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Background & Aims: There are limited data on patients with chronic HCV infection in whom combination voxilaprevir (VOX), velpatasvir (VEL), sofosbuvir (SOF) retreatment fails. Thus, we aimed to assess treatment failure and rescue treatment options in these patients., Methods: Samples from 40 patients with HCV genotypes (GT) 1-4 in whom VOX/VEL/SOF retreatment failed were collected within the European Resistance Study Group. Population-based resistance analyses were conducted and clinical parameters and retreatment efficacies were evaluated retrospectively in 22 patients., Results: Most VOX/VEL/SOF failure patients were infected with HCV GT3a (n = 18, 45%) or GT1a (n = 11, 28%) and had cirrhosis (n = 28, 70%). Previous treatments included an NS3-inhibitor (30%), an NS5A-inhibitor (100%) and SOF (85%). Baseline RAS data from a subgroup of patients before VOX/VEL/SOF retreatment (78%) showed few NS3 RASs apart from Q80K in GT1a (40%), typical NS5A RAS patterns in most patients (74%) and no S282T in NS5B. Sequencing after VOX/VEL/SOF failure was available in 98% of patients and showed only minor changes for NS3 and NS5A RASs. In 22 patients, rescue treatment was initiated with glecaprevir, pibrentasvir alone (n = 2) or with SOF±ribavirin (n = 15), VOX/VEL/SOF±ribavirin (n = 4) or VEL/SOF and ribavirin (n = 1) for 12 to 24 weeks. Sustained virologic response was achieved in 17/21 (81%) patients with a final treatment outcome. Of these, 2 GT3a-infected patients had virologic failure after rescue treatment with VEL/SOF or glecaprevir/pibrentasvir+SOF+ribavirin, and 2 patients with cirrhosis died during treatment or before reaching SVR12., Conclusions: VOX/VEL/SOF failure was mainly observed in HCV GT3- and GT1a-infected patients with cirrhosis and was not associated with specific RAS patterns within NS3, NS5A or NS5B target regions. Rescue treatment with multiple targeted therapies was effective in most patients., Lay Summary: The advent of direct-acting antivirals has enabled the effective cure of chronic hepatitis C in most patients. However, treatment failure occurs in some patients, who are often retreated with a combination regimen called VOX/VEL/SOF, which is associated with very high rates of cure. However, VOX/VEL/SOF retreatment also fails in some patients. Herein, we analysed samples from patients in whom VOX/VEL/SOF retreatment failed and we assessed the efficacy of different rescue therapies, showing that rescue treatment is effective in most patients (81%)., Competing Interests: Conflict of interest Julia Dietz: Research support from Gilead. Dolores Merino: Speaking and/or consulting fees from Gilead, ViiV Health Care, Merck/MSD, Janssen. Johannes Vermehren: Speaking and/or consulting fees from Abbott, AbbVie, Gilead, Bristol-Myers Squibb, Medtronic, Merck/MSD, and Roche. Andreas E. Kremer: Speaking and/or consulting fees: AbbVie, Beiersdorf, Bristol-Myers Squibb, CymaBay, Eisai, Falk, Gilead, GSK, Intercept, Lilly, MSD, and Zambon. Heinz Zoller: Speaking and/or consulting fees: Abbott, AbbVie, Bristol-Myers Squibb, Gilead, Merck/MSD, Pharmacosmos, Roche, Vifor. Grant support from Abbvie, Gilead, Pharmacosmos, and Vifor. Elisabetta Degasperi: Speaking and/or consulting fees: AbbVie, Gilead, MSD. Laura Sighinolfi: Speaking and/or consulting fees: Merck/MSD, ViiV Healthcare. Elisa Fernández-Fuertes: Speaking and/or consulting fees: Abbvie, Gilead, Merck/MSD, Janssen, ViiV. Leopoldo Muñoz-Medina: Speaking and/or consulting fees: AbbVie, Gilead, Janssen, ViiV. Rudolf Stauber: Speaking and/or consulting fees: AbbVie, Bayer, BMS, Eisai, Ipsen Gilead, Roche. Pietro Lampertico: Speaking and/or consulting fees: AbbVie, Alnylam, Arrowhead, BMS, Eiger, Gilead, GSK, Janssen, MSD, MYR, Roche, Spring Bank. Stefan Zeuzem: Speaking and/or consulting fees: Abbvie, BMS, Gilead, Janssen, Merck/MSD. Francesca Ceccherini-Silberstein: Speaking and/or consulting fees: Abbvie, Gilead, Janssen, Merck/MSD, ViiV Healthcare. Federico García: Speaking and/or consulting fees: Abbvie, Gilead, Hologic, Merck/MSD, Roche, Qiagen. Christoph Sarrazin: Speaking and/or consulting fees: Abbvie, Gilead, Merck/MSD, Research support: Abbvie, Gilead. All other authors report no conflicts of interest. Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background: Multidrug-resistant pathogens are resistant to many antibiotics and associated with serious infections. Amomum tsaoko Crevost et Lemaire, Sanguisorba officinalis, Terminalia chebula Retz and Salvia miltiorrhiza Bge, are all used in Traditional Chinese Medicine (TCM) against multidrug-resistant pathogens, and the purpose of this study was to evaluate the antibacterial and anti-virulence activity of extracts derived from them., Methods: The antibacterial activity of ethanol and aqueous extracts from these four plants was examined against several multi-drug resistant bacterial strains, and their anti-virulence potential (including quorum quenching activity, biofilm inhibition, and blocking production of virulence factor δ-toxin) was assessed against different S. aureus strains. The chemical composition of the most effective extract was determined by LC-FTMS., Results: Only extracts from S. officinalis and A. tsaoko were shown to exhibit limited growth inhibition activity at a dose of 256 μg·mL-1. The S. officinalis ethanol extract, the ethanol and aqueous extract of A. tsaoko, and the aqueous extract of S. miltiorrhiza all demonstrated quorum quenching activity, but didn't significantly inhibit bacterial growth. The ethanol extract of S. officinalis inhibited bacterial toxin production and biofilm formation at low concentrations. Chemical composition analysis of the most effective extract of S. officinalis showed that it mainly contained saponins., Conclusions: The most active extract tested in this study was the ethanol root extract of S. officinalis. It inhibited δ-toxin production and biofilm formation at low concentrations and saponins may be its key active components. While the four plants showed no direct antibacterial effects, their anti-virulence properties may be key to fighting bacterial infections.

