Antiviral Therapy

doi: 10.1177/135965350400900402pmid: N/A

Hill, Andrew M; Telenti, Amalio

doi: 10.1177/135965350400900401pmid: N/A

Bruno, Raffaele; Sacchi, Paolo; Ciappina, Valentina; Zochetti, Cristina; Patruno, Savino; Maiocchi, Laura; Filice, Gaetano

doi: 10.1177/135965350400900405pmid: N/A

The two available pegylated interferon formulations, peginterferon alpha-2a and peginterferon alpha-2b, have different pharmacokinetic profiles; as a result they may have differing abilities to suppress the hepatitis C virus. A recently reported study by Formann and colleagues assessing early viral kinetics among 20 patients receiving peginterferon alpha-2b either once or twice weekly suggests that once-weekly administration of peginterferon alpha-2b is not sufficient for continuous exposure to interferon over 160 h. Twice-weekly administration is recommended to avoid increases in viral load as interferon levels decline prior to the end of the one-week dosing period. The objective of this study was to compare viral dynamics and pharmacokinetics between peginterferon alpha-2a and peginterferon alpha-2b in interferon-naive chronic hepatitis C patients. Patients were randomized to receive peginterferon alpha-2a 180 μg (n=10) or peginterferon alpha-2b 1.0 μg/kg (n=12) once weekly. Serum peginterferon concentrations were measured at baseline, 24, 48, 120 and 168 h. Hepatitis C virus (HCV) RNA was measured at baseline, 24, 48, 120 and 168 h during week 1 and then at 4 and 12 weeks. Peginterferon alpha-2b achieved maximal serum levels at 24 h, and then decreased rapidly. Of the 12 patients who received peginterferon alpha-2b, no drug was detectable in seven (58%) patients at 120 h and in 11 (92%) at 168 h. In contrast, peginterferon alpha-2a concentrations increased continuously over time, reaching maximal serum levels from 48 to 168 h. Drug was detectable in all 10 patients at 168 h. At weeks 1 and 4 no significant difference was observed in mean HCV RNA between the groups. However, at week 12, mean HCV RNA was significantly lower in the peginterferon alpha-2a group versus the peginterferon alpha-2b group (2.8126 vs 3.8726; P<0.01). The differences in mean HCV RNA values at 12 weeks may be related to the different absorption and distribution profiles of the two drugs. In conclusion, once-weekly administration of peginterferon alpha-2b (1.0 μg/kg/wk) may be insufficient for continuous interferon exposure; twice-weekly administration may help avoid increases in viral replication as interferon levels decline. Larger-scale studies assessing both viral kinetics and sustained virological responses are needed to confirm these observations.

Hasan, Fuad; Al-Khaldi, Jameela; Asker, Haifa; Al-Ajmi, Misfer; Owayed, Salem; Varghese, Rosh; Siddique, Iqbal; Al-Nakib, Basil

doi: 10.1177/135965350400900409pmid: N/A

Background A significant proportion of hepatitis C patients treated with unmodified interferon plus ribavirin fail to respond. The optimal therapy for these patients has not been established yet. The objective of this study was to assess the efficacy and safety of peginterferon plus ribavirin with or without amantidine in such patients. Methods In this open-label, prospective controlled trial, a total of 63 patients were randomly divided into groups A and B with a ratio of 1:2. Group A (21 patients) received weekly peginterferon alpha-2b, 1.5 μg/kg concomitantly with ribavirin 1000–1200 mg per day. Group B (42 patients) received peginterferon and ribavirin as in group A, plus amantidine 200 mg per day. Results At the completion of treatment, serum levels of hepatitis C virus RNA were undetectable in 14% and 12% of patients in groups A and B, respectively (P=NS). Hepatitis C virus RNA remained undetectable 24 weeks after the end of treatment in one patient (5%) in group A and three patients (7%) in group B (P=NS). Sustained viral clearance was associated with sustained normalization of serum alanine aminotransferase level. Both drug regimens had similar side effect profiles. Conclusion Peginterferon plus ribavirin therapy with or without amantidine is associated with a low sustained virological response in patients who failed interferon and ribavirin combination therapy.

