Solution Structure and Dynamics of Hf-Al and Hf-Zn Heterobimetallic Adducts Mimicking Relevant Intermediates in Chain Transfer Reactions.

Cationic cyclometalated hafnocenes [CpPrCpCH2CH2CH2Hf][B(C6F5)4] (4Pr) and [CpiBuCpCH2CH(Me)CH2Hf][B(C6F5)4] (4aiBu and 4biBu) were synthesized from the corresponding [(CpPr)2HfMe][B(C6F5)4] (1Pr) and [(CpiBu)2HfMe][B(C6F5)4] (1iBu) complexes via C-H activation. 4aiBu, 4biBu, and 4Pr, mimicking a propagating M-polymeryl species (M = transition metal) with or without a ß-methyl branch on the metalated chains, serve to investigate whether and how the nature of the last inserted olefin molecules changes the structure, stability, and reactivity of the corresponding heterobimetallic complexes, formed in the presence of aluminum- or zinc-alkyl chain transfer agents (CTAs), which are considered relevant intermediates in coordinative chain transfer polymerization (CCTP) and chain shuttling polymerization (CSP) technologies. NMR and DFT data indicate no major structural difference between the resulting heterobridged complexes, all characterized by the presence of multiple α-agostic interactions. On the contrary, thermodynamic and kinetic investigations, concerning the reversible formation and breaking of heterobimetallic adducts, demonstrate that isomer 4aiBu, in which the ß-Me is oriented away from the reactive coordination site on Hf, but not 4biBu, having the ß-Me pointing in the opposite direction, is capable of reacting with CTAs. Quantification of kinetic rate constants highlights that the formation process is rate limiting and that the nature of the last inserted α-olefin unit modulates transalkylation kinetics. The reaction of 4aiBu, 4biBu, and 4Pr with diisobutylaluminum hydride (DiBAlH) allows the interception and characterization of new heterobinuclear and heterotrinuclear species, featuring both hydride and alkyl bridging moieties, which represent structural models of elusive intermediates in CCTP and CSP processes, capturing the instant when an alkyl chain has just transferred from a transition metal to a main group metal, while the two metals remain engaged in a single heterobimetallic intermediate.

Virus-Encoded Circular RNAs: Role and Significance in Viral Infections.

Circular RNAs (circRNAs) have been the focus of intense scientific research to understand their biogenesis, mechanisms of action and regulatory functions. CircRNAs are single stranded, covalently closed RNA molecules lacking the 5'-terminal cap and the 3'-terminal polyadenine chain, characteristics that make them very stable and resistant. Synthesised by both cells and viruses, in the past circRNAs were considered to have no precise function. Today, increasing evidence shows that circRNAs are ubiquitous, some of them are tissue- and cell-specific, and critical in multiple regulatory processes (i.e., infections, inflammation, oncogenesis, gene expression). Moreover, circRNAs are emerging as important biomarkers of viral infection and disease progression. In this review, we provided an updated overview of current understanding of virus-encoded and cellular-encoded circRNAs and their involvement in cellular pathways during viral infection.

Slow or fast viral load decay as a predictor of residual viremia level in HIV-infected patients undergoing successful first-line cART.

Persistent residual viremia (RV) has been demonstrated in 70-90% of patients under successful cART. We analyzed the RV trend during the first year following cART-induced virological suppression (VS; HIVRNA <50 copies/ml) to identify predictors of achievement and maintenance of ultra-deep RV suppression (URVS; HIV-RNA <5 copies/ml) in 60 naïve patients. These patients were aligned at the time of reaching VS and were longitudinally tested with an ultrasensitive HIV-RNA assay. The influence of demographics, primary/chronic infection, pre-therapy HIV-RNA and CD4, cART regimen and time to reach VS on RV trends was evaluated. During the first year following VS, median RV levels steadily decreased. RV dropped below 5 copies/ml at least once in each patient, but URVS was maintained in 45% of patients. RV rebounded to levels fluctuating around 5-10 copies/ml while in the remaining 55% of patients. Predictors of early achievement and maintenance of stable URVS were fast (<12 weeks) VS achievement after the start of therapy, better pre-treatment viro-immunological conditions (lower viremia and higher CD4 before cART), and treatment initiation during primary infection. These findings emphasize the importance of an early onset of potent antiretroviral regimens. RV trends should be further studied in detail in the following years of cART.