Background: We projected the clinical outcomes, cost-effectiveness, and budget impact of ibalizumab plus an optimized background regimen (OBR) for people with multidrug-resistant (MDR) HIV in the United States., Methods: Using the Cost-Effectiveness of Preventing AIDS Complications microsimulation model and a health care sector perspective, we compared 2 treatment strategies for MDR HIV: (1) IBA + OBR-ibalizumab plus OBR and (2) OBR-OBR alone. Ibalizumab efficacy and cohort characteristics were from trial data: mean age 49 years, 85% male, and mean CD4 150/µL. Six-month viral suppression was 50% with IBA + OBR and 0% with OBR. The ibalizumab loading dose cost $10,500, and subsequent ibalizumab injections cost $8400/month; OBR cost $4500/month. Incremental cost-effectiveness ratios (ICERs) were calculated using discounted (3%/year) quality-adjusted life years (QALYs) and costs. ICERs ≤$100,000/QALY were considered cost-effective. We performed sensitivity analysis on key parameters and examined budget impact., Results: In the base case, 5-year survival increased from 38% with OBR to 47% with IBA + OBR. Lifetime costs were $301,700/person with OBR and $661,800/person with IBA + OBR; the ICER for IBA + OBR compared with OBR was $260,900/QALY. IBA + OBR was not cost-effective even with 100% efficacy. IBA + OBR became cost-effective at base case efficacy if ibalizumab cost was reduced by ≥88%. For an estimated 12,000 people with MDR HIV in the United States, IBA + OBR increased care costs by $1.8 billion (1.5% of total treatment budget) over 5 years., Conclusions: For people with MDR HIV lacking other treatment options, ibalizumab will substantially increase survival when effective. Although adding ibalizumab to OBR is not cost-effective, the low number of eligible patients in the United States makes the budget impact relatively small.

Acquired immune deficiency syndrome (AIDS)/human immunodeficiency virus (HIV) is one of the largest and most devastating public health pandemics throughout the world. The global pandemic of drug-sensitive HIV and the increasing threat from drug-resistant HIV result in an urgent need to develop more effective anti-HIV candidates. Quinolone represents a significant class of privileged heterocycles, and its derivatives possess promising in vitro and in vivo anti-HIV properties. The 4-quinolone elvitegravir has already been approved for the treatment of HIV; thus, quinolone derivatives might be promising candidates with anti-HIV activity. This review emphasizes quinolone derivatives with potential anti-HIV activity, covering articles published between 1992 and 2019. The structure-activity relationship is also discussed to provide insights for further development of more active quinolone derivatives., (© 2019 Deutsche Pharmazeutische Gesellschaft.)

Cytomegalovirus (CMV) is one of the most common opportunistic infections after transplantation. To prevent CMV infections, universal prophylaxis and pre-emptive therapy with ganciclovir or its prodrug valganciclovir is applied. However, prolonged antiviral therapy may result in drug-resistance emergence. We describe a case of a 43-year-old CMV-seronegative patient who underwent kidney transplantation from a CMV-seropositive donor and developed CMV disease despite valganciclovir prophylaxis. CMV viral load increased even though valgangiclovir dose was augmented and immunosuppressive therapy reduced. CMV genotyping revealed mutations in the viral UL97 protein kinase, explaining ganciclovir-resistant CMV infection. The viral load failed to respond to foscavir, cidofovir and CMV-neutralizing immunoglobulins. Kidney allograft dysfunction developed 3 months post-transplantation with a histopathologic diagnosis of CMV nephropathy and potentially concomitant T-cell mediated rejection. A transplantectomy was performed on day 164 post-transplantation since the patient had uncontrollable CMV disease associated with a circulating multidrug-resistant DNA polymerase-mutant virus. Detailed monitoring in this patient demonstrated hallmarks of complicated CMV disease: (i) relatively rapid evolution of drug-resistant CMV mutants in the setting of persistent high blood viral loads, (ii) emergence of viral drug-resistance linked to acute graft rejection, (iii) transient and, thereafter, lack of response to various anti-CMV treatments, (iv) compartmentalization and heterogeneity of CMV viral populations, (v) possible differential ability of viral mutants to cause disease in the graft, and (vi) detection of minor viral variants by next generation sequencing. Translational research platforms that provide rapid molecular genotyping for detection of CMV drug-resistance are essential in guiding CMV disease management in high-risk transplant recipients., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Combination antiretroviral therapy has achieved dramatic reductions in the mortality and morbidity in people with HIV-1 infection. Darunavir (DRV) represents a most efficacious and well-tolerated protease inhibitor (PI) with a high genetic barrier to the emergence of drug-resistant HIV-1. However, highly DRV-resistant variants have been reported in patients receiving long-term DRV-containing regimens. Here, we report three novel HIV-1 PIs (GRL-057-14, GRL-058-14, and GRL-059-14), all of which contain a P2-amino-substituted- bis -tetrahydrofuranylurethane ( bis -THF) and a P2'-cyclopropyl-amino-benzothiazole (Cp-Abt). These PIs not only potently inhibit the replication of wild-type HIV-1 (50% effective concentration [EC 50 ], 0.22 nM to 10.4 nM) but also inhibit multi-PI-resistant HIV-1 variants, including highly DRV-resistant HIV DRV R P51 (EC 50 , 1.6 nM to 30.7 nM). The emergence of HIV-1 variants resistant to the three compounds was much delayed in selection experiments compared to resistance to DRV, using a mixture of 11 highly multi-PI-resistant HIV-1 isolates as a starting HIV-1 population. GRL-057-14 showed the most potent anti-HIV-1 activity and greatest thermal stability with wild-type protease, and potently inhibited HIV-1 protease's proteolytic activity ( K i value, 0.10 nM) among the three PIs. Structural models indicate that the C-5-isopropylamino- bis -THF moiety of GRL-057-14 forms additional polar interactions with the active site of HIV-1 protease. Moreover, GRL-057-14's P1- bis -fluoro-methylbenzene forms strong hydrogen bonding and effective van der Waals interactions. The present data suggest that the combination of C-5-aminoalkyl- bis -THF, P1- bis -fluoro-methylbenzene, and P2'-Cp-Abt confers highly potent activity against wild-type and multi-PI-resistant HIV strains and warrant further development of the three PIs, in particular, that of GRL-057-14, as potential therapeutic for HIV-1 infection and AIDS., (Copyright © 2019 American Society for Microbiology.)

Background: According to the EASL and AASLD guidelines, the recommended treatment for patients who failed to achieve a sustained virologic response (SVR) on prior interferon-based triple therapy with protease inhibitors (PI), is a combination of sofosbuvir and NS5A inhibitors. Polish national recommendations also allow the use of paritaprevir/ritonavir/ombitasvir+dasasbuvir±ribavirin (PrODR) in this group of patients. The aim of the study was to evaluate the efficacy and safety of PrODR vs. ledipasvir/sofosbuvir±RBV (LSR) in PI-experienced patients in real-life setting., Methods: Our analysis included patients registered in the nationwide, investigators initiated, multicentre EpiTer-2 database. Among 4530 patients registered, 335 with genotype 1 (93% 1b) were previously treated with IFN-based regimens with PIs: 127 with boceprevir (BOC), 208 with telaprevir (TVR). Patients with advanced fibrosis (F3/F4) were significantly predominant (BOC 28.4%/61.4%, TVR 18.8%/64.4%, respectively). Subjects were assigned to IFN-free retreatment as follows: BOC - 64 (50.4%) PrODR and 63 (49.6%) LSR; TVR- 103 (49.5%) PrODR and 105 (50.5%) LSR., Results: SVR rates were comparable for particular groups: BOC → PrODR- 100%; BOC → LSR - 98%; TVR → PrODR - 97%; TVR → LSR - 96% (intent-to treat analysis-ITT) and BOC → PrODR→100%; BOC → LSR - 99%; TVR → PrODR - 99%; TVR → LSR - 98% (modified intent-to treat analysis-mITT). Both treatment regimens had a favourable safety profile. Adverse events (AEs) were generally mild or moderate in severity. Three deaths were reported. The treatment was stopped due to AEs in five patients (three treated with PrODR and two with LSR)., Conclusion: Efficacy and safety of treatment with PrODR and LSR is comparable in BOC or TVR-experienced patients.

