One Year of Long-Acting Cabotegravir and Rilpivirine in People With Human Immunodeficiency Virus and Long Exposure to Antiretroviral Therapy: Data From the SCohoLART Study.

Background: The aim of the study was to evaluate the 12-month cumulative probability of treatment discontinuation (TD) in people with human immunodeficiency virus (HIV; PWH) and a long exposure to antiretroviral therapy (ART) switching to long-acting cabotegravir and rilpivirine (CAB/RPV). Methods: SCohoLART is a single-center, prospective, cohort study designed to collect both samples and clinical data from PWH with virological suppression who switched to bimonthly long-acting CAB/RPV. TD occurred at switch to another regimen for any reason including virological failure (VF); VF was defined as HIV RNA levels ≥50 copies/mL at 2 consecutive measurements or a single HIV RNA level ≥1000 copies/mL. Results were reported as median (interquartile range [IQR]) or frequency (percentage). Cumulative probabilities of TD were estimated using Kaplan-Meier curves. Results: We evaluated 514 participants; 467 (90.9%) were male, and their median age (IQR) was 49 (40-56) years. At the time of switching, the median time from HIV diagnosis and the median duration of ART were 14.0 (IQR, 8.8-20.5) and 11.4 (7.9-17.4) years, respectively; before starting CAB/RPV, the median number of antiretroviral regimens was 3 (2-4). During a median study follow-up (IQR) of 13.1 (9.1-15.5) months, 52 PWH (10.1%) experienced TD, including 4 (0.8%) for VF. The 12-month cumulative probability of TD was 11% (95% confidence interval, 8%-14%). The main cause of TD was injection site reaction (15 participants [28.8%]). Conclusions: The 1-year cumulative probability of TD with long-acting CAB/RPV was quite low in this cohort of people with a median exposure to ART of 10 years, in whom injection site reaction was the leading cause of TD. VFs were rare during study follow-up.

Clinico-Virological Outcomes and Mutational Profile of SARS-CoV-2 in Adults Treated with Ribavirin Aerosol for COVID-19 Pneumonia.

The emergence of new SARS-CoV-2 variants can affect vaccine efficacy, laboratory diagnosis and the therapies already available, triggering interest in the search for antiviral agents for SARS-CoV-2 infections. Ribavirin (RBV) is a broad-spectrum antiviral with demonstrated in vitro activity against multiple viruses, including SARS-CoV-2. This retrospective study evaluated the dynamics and viral clearance of SARS-CoV-2 in hospitalised adult participants (PTs) with COVID-19 pneumonia who received an RBV aerosol within a compassionate use study. The impact of RBV on the clinical outcome and the mutational profile of SARS-CoV-2 was also assessed. The median RNA values measured in nine PTs included in this study decreased from baseline to discharge (at BL, threshold cycle (Ct) = 22.4, IQR 19.84-5.07; at discharge, Ct = 27.92, IQR 26.43-36.11), with a significant decline in the Ct value evaluated by Friedman rank ANOVA analysis, p = 0.032. Seven out of nine PTs experienced a clinical improvement, while two PTs deceased during hospitalisation. In PTs with a favourable outcome, the virus clearance rate at discharge was 28.6%. The cumulative clearance rate was 71.4% within 14 days from discharge. A mutational pattern after RBV was detected in three out of five PTs in whom whole-genome sequencing was available. Our findings suggest that RBV limits SARS-CoV-2 replication, possibly resulting in a favourable clinical outcome. Ribavirin may also contribute to the mutational spectrum of SARS-CoV-2.

Modelling the impact of protein-kinase R allelic variant on HIV biomarkers trajectories by means of latent class mixed models.

This paper is based on a retrospective longitudinal study on people living with HIV under antiretroviral treatment (ART) where allelic variants (either heterozygous CT genotype or homozygous CC genotype) have been evaluated at position -168 of the promoter region of the protein kinase R (-168/PKR). In general, antiviral effects of interferon are partially mediated by a RNA-dependent protein kinase (PKR) that, once activated, inhibits protein synthesis. Indeed, activation of PKR response can inhibit HIV replication. To explore the role of allelic variants in shaping dynamics of commonly monitored HIV biomarkers, CD4 cells, CD8 cells and HIV-load were modelled within a latent class mixed model (LCMM) to account for participants' heterogeneity over time. The estimated models identified two sub-groups from CD4 and HIV-load dynamics, revealing better outcomes for subgroups of participants with the heterozygous CT genotype. Heterozygous CT subjects in one of the two identified subgroups exhibited higher increase of CD4 cells and more marked decrease of HIV-load, over time, with respect to the homozygous CC subjects assigned to the same group.

