Pretreatment HIV-1 Resistance in Argentina: Results from the Second Surveillance Study Following World Health Organization Guidelines (2019).

More than 62,000 individuals are currently on antiretroviral treatment within the public health system in Argentina. In 2019, more than 50% of people on ART received non-nucleoside reverse transcriptase inhibitors (NNRTIs). In this context, the second nationwide HIV-1 pretreatment drug resistance surveillance study was carried out between April and December 2019 to assess the prevalence of HIV-1 drug resistance in Argentina using the World Health Organization guidelines. This was a nationwide cross-sectional study enrolling consecutive 18-year-old and older individuals starting ARVs at 19 ART-dispensing centers. This allowed us to estimate a point prevalence rate of resistance-associated mutations (RAMs) with a confidence interval (CI) of 5% (for the total population and for those without antiretroviral exposure). Four-hundred forty-seven individuals were included in the study. The prevalence of mutations associated with resistance was detected in 27.7% (95% CI 25.6-34.9%) of the population. For NNRTI, it was 19.6% (95% CI 16.3-24.5%), for integrase strand transfer inhibitor (INSTI) 6.1% (95% CI 6.1-11.9%), for nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) 3% (95% CI 1.9-5.9%), and for protease inhibitors 1.5% (95% CI 0.7-3.6%). Naive individuals had variants of resistance to NRTIs in 16.8% (95% CI 12.8-21.4) and 5.7% (95% CI 2.9-15.9) to INSTI. For experienced individuals, the prevalence of variants associated with resistance was 30.38% (95% CI 20.8-42.2) for NRTIs and 7.7% (95% CI 2.9-15.9) for INSTI. This study shows an increase in the frequency of nonpolymorphic RAMs associated with resistance to NNRTI. This study generates the framework of evidence that supports the use of schemes based on high genetic barrier integrase inhibitors as the first line of treatment and the need for the use of resistance test before prescribing schemes based on NNRTI. We report for the first time the presence of a natural polymorphism associated with the most prevalent recombinant viral form in Argentina and the presence of a mutation linked to first-line integrase inhibitors such as raltegravir.

Liver cirrhosis in HIV/HCV-coinfected individuals is related to NK cell dysfunction and exhaustion, but not to an impaired NK cell modulation by CD4+ T-cells.

INTRODUCTION: HIV worsens HCV-related liver disease by accelerating fibrosis progression; however, progression rates are extremely variable among HIV/HCV-coinfected individuals. NK cells are associated with modulation of liver fibrosis and are profoundly altered during HCV and HIV infections. CD4+ T-cells modulate NK cell function, and are also affected by HIV infection. Here, we aim to characterize the association of hepatic fibrosis with both the phenotype and function of peripheral NK cells and their regulation by CD4+ T-cells, in HIV/HCV-coinfected individuals. METHODS: Thirty-four HIV/HCV-coinfected individuals with minimal (n = 16) and advanced (n = 18) fibrosis (METAVIR F0/F1 and F4 scores respectively) and 20 healthy volunteers were enrolled. PBMC were obtained from peripheral blood samples and NK and CD4+ T-cells were isolated and analysed. NK cell phenotype (CD25, CD69, Nkp46, NKG2D, PD-1), degranulation (CD107a) and IFN-γ and TNF-α production, as well as CD4+ T-cell activation (CD69, CD25 and CD38) were measured by flow cytometry. CD4+ T-cell conditioned medium (CM) derived from F0/F1 or F4 individuals was assessed for IL-2 levels by ELISA. Modulation of NK cell functionality by these CMs was also analysed. RESULTS: When comparing to NK cells from individuals with minimal fibrosis, degranulation and cytokine secretion by NK cells from subjects with F4 scores was significantly impaired, while PD-1 expression was augmented. On the one hand, neither the expression of activation markers nor IL-2 secretion was distinctly induced in CD4+ T-cells from subjects with F0/F1 or F4 METAVIR scores. Finally, NK cell degranulation and cytokine secretion were not differentially modulated by CD4+ T-cell CM, whether CD4+ T-cells derived from subjects with minimal or advanced fibrosis. CONCLUSIONS: Low levels of NK and CD4+ T-cells in HIV/HCV-coinfected individuals with advanced liver fibrosis have been previously described. Here, we show that advanced liver fibrosis in coinfected individuals is associated to a defective function of NK cells and an increased expression of the exhaustion/senescence marker PD-1. This NK signature could not be attributed to changes in the ability of CD4+ T-cells to modulate NK cell function.