Evaluation of the Aptima(®) HIV-1 Quant Dx assay for HIV-1 RNA viral load detection and quantitation in plasma of HIV-1-infected individuals: A comparison with Abbott RealTime HIV-1 assay.

The Hologic Aptima(®) HIV-1 Quant Dx assay (Aptima HIV) is a real-time transcription-mediated amplification method CE-approved for use in diagnosis and monitoring of HIV-1 infection. The analytical performance of this new assay was compared to the FDA-approved Abbott RealTime HIV-1 (RealTime). The evaluation was performed using 220 clinical plasma samples, the WHO 3rd HIV-1 International Standard, and the QCMD HIV-1 RNA EQA. Concordance on qualitative results, correlation between quantitative results, accuracy, and reproducibility of viral load data were analyzed. The ability to measure HIV-1 subtypes was assessed on the second WHO International Reference Preparation Panel for HIV-1 Subtypes. With clinical samples, inter-assay agreement for qualitative results was high (91.8%) with Cohen's kappa statistic equal to 0.836. For samples with quantitative results in both assays (n = 93), Lin's concordance correlation coefficient was 0.980 (P < 0.0001) and mean differences of measurement, conducted according to Bland-Altman method, was low (0.115 log10 copies/ml). The Aptima HIV quantified the WHO 3rd HIV-1 International Standard diluted from 2000 to 31 cp/ml (5,700-88 IU/ml) at expected values with excellent linearity (R(2) > 0.970) and showed higher sensitivity compared to RealTime being able to detect HIV-1 RNA in 10 out of 10 replicates containing down to 7 cp/ml (20 IU/ml). Reproducibility was very high, even at low HIV-1 RNA values. The Aptima HIV was able to detect and accurately quantify all the main HIV-1 subtypes in both reference panels and clinical samples. Besides excellent performance, Aptima HIV shows full automation, ease of use, and improved workflow compared to RealTime. J. Med. Virol. 88:1535-1544, 2016. © 2016 Wiley Periodicals, Inc.

Ability of two commercially available assays (Abbott RealTime HIV-1 and Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 Version 2.0) to quantify low HIV-1 RNA Levels (<1,000 copies/milliliter): comparison with clinical samples and NIBSC working reagent for nucleic acid testing assays.

Concordance between molecular assays may be suboptimal at low HIV-1 viremia levels (<1,000 copies/ml); therefore, it may be difficult to define and compare virologic endpoints for successful and failed therapy. We compared two commercial assays (the Abbott RealTime HIV-1 and the Roche Cobas AmpliPrep/TaqMan HIV-1 version 2.0) for their ability to detect and quantify low viral loads. A comparison was performed using 167 residual clinical samples (with values ranging from "not detected" to 1,000 copies/ml, as measured by the Abbott assay) and the National Institute and Biological Standards and Control (NIBSC) HIV-1 RNA working reagent 1 for nucleic acid amplification techniques (NAT) assays (serially diluted to a range from 1 to 1,000 copies/ml). Quantitative results were compared using Lin's concordance correlation coefficient and a Bland-Altman plot. Concordance with the qualitative results was measured by Cohen's kappa statistic. With clinical samples, the degree of interassay concordance of the qualitative results at a 40-copies/ml HIV-1 RNA threshold was substantial (κ = 0.762); the correlation among the quantified samples was suboptimal (concordance correlation coefficient, 0.728; P < 0.0001); the mean difference of the values between the Roche and Abbott assays was 0.193 log10 copies/ml. Using the HIV-1 RNA working reagent 1 for NAT assays, the results provided by the Roche assay were, on average, 3 times higher than expected, while the Abbott assay showed high accuracy. The Roche assay was highly sensitive, being able to detect a level as low as 3.5 copies/ml HIV-1 RNA with 95% probability. The performance characteristics of each molecular assay should be taken into account when HIV-1 RNA threshold values for "virologic suppression," "virologic failure," "persistent low viral loads," etc., are defined and indicated in the support of clinical decisions.