Levels of Alpha-Fetoprotein and Association with Mortality in Hepatocellular Carcinoma of HIV-1-Infected Patients.

METHODS: This is a retrospective cohort study on patients living with HIV-1 infection (PLWH) followed at the Division of Infectious Diseases of the San Raffaele Hospital, with cirrhosis and HCC diagnosed between 1999 and 2018 and with an available AFP value at HCC diagnosis. The area under the receiver operating characteristic curve (AUC) was used to estimate the accuracy of baseline AFP in predicting death. Factors associated with the risk of death were identified using multivariable Cox proportional-hazards regression models. RESULTS: Overall, 53 PLWH were evaluated: 18 patients received a curative treatment (9 liver transplantation, 5 liver resections and 4 radiofrequency ablation) and 35 a noncurative treatment (17 chemo or radio embolization, 10 sorafenib and 8 best supportive care). Baseline AFP was predictive of death [AUC 0.71, 95% confidence interval (CI) 0.54-0.83], and the optimal cut-off was 28.8 ng/mL. At multivariable analysis, BL AFP ≥28.8 ng/mL was associated with death [adjusted hazard ratio (aHR) 7.05, 95% CI 1.94-25.71 P = 0.003]. Other factors were HBV infection (aHR 8.57, 95% CI 1.47-50.08, P = 0.017) and treatment allocation (curative vs. noncurative, aHR 0.08, 95% CI 0.02-0.40, P = 0.0004). CONCLUSIONS: Our findings suggest that in PLWH AFP serum levels ≥28.8 ng/mL, HBV coinfection and treatment allocation represent predictive markers for death at the time of HCC diagnosis.

Risk of HIV viral rebound in HIV infected patients on direct acting antivirals (DAAs) treatment for HCV.

BACKGROUND: The dynamic of HIV-viral load (VL) remains poorly investigated in HIV/HCV patients under direct acting antivirals (DAAs). METHODS: We retrospectively evaluated HIV-VL at baseline (BL) during and up to 24 weeks post-DAAs in a cohort of 305 HIV-1/HCV patients, on ART and with no HIV virological failure (VF) in the 6 months before treatment with DAAs; during the period of observation VF was defined as confirmed VL≥50 copies/mL; virological blips (VB, transient, not confirmed, VL ≥50 copies/mL). Stepwise Cox regression models were fitted to estimate adjusted hazard ratios (aHR) of VF. RESULTS: Fifteen VF occurred in 13 patients over 187 person-years of follow-up (PYFU): incidence rate (IR) of 8.0 per 100-PYFU (95% CI = 4.0-12.1); 29 VBs were detected in 26 patients over 184 PYFU: IR = 15.8 per 100-PYFU (95% CI = 10.0-21.5). The most prominent factor associated with VF was the presence of BL HIV residual viremia (RV = HIV-RNA detectable but not precisely quantifiable) [aHR = 12.26 (95% CI = 3.74-40.17), P<0.0001]. Other factors were ≥1 VBs in the 6 months before DAAs [aHR = 6.95 (95% CI = 1.77-27.37) P = 0.006] number of ART regimens failed before DAAs initiation [aHR (per more regimen) = 1.22 (95% CI = 1.04-1.42), P = 0.012] and age [aHR (per year older) = 1.16 (95% CI = 1.04-1.29), P = 0.010]. CONCLUSIONS: Our findings underline the importance for close monitoring HIV-VL in selected patients. Whether this phenomenon is triggered by the rapid clearance of HCV remains to be established.

Compartmentalization of Resistance-Associated Substitutions in HIV/HCV-Infected Patients: Possible Correlation with Infecting HCV Genotype.