Viral diseases, such as human immune deficiency virus (HIV), influenza, hepatitis, and herpes, are the leading causes of human death in the world. The shortage of effective vaccines or therapeutics for the prevention and treatment of the numerous viral infections, and the great increase in the number of new drug-resistant viruses, indicate that there is a great need for the development of novel and potent antiviral drugs. Natural products are one of the most valuable sources for drug discovery. Most natural triterpenoids, such as oleanolic acid (OA), possess notable antiviral activity. Therefore, it is important to validate how plant isolates, such as OA and its analogues, can improve and produce potent drugs for the treatment of viral disease. This article reports a review of the analogues of oleanolic acid and their selected pathogenic antiviral activities, which include HIV, the influenza virus, hepatitis B and C viruses, and herpes viruses.

Letermovir is an investigational antiviral agent with a novel mechanism of action involving the viral terminase (pUL56). We evaluated the impact of the V236M mutation in the UL56 gene alone and in combination with the E756K mutation in the UL54 gene on drug susceptibility and viral replicative capacity of recombinant human cytomegalovirus. The double mutant exhibited at least borderline resistance to all antivirals tested (ganciclovir, foscarnet, cidofovir, brincidofovir, and letermovir) and replicated less efficiently than the wild-type virus in vitro ., (Copyright © 2017 American Society for Microbiology.)

The efficacy of current influenza vaccines and small molecule antiviral drugs is curtailed by the emerging of multidrug-resistant influenza viruses. As resistance to the only FDA-approved oral influenza antiviral, oseltamivir (Tamiflu), continues to rise, there is a clear need to develop the next-generation of antiviral drugs. Since more than 95% of current circulating influenza A viruses carry the S31N mutation in their M2 genes, the AM2-S31N mutant proton channel represents an attractive target for the development of broad-spectrum antivirals. In this study we report the design and synthesis of the first class of organosilanes that have potent antiviral activity against a panel of human clinical isolates of influenza A viruses, including viruses that are resistant to amantadine, oseltamivir, or both., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

A vaginal ring containing dapivirine (DPV) has shown moderate protective efficacy against HIV-1 acquisition, but the activity of DPV against efavirenz (EFV)- and nevirapine (NVP)-resistant viruses that could be transmitted is not well defined. We investigated DPV cross-resistance of subtype C HIV-1 from individuals on failing NVP- or EFV-containing antiretroviral therapy (ART) in South Africa. Plasma samples were obtained from individuals with >10,000 copies of HIV RNA/ml and with HIV-1 containing at least one non-nucleoside reverse transcriptase (NNRTI) mutation. Susceptibility to NVP, EFV, and DPV in TZM-bl cells was determined for recombinant HIV-1 LAI containing bulk-amplified, plasma-derived, full-length reverse transcriptase sequences. Fold change (FC) values were calculated compared with a composite 50% inhibitory concentration (IC 50 ) from 12 recombinant subtype C HIV-1 LAI plasma-derived viruses from treatment-naive individuals in South Africa. A total of 25/100 (25%) samples showed >500-FCs to DPV compared to treatment-naive samples with IC 50 s exceeding the maximum DPV concentration tested (132 ng/ml). A total of 66/100 (66%) samples displayed 3- to 306-FCs, with a median IC 50 of 17.6 ng/ml. Only 9/100 (9%) samples were susceptible to DPV (FC < 3). Mutations L100I and K103N were significantly more frequent in samples with >500-fold resistance to DPV compared to samples with a ≤500-fold resistance. A total of 91% of samples with NNRTI-resistant HIV-1 from individuals on failing first-line ART in South Africa exhibited ≥3-fold cross-resistance to DPV. This level of resistance exceeds expected plasma concentrations, but very high genital tract DPV concentrations from DPV ring use could block viral replication. It is critically important to assess the frequency of transmitted and selected DPV resistance in individuals using the DPV ring., (Copyright © 2017 American Society for Microbiology.)

We report here that GRL-10413, a novel nonpeptidic HIV-1 protease inhibitor (PI) containing a modified P1 moiety and a hydroxyethylamine sulfonamide isostere, is highly active against laboratory HIV-1 strains and primary clinical isolates (50% effective concentration [EC 50 ] of 0.00035 to 0.0018 μM), with minimal cytotoxicity (50% cytotoxic concentration [CC 50 ] = 35.7 μM). GRL-10413 blocked the infectivity and replication of HIV-1 NL4-3 variants selected by use of atazanavir, lopinavir, or amprenavir (APV) at concentrations of up to 5 μM (EC 50 = 0.0021 to 0.0023 μM). GRL-10413 also maintained its strong antiviral activity against multidrug-resistant clinical HIV-1 variants isolated from patients who no longer responded to various antiviral regimens after long-term antiretroviral therapy. The development of resistance against GRL-10413 was significantly delayed compared to that against APV. In addition, GRL-10413 showed favorable central nervous system (CNS) penetration properties as assessed with an in vitro blood-brain barrier (BBB) reconstruction system. Analysis of the crystal structure of HIV-1 protease in complex with GRL-10413 demonstrated that the modified P1 moiety of GRL-10413 has a greater hydrophobic surface area and makes greater van der Waals contacts with active site amino acids of protease than in the case of darunavir. Moreover, the chlorine substituent in the P1 moiety interacts with protease in two distinct configurations. The present data demonstrate that GRL-10413 has desirable features for treating patients infected with wild-type and/or multidrug-resistant HIV-1 variants, with favorable CNS penetration capability, and that the newly modified P1 moiety may confer desirable features in designing novel anti-HIV-1 PIs., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

Background: Data on pediatric treatment outcomes and drug resistance while on second-line antiretroviral therapy (ART) are needed to guide HIV care in resource-limited countries., Methods: HIV-infected children <18 years who were switched or switching to second-line ART after first-line failure were enrolled from 8 sites in Indonesia, Thailand, and Vietnam. Genotyping was performed at virologic failure (VF; HIV-RNA >1000 copies/mL). Cox proportional hazards regression was used to evaluate factors predicting VF., Results: Of 277 children, 41% were female. At second-line switch, age was 7.5 (5.3-10.3) years, CD4 count was 300 (146-562) cells per cubic millimeter, and percentage was 13 (7-20%); HIV-RNA was 5.0 (4.4-5.5) log10 copies per milliliter. Second-line regimens contained lamivudine (90%), tenofovir (43%), zidovudine or abacavir (30%), lopinavir (LPV/r; 91%), and atazanavir (ATV; 7%). After 3.3 (1.8-5.3) years on second-line ART, CD4 was 763 (556-1060) cells per cubic millimeter and 26% (20-31%). VF occurred in 73 (27%), with an incidence of 7.25 per 100 person-years (95% confidence interval [CI]: 5.77 to 9.12). Resistance mutations in 50 of 73 children with available genotyping at first VF included M184V (56%), ≥1 thymidine analogue mutation (TAM; 40%), ≥4 TAMs (10%), Q151M (4%), any major LPV mutation (8%), ≥6 LPV mutations (2%), and any major ATV mutation (4%). Associations with VF included age >11 years (hazard ratio [HR] 4.06; 95% CI: 2.15 to 7.66) and HIV-RNA >5.0 log10 copies per milliliter (HR 2.42; 95% CI: 1.27 to 4.59) at switch and were seen more commonly in children from Vietnam (HR 2.79; 95% CI: 1.55 to 5.02)., Conclusions: One-fourth of children developed VF while on second-line ART. However, few developed major mutations to protease inhibitors.