Comparative performances of HIV-1 RNA load assays at low viral load levels: results of an international collaboration.

Low-level viremia during antiretroviral therapy and its accurate measurement are increasingly relevant. Here, we present an international collaboration of 4,221 paired blood plasma viral load (pVL) results from four commercial assays, emphasizing the data with low pVL. The assays compared were the Abbott RealTime assay, the Roche Amplicor assay, and the Roche TaqMan version 1 and version 2 assays. The correlation between the assays was 0.90 to 0.97. However, at a low pVL, the correlation fell to 0.45 to 0.85. The observed interassay concordance was higher when detectability was defined as 200 copies/ml than when it was defined as 50 copies/ml. A pVL of ∼100 to 125 copies/ml by the TaqMan version 1 and version 2 assays corresponded best to a 50-copies/ml threshold with the Amplicor assay. Correlation and concordance between the viral load assays were lower at a low pVL. Clear guidelines are needed on the clinical significance of low-level viremia.

HIV-1 RNA monitoring with a dual-target diagnostic assay: A case report.

In a restricted subset of people living with HIV-1 (PLWH) on antiretroviral therapy (ART) with persistent suppressed viral load (i.e., pol-based HIV-RNA repeatedly undetected), a dual-target (pol and LTR) diagnostic assay for HIV-RNA monitoring can measure quantifiable levels of viral loads (VL) above 30 copies/mL exclusively through the amplification of the LTR region, while the pol target results undetected. We report a patient who shows high levels of HIV-RNA detected exclusively through amplification of the LTR region while undetected by the pol region, during a long monitoring period, from 2018 to date. In this follow-up, the ART was modified without reaching LTR-based undetected HIV-RNA values. Immunological and virological parameters remained optimal with a progressive and steady gain of the CD4/CD8 ratio. The clinical history of this patient, shows that LTR-based viremia above 50 copies/mL can be found occasionally or persistently in the plasma of PLWH under suppressive ART, even at high levels. Based on previous studies, VL detected and quantified exclusively through the amplification of the LTR region corresponds to partial or incomplete HIV-RNA transcripts, which cannot trigger new infections. Interestingly, changes in ART do not eliminate repeated findings of these unusual viral elements.

Rapid ART initiation with bictegravir/emtricitabine/tenofovir alafenamide in individuals presenting with advanced HIV disease (Rainbow study).

BACKGROUND: A rapid ART initiation approach can be beneficial in people with advanced HIV disease, in consideration of their high morbidity and mortality. The aim of our study was to evaluate the feasibility, efficacy and safety of rapid ART start with BIC/FTC/TAF in this setting. METHODS: Pilot, single-centre, single-arm, prospective, phase IV clinical trial conducted in a tertiary Italian hospital. Thirty ART-naïve people presenting with advanced HIV-1 diagnosis (defined as the presence of an AIDS-defining event and/or CD4 cell count <200 µL), were enrolled. Main exclusion criteria were active tuberculosis, cryptococcosis and pregnant/breastfeeding women. BIC/FTC/TAF was started within 7 days from HIV diagnosis. The primary endpoint was clinical or virologic failure (VF). Immunological parameters, safety, feasibility, neurocognitive performances and patient-reported outcomes were assessed as well. RESULTS: Over the study period, 40 (34%) of 116 patients diagnosed with HIV infection at INMI Spallanzani had advanced disease, of whom 30 (26%) were enrolled. The proportion of participants with HIV-RNA <50 cp/mL was 9/30 (30%) at week (w) 4, 19/30 (63%) at w12, 24/30 (80%) at w24, 23/30 (77%) at w36 and 27/30 (90%) at w48. Two unconfirmed VF occurred. No ART discontinuation due to toxicity or VF was observed. No ART modification was performed based on the review of genotype and no mutations for the study drugs were detected. Mean CD4 cells count changed by 133 cells/µL at BL to 309 cells/µL at w 48 and 83% of participants had a CD4 > 200 cells/µL at w 48. Two participants developed IRIS and one was diagnosed with disseminated TB and needed an ART switch. INTERPRETATIONS: Our results support the feasibility, efficacy and safety of BIC/FTC/TAF as a rapid ART strategy in patients with advanced HIV disease.