Resistance-associated substitutions (RASs) may exist prior to treatment and contribute to the failure of treatment with direct-acting antivirals (DAAs). As the major site of HCV replication, naturally occurring variants with RASs may segregate into the liver. In the present study, we performed viral population sequencing to retrospectively investigate the NS3 and NS5A RAS profiles in 34 HIV/HCV coinfected patients naïve to anti-HCV treatment who underwent diagnostic liver biopsy between 2000 and 2006 and had liver and plasma samples available. Sixteen were infected by HCV genotype (GT) 1a, 11 by GT3a, and 7 by GT4d. The analysis of the NS3 domain in GT1a showed a difference in strain between the liver and plasma in three cases, with a preponderance of specific RASs in the liver compartment. In GT4d samples, 6/7 coupled liver and plasma samples were concordant with no RASs. Sequence analysis of the NS5A domain showed the presence of RASs in the livers of 2/16 patients harboring GT1a but not in the corresponding plasma. In GT4d, NS5A RASs were detected in 7/7 liver tissues and 5/7 plasma samples. NS3 domain and NS5A domain were found to be conserved in plasma and livers of patients infected with GT3a. Thus, RASs within GT1a and GT4d more likely segregate into the liver and may explain the emergence of resistant strains during DAA treatment.

Detection of low-level HCV variants in DAA treated patients: comparison amongst three different NGS data analysis protocols.

BACKGROUND: Notwithstanding the efforts of direct-acting antivirals (DAAs) for the treatment of chronically infected hepatitis C virus (HCV) patients, concerns exist regarding the emergence of resistance-associated substitutions (RAS) related to therapy failure. Sanger sequencing is still the reference technique used for the detection of RAS and it detects viral variants present up to 15%, meaning that minority variants are undetectable, using this technique. To date, many studies are focused on the analysis of the impact of HCV low variants using next-generation sequencing (NGS) techniques, but the importance of these minority variants is still debated, and importantly, a common data analysis method is still not defined. METHODS: Serum samples from four patients failing DAAs therapy were collected at baseline and failure, and amplification of NS3, NS5A and NS5B genes was performed on each sample. The genes amplified were sequenced using Sanger and NGS Illumina sequencing and the data generated were analyzed with different approaches. Three different NGS data analysis methods, two homemade in silico pipeline and one commercially available certified user-friendly software, were used to detect low-level variants. RESULTS: The NGS approach allowed to infer also very-low level virus variants. Moreover, data processing allowed to generate high accuracy data which results in reduction in the error rates for each single sequence polymorphism. The results improved the detection of low-level viral variants in the HCV quasispecies of the analyzed patients, and in one patient a low-level RAS related to treatment failure was identified. Importantly, the results obtained from only two out of the three data analysis strategies were in complete agreement in terms of both detection and frequency of RAS. CONCLUSIONS: These results highlight the need to find a robust NGS data analysis method to standardize NGS results for a better comprehension of the clinical role of low-level HCV variants. Based on the extreme importance of data analysis approaches for wet-data interpretation, a detailed description of the used pipelines and further standardization of the in silico analysis could allow increasing diagnostic laboratory networking to unleash true potentials of NGS.

HIV-1 recombinant forms in immigrants regularly residing in Milan, northern Italy.

To assess the HIV -1subtypes distribution in HIV-1 positive migrants living in Milan we studied 77 HIV-1 patients followed at the San Raffaele Hospital of Milan. Twenty subjects were born in Europe, 43 in the Americas, 10 in Africa and 4 in Asia. Unsafe heterosexual activity prevailed in migrants born in Africa and male homosexuality in those born in European, American and Asian countries (p = 0.05). The phylogeny showed that 38/77 (49.3%) subjects carried HIV-B subtype while the remaining strains were classified as not pure HIV-1 B subtypes 13/77 (16.9%) or recombinant forms 26/77 (33.8%). Female gender more frequently showed HIV-1 non-B strains and rarely HIV-1 B subtypes (12/39, 30.8% vs. 3/38, 7.9%, p = 0.02). Transmitted drug resistance was identified in 10/77 (13%) patients predominately with B subtype. Our data underscore a large heterogeneity in HIV-1 subtypes and a large proportion of recombinant forms.

A Prospective Italian Study on Baseline NS3 and NS5A Resistance to Direct-Acting Antivirals in a Real-World Setting of HIV-1/HCV Coinfected Patients and Association with Treatment Outcome.