Soriano, Vincent; Núñez, Marina; Camino, Nuria; Maida, Ivana; Barreiro, Pablo; Romero, Miriam; Martín-Carbonero, Luz; Garcia-Samaniego, Javier; González-Lahoz, Juan

doi: 10.1177/135965350400900411pmid: N/A

Hepatitis C virus (HCV)-RNA clearance seems to occur more slowly in HIV/HCV-coinfected patients than in HCV-monoinfected subjects treated with pegylated interferon alpha (peg-IFN) plus ribavirin (RBV). As a consequence, concern has arisen over the feasibility of following the treatment rules applied to HIV-negative patients with chronic hepatitis C. A total of 89 HIV/HCV-coinfected patients who had fully completed a course of peg-IFN plus RBV were analysed. Of these, 29 (32.6%) reached sustained virological response (SVR). Reductions >2 logs in plasma HCV-RNA occurred in 52 (58%) patients at week 12 of treatment (early virological response; EVR). None of patients who showed HCV-RNA drops <2 logs at week 12 reached SVR (negative predictive value: 100%). The positive predictive value of EVR was 56%. On the other hand, relapses occurred in 19 (39.6%) out of the 48 patients who had negative HCV-RNA at the end of treatment, and there were no differences noted when comparing patients with HCV genotypes 2/3 and 1/4. In summary, the quantitative assessment of plasma HCV-RNA at week 12 predicts the chance of SVR using peg-IFN plus RBV in HIV-positive patients with chronic hepatitis C, as it does in HIV-negative individuals. Thus, discontinuation of anti-HCV therapy, which is associated with frequent side effects, might be warranted in HIV/HCV-coinfected patients showing HCV-RNA reductions <2 logs at week 12 of treatment. On the other hand, relapses in virological responders were unexpectedly high in HIV/HCV-coinfected patients when treatment was provided following the rules applied to HIV-negative subjects. This is particularly relevant for HCV genotypes 2/3, which only rarely relapse in HIV-negative patients. Therefore, extending therapy (for 12 months in HCV genotypes 2/3 and perhaps for 18 months in HCV genotypes 1/4) might be warranted in HIV/HCV-coinfected patients showing EVR.

Jorajuria, Sylvie; Dereuddre-Bosquet, Nathalie; Becher, François; Martin, Solenne; Porcheray, Fabrice; Garrigues, Alexia; Mabondzo, Aloise; Benech, Henri; Grassi, Jacques; Orlowski, Stéphane; Dormont, Dominique; Clayette, Pascal

doi: 10.1177/135965350400900403pmid: N/A

Objectives To investigate whether P-glycoprotein (P-gp) and multidrug resistance proteins (MRPs), which limit the bioavailability of HIV protease inhibitors (PIs) and nucleoside reverse transcriptase inhibitors (NRTIs), modulate the anti-HIV activity of NRTIs, non-NRTIs and PIs in vitro. Design: We used primary cultures of major HIV target cells: human monocyte-derived macrophages (MDMs) and lymphocytes. Methods P-gp and MRP expression in response to long-term zidovudine (3′-azido-3′-deoxythymidine; AZT) or indinavir treatment was quantified by RT-PCR. MDM and lymphocytes were infected in vitro with HIV-1/Ba-L and HIV-1-LAI, respectively, and treated with antiretroviral drugs. We evaluated the activity of these drugs in combination with PSC833, a P-gp inhibitor, and/or probenecid, an MRP1 inhibitor. Intracellular AZT triphosphate derivative (AZT-TP) was quantified by HPLC-MSMS. P-gp ATPase activity was measured with inside-out native membrane vesicles enriched in P-gp. Results Levels of MDR1, mrp4 and mrp5 mRNA were high following AZT treatment. In infected MDM, PSC833 and probenecid increased the anti-HIV activity of AZT and indinavir. AZT (5 nM) decreased HIV replication by 34% alone and by 72% in combination with P-gp/MRP inhibitors. Indinavir (10 nM) gave 14% inhibition alone and 81% in combination. The increase in anti-HIV activity of AZT was correlated with an increase in intracellular AZT-TP concentration. However, unlike PIs, neither AZT nor its metabolites interacted with P-gp. Conclusion AZT increases the expression of multidrug transporters, thereby decreasing its pharmacological activity. The cellular efflux of AZT probably involves MRP4 or MRP5. In contrast, increases in indinavir anti-HIV activity require the inhibition of both P-gp and MRP1.

