Switching from abacavir/lamivudine plus nevirapine to abacavir/lamivudine/dolutegravir in virologically controlled HIV-infected adults (SWAD study).

INTRODUCTION: The metabolic pathways of dolutegravir suggest a potential predator effect of nevirapine on dolutegravir pharmacokinetics and switching from a nevirapine- to a dolutegravir-containing regimen could lead to a lower and suboptimal exposure to dolutegravir several weeks after the switch in case of persistent inducer effect. PATIENTS AND METHOD: Prospective, pilot, single-arm, open-label, non-comparative, bicentric study to evaluate the pharmacokinetics, virologic outcomes, safety, and patient satisfaction of switching from abacavir/lamivudine and nevirapine to a single tablet of abacavir/lamivudine/dolutegravir. The primary endpoint was the maintenance of virologic suppression (HIV-1 RNA<50 copies/mL) at week 12. Secondary endpoints were virologic suppression at week 48, safety and tolerability, patient satisfaction, and pharmacokinetic interaction between nevirapine and dolutegravir. Fifty-three adults on stable abacavir/lamivudine and nevirapine regimen for a median duration of 6years and virologically suppressed for 9.6years were included. RESULTS: Dolutegravir reached steady state by week 4/week 12 when expected by day 5/day 10. All subjects maintained plasma HIV-RNA˂50 copies/mL at week 12 and week 48. Abacavir/lamivudine/dolutegravir was well-tolerated, with two cases of serious adverse events deemed unrelated to study drugs (coronary syndrome in both cases), and one discontinuation for renal impairment at week 24 with a slight improvement after dolutegravir discontinuation. Level of treatment satisfaction remained high after the switch. CONCLUSION: The transient predator effect of nevirapine on dolutegravir had no clinical consequences after switching from nevirapine to dolutegravir, neither on safety nor maintenance of virologic suppression. It also had no consequences on patient satisfaction.

Interest of proviral HIV-1 DNA genotypic resistance testing in virologically suppressed patients candidate for maintenance therapy.

Switch of antiretroviral therapy in virologically suppressed HIV-infected patients is frequent, to prevent toxicities, for simplification or convenience reasons. Pretherapeutic genotypic resistance testing on RNA can be lacking in some patients, which could enhance the risk of virologic failure, if resistance-associated mutations of the new regimen are not taken into account. Proviral DNA resistance testing in 69 virologically suppressed patients on antiretroviral treatment with no history of virological failure were pair-wised compared with pre-ART plasma RNA resistance testing. The median time between plasma (RNA testing) and whole blood (proviral DNA testing) was 47 months (IQR 29-63). A stop codon was evidenced in 23% (16/69) of proviral DNA sequences; these strains were considered as defective, non-replicative, and not taken into consideration. Within the non defective strains, concordance rate between plasma RNA and non-defective proviral DNA was high both on protease (194/220 concordant resistance-associated mutations=88%) and reverse transcriptase (28/37 concordant resistance-associated mutations=76%) genes. This study supports that proviral DNA testing might be an informative tool before switching antiretrovirals in virologically suppressed patients with no history of virological failure, but the interpretation should be restricted to non-defective viruses.

Identification of a duplicated V3 domain in NS5A associated with cirrhosis and hepatocellular carcinoma in HCV-1b patients.