We prospectively evaluated the frequency of natural resistance-associated substitutions (RASs) in the NS3 and NS5A regions according to different HCV genotypes and their possible effect on treatment outcome in HIV-1/HCV patients treated with direct-acting antivirals (DAAs). Baseline RASs in the NS3 and NS5A domains were investigated in 62 HIV-1/HCV patients treated with DAAs: 23 patients harbored HCV-GT1a, 26 harbored GT3a, and 13 harbored GT4d. A higher occurrence of RASs was found in the NS3 domain within GT1a (13/23) than GT3a (0/26) or GT4d (2/13). With regard to treatment outcome, NS3 RASs were detected in 14/56 patients with sustained virological response (SVR) and in 1/6 non-responder (NR) patients. Occurrence of RASs of NS5A domain was lower in SVR (4/56, had RASs) than in NR (3/6, had RASs). Evaluation of RASs at baseline instead of at virological failure, especially in the NS5A domain, could positively influence the choice of new DAA combinations for the treatment of HIV-1/HCV patients.

Molecular epidemiology of HIV-1 infection in immigrant population in northern Italy.

Human immunodeficiency virus-1 (HIV-1) is characterised by a vast genetic diversity classified into distinct phylogenetic strains and recombinant forms. We describe the HIV-1 molecular epidemiology and evolution of 129 consecutive HIV-1 positive migrants living in Milan (northern Italy). Polymerase gene sequences of 116 HIV-1 subtype-B positive patients were aligned with HIV-1 reference sequences (https://www.ncbi.nlm.nih.gov/) by using MAFFT alignment and edited by using Bioedit software. A maximum likelihood (ML) phylogenetic tree was performed by MEGA7 and was visualised by using FigTree v1.4.3. Of 129 migrants, 35 were born in Europe (28 in Eastern Europe), 70 in the Americas (67 in South America), 15 in Africa and nine in Asia; 76.4% were men who have sex with men (MSM). The serotype HIV-1-B prevailed (89.9%), followed by -C, -F1, -D and -A. Compared with 116 HIV-B patients, the 13 with HIV-non-B showed lower Nadir of CD4+ cell/mmc (P = 0.043), more frequently had sub Saharan origin (38.5 vs. 1.72%, P = 0.0001) and less frequently were MSM (40 vs. 74.5%, P = 0.02). The ML phylogenetic tree of the 116 HIV-1 subtype-B positive patients showed 13 statistically supported nodes (bootstrap > 70%). Most of the sequences included in these nodes have been isolated from male patients from the Americas and the most common risk factor was MSM. The low number of HIV-1 non-B subtype patients did not allow to perform this analysis. These results suggest a shift of HIV-1 prevention projects' focus and a continuous monitoring of HIV-1 molecular epidemiology among entry populations. Prevention efforts based on HIV molecular epidemiology may improve public health surveillance setting.

Brief Report: Outcome of Acute Hepatitis B Virus Infection in HIV-1-Infected Patients: Possible Factors Associated With Resolution or Chronicity.

BACKGROUND: HIV-1 infection impairs cellular immunity, causing a detrimental effect on the natural course of hepatitis B virus (HBV) infection. HBV vaccination is less effective in HIV-1-infected patients. This study aimed to gain insight into HIV-1 infection with persistence of hepatitis B surface antigen (HBsAg) defining chronic hepatitis B infection (CBI) after a primary infection and the possible associated factors. SETTING: Division of Infectious Diseases, San Raffaele Hospital, Italy. METHODS: This retrospective study analyzed HIV-1-infected patients diagnosed with acute hepatitis B infection (AHB) based on clinical or laboratory records. CBI was defined as a positive HBsAg result recorded >6 months after an AHB diagnosis. Multivariate logistic regression was applied to assess factors (evaluated at AHB diagnosis) that were associated with CBI. RESULTS: Of 63 HIV-1-infected patients with AHB, 23 (36.5%) developed CBI. On multivariate analysis, CBI risk was less likely in patients with HIV-RNA of >50 copies/mL (adjusted odds ratio = 0.03, 95% confidence interval: 0.001 to 0.58, P = 0.021). Dually acting antiretroviral treatment, including one or more drugs active against HIV/HBV (lamivudine, emtricitabine, and tenofovir), seemed to be protective in terms of the clinical outcome of CBI (adjusted odds ratio = 0.07, 95% confidence interval: 0.01 to 1.02, P = 0.050). Among the 23 patients with CBI, 15 (65.2%) lost the hepatitis B e-antigen, while 11 (47.8%) had HBsAg seroclearance during follow-up. CONCLUSIONS: In HIV-1-infected subjects with AHB, the persistence of HBsAg seemed to occur frequently. Factors associated with a lower CBI risk were detectable HIV load and the use of dually acting antiretroviral treatment during AHB.