Previous failure of interferon-based therapy does not alter the frequency of HCV NS3 protease or NS5B polymerase inhibitor resistance-associated variants: longitudinal analysis in HCV/HIV co-infected patients.

Since 2011, treatment of chronic hepatitis C virus (HCV) includes direct-acting antivirals (DAAs) in addition to pegylated interferon-α (peg-IFN) and ribavirin (RBV). IFN-based treatment induces strong cytotoxic T-lymphocyte activity directed to the protease- and polymerase-derived epitopes. This enhanced immunological pressure could favour the emergence of viral epitope variants able to evade immune surveillance and, when resistance-associated variants (RAVs) are implicated, could also be co-selected as a hitchhiking effect. This study analysed the dynamics of the frequency of protease and polymerase inhibitor RAVs that could affect future HCV treatment in human immunodeficiency virus (HIV) co-infected patients on stable antiretroviral therapy with previous IFN-based treatment failure. HCV genotype 1a RNA was extracted from plasma samples of 18 patients prior to and during (24h and 4, 12, 24 and 48 weeks) therapy with peg-IFN+RBV. Next-generation sequencing was performed on HCV-RNA populations using NS3 and NS5B PCR-amplified coding regions. Two measures of genetic diversity were used to compare virus populations: average pairwise nucleotide diversity (π) and Tajima's D statistic. Several protease and polymerase RAVs were detected in all subjects at very low frequencies (<5%), and in most cases their presence was not constant during follow-up. Only samples from two patients for each region exhibited Q80R/K/L and A421V as highly predominant variants. No significant differences were observed among sampling times for either π or D values. In conclusion, previous therapy and failure of peg-IFN+RBV were not associated with an increase in DAA-targeting NS3 or NS5B RAVs that naturally exist in HIV co-infected subjects.

HIV-1 tropism dynamics and phylogenetic analysis from longitudinal ultra-deep sequencing data of CCR5- and CXCR4-using variants.

OBJECTIVE: Coreceptor switch from CCR5 to CXCR4 is associated with HIV disease progression. The molecular and evolutionary mechanisms underlying the CCR5 to CXCR4 switch are the focus of intense recent research. We studied the HIV-1 tropism dynamics in relation to coreceptor usage, the nature of quasispecies from ultra deep sequencing (UDPS) data and their phylogenetic relationships. METHODS: Here, we characterized C2-V3-C3 sequences of HIV obtained from 19 patients followed up for 54 to 114 months using UDPS, with further genotyping and phylogenetic analysis for coreceptor usage. HIV quasispecies diversity and variability as well as HIV plasma viral load were measured longitudinally and their relationship with the HIV coreceptor usage was analyzed. The longitudinal UDPS data were submitted to phylogenetic analysis and sampling times and coreceptor usage were mapped onto the trees obtained. RESULTS: Although a temporal viral genetic structuring was evident, the persistence of several viral lineages evolving independently along the infection was statistically supported, indicating a complex scenario for the evolution of viral quasispecies. HIV X4-using variants were present in most of our patients, exhibiting a dissimilar inter- and intra-patient predominance as the component of quasispecies even on antiretroviral therapy. The viral populations from some of the patients studied displayed evidences of the evolution of X4 variants through fitness valleys, whereas for other patients the data favored a gradual mode of emergence. CONCLUSIONS: CXCR4 usage can emerge independently, in multiple lineages, along the course of HIV infection. The mode of emergence, i.e. gradual or through fitness valleys seems to depend on both virus and patient factors. Furthermore, our analyses suggest that, besides becoming dominant after population-level switches, minor proportions of X4 viruses might exist along the infection, perhaps even at early stages of it. The fate of these minor variants might depend on both viral and host factors.