Background & Aims: Sequential therapy posed a high risk of emergence of multidrug resistance and presented a management issue in chronic hepatitis B (CHB) treatment. We evaluated the antiviral efficacy and safety of entecavir (ETV) plus tenofovir (TDF) combination therapy in multidrug-resistant (MDR) CHB patients., Methods: In this prospective, multicentre study, MDR CHB patients, defined as measurable serum HBV DNA (≥60 IU/ml) while on any rescue treatment regimen for at least 24 weeks and the presence of documented prior genotypic resistance to both nucleoside analogue(s) and nucleotide analogue, were treated with ETV 1.0 mg and TDF 300 mg combination therapy for 48 weeks., Results: A total of 64 eligible patients who had previously failed to a median three lines of antiviral therapy (range, 2-6) were included. At baseline, median age was 47.0 years, 89.1% were HBeAg(+), and median HBV DNA was 4.24 (range, 2.11-6.73) log10 IU/ml. By week 4, 12, 24 and 48, 15/64 (23.4%), 36/64 (56.3%), 43/64 (67.2%) and 55/64 (85.9%) patients achieved a HBV DNA <60 IU/ml respectively. The mean reduction of HBV DNA from baseline to 4 and 48 weeks was 1.23 log10 IU/ml and 2.38 log10 IU/ml respectively. Although five patients experienced virological breakthrough, all were transient and no resistant mutation to TDF or novel mutation was detected in any patients., Conclusions: In difficult-to-treat MDR CHB patients with a high exposure to multiple antiviral drugs, ETV plus TDF combination therapy can provide a very high rate of viral suppression through 48 weeks of treatment., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

We investigated the biological effect of hepatitis B virus (HBV) rtA181T/sW172* point mutation on HBsAg secretion and the potential mechanisms involved in hepatocarcinogenesis. Full-length HBV wild type (wt) and HBV rtA181T/sW172* expression plasmids were transfected into HepG2 cell lines or were injected into C57BL/6 mice. The extracellular and intracellular expression levels of HBsAg and HBeAg proteins, in mouse serum and liver tissues were detected by ELISA. The localization of the truncated protein was characterized in vitro. The mRNA expression of endoplasmic reticulum (ER) stress gene GRP78 was determined. HBsAg levels were significantly higher in both supernatant of cells transfected with HBV wt and serum of mice injected with HBV wt, compared with that of HBV rtA181T/sW172* mutant. The reversed trend was observed in intracellular cells and intrahepatic liver cells. Wild type S protein alone could rescue this dysfunction. HBV rtA181T/sW172* truncated surface proteins showed a more aggregated cytoplasmic pattern which were also localized to the ER in comparison with HBV wt. Furthermore, GRP78 mRNA expression was increased 72 h post-transfection in HBV rtA181T/sW172* cells relative to HBV wt cells (P = 0.0154). The HBV sW172* truncation variant has a defect on HBsAg secretion which can lead to surface protein retention in the ER, where it may contribute to hepatocarcinogenesis through activating the ER stress signaling pathway.

Cidofovir, a nucleoside analog of deoxycytidine monophosphate, is a water-soluble polar molecule that exhibits antiviral activity against a broad range of DNA viruses. Cidofovir for injection is approved for the treatment of cytomegalovirus retinitis in patients with acquired immune deficiency syndrome. The safety and efficacy of topical cidofovir has been described in a limited number of patients. We present two cases of multidrug-resistant herpes simplex virus infections that responded to topical cidofovir therapy yet resulted in irreversible acute kidney injury., (© The Author(s) 2014.)

Background: Tolerability, long-term toxicities and selection of resistant variants limit the use and efficacy of antiretroviral drugs in HIV-positive patients. Novel combinations are needed for mantaining long-term control of HIV replication; nevertheless scarse data are available on protease inhibitor-free dual antiretroviral therapies., Methods: A multi-centric retrospective study was conducted including HIV-1-positive patients on raltegravir/nevirapine dual regimens. Plasma concentrations were measured as therapeutic drug monitoring while a subset of patients underwent intensive 12-hour pharmacokinetic evaluation., Results: A total of 77 patients switching from successful regimens (76.6% male, median age 52 years) was included; 10 patients on raltegravir plus nevirapine once-daily while 67 subjects on twice-daily schedule. After a median follow-up of 32 months 69 patients (89.6%) were still successfully on treatment. Three patients discontinued for side effects (skin rash or hepatoxicity). Virological failure was observed in five patients (6.5%, 3 on once-daily schedule): in 4 patients (80%) resistance-associated mutations were observed (4 reverse transcriptase, 2 integrase). Triglycerides decreased in patients switching with lipid abnormalities (n=52) and estimated creatinine clearance increased in those with less than 60 ml/min (n=13). Median trough raltegravir and nevirapine concentrations were 83 ng/ml (32-227) and 5460 ng/ml (4037-7221); intensive 12-hours pharmacokinetic parameters (n=7) were similar to published data., Conclusion: Dual therapy with raltegravir/nevirapine in selected patients was highly effective over a 32-month follow up: virological failure was infrequent (6.5%), most common with once-daily schedule (60%) and often associated with the selection of resistance-associated mutations (80%). Twice-daily raltegravir plus nevirapine deserves further clinical evaluation as an NRTI- and PI-sparing strategy in selected patients.

Introduction: Respiratory viruses are increasingly recognized as significant etiologies of pneumonia among hospitalized patients. Advanced technologies using multiplex molecular assays and polymerase-chain reaction increase the ability to identify viral pathogens and may ultimately impact antibacterial use., Method: This was a single-center retrospective cohort study to evaluate the impact of antibacterials in viral pneumonia on clinical outcomes and subsequent multidrug-resistant organism (MDRO) infections/colonization. Patients admitted from March 2013 to November 2014 with positive respiratory viral panels (RVP) and radiographic findings of pneumonia were included. Patients transferred from an outside hospital or not still hospitalized 72 hours after the RVP report date were excluded. Patients were categorized based on exposure to systemic antibacterials: less than 3 days representing short-course therapy and 3 to 10 days being long-course therapy., Results: A total of 174 patients (long-course, n = 67; short-course, n = 28; mixed bacterial-viral infection, n = 79) were included with most being immunocompromised (56.3 %) with active malignancy the primary etiology (69.4 %). Rhinovirus/Enterovirus (23 %), Influenza (19 %), and Parainfluenza (15.5 %) were the viruses most commonly identified. A total of 13 different systemic antibacterials were used as empiric therapy in the 95 patients with pure viral infection for a total of 466 days-of-therapy. Vancomycin (50.7 %), cefepime (40.3 %), azithromycin (40.3 %), meropenem (23.9 %), and linezolid (20.9 %) were most frequently used. In-hospital mortality did not differ between patients with viral pneumonia in the short-course and long-course groups. Subsequent infection/colonization with a MDRO was more frequent in the long-course group compared to the short-course group (53.2 vs 21.1 %; P = 0.027)., Conclusion: This study found that long-course antibacterial use in the setting of viral pneumonia had no impact on clinical outcomes but increased the incidence of subsequent MDRO infection/colonization.