HIV-1 drug resistance in recently HIV-infected pregnant mother's naïve to antiretroviral therapy in Dodoma urban, Tanzania.

BACKGROUND: HIV resistance affects virological response to therapy and efficacy of prophylaxis in mother-to-child-transmission. The study aims to assess the prevalence of HIV primary resistance in pregnant women naïve to antiretrovirals. METHODS: Cross sectional baseline analysis of a cohort of HIV + pregnant women (HPW) enrolled in the study entitled Antiretroviral Management of Antenatal and Natal HIV Infection (AMANI, peace in Kiswahili language). The AMANI study began in May 2010 in Dodoma, Tanzania. In this observational cohort, antiretroviral treatment was provided to all women from the 28th week of gestation until the end of the breastfeeding period. Baseline CD4 cell count, viral load and HIV drug-resistance genotype were collected. RESULTS: Drug-resistance analysis was performed on 97 naïve infected-mothers. The prevalence of all primary drug resistance and primary non-nucleoside reverse-transcriptase inhibitors resistance was 11.9% and 7.5%, respectively. K103S was found in two women with no M184V detection. HIV-1 subtype A was the most commonly identified, with a high prevalence of subtype A1, followed by C, D, C/D recombinant, A/C recombinant and A/D recombinant. HIV drug- resistance mutations were detected in A1 and C subtypes. CONCLUSION: Our study reports an 11.9% prevalence rate of primary drug resistance in naïve HIV-infected pregnant women from a remote area of Tanzania. Considering that the non-nucleoside reverse-transcriptase inhibitors are part of the first-line antiretroviral regimen in Tanzania and all of Africa, resistance surveys should be prioritized in settings where antiretroviral therapy programs are scaled up.

Virological characterization of HIV-1 RNA elements detected exclusively through the LTR region by the dual-target Aptima HIV-1 Quant Dx assay in a subset of positive patients.

BACKGROUND: In a restricted subset of HIV patients with suppressed viral load (i.e., pol-undetected HIV-RNA), the Aptima HIV-1 Quant Dx Assay (Aptima), a dual-target (pol and LTR) and dual-probe test for viral load (VL) monitoring, can detect HIV-RNA exclusively through amplification of the LTR region. OBJECTIVES: To analyze the virological characteristics of the HIV-RNA elements detected only through LTR amplification (LTR-e). STUDY DESIGN: LTR-e isolated from plasma and peripheral blood mononuclear cells (PBMC) were evaluated for their ability to trigger productive infections. Viral pellets morphology and ultrastructural characteristics of PBMC from LTR-e patients were examined by electron microscopy. Plasma LTR-e underwent Sanger sequencing. Exosomes were examined with Aptima for LTR-e content. RESULTS: In-vitro, LTR-e could not infect PBMC, induce cytopathic effects, or cause syncytia, even at high VL (e.g., >10,000 copies/mL). Under the electron microscope, plasma pellets and PBMC from patients with LTR-e showed atypical vesicles. Sanger sequencing of LTR-e yielded no results. Moreover, in plasma samples, LTR-e were associated with cell debris, never with exosomes. CONCLUSIONS: Differently from other dual-target but single-probe assays, Aptima unveils VL based only on LTR amplification in some HIV patients. Here, we show that LTR-e represent partial/incomplete/non-canonical transcripts unable to trigger productive infection or transmit HIV-1 infection. The recognition of VL based only on LTR-e in infected individuals is crucial as it allows to avoid inappropriate decisions in the clinical management of HIV patients, such as retesting of VL and switching of ART. Physicians and HIV-RNA dual-target assay manufacturers should consider the important implications of not recognizing this singular type of VL.