Stuyver, Lieven J; McBrayer, Tamara R; Schürmann, Dirk; Kravec, Irena; Beard, Amanda; Cartee, Leanne; Schinazi, Raymond F; De La Rosa, Abel; Murphy, Robert L; Otto, Michael J

doi: 10.1177/135965350400900410pmid: N/A

Reverset™ (2′,3′-didehydro-2′,3′-dideoxy-5-fluorocyti-dine, RVT) is a potent inhibitor of HIV-1 replication in cell culture, with a 90% effective concentration at or below 1 μM. In vitro, RVT retains its activity against isolates harbouring mutations in the reverse transcriptase (RT) gene that otherwise confer resistance to lamivudine and/or zidovudine. The pharmacokinetics and safety of single oral doses of RVT (10–200 mg) were evaluated in an initial Phase I clinical trial. The viral load changes were determined on 18 HIV-1-infected antiretroviral therapy-naive subjects that were randomized into three cohorts, each cohort consisting of three study periods. The subjects received up to two oral doses of active drug and one placebo dose with a 1-week washout period separating the three study periods. Quantification of viral RNA was performed on the pre-dose, 12, 24 and 48 h post-dose plasma samples. A single oral dose of RVT to antiretroviral-naive subjects significantly reduced plasma viral load by 0.45 ±0.10 log10 copies/ml (P=0.0003). A mean drop of 0.37 ±0.12 log10 copies/ml (P=0.001) was obtained at the lowest dose of 10 mg. Sequence analysis of the HIV-1 RT gene performed before and after RVT dosing detected no genotypic changes in this short-term study. The viral RT gene of one subject had at predose the following genotype: L41 + N103 + C181 + W210 + D215, indicating prior exposure to zidovudine and non-nucleoside analogues, and anticipating high-level resistance against these agents. A single 10 mg RVT dose resulted in a viral load drop of 0.61 ±0.05 log10 providing evidence that a viral strain with the indicated genotype is susceptible to RVT.

Castagna, Antonella; Gianotti, Nicola; Galli, Laura; Danise, Anna; Hasson, Hamid; Boeri, Enzo; Hoetelmans, Richard; Nauwelaers, David; Lazzarin, Adriano

doi: 10.1177/135965350400900408pmid: N/A

Objective To investigate the normalized inhibitory quotient (NIQ) of lopinavir (LPV) as a predictor of 48-week virological responses to a lopinavir/ritonavir (LPV/RTV)-containing regimen in highly treatment-experienced patients. Design We calculated the NIQ for 59 patients who completed 48 weeks’ treatment and assessed the factors predicting a week-48 virological response. Methods The NIQ was calculated by dividing each subject's IQ (LPV Ctrough/fold change in LPV susceptibility, as assessed by VirtualPhenotype™) by a reference IQ (mean population LPV Ctrough/fold change in LPV IC50, as assessed by VirtualPhenotype™). HIV-1 RNA was assessed by NASBA (quantification limit: 80 copies/ml). The general linear model and multiple logistic regression, respectively, were used to estimate the independent predictors of a change in viral load and HIV-1 RNA <80 copies/ml. Results The median (interquartile range) baseline levels of CD4+ cells and HIV-1 RNA were 251 (141–385) cells/μl and 4.85 (4.49–5.23) log10 copies/ml, respectively. The median NIQ was 2.2 (0.5–14). At week 48, the median decrease in HIV-1 RNA was 1.4 (0.59–2.79) log10 copies/ml (P<0.0001), with 24 subjects (41%) reaching <80 copies/ml. Baseline HIV-1 RNA (P=0.001), CD4+ cells (P=0.002) and NIQ (P=0.0006) independently predicted the week-48 change in viral load, whereas baseline CD4+ cells (P=0.011) and NIQ (P=0.009) independently predicted a week-48 HIV-1 RNA level of <80 copies/ml. Conclusion The LPV NIQ independently predicts virological responses to an LPV/RTV-containing regimen in highly treatment-experienced HIV-1-infected patients.

