Characterization of the patterns of drug-resistance mutations in newly diagnosed HIV-1 infected patients naïve to the antiretroviral drugs

<p>Abstract</p> <p>Background</p> <p>The transmission of HIV-1 drug-resistant strains in drug naive patients may seriously compromise the efficacy of a first-line antiretroviral treatment. To better define this problem, a study in a cohort of newly diagnosed HIV-1 infected individuals has been conducted. This study is aimed to assess the prevalence and the patterns of the mutations recently associated with transmitted drug resistance in the reverse transcriptase (RT) and in protease (PR) of HIV-1.</p> <p>Methods</p> <p>Prevalence of transmitted drug resistant strains is determined in 255 newly diagnosed HIV-1 infected patients enrolled in different counselling and testing (CT) centres in Central Italy; the Avidity Index (AI) on the first available serum sample is also used to estimate time since infection. Logistic regression models are used to determine factors associated with infection by drug resistant HIV-1 strains.</p> <p>Results</p> <p>The prevalence of HIV-1 strains with at least one major drug resistance mutation is 5.9% (15/255); moreover, 3.9% (10/255) of patients is infected with HIV nucleoside reverse transcriptase inhibitor (NRTI)-resistant viruses, 3.5% (9/255) with HIV non-NRTI-resistant viruses and 0.4% (1/255) with HIV protease inhibitor (PI)-resistant viruses. Most importantly, almost half (60.0%) of patients carries HIV-1 resistant strains with more than one major drug resistance mutation. In addition, patients who had acquired HIV through homosexual intercourses are more likely to harbour a virus with at least one primary resistance mutation (OR 7.7; 95% CI: 1.7–35.0, P = 0.008).</p> <p>Conclusion</p> <p>The prevalence of drug resistant HIV-1 strains among newly diagnosed individuals in Central Italy is consistent with the data from other European countries. Nevertheless, the presence of drug-resistance HIV-1 mutations in complex patterns highlights an additional potential risk for public health and strongly supports the extension of wide genotyping to newly diagnosed HIV-1 infected patients.</p

HCV genotypes are differently prone to the development of resistance to linear and macrocyclic protease inhibitors

Because of the extreme genetic variability of hepatitis C virus (HCV), we analyzed whether specific HCV-genotypes are differently prone to develop resistance to linear and macrocyclic protease-inhibitors (PIs)

Immune-escape mutations and stop-codons in HBsAg develop in a large proportion of patients with chronic HBV infection exposed to anti-HBV drugs in Europe

Background: HBsAg immune-escape mutations can favor HBV-transmission also in vaccinated individuals, promote immunosuppression-driven HBV-reactivation, and increase fitness of drug-resistant strains. Stop-codons can enhance HBV oncogenic-properties. Furthermore, as a consequence of the overlapping structure of HBV genome, some immune-escape mutations or stop-codons in HBsAg can derive from drug-resistance mutations in RT. This study is aimed at gaining insight in prevalence and characteristics of immune-associated escape mutations, and stop-codons in HBsAg in chronically HBV-infected patients experiencing nucleos(t)ide analogues (NA) in Europe. Methods: This study analyzed 828 chronically HBV-infected European patients exposed to ≥ 1 NA, with detectable HBV-DNA and with an available HBsAg-sequence. The immune-associated escape mutations and the NA-induced immune-escape mutations sI195M, sI196S, and sE164D (resulting from drug-resistance mutation rtM204 V, rtM204I, and rtV173L) were retrieved from literature and examined. Mutations were defined as an aminoacid substitution with respect to a genotype A or D reference sequence. Results: At least one immune-associated escape mutation was detected in 22.1% of patients with rising temporal-trend. By multivariable-analysis, genotype-D correlated with higher selection of ≥ 1 immune-associated escape mutation (OR[95%CI]:2.20[1.32-3.67], P = 0.002). In genotype-D, the presence of ≥ 1 immune-associated escape mutations was significantly higher in drug-exposed patients with drug-resistant strains than with wild-type virus (29.5% vs 20.3% P = 0.012). Result confirmed by ana

Impact of pre-therapy viral load on virological response to modern first-line HAART

BACKGROUND: We tested whether pre-HAART (Highly Active Antiretroviral Therapy) viremia affects the achievement and maintenance of virological-success in HIV-1 infected patients starting modern first-line therapies. METHODS: 1430 patients starting their first HAART (genotype-tailored) in median in 2008 (IQR: 2006-2009) were grouped according to levels of pre-HAART viremia (500K copies/mL). The impact of pre-therapy viremia on the time to virological-success (viremia ≤50 copies/mL) and on the time to virological-rebound (first of two consecutive viremia-values >50 copies/mL after virological-success) were evaluated by Kaplan-Meier curves and Cox regression analyses. RESULTS: Median pre-HAART-viremia was 5.1(IQR:4.5-5.5) log(10) copies/mL, and 53% of patients had viremia >100K copies/mL. By week 48, the prevalence of patients reaching the virological-success was >90% in all pre-HAART viremia ranges, with the only exception of range >500K copies/mL (virological-success = 83%) (p500K copies/mL showed the lowest hazard of virological undetectability after adjusting for age, gender, pre-HAART CD4 cell-count, transmitted drug-resistance, calendar year, third drug-administered (adjusted RH[95%CI]: 0.27[0.21-0.35], p500K copies/mL was also associated with higher probability of virological-rebound compared to patients belonging to lower viremia strata at weeks 4/12/24 (p=0.050). CONCLUSIONS: At the time of modern HAART, and beside an average >90% of virological-success, high pre-HAART viremia remains an independent factor associated with delayed and decreased virological-success. Patients starting HAART with >500K copies/mL represent a significant population that may deserve special attention

Specific enfuvirtide-associated mutational pathways in HIV-1 Gp41 are significantly correlated with an increase in CD4(+) cell count, despite virological failure

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) gp41 is a crucial determinant for HIV-1 pathogenicity. We investigated the correlation of enfuvirtide (ENF)-associated gp41 mutational clusters with viroimmunological parameters, as well as the potential underlying mechanisms. METHODS: A total of 172 gp41 sequences and clinical follow-up data from 73 ENF-treated patients were analyzed monthly, from baseline to week 48. RESULTS: There were 7 novel gp41 mutations positively associated with ENF treatment and correlated with classic ENF mutations. The ENF-associated clusters [V38A + N140I ] and [V 38A +T18A ] significantly correlated with an increase in CD4 cell count at week 48 ( an increase from baseline of 112 and 209 cells/microL, respectively), whereas [Q40H + L45M + 268A] significantly correlated with a decrease in CD4 cell count (-53 cells/microL), without a change in the level of viremia. Residues 38 and 18 are located complementarily to each other in the Rev-responsive element, whereas analysis of molecular dynamics showed that the copresence of [V38A + N140 I] abolishes the interaction between residue 38 and 145 important for stabilization of the 6-helix bundle. In contrast, T268A localizes in the gp41 calmodulin-binding domain responsible for gp41-induced CD4(+) T lymphocyte apoptosis. CONCLUSION: Specific gp41 mutational clusters associated with ENF treatment significantly correlate with increases in CD4(+) cell count. Structural analysis suggests that this immunological gain is associated with mechanisms that act at both the protein level and the RNA level (even under conditions of virological failure). This result may help in the selection of patients who can benefit most from ENF treatment and represents a driving force for the design of the next generation of entry inhibitors

Novelties in Evaluation and Monitoring of Human Immunodeficiency Virus-1 Infection: Is Standard Virological Suppression Enough for Measuring Antiretroviral Treatment Success?

The high potency and tolerability of the currently available antiretroviral drugs has modified HIV-1 infection from a life-threatening disease to a chronic illness. Nevertheless, some issues still remain open to optimize the management of HIV-1 infected patients in term of maintenance of virological suppression over time, identifying patients that could benefit from simplification therapy, and reducing co-mordibities driven by chronic inflammation. The availability of robust and affordable virological and immunological markers can help in solving these issues by providing information on the burden of HIV-1 reservoir in all the anatomical compartments in which the virus replicates as well as on persistent inflammation, immune activation and senescence despite successful virological suppression. In this light, this review is aimed at providing new insights (arising from a two-day Italian expert meeting hold in Rome in March 2016) in evaluation and monitoring of HIV-1 infection from a virological, immunological and clinical perspective. Particular attention has been focused on role of novel parameters (such as total HIV-1 DNA, residual viremia, and immunological markers) in optimizing treatment strategies, enhancing medical adherence, and individualizing monitoring

Novelties in Evaluation and Monitoring of Human Immunodeficiency Virus-1 Infection: Is Standard Virological Suppression Enough for Measuring Antiretroviral Treatment Success?

The high potency and tolerability of the currently available antiretroviral drugs has modified HIV-1 infection from a life-threatening disease to a chronic illness. Nevertheless, some issues still remain open to optimize the management of HIV-1 infected patients in term of maintenance of virological suppression over time, identifying patients that could benefit from simplification therapy, and reducing co-mordibities driven by chronic inflammation. The availability of robust and affordable virological and immunological markers can help in solving these issues by providing information on the burden of HIV-1 reservoir in all the anatomical compartments in which the virus replicates as well as on persistent inflammation, immune activation and senescence despite successful virological suppression. In this light, this review is aimed at providing new insights (arising from a two-day Italian expert meeting hold in Rome in March 2016) in evaluation and monitoring of HIV-1 infection from a virological, immunological and clinical perspective. Particular attention has been focused on role of novel parameters (such as total HIV-1 DNA, residual viremia, and immunological markers) in optimizing treatment strategies, enhancing medical adherence, and individualizing monitoring

Novelties in Evaluation and Monitoring of Human Immunodeficiency Virus-1 Infection: Is Standard Virological Suppression Enough for Measuring Antiretroviral Treatment Success?

The high potency and tolerability of the currently available antiretroviral drugs has modified HIV-1 infection from a life-threatening disease to a chronic illness. Nevertheless, some issues still remain open to optimize the management of HIV-1 infected patients in term of maintenance of virological suppression over time, identifying patients that could benefit from simplification therapy, and reducing co-mordibities driven by chronic inflammation. The availability of robust and affordable virological and immunological markers can help in solving these issues by providing information on the burden of HIV-1 reservoir in all the anatomical compartments in which the virus replicates as well as on persistent inflammation, immune activation and senescence despite successful virological suppression. In this light, this review is aimed at providing new insights (arising from a two-day Italian expert meeting hold in Rome in March 2016) in evaluation and monitoring of HIV-1 infection from a virological, immunological and clinical perspective. Particular attention has been focused on role of novel parameters (such as total HIV-1 DNA, residual viremia, and immunological markers) in optimizing treatment strategies, enhancing medical adherence, and individualizing monitoring