Detection of SARS-CoV-2 Variants via Different Diagnostics Assays Based on Single-Nucleotide Polymorphism Analysis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is characterized by fast evolution with the appearance of several variants. Next-Generation Sequencing (NGS) technology is considered the gold standard for monitoring known and new SARS-CoV-2 variants. However, the complexity of this technology renders this approach impracticable in laboratories located in areas with limited resources. We analyzed the capability of the ThermoFisher TaqPath COVID-19 RT-PCR (TaqPath) and the Seegene Novaplex SARS-CoV-2 Variant assay (Novaplex) to detect Omicron variants; the Allplex VariantII (Allplex) was also evaluated for Delta variants. Sanger sequencing (SaS) was the reference method. The results obtained with n = 355 nasopharyngeal samples were: negative with TaqPath, although positive with other qualitative molecular assays (n = 35); undetermined (n = 40) with both the assays; negative for the ∆69/70 mutation and confirmed as the Delta variant via SaS (n = 100); positive for ∆69/70 and confirmed as Omicron BA.1 via SaS (n = 80); negative for ∆69/70 and typed as Omicron BA.2 via SaS (n = 80). Novaplex typed 27.5% of samples as undetermined with TaqPath, 11.4% of samples as negative with TaqPath, and confirmed 100% of samples were Omicron subtypes. In total, 99/100 samples were confirmed as the Delta variant with Allplex with a positive per cent agreement (PPA) of 98% compared to SaS. As undermined samples with Novaplex showed RdRp median Ct values (Ct = 35.4) statistically higher than those of typed samples (median Ct value = 22.0; p < 0.0001, Mann-Whitney test), the inability to establish SARS-CoV-2 variants was probably linked to the low viral load. No amplification was obtained with SaS among all 35 negative TaqPath samples. Overall, 20% of samples which were typed as negative or undetermined with TaqPath, and among them, twelve were not typed even by SaS, but they were instead correctly identified with Novaplex. Although full-genome sequencing remains the elected method to characterize new strains, our data show the high ability of a SNP-based assay to identify VOCs, also resolving samples typed as undetermined with TaqPath.

Changes in the Circulation of Common Respiratory Pathogens among Hospitalized Patients with Influenza-like Illnesses in the Lazio Region (Italy) during Fall Season of the Past Three Years.

A descriptive analysis of common respiratory pathogens (CRPs) detected in nasopharyngeal swabs (NPSs) from hospitalized patients with influenza-like illness during the fall seasons of the past three years, 2019-2021, in the Lazio region, Italy, was conducted to assess whether or not CRP circulation changed because of COVID-19 during the fall season. The results observed in a total of 633 NPSs subjected to molecular diagnosis for CRPs by multiplex PCR assay during the autumn seasons (exactly from week 41 to week 50) were compared with each other. In 2019, in 144 NPSs, the more represented CRPs were rhinovirus/enterovirus (7.6%) and influenza A/B (4.2%). In 2020, 55 (21.6%) out of 255 NPSs resulted positive for SARS-CoV-2 and, except for one case of Legionella pneumophila, the CRPs detected were exclusively rhinovirus/enterovirus (4.7%). In 2021, among 234 NPSs, 25.6% resulted positive for SARS-CoV-2, 14.5% for respiratory syncytial virus (RSV), and 12.8% for rhinovirus/enterovirus. Compared with 2019, in 2020, CRP circulation was severely limited to a few cases; in 2021, instead, infections by RSV (detected also among adults), rhinovirus/enterovirus, and other respiratory pathogens were observed again, while influenza was practically absent. The comparison of the CRPs detected in the NPSs depicts a different circulation in the Lazio region during the last three fall seasons. CRP monitoring has a direct impact on the prevention and control strategies of respiratory infectious diseases, such as the non-pharmacological interventions implemented in response to the COVID-19 pandemic. Future studies should investigate the impact of specific interventions on the spread of respiratory infections.