Background: Drug resistance is one of the most important causes for failure of anti-AIDS treatment. During therapy, multiple mutations accumulate in the HIV genome, eventually rendering the drugs ineffective in blocking replication of the mutant virus. The huge number of possible mutants precludes experimental analysis to explore the molecular mechanisms of resistance and develop improved antiviral drugs., Results: In order to solve this problem, we have developed a new algorithm to reveal the most representative mutants from the whole drug resistant mutant database based on our newly proposed unified protein sequence and 3D structure encoding method. Mean shift clustering and multiple regression analysis were applied on genotype-resistance data for mutants of HIV protease and reverse transcriptase. This approach successfully chooses less than 100 mutants with the highest resistance to each drug out of about 10K in the whole database. When considering high level resistance to multiple drugs, the numbers reduce to one or two representative mutants., Conclusion: This approach for predicting the most representative mutants for each drug has major importance for experimental verification since the results provide a small number of representative sequences, which will be amenable for in vitro testing and characterization of the expressed mutant proteins.

Antiviral susceptibility testing and reporting of viruses carrying amino acid substitutions conferring antiviral drug resistance is essential to assess the spread and clinical impact of these viruses. Here, we report on a patient who was infected with a primarily oseltamivir-resistant influenza A (H1N1pdm09) virus following allogeneic stem cell transplantation and rituximab treatment. Under prolonged virus replication and zanamivir therapy the neuraminidase amino acid substitutions H275Y and I223R were detected conferring high-level resistance to oseltamivir and cross-resistance to zanamivir. The emergence of these amino acid changes has been reported rarely worldwide and has been associated with fatal clinical outcomes. The patient survived the influenza infection after 170 days of follow-up.

Background/purpose: Insulin resistance (IR) affects sustained virological response (SVR) to peginterferon alfa plus ribavirin (PR) in patients with chronic hepatitis C (CHC). Whether add-on oral hypoglycemic agents (OHAs) to PR improve SVR remains unclear; therefore, we conducted a prospective, randomized pilot trial on 23 consecutive patients with genotype 1 CHC and IR in Taiwan., Methods: Patients were randomized to receive acarbose (Arm A; n = 7) or metformin (Arm B; n = 6) or pioglitazone (Arm C; n = 5) in addition to peginterferon alfa-2b (1.5 μg/kg/week) plus ribavirin (1000-1200 mg/day) or just PR (Arm D; n = 5). The primary end point was SVR, and secondary end points were viral clearance at Weeks 17, 29, and 53. There were no differences among all arms at baseline., Results: Using intent-to-treat analysis, SVR was observed in 66.7% (4/6), 83.3% (5/6), 66.7% (4/6), and 60% (3/5) in Arms A, B, C, and D, respectively. SVR was higher in female patients receiving OHA [90% (9/10)] than in male patients [50% (4/8)]. Results of per protocol analysis showed that SVR was 80.0% (4/5) in Arm A, 100% (5/5) in Arm B, 66.7% (4/6) in Arm C, and 60% (3/5) in Arm D. Patients receiving OHA had a higher rapid virologic response: 11/18 (61%) versus 2/5 (40%). Complete early virologic response was comparable between patients receiving OHA and PR [15/18 (83%) vs. 4/5 (80%)]., Conclusion: Our preliminary data show add-on OHAs to PR might achieve better early viral kinetics and SVR. However, further larger studies are needed to confirm these findings., (Copyright © 2014. Published by Elsevier B.V.)

In the present study, GRL008, a novel nonpeptidic human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI), and darunavir (DRV), both of which contain a P2-bis-tetrahydrofuranyl urethane (bis-THF) moiety, were found to exert potent antiviral activity (50% effective concentrations [EC50s], 0.029 and 0.002 μM, respectively) against a multidrug-resistant clinical isolate of HIV-1 (HIVA02) compared to ritonavir (RTV; EC50, >1.0 μM) and tipranavir (TPV; EC50, 0.364 μM). Additionally, GRL008 showed potent antiviral activity against an HIV-1 variant selected in the presence of DRV over 20 passages (HIVDRV(R)P20), with a 2.6-fold increase in its EC50 (0.097 μM) compared to its corresponding EC50 (0.038 μM) against wild-type HIV-1NL4-3 (HIVWT). Based on X-ray crystallographic analysis, both GRL008 and DRV showed strong hydrogen bonds (H-bonds) with the backbone-amide nitrogen/carbonyl oxygen atoms of conserved active-site amino acids G27, D29, D30, and D30' of HIVA02 protease (PRA02) and wild-type PR in their corresponding crystal structures, while TPV lacked H-bonds with G27 and D30' due to an absence of polar groups. The P2' thiazolyl moiety of RTV showed two conformations in the crystal structure of the PRA02-RTV complex, one of which showed loss of contacts in the S2' binding pocket of PRA02, supporting RTV's compromised antiviral activity (EC50, >1 μM). Thus, the conserved H-bonding network of P2-bis-THF-containing GRL008 with the backbone of G27, D29, D30, and D30' most likely contributes to its persistently greater antiviral activity against HIVWT, HIVA02, and HIVDRV(R)P20., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

BMS-986001 is a novel HIV nucleoside reverse transcriptase inhibitor (NRTI). To date, little is known about its resistance profile. In order to examine the cross-resistance profile of BMS-986001 to NRTI mutations, a replicating virus system was used to examine specific amino acid mutations known to confer resistance to various NRTIs. In addition, reverse transcriptases from 19 clinical isolates with various NRTI mutations were examined in the Monogram PhenoSense HIV assay. In the site-directed mutagenesis studies, a virus containing a K65R substitution exhibited a 0.4-fold change in 50% effective concentration (EC50) versus the wild type, while the majority of viruses with the Q151M constellation (without M184V) exhibited changes in EC50 versus wild type of 0.23- to 0.48-fold. Susceptibility to BMS-986001 was also maintained in an L74V-containing virus (0.7-fold change), while an M184V-only-containing virus induced a 2- to 3-fold decrease in susceptibility. Increasing numbers of thymidine analog mutation pattern 1 (TAM-1) pathway mutations correlated with decreases in susceptibility to BMS-986001, while viruses with TAM-2 pathway mutations exhibited a 5- to 8-fold decrease in susceptibility, regardless of the number of TAMs. A 22-fold decrease in susceptibility to BMS-986001 was observed in a site-directed mutant containing the T69 insertion complex. Common non-NRTI (NNRTI) mutations had little impact on susceptibility to BMS-986001. The results from the site-directed mutants correlated well with the more complicated genotypes found in NRTI-resistant clinical isolates. Data from clinical studies are needed to determine the clinically relevant resistance cutoff values for BMS-986001.