A liquid chromatography-tandem mass spectrometry method for simultaneous determination of simeprevir, daclatasvir, sofosbuvir, and GS-331007 applied to a retrospective clinical pharmacological study.

A highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous determination of daclatasvir (DCV), simeprevir (SMV), sofosbuvir (SOF), and its major metabolite GS-331007 in human plasma using stable-isotope-labeled (SIL) analogs as internal standards (IS) to minimize a possible matrix effect. Liquid-liquid extraction (LLE) of the analytes and IS from human plasma was performed using a commercial extraction kit requiring low sample volume (50 µL). The analytes were eluted under a gradient program with mobile phase A (water + 0.1% formic acid) and mobile phase B (methanol + 0.1% formic acid) at a flow-rate of 0.6 mL/min for 10 min. The detection was performed on a Qtrap 5500 triple quadrupole tandem-mass spectrometer using multiple reaction monitoring (MRM) mode via the positive electrospray ionization interface. The method was validated according to the European Medicine Agency (EMA) guidelines over the clinically relevant concentration range of 15.6-2000 ng/mL. The high reproducibility, the low matrix effect associated with the use of SIL-IS, and the need of small sample amounts make this method particularly suited for high-throughput routine analysis. The proposed method was successfully applied to a retrospective clinical pharmacology study involving 67 HIV/HCV co-infected patients treated with a SOF-based therapy. DCV, SMV, SOF, and GS-331007 plasma levels were measured at week 4 of treatment and compared with the patients' clinical and laboratory characteristics. Higher GS-331007 plasma concentrations were observed in female patients compared to males, which can be explained by different anthropometric characteristics between genders. Importantly, patients with high plasma levels of GS-331007 also showed enhanced concentration of DCV and SMV probably due to a specific metabolic/pathological condition. Altogether, our findings indicate that the proposed method is a reliable and accurate new tool for high-throughput screening of large patient cohorts that could be readily used to optimize treatment modalities and reduce drug-related toxicities.

Geographic Distribution of HCV-GT3 Subtypes and Naturally Occurring Resistance Associated Substitutions.

BACKGROUND: Little is known about the frequency or geographic distributions of naturally occurring resistance-associated substitutions (RASs) in the nonstructural protein 5A (NS5A) domain of hepatitis-C virus (HCV) genotype-3 (GT-3) different subtypes. We investigated naturally occurring GT-3 RASs that confer resistance to NS5A inhibitors. METHODS: From a publicly accessible database, we retrieved 58 complete GT-3 genomes and an additional 731 worldwide NS5A sequences from patients infected with GT-3 that were naive to direct-acting antiviral treatment. RESULTS: We performed a phylogenetic analysis of NS5A domains in complete HCV genomes to determine more precisely HCV-GT-3 subtypes, based on commonly used target regions (e.g., 5'untranslated region and NS5B partial domain). Among 789 NS5A sequences, GT-3nonA subtypes were more prevalent in Asia than in other geographic regions (P<0.0001). The A30K RAS was detected more frequently in HCV GT3nonA (84.6%) than in GT-3A subtypes (0.8%), and the amino acid change was polymorphic in isolates from Asia. CONCLUSIONS: These results provided information on the accuracy of HCV-3 subtyping with a phylogenetic analysis of the NS5A domain with data from the Los Alamos HCV genome database. This information and the worldwide geographic distribution of RASs according to HCV GT-3 subtypes are crucial steps in meeting the challenges of treating HCV GT-3.

Natural polymorphisms in the resistance associated sites of HCV-G1 NS5B domain and correlation with geographic origin of HCV isolates.

