an HIV-1-infected patient exhibiting a failure to an antiretroviral regimen including tenofovir DF.

The human immunodeficiency virus type 1 (HIV-1) resistance profile, K65R, K70E and M184V, on reverse transcriptase gene was associated with the virologic rebound consecutively to the switch of lopinavir/r to tenofovir DF in a stable regimen with nucleoside backbone of abacavir, lamivudine and didanosine. The high selective pressure on the same resistance pathway was probably associated with the loss of antiviral potency, even in well-controlled patient.

Adenine↗