We report on a case of severe cutaneous reaction to darunavir/r and a successful desensitization protocol. The patient was a 41-yr old female. known to be HIV infective for 18 years and who had received several drug regiments in the past. As a consequence, her virus had triple-class mutations but was susceptible to darunavir/r. Her CD4 was 200 cells/mm(3) and HIV viral load 56,000 copies/mL. Eight days after initiation of darunavir/r the patient developed a severe pruritic vesicular extended cutaneous allergic reaction which required cessation of all drugs. Due to the severity of the allergic reaction no rechallenge was done. After the patient's recovery, the virus was found to be susceptible only to maraviroc, raltegravir, and darunavir/r. Since darunavir/r was an essential component in treating this triple-class mutated virus, a desensitization protocol was applied successfully. Six months after desensitization protocol was applied successfully. Six months after desensitization, the patient is asymptomatic, compliant, and her HIV viral load remains at <20 copies/mL.

We present the first fatal case of extensively drug-resistant tuberculosis (XDR-TB) in an injecting drug user (IDU) in Athens, Greece, co-infected with human immunodeficiency virus and hepatitis C virus and discuss the implications for public health. Despite immediate initiation of treatment, the patient's condition gradually deteriorated and he died 16 days after hospital admission because of multiple organ failure. The contact tracing investigation revealed no further infections among the patient's contacts.

We report long-term virologic response to etravirine and tenofovir/emtricitabine in four HIV-1-infected patients who had prior standard genotypic resistance testing showing an isolated K103N mutation (three acquired, one transmitted). In three patients tested, the K103N mutation was detected in cellular HIV-1 DNA whereas remaining suppressed on etravirine plus tenofovir/emtricitabine.

The adherence of patients to therapy is a crucial factor for successful HIV anti-retroviral therapy. Imperfect adherence may lead to treatment failure, which can cause the emergence of resistance within viral populations. We have developed a stochastic model that incorporates compartments of latently infected cells and virus genotypes with different susceptibilities to three simultaneously used drugs. With this model, we study the impact of several key parameters on the probability of treatment failure, i.e. insufficient viral suppression, and the emergence of resistance. Specifically, we consider the impact of drug dosage, drug half-lives, fitness costs for resistance, different basic reproductive numbers of the virus and the influence of pre-existing mutations under various levels of adherence. Furthermore, we also investigate the influence of different temporal distributions of non-adherent days (drug holidays) during a treatment. Factors that promote resistance evolution include a high reproductive number, extended drug holidays and poor adherence. Pre-existing mutations only have a substantial effect if they confer resistance against more than one drug. Overall, our study highlights the importance of the interactions between imperfect adherence, pharmacodynamics, pharmacokinetics and latently infected cells for our understanding of drug resistance and therapy failure in HIV anti-retroviral therapy.

Determining the phenotypic impacts of reverse transcriptase (RT) mutations on individual nucleoside RT inhibitors (NRTIs) has remained a statistical challenge because clinical NRTI-resistant HIV-1 isolates usually contain multiple mutations, often in complex patterns, complicating the task of determining the relative contribution of each mutation to HIV drug resistance. Furthermore, the NRTIs have highly variable dynamic susceptibility ranges, making it difficult to determine the relative effect of an RT mutation on susceptibility to different NRTIs. In this study, we analyzed 1,273 genotyped HIV-1 isolates for which phenotypic results were obtained using the PhenoSense assay (Monogram, South San Francisco, CA). We used a parsimonious feature selection algorithm, LASSO, to assess the possible contributions of 177 mutations that occurred in 10 or more isolates in our data set. We then used least-squares regression to quantify the impact of each LASSO-selected mutation on each NRTI. Our study provides a comprehensive view of the most common NRTI resistance mutations. Because our results were standardized, the study provides the first analysis that quantifies the relative phenotypic effects of NRTI resistance mutations on each of the NRTIs. In addition, the study contains new findings on the relative impacts of thymidine analog mutations (TAMs) on susceptibility to abacavir and tenofovir; the impacts of several known but incompletely characterized mutations, including E40F, V75T, Y115F, and K219R; and a tentative role in reduced NRTI susceptibility for K64H, a novel NRTI resistance mutation.

Among 103 patients with multidrug-resistant HIV who initiated raltegravir, etravirine, and darunavir/ritonavir-containing regimen in the ANRS 139 TRIO trial, 100 participated in extended follow-up and continued study treatment until week 96. Among them, 87 (87%) received an optimized background therapy including either nucleoside reverse transcriptase inhibitors or enfuvirtide, they were 78 (78%) at week 96. At week 96, 88% achieved durable virologic response (<50 copies/mL). CD4 response was maintained (median change of +150 cells/mm(3)). No major toxicity was reported. This triple drug combination showed sustained efficacy and thus should be strongly considered for patients with multiclass-resistant virus.

Multidrug-resistant viruses remain a clinically challenging complication in the immunocompromised host. This review discusses mechanisms of viral resistance and treatment options in this context with particular emphasis on the immunocompromised haematology patient. We also outline some of the newer agents and treatment strategies being developed to treat multidrug-resistant viruses., (© 2011 Blackwell Publishing Ltd.)

Background/aim: The aim of this study was to assess the patterns of lamivudine (LAM)-resistant mutations and the influence on biochemical and virological responses to adefovir (ADV) add-on LAM combination therapy in patients with LAM-resistant chronic hepatitis B (CHB)., Methods: Seventy-eight CHB patients with confirmed genotypic resistance to LAM, who initiated ADV add-on LAM combination treatment, were enrolled at our institution between April 2007 and April 2009., Results: The baseline tyrosine-methionine-aspartate-aspartate (YMDD) mutation patterns were as follows: rtM204I 45 (57.7%); and rtM204V + rtM204I/V 33 (42.3%). The decrease in the mean ± standard deviation (SD) serum log(10) HBV-DNA level did not differ between the patients carrying the rtM204I vs. rtM204IV +rtM204I/V mutations at 3, 6 and 12 months after the initiation of ADV add-on LAM combination treatment. The proportion of patients who achieved ALT normalization (<40 IU/L) 12 months after the initiation of ADV add-on LAM combination treatment were significantly higher in patients with a rtM204I mutation than rtM204V+ rtM204I/V mutations (39 [86.7%] vs. 22 [66.7%], P = 0.05). The proportion of patients in whom the log(10) HBV-DNA decreased <2 log(10) copies/ml, 6 months after the initiation of ADV add-on LAM combination treatment (non-responders), was significantly higher in patients with a rtM204V + rtM204I/V mutations than rtM204I mutation (7 [21.2%] vs. 2 [4.4%], P = 0.032)., Conclusion: Biochemical response at 12 months from baseline was better in patients with a rtM204I mutation than rtM204V+ rtM204I/V mutations. In addition, early treatment failure was more common in patients with rtM204V+ rtM204I/V mutations than a rtM204I mutation., (© 2011 John Wiley & Sons A/S.)