BACKGROUND: The NS5A protein of the hepatitis C virus has been shown to be involved in the development of hepatocellular carcinoma. OBJECTIVES: In a French multicenter study, we investigated the clinical and epidemiological features of a new HCV genotype 1b strain bearing a wide insertion into the V3 domain. STUDY DESIGN: We studied NS5A gene sequences in 821 French patients infected with genotype 1b HCV. RESULTS: We identified an uncharacterized V3 insertion without ORF disruption in 3.05% of the HCV sequences. The insertion comprised 31 amino-acids for the majority of patients; 3 patients had 27 amino-acids insertions and 1 had a 12 amino-acids insertion. Sequence identity between the 31 amino-acids insertions and the V3 domain ranged from 48 to 96% with E-values above 4e(-5), thus illustrating sequence homology and a partial gene duplication event that to our knowledge has never been reported in HCV. Moreover we showed the presence of the duplication at the time of infection and its persistence at least during 12 years in the entire quasispecies. No association was found with extrahepatic diseases. Conversely, patients with cirrhosis were two times more likely to have HCV with this genetic characteristic (p=0.04). Moreover, its prevalence increased with liver disease severity (from 3.0% in patients without cirrhosis to 9.4% in patients with both cirrhosis and HCC, p for trend=0.045). CONCLUSIONS: We identified a duplicated V3 domain in the HCV-1b NS5A protein for the first time. The duplication may be associated with unfavorable evolution of liver disease including a possible involvement in liver carcinogenesis.

Switching from tenofovir/emtricitabine and nevirapine to a tenofovir/emtricitabine/rilpivirine single-tablet regimen in virologically suppressed, HIV-1-infected subjects.

OBJECTIVES: Nevirapine is an inducer of hepatic metabolism. After discontinuation, nevirapine has an inductive effect on cytochrome P450 3A4, which persists for a few weeks and which, after switching to rilpivirine, may reduce rilpivirine exposures and have a negative clinical impact. This study evaluates the virological outcome, pharmacokinetics and safety of switching virologically suppressed, HIV-1-infected patients from nevirapine to rilpivirine. PATIENTS AND METHODS: This 24 week open-label single-centre study included HIV-1-infected adults with HIV-1 RNA <50 copies/mL for >6 months on tenofovir/emtricitabine and nevirapine, who were willing to simplify their regimen to tenofovir/emtricitabine/rilpivirine. Virological suppression, safety and nevirapine and rilpivirine pharmacokinetics were assessed. RESULTS: At weeks 12 and 24, all 32 subjects remained virologically suppressed. One subject discontinued at week 1 for rilpivirine-associated insomnia and two patients chose to resume tenofovir/emtricitabine and nevirapine after week 12 because of rilpivirine-associated food constraint. There was no grade 3/4 laboratory abnormality. Rilpivirine trough concentrations were above the mean trough concentrations observed in Phase 3 studies by 1 week post-switch. Twenty-seven out of 32 patients had no measurable levels of nevirapine by 2 weeks post-switch. The meal accompanying tenofovir/emtricitabine/rilpivirine intake satisfied food requirements in 81% of cases. Overall general satisfaction was improved in 90% of the subjects despite food constraints. CONCLUSION: Nevirapine has a short and limited inductive effect on rilpivirine metabolism, which is not clinically significant. Tenofovir/emtricitabine/rilpivirine is an efficacious and safe option for virologically suppressed HIV-infected patients on nevirapine wishing to simplify their regimen.

Constant mitochondrial DNA levels in blood leukocytes of patients enrolled in a NRTI-free therapeutic trial (BIKS-2 study).

OBJECTIVES: Determine if a nucleoside reverse transcriptase inhibitors (NRTI)-free regimen affected mitochondrial DNA (mtDNA) levels in peripheral blood mononuclear cells (PBMCs) of patients enrolled in BIKS-2 trial. METHODS: Antiretroviral (ARV) naïve (N=13) and NRTI experienced (N=7) patients, received lopinavir/ritonavir, a boosted protease inhibitor, and efavirenz, a non-nucleoside reverse transcriptase inhibitor from Month (M) 0 to M12 (1-year BIKS trial) and from M12 to M36 (2-year BIKS-2 trial). MtDNA was quantified at M12, M24 and M36 via real-time PCR assay. RESULTS: From M12 to M36, the 20 patients have maintained undetectable plasma HIV-1 RNA, gained CD4 cells and had no side effects attributable to these drugs. Median mtDNA contents were constant: 478.6 at M12, 478.6 at M24 and 324.4 copies/cell at M36 (pM12-M36=0.5). Because M0 data is missing, these results were compared to those of two groups of age matched individuals: healthy donors and HIV-infected patients before and after exposure to NRTIs. Healthy donors have higher contents (871), followed by patients never treated (602), than by BIKS patients where 7 had toxic NRTIs (478.6) and at last by patients exposed for six months to the most toxic combination (ddI-d4T) (85 copies/cell). CONCLUSION: Lopinavir/ritonavir+efavirenz did not affect mtDNA contents in PBMCs.