BACKGROUND: We evaluated the frequency of naturally occurring resistance associated substitutions (RASs) and their characteristic of polymorphic or non-polymorphic amino acid change to direct acting antivirals (DAAs) in NS5b HCV subtypes 1a and 1b according to different geographic origin of isolates. METHODS: Using a public database we retrieved 738 worldwide NS5b sequences (for which was available the geographic origin) from HCV genotype (G)1 infected patients naive to DAAs. NS5b sequences clustering with G1a were more conserved in regard of RASs than G1b isolates, (14% vs 57% RASs, P < 0.0001). RESULTS: In G1a, RASs were differently distributed between isolates from Europe (24%) and USA, (12%) P = 0.0186. In particular, 421 V associated with resistance to non-nucleoside inhibitor beclabuvir was polymorphic in Europe and USA, being detected in 24% and 11% of sequences, respectively, P = 0.0140. In G1b, RASs were found in 45% of sequences from Europe, in 54% of isolates from USA and in 70% of sequences from Asia (P = 0.0051). The 316 N polymorphism was detected in 54% of Asian isolates and at lower frequency, in 28% of isolates from USA and in 20% of European sequences (P < 0.0001). CONCLUSIONS: In conclusion, a higher prevalence of RASs in G1b respect to G1a was found and a geographical distribution of RASs and polymorphic aa changes was observed in G1a as well in G1b. The clinical and therapeutic impact of the geographic distribution of RASs to polymerase inhibitors remains to be established, particularly in patients with virologic failure to DAAs and/or advanced liver disease.

Immune response to hepatitis B vaccination in HIV-positive individuals with isolated antibodies against hepatitis B core antigen: Results of a prospective Italian study.

BACKGROUND AND AIM: Antibodies against hepatitis B core antigen (anti-HBc) are found in 14-44% of patients with HIV infection, but it is still unclear whether hepatitis B virus (HBV) vaccination should be recommended for HIV-positive subjects with isolated anti-HBc (IAHBc). We examined the rate of anamnestic and primary responses (ARs and PRs) and associated factors in a group of HIV-infected patients with an IAHBc profile. METHODS: This prospective study recruited 25 HIV-positive patients with anti-HBc alone who were vaccinated against HBV infection. Those without an AR (anti-hepatitis B envelope antigen [anti-HBs] levels of <10 U/L) or who were hypo-responsiveness (anti-HBs levels of >10 but <100 U/L) four weeks after the first dose of vaccine underwent a full course of vaccinations. Their clinical and virological data, including the presence of occult hepatitis B infection (OBI), were evaluated in accordance with the vaccination schedule. RESULTS: Six of the 25 patients (24%) showed an AR, four of whom had anti-HBs levels of <100 U/L. Ten of 19 (52.6%) remaining patients became seroprotected after the third dose. OBI was detected in four of the six patients with an AR, two of the 10 patients with a PR, and none of the nine patients who did not respond. Multivariate analysis showed that an AR was associated with the presence of OBI (P = 0.0162), and a PR was associated with HCV antibody status. (P = 0.0191). CONCLUSIONS: Our data suggest that testing for anti-HBc alone may not be a reliable means of assessing protection from HBV infection in HIV-positive patients. OBI-positive patients may benefit from a single vaccine dose. Anti-HCV serostatus may affect PRs.

Resistance Mechanisms in Hepatitis C Virus: implications for Direct-Acting Antiviral Use.

Multiple direct-acting antiviral (DAA)-based regimens are currently approved that provide one or more interferon-free treatment options for hepatitis C virus (HCV) genotypes (G) 1-6. The choice of a DAA regimen, duration of therapy, and use of ribavirin depends on multiple viral and host factors, including HCV genotype, the detection of resistance-associated amino acid (aa) substitutions (RASs), prior treatment experience, and presence of cirrhosis. In regard to viral factors that may guide the treatment choice, the most important is the infecting genotype because a number of DAAs are genotype-designed. The potency and the genetic barrier may also impact the choice of treatment. One important and debated possible virologic factor that may negatively influence the response to DAAs is the presence of baseline RASs. Baseline resistance testing is currently not routinely considered or recommended for initiating HCV treatment, due to the overall high response rates (sustained virological response >90%) obtained. Exceptions are patients infected by HCV G1a when initiating treatment with simeprevir and elbasvir/grazoprevir or in those with cirrhosis prior to daclatasvir/sofosbuvir treatment because of natural polymorphisms demonstrated in sites of resistance. On the basis of these observations, first-line strategies should be optimized to overcome treatment failure due to HCV resistance.

NS3 protease resistance-associated substitutions in liver tissue and plasma samples from patients infected by hepatitis C virus genotype 1A or 1B.