Evaluating the Dual-Target Aptima HIV-1 Quant Dx Assay: Comparison between Viral Loads Measured with pol and LTR Targets in the Same Samples.

For effective management of HIV-1 patients, accurate measurement of HIV-1-RNA viral load (VL) is fundamental. The latest generation molecular assays for monitoring VL perform simultaneous detection of two regions of the viral genome, but without specifying the target used for VL quantitation. By using the "open" software (research use only [RUO]) of Aptima HIV-1 Quant Dx Assay (Aptima) which provides both results obtained with the pol and LTR targets, we were able to compare n = 500 plasma samples results from chronically HIV-1-infected patients under antiretroviral therapy (ART). Correlation and concordance were analyzed. By stratifying VL into two groups (<30 and ≥30 copies/mL HIV-1-RNA) according to pol-based results and matching them with their respective LTR values, concordance was substantial (κ = 0.635; 95%CI = 0.569 to 0.700) as expected. Considering the specimens (n = 224) with VL exactly quantified (i.e., ≥30 copies/mL) with both targets, an optimal correlation subsisted (r = 0.8882; P < 0.0001) and Bland-Altman plot showed no significant mean difference between them. However, by stratifying all these data in three ranges (30 to 200, 201 to 1,000, and >1,000 copies/mL) according to pol-based results, concordance analysis showed fair agreement (κ = 0.344; 95%CI = 0.257 to 0.432). Indeed, after excluding mutually concordant VL values in each range (n = 134), the remaining discordant samples (n = 90; 40.1%) showed significant (P < 0.05) difference between VL measured with the two targets. With the Aptima "open" software, samples with pol-based VL <1,000 copies (cp)/mL HIV-1-RNA, the corresponding LTR values were on average 0.5 log10 cp/mL higher. Further studies on these discrepancies and the nature of viral RNA elements detected only with the LTR despite efficient ART are in progress. IMPORTANCE The last generation dual-target platforms for quantification of HIV-1 RNA return a single value of viral load (VL) derived from a combined reading of two HIV-1 genome targets. By using a modified version of Aptima software, providing both the VL results obtained from pol and LTR amplification separately, we observed discordant VL results in some samples from HIV-1-infected patients on antiretroviral therapy. In particular, some samples with pol-based quantified <1,000 copies/mL VL showed the LTR-based value on average 0.5 log10 copies/mL higher, and other samples, always by treated patients, showed VL exclusively quantified with LTR target while the corresponding pol-based VL results were completely undetected. Standard software of double-target based diagnostic systems does not allow recognizing discrepant VL values in these particular, but not rare, clinical specimens. This issue could have implications for clinical management by leading physicians to consider changing antiretroviral regimen based on presumed failure of antiretroviral therapy.

Use of Pembrolizumab for Treatment of Progressive Multifocal Leukoencephalopathy in People Living with HIV.

Progressive Multifocal Leukoencephalopathy (PML) is a demyelinating disease occurring in advanced HIV infection, caused by the reactivation of poliomavirus JC (JCV). The use of pembrolizumab for treatment is based on the inhibition of programmed cell death protein 1 (PD-1), potentially improving the anti JCV-specific response. We used pembrolizumab with combined antiretroviral treatment (cART) on a compassionate-use basis. At each administration, clinical evaluation, MRI and laboratory testing, including CD3, CD4, CD8, PD-1 markers, HIV-RNA and JCV-DNA in cerebrospinal fluid (CSF)/plasma pairs, were performed. The JCV-specific T cell response was analysed by Elispot assay. This study included five HIV