Viruses can create complex genetic populations within a host, and deep sequencing technologies allow extensive sampling of these populations. Limitations of these technologies, however, potentially bias this sampling, particularly when a PCR step precedes the sequencing protocol. Typically, an unknown number of templates are used in initiating the PCR amplification, and this can lead to unrecognized sequence resampling creating apparent homogeneity; also, PCR-mediated recombination can disrupt linkage, and differential amplification can skew allele frequency. Finally, misincorporation of nucleotides during PCR and errors during the sequencing protocol can inflate diversity. We have solved these problems by including a random sequence tag in the initial primer such that each template receives a unique Primer ID. After sequencing, repeated identification of a Primer ID reveals sequence resampling. These resampled sequences are then used to create an accurate consensus sequence for each template, correcting for recombination, allelic skewing, and misincorporation/sequencing errors. The resulting population of consensus sequences directly represents the initial sampled templates. We applied this approach to the HIV-1 protease (pro) gene to view the distribution of sequence variation of a complex viral population within a host. We identified major and minor polymorphisms at coding and noncoding positions. In addition, we observed dynamic genetic changes within the population during intermittent drug exposure, including the emergence of multiple resistant alleles. These results provide an unprecedented view of a complex viral population in the absence of PCR resampling.

Analysis of a large number of HIV-1 genomes at multiple time points after antiretroviral treatment (ART) interruption allows determination of the evolution of drug-resistant viruses and viral fitness in vivo in the absence of drug selection pressure. Using a parallel allele-specific sequencing (PASS) assay, potential primary drug-resistant mutations in five individual patients were studied by analyzing over 18,000 viral genomes. A three-phase evolution of drug-resistant viruses was observed after termination of ART. In the first phase, viruses carrying various combinations of multiple-drug-resistant (MDR) mutations predominated with each mutation persisting in relatively stable proportions while the overall number of resistant viruses gradually increased. In the second phase, viruses with linked MDR mutations rapidly became undetectable and single-drug-resistant (SDR) viruses emerged as minority populations while wild-type viruses quickly predominated. In the third phase, low-frequency SDR viruses remained detectable as long as 59 weeks after treatment interruption. Mathematical modeling showed that the loss in relative fitness increased with the number of mutations in each viral genome and that viruses with MDR mutations had lower fitness than viruses with SDR mutations. No single viral genome had seven or more drug resistance mutations, suggesting that such severely mutated viruses were too unfit to be detected or that the resistance gain offered by the seventh mutation did not outweigh its contribution to the overall fitness loss of the virus. These data provide a more comprehensive understanding of evolution and fitness of drug-resistant viruses in vivo and may lead to improved treatment strategies for ART-experienced patients.

We report a 33-year-old HIV type-1 (HIV-1)-infected male from Sierra Leone who harboured extensive drug resistance mutations to all nucleoside reverse transcriptase inhibitors (NRTIs) and non-NRTIs, including the multi-NRTI-resistance Q151M complex, K65R, M184I and Y181I, after using standard first-line generic fixed-dose stavudine, lamivudine and nevirapine (Triomune™) for 36 months. In the context of non-B subtypes in resource-limited countries, first-line stavudine-containing regimens have been associated with more extensive and complex mutation patterns, compared with subtype B viruses. Whether the extensive and complex NRTI resistance patterns found among African patients failing first-line antiretroviral therapy is explained by viral genetic diversity or by different patient monitoring strategies remains to be elucidated. Emerging multi-NRTI resistance in sub-Saharan Africa would not only compromise second-line treatment options and the success of antiretroviral rollout, but could also contribute to the spread of drug-resistant variants worldwide.

The preexistence of mutations to integrase inhibitors in HIV-1-infected Venezuelan patients was evaluated. The integrase region of the HIV-1 genome was amplified by nested-PCR and sequenced in 57 isolates from both naive (n = 24) and treated patients who received protease and/or reverse transcriptase inhibitors (PI and RTI, n = 33), but were never exposed to integrase inhibitors. Only one primary integrase resistance mutation, not conferring drug resistance by itself, was found among these patients, although several minor viral mutations, equally distributed among naive and PI- and RTI-treated patients, were also found. In the limited number of samples, no relation was found among the presence of resistance mutations to PI or RTI and the presence of minor mutations to integrase. The absence of resistance to integrase inhibitors may be related to the recent introduction of these drugs in our country. The availability of in-house assays allows for a more comprehensive surveillance of drug resistance to integrase inhibitors in Venezuela.

A survey for transmitted HIV drug resistance (HIVDR) was conducted according to WHO guidelines among clients newly diagnosed with HIV-1 infection at two voluntary counseling and testing centers (VCTC) in Mumbai. HIVDR testing was performed using the ViroSeq RT-PCR method (Abbott). Out of 50 successfully amplified and sequenced specimens, analysis of the first 34 consecutively collected specimens revealed no nucleoside reverse transcriptase inhibitor, nonnucleoside reverse transcriptase inhibitor, or protease inhibitor mutations from the 2007 WHO list of mutations for surveillance of transmitted HIVDR, indicating that the prevalence of transmitted HIVDR to all three drug classes was <5% among recently infected VCTC clients in Mumbai. The phylogenetic analysis revealed that all samples belonged to HIV-1 subtype C. Continued ART program monitoring and further evaluation of transmitted HIV drug resistance in coming years are essential in Mumbai as well as in other regions of the country in which ART is being scaled up rapidly.

Therapeutic options for treatment-experienced HIV-infected patients have been limited. The DUET trial evaluated the use of etravirine, a second-generation non-nucleoside reverse transcriptase inhibitor (NNRTI), or placebo, in 1203 treatment-experienced, HIV-infected patients. Eligible patients had to have evidence of NNRTI and protease inhibitor resistance-associated mutations, and evidence of virologic failure, as defined as a plasma viral load > 5000 copies/ml on antiretroviral therapy at the time of screening. Patients in both arms received an optimized background regimen including darunavir/ritonavir. DUET demonstrated superior outcomes in virologic suppression (plasma viral load < 50 copies/ml) and clinical end points including new AIDS-defining illnesses and death, in those randomized to receive etravirine. These results were maintained at 48 weeks of follow-up. Furthermore, etravirine was shown to be safe and well-tolerated over this period. In exploratory analyses, patients in the DUET study with greater number of active agents within the background regimen were more likely to have a fully suppressive response. Taken together, the DUET results highlight the high rates of virological success that can be achieved using new active agents, such as ritonavir-boosted darunavir and etravirine, in treatment-experienced patients with underlying drug-resistant HIV infection.

Background: Multi-class HIV-1 resistant variants are not rare nowadays. Genotypic and phenotypic resistance testing (including virtual phenotype) constitutes an important tool for optimizing antiretroviral treatment., Aim: To report a case of discrepancy between resistance interpretation and virological outcome., Methods: A case of a multi-drug experienced patient is presented. Genotypic and/or virtual phenotypic testing analysis was used., Results: The patient after 10 years of antiretroviral therapy with 11 different regimens unable to produce full virological suppression and with a rapidly declining CD4 count, achieved a successful virological outcome with a scheme containing Tipranavir boosted with low dose of ritonavir. Of note, the patient was screened for Tipranavir 1182.48 study and was found ineligible after genotypic analysis., Conclusions: Virologic suppression was achieved despite the fact that neither an active agent was included in the backbone regimen nor the resistance profile could ensure the effectiveness of Tipranavir.

Etravirine is a recently approved nonnucleoside reverse transcriptase inhibitor. The ability of etravirine to limit the emergence of resistance to protease inhibitors, and specifically to darunavir, was investigated in the subset of treatment-experienced patients with virologic rebound in the phase III DUET trials. Of those experiencing rebound, fewer etravirine-treated than placebo-treated patients developed mutations associated with resistance to protease inhibitors in general and to darunavir in particular, and more patients in the etravirine than the placebo-group maintained baseline darunavir susceptibility at endpoint.

We describe a case of multidrug and class resistant HIV in a patient with psychological issues affecting his adherence. The complexities involved in subsequent treatment decisions when resistance interpretation algorithms are discordant are discussed.

Background: The introduction of 2 or 3 fully active drugs in human immunodeficiency virus (HIV)-infected patients receiving failing antiretroviral therapy is a key determinant of subsequent treatment efficacy. The aim of this study was to assess the safety and efficacy of a regimen containing raltegravir, etravirine, and darunavir/ritonavir for treatment-experienced patients infected with multidrug-resistant HIV., Methods: Patients enrolled in this phase II, noncomparative, multicenter trial were naive to the investigational drugs and had plasma HIV RNA levels >1000 copies/mL, a history of virologic failure while receiving nonnucleoside reverse-transcriptase inhibitors (NNRTI), > or =3 primary protease inhibitor and nucleoside reverse transcriptase inhibitor (NRTI) mutations, and < or =3 darunavir and NNRTI mutations. The primary end point was the proportion of patients with plasma HIV RNA levels <50 copies/mL at 24 weeks., Results: A total of 103 patients enrolled in the study. At baseline, genotypic resistance profiles showed a median of 4 primary protease inhibitor mutations, 1 NNRTI mutation, and 6 NRTI mutations. In addition to the investigational drugs, 90 patients (87%) received optimized background therapy that included NRTIs (86 patients) or enfuvirtide (12 patients). At week 24, 90% of patients (95% confidence interval, 85%-96%) had an HIV RNA level <50 copies/mL. At week 48, 86% (95% confidence interval, 80%-93%) had an HIV RNA level <50 copies/mL. The median CD4 cell count increase was 108 cells/mm(3). Grade 3 or 4 clinical adverse events were reported in 15 patients (14.6%). Only 1 patient discontinued the investigational antiretroviral regimen, because of an adverse event., Conclusion: In patients infected with multidrug-resistant virus who have few remaining treatment options, the combination of raltegravir, etravirine, and darunavir/ritonavir is well tolerated and is associated with a rate of virologic suppression similar to that expected in treatment-naive patients.

We described differential selective pressures along codon sites of the RT and PR genes of HIV-1 from HAART-failing and naïve-treated individuals, through the comparison of the ratio of non-synonymous mutations (d(N)) to synonymous mutations (d(S)) substitution per site. Resistance-associated mutations were found in 1/71 (1.4%) and 109/117 (93.1%) samples from naïve-treated and HAART-failing individuals, respectively, although most of positively selected codons represented polymorphisms in positions 123, 211, 245, 297 in RT and 37, 63 in PR of naïve-treated samples and positions 122, 123, 245, 272, 277, 286, 297 in RT and 10, 15, 20, 35, 37, 62, 63, 64, 71, 72, 77, 93 in PR of HAART-failing samples, except by ARV-resistance codons 74, 184, 215 in RT and 90 in PR exclusively found in HAART-failing group. The number and diversity of sites under selective pressure at populational level also increased in RT but not in PR of treated individuals. Our results demonstrated no evolution of drug-associated codons among untreated individuals, indicating unlikely transmission and adaptation of resistant HIV-1 strains in a free drug environment. Polymorphic sites observed exclusively in HAART-failing group, may contribute to HIV-1 escape and adaptation at individual and populational levels in a drug environment, although those mutually found in HIV-1 despite of previous exposure to ARV treatment, should not be considered accurate resistance markers.

Multiclass-drug resistance, often caused by poor treatment compliance, is a challenging problem in all categories of HIV-infected patients. Selective pressure is higher in youth for both biological and behavioral reasons. We report the case of a 15-year-old Caucasian male, with vertically acquired HIV-1 infection, who failed several lines of antiretroviral therapy and was successfully treated with darunavir/ritonavir and etravirine.

For intensively pretreated pediatric patients with human immunodeficiency virus type 1 (HIV-1) infection, the treatment options available are limited. We report the case of a highly treatment-experienced 12-year-old boy with multidrug-resistant HIV-1, who was successfully treated with highly active antiretroviral therapy (HAART) including ritonavir-boosted tipranavir oral solution, a novel non-peptic protease inhibitor, and enfuvirtide.

Objective: To assess outcomes after antiretroviral therapy (ART) in adolescents and youth in Haiti, a country with a generalized epidemic of infection with HIV-1., Methods: An assessment was made of survival, plasma HIV-1 ribonucleic acid (RNA) concentrations and HIV-1 drug resistance patterns after 12 months of ART in patients aged 13-25 years who presented to a clinic in Port-au-Prince, Haiti, with AIDS between 1 March 2003 and 31 December 2005. Participants received ART in accordance with WHO guidelines. Kaplan-Meier analysis was used to estimate survival probabilities and their 95% confidence intervals (CI) for the period from ART initiation to death., Findings: Of a total of 146 patients, 96 (66%) were female; the median CD4+ T-cell count at baseline was 129 cells/ml. By Kaplan-Meier analysis, 13% of the patients had died at 12 months, 17% at 24 months and 20% at 36 months. A plasma HIV-1 RNA concentration > or = 50 copies/ml was seen in 40 (51%) of 79 patients 12 months after treatment initiation and was associated with poor ART adherence. Among 29 patients with > 1000 copies/ml at 12 months, resistance mutations to non-nucleoside reverse transcriptase inhibitors (NNRTIs) were detected in 23 cases (79%); to both NNRTIs and lamivudine in 21 (72%) cases; and to NNRTIs, lamivudine and other nucleoside reverse transcriptase inhibitors in 10 (35%) cases. One hundred and six participants (73%) reported sexual intercourse without condoms, and 35 of the 96 women (36%) were pregnant during follow-up., Conclusion: Adolescents and youth with AIDS receiving ART are at risk of virologic failure and disease progression and can therefore transmit HIV-1 to sexual partners and infants. Strategies to target the special needs of this age group are urgently needed.

The antiviral drug acyclovir is a guanosine nucleoside analog that potently inhibits herpes simplex virus (HSV) replication. Acyclovir treatment in patients coinfected with HSV and human immunodeficiency virus (HIV) has been observed to alter disease course and decrease HIV viral load, a finding that has been attributed to indirect effects of HSV suppression on HIV replication. Based on this hypothesis, several clinical studies have recently investigated the use of acyclovir for treatment of patients coinfected with HSV and HIV or for prophylaxis against HIV transmission. In this report, we use a single round HIV infectivity assay to show that acyclovir directly inhibits HIV infection with an IC50 of approximately 5 microm. The target of acyclovir in HIV-infected cells is validated as HIV reverse transcriptase (RT) by the emergence of the RT variant V75I under the selective pressure of acyclovir. The V75I mutation is part of the multidrug resistance pathway that enhances viral resistance to many of the best RT inhibitors approved for the treatment of HIV. Biochemical analyses demonstrate that acyclovir triphosphate is a chain terminator substrate for HIV RT and can compete with dGTP for incorporation into DNA. Although acyclovir may prove a useful lead for development of new HIV treatments, the selection of resistant mutants raises a cautionary note to the use of acyclovir monotherapy in patients coinfected with HSV and HIV.