The presence of naturally occurring resistance-associated substitutions (RASs) in the HCV-protease domain has been poorly investigated in the liver, the main site of HCV replication. We evaluated the natural resistance of the virus to NS3 protease inhibitors in liver tissue and plasma samples taken from HCV-infected patients. RASs were investigated by means of viral population sequencing in liver tissue samples from 18 HCV-infected patients harbouring genotype 1a or genotype 1b; plasma samples from 12 of these patients were also available for virological investigation. A discordant genotype was found in two of the 12 patients (16.6%) who provided samples from both compartments. Sequence analysis of the NS3 protease domain showed the presence of RASs in four of the 18 liver tissue samples (22.2%), two of which showed cross-resistance to protease inhibitors in clinical use or phase 2-3 trials. The analysis of the 12 paired tissues and plasma samples excluded the presence of RASs in the plasma compartment. The dominance of discordant genotypes in the paired liver and plasma samples of some HCV-infected patients suggests mixed infection possibly leading to the selective advantage of different genotype in the two compartments. The presence of RASs at intra-hepatic level is not uncommon and may lead to the early emergence of cross-resistant strains.

Diagnostic accuracy of APRI, FIB-4 and Forns for the detection of liver cirrhosis in HIV/HCV-coinfected patients.

We determined the diagnostic accuracy and optimal cut off of three indirect fibrosis biomarkers (APRI, FIB-4, Forns) compared with liver stiffness (LS) for the detection of liver cirrhosis in HIV/HCV-coinfected patients. An observational retrospective study on HIV/HCV-coinfected patients with concomitant LS measurement and APRI, FIB-4 and Forns was performed. The presence of liver cirrhosis was defined as a LS ≥13 KPa. The diagnostic accuracy and optimal cut-off values, compared with LS categorization (<13 vs ≥13 KPa), were determined by receiver operating characteristics (ROC) curves. The study sample included 646 patients. The area-under-the ROC curve (95% confidence interval) for the detection of liver cirrhosis were 0.84 (0.81-0.88), 0.87 (0.84-0.91) and 0.87 (0.84-0.90) for APRI, FIB-4 and Forns, respectively. According to the optimal cut off values for liver cirrhosis (≥0.97 for APRI, ≥2.02 for FIB-4 and ≥7.8 for Forns), 80%, 80% and 82% of subjects were correctly classified by the three indirect fibrosis biomarkers, respectively. Misclassifications were mostly due to false positive cases. The study suggests that indirect fibrosis biomarkers can help clinicians to exclude liver cirrhosis in the management of HIV/HCV co-infected patients, reducing the frequency of more expensive or invasive assessments.

Frequency of Natural Resistance within NS5a Replication Complex Domain in Hepatitis C Genotypes 1a, 1b: Possible Implication of Subtype-Specific Resistance Selection in Multiple Direct Acting Antivirals Drugs Combination Treatment.

Different HCV subtypes may naturally harbor different resistance selection to anti-NS5a inhibitors. 2761 sequences retrieved from the Los Alamos HCV database were analyzed in the NS5a domain 1, the target of NS5a inhibitors. The NS5a resistance-associated polymorphisms (RAPs) were more frequently detected in HCV G1b compared to G1a. The prevalence of polymorphisms associated with cross-resistance to compounds in clinical use (daclatasvir, DCV, ledipasvir, LDV, ombitasvir, and OMV) or scheduled to come into clinical use in the near future (IDX719, elbasvir, and ELV) was higher in G1b compared to G1a (37/1552 (2.4%) in 1b sequences and 15/1209 (1.2%) in 1a isolates, p = 0.040). Interestingly, on the basis of the genotype-specific resistance pattern, 95 (6.1%) G1b sequences had L31M RAP to DCV/IDX719, while 6 sequences of G1a (0.5%) harbored L31M RAP, conferring resistance to DCV/LDV/IDX719/ELV (p < 0.0001). Finally, 28 (2.3%) G1a and none of G1b isolates harbored M28V RAP to OMV (p < 0.0001). In conclusion, the pattern of subtype-specific resistance selection in the naturally occurring strains may guide the treatment option in association with direct acting antivirals (DAAs) targeting different regions, particularly in patients that are difficult to cure, such as those with advanced liver disease or individuals who have failed previous DAAs.