A multiparametric flow cytometry method for detection of modifications of antigen expression in polymorphonuclear cells infected by human cytomegalovirus.

Human cytomegalovirus (CMV) has been shown to alter adhesion molecule expression on permissive cells such as endothelial cells. The aim of the present study was to investigate expression of receptors for these molecules on CMV infected polymorphonuclear leukocytes (PMNLs). CMV-induced variations on cellular integrin expression were examined using an in vitro system to obtain infected PMNLs. A triparametric flow cytometry approach was developed, which allows combined detection, in a single experiment, of both viral intranuclear antigen in the selected PMNLs and cellular CD11/CD18 expression. Comparison of infected PMNLs with uninfected cells showed a decrease of up to 50% in the expression of CD11b, CD11c, and CD18. This study thus demonstrates that the presence of CMV in PMNLs, which characterizes active infection, modifies the expression of integrins and may thus affect cell-to-cell interactions and immune functions.

A prospective longitudinal study of BK virus infection in 104 renal transplant recipients.

BK virus (BKV) infection during the first year after renal transplantation was studied prospectively in 104 unselected consecutive patients. Viral DNA in urine (DNAuria) and plasma (DNAemia) samples was detected and quantified by real-time PCR. The noncoding control region (NCCR) of BKV isolates was sequenced. DNAuria and DNAemia occurred in 57% and 29% of patients, respectively. Three groups were defined, uninfected patients (group 1, n=45), patients with DNAuria (group 2, n=29) and patients with positive DNAemia (group 3, n=30). Active infection started within the first 3 months in 80% of patients. Cold ischemia duration over 24 h and the administration of tacrolimus were identified as significant risks factors for DNAuria, whereas it remains more frequently negative in patients receiving cyclosporine A. The risk for positive DNAemia was higher in patients with DNAuria (notably for viral load (VL)>4 log/mL) or treated with tacrolimus. No relationship was found with genetic variability in the NCCR sequence. Our data highlight the high frequency of active BKV infection after renal transplantation. Although high VL was detected in some patients, none developed a BKV nephropathy. A prospective follow-up of the whole population during the first year post renal transplantation is thus not useful to predict BKV disease.

A one-step RT-PCR and a flow cytometry method as two specific tools for direct evaluation of human herpesvirus-6 replication.

In order to confirm the occurrence of active Human herpesvirus-6 (HHV-6) infection, two optimal procedures were developed to detect directly replicating virus. MT4 cells and peripheral blood mononuclear cells (PBMCs) infected with two different strains (HST and a patient strain GUI) were used. The first method consisted of a one-step reverse transcription PCR amplifying a part of the late alternatively spliced U100 gene which encode the gp 82-105 viral glycoprotein. Two extraction methods and two RT-PCR kits were evaluated, leading to the selection of TaKaRa mRNA selective PCR kit. The second procedure consisted in a flow cytometry method to analyze the expression of two late viral HHV-6 antigens using 7C7 and 10G6 monoclonal antibodies. Four fixation permeabilization procedures were compared and the preparation of cells with paraformaldehyde (PFA) 4% was found to be optimal. Evaluation of these methods was then realized during a sequential culture of HST strain on MT4 cells. This kinetic study confirmed that Mabs recognized late antigens and demonstrate that the U100 gene splicing starts at a late stage of multiplication whereas unspliced forms are detectable earlier in the cycle.