Jan, Véronique; Cervera, Pascale; Maachi, Mustapha; Baudrimont, Marielle; Kim, Minji; Vidal, Hubert; Girard, Pierre-Marie; Levan, Philippe; Rozenbaum, Willy; Lombès, Anne; Capeau, Jacqueline; Bastard, Jean-Philippe

doi: 10.1177/135965350400900412pmid: N/A

Objective To achieve a better understand of the pathophysiology of HIV-related lipoatrophy, we compared the mRNA expression of adipocytokines in fat samples from patients and healthy HIV-seronegative controls together with fat morphology and we studied the relationship between changes in fat morphology, adipocytokine expression, markers of adipose tissue differentiation and whole body insulin sensitivity. Design Cross-sectional analytical study. Subjects and methods The mRNA expression of adipocytokines and transcriptional factors in fat samples from 26 patients with peripheral lipoatrophy (all under anti-retroviral therapy associating protease inhibitor and nucleoside-analogue reverse transcriptase inhibitors) and from 16 non-HIV-infected controls was measured by real time quantitative RT-PCR. Fat morphology was assessed histologically on a subgroup of 10 patients and six controls: collagen fibres by Sirius Red staining, apoptosis by the TUNEL technique, vessels by smooth muscle α-actin staining and macrophages by CD68 staining. Insulin resistance was assessed by using the homeostasis model assessment. Results The patients’ fat showed higher values of apoptosis (P=0.005), fibrosis (P<0.05), vessel density (P=0.001) and macrophage infiltration (P<0.05) than the controls’ fat, together with lower adiponectin and leptin mRNA levels and higher interleukin (IL)-6 and tumour necrosis factor (TNF)α mRNA levels. TNFα and IL-6 expression correlated positively with the level of apoptosis (P=0.05 and P<0.05, respectively) and negatively with CCAAT-enhancer binding protein (C/EBP)α (P<0.001 and P<0.05, respectively). Apoptosis correlated negatively with the expression level of sterol-regulatory-element-binding-protein-1c (SREBP1c) (P=0.01) and C/EBPα (P=0.01) whilst the vessel density correlated negatively with SREBP1c (P<0.005), C/EBPα (P=0.001) and β (P=0.001). Adiponectin and leptin expression correlated positively with each other, and also with adipogenic marker expression and overall insulin sensitivity. These relationships were also present when the patient group was studied separately. Finally, fat morphological abnormalities correlated positively with whole body insulin resistance. Conclusions Adipose tissue from patients with HIV-1-related lipoatrophy shows increased apoptosis, together with decreased adipocyte differentiation. Increased TNFα and IL-6 expression could be a major phenomenon linking these alterations. Decreased adiponectin and leptin expression, which may result from decreased adipocyte differentiation, could be involved in the observed whole body insulin resistance.

Stránská, Růžena; van Loon, Anton M; Polman, Merjo; Beersma, Matthias FC; Bredius, Robbert GM; Lankester, Arjan C; Meijer, Ellen; Schuurman, Rob

doi: 10.1177/135965350400900413pmid: N/A

Thirty-one herpes simplex virus type one (HSV-1) isolates from 12 haematopoietic stem cell transplant recipients with persistent HSV infections despite acyclovir (ACV) prophylaxis or treatment, were genotypically and phenotypically characterized. The relationship between drug susceptibility of the isolates and mutations in thymidine kinase (TK) and DNA polymerase (DNA pol) genes was examined. In all 12 patients, HSV infections were due to ACV-resistant, foscarnet-sensitive viruses. Out of 31 isolates examined, 23 were resistant and eight were sensitive to ACV; eight patients carried viruses with frameshift mutations in the TK gene (due to addition or deletion of single nucleotides in homopolymeric repeats). These mutations were found at codon 61 (G deletion, one patient), 146 (G insertion, five patients) and 153 or 185 (C deletion, one patient each). In four patients, viruses were selected during ACV therapy that contained novel amino acid substitutions in the TK gene (H58R, G129D, A189V, R216H, R220C). Their possible role in ACV resistance was further confirmed phenotypically and by the absence of any resistance-associated mutations in the DNA pol gene. These substitutions were located in ATP- or nucleoside-binding sites or in conserved regions of the TK gene. In addition, a single mutation, Q570R, in the δ-region C of the DNA pol gene, was identified in an isolate from a single patient with resistance to ACV. Our study confirms and expands previous data on genotypic changes associated with ACV resistance of HSV-1 clinical isolates.