[HBV and HCV co-infections in HIV positive patients in the "HAART era": new challenges]. / Coinfecciones por HBV y HCV en pacientes hiv positivos en la "era HAART": nuevos desafios.

Co-infections with HIV and HCV/HBV are frequently found due to the similar routes of transmission (sexual, parenteral and vertical). Since the introduction of highly active antiretroviral therapy (HAART) there has been a notably decrease in patients morbidity and mortality, nevertheless with the prolonged survival, many of these patients are at risk of developing chronic complication, secondary to the infection of hepatotropic viruses. End stage liver disease is one of the main causes of morbid-mortality among HIV patients in developed countries. Nowadays there are new available therapies, diagnostic and follow up techniques for HBV and HCV, what provides a better control of both co-infections.

Coinfecciones por HBV y HCV en pacientes HIV positivos en la era HAART: nuevos desafíos / HBV and HCV co-infections in HIV positive patients in the HAART era: new challenges

Las coinfecciones con virus de la hepatitis C (HCV) y/o virus de la hepatitis B (HBV) en pacientes infectados por el virus de la inmunodeficiencia humana (HIV) son un hallazgo frecuente en virtud de las similares vías de transmisión que estos agentes presentan (sexual, parenteral y vertical). Desde el advenimiento del tratamiento antirretroviral de alta eficiencia (TARV) se evidenció una marcada disminución en la morbi-mortalidad de los pacientes; sin embargo, ante la prolongación de su sobrevida, las complicaciones crónicas debidas a las coinfecciones con estos virus hepatotropos han cobrado importancia, convirtiéndose la enfermedad hepática en una de las primeras causas de morbi-mortalidad de los pacientes HIV positivos en los países desarrollados. Se disponen en la actualidad de nuevas terapias y métodos de diagnóstico y seguimiento para HBV y HCV, lo cual permite un mejor control de ambas coinfecciones.

Co-infections with HIV and HCV/HBV are frequently found due to the similar routes of transmission (sexual, parenteral and vertical). Since the introduction of highly active antiretroviral therapy (HAART) there has been a notably decrease in patients morbidity and mortality, nevertheless with the prolonged survival, many of these patients are at risk of developing chronic complication, secondary to the infection of hepatotropic viruses. End stage liver disease is one of the main causes of morbid-mortality among HIV patients in developed countries. Nowadays there are new available therapies, diagnostic and follow up techniques for HBV and HCV, what provides a better control of both co-infections.

Coinfecciones por HBV y HCV en pacientes HIV positivos en la era HAART: nuevos desafíos / HBV and HCV co-infections in HIV positive patients in the HAART era: new challenges

Las coinfecciones con virus de la hepatitis C (HCV) y/o virus de la hepatitis B (HBV) en pacientes infectados por el virus de la inmunodeficiencia humana (HIV) son un hallazgo frecuente en virtud de las similares vías de transmisión que estos agentes presentan (sexual, parenteral y vertical). Desde el advenimiento del tratamiento antirretroviral de alta eficiencia (TARV) se evidenció una marcada disminución en la morbi-mortalidad de los pacientes; sin embargo, ante la prolongación de su sobrevida, las complicaciones crónicas debidas a las coinfecciones con estos virus hepatotropos han cobrado importancia, convirtiéndose la enfermedad hepática en una de las primeras causas de morbi-mortalidad de los pacientes HIV positivos en los países desarrollados. Se disponen en la actualidad de nuevas terapias y métodos de diagnóstico y seguimiento para HBV y HCV, lo cual permite un mejor control de ambas coinfecciones. (AU)

Co-infections with HIV and HCV/HBV are frequently found due to the similar routes of transmission (sexual, parenteral and vertical). Since the introduction of highly active antiretroviral therapy (HAART) there has been a notably decrease in patients morbidity and mortality, nevertheless with the prolonged survival, many of these patients are at risk of developing chronic complication, secondary to the infection of hepatotropic viruses. End stage liver disease is one of the main causes of morbid-mortality among HIV patients in developed countries. Nowadays there are new available therapies, diagnostic and follow up techniques for HBV and HCV, what provides a better control of both co-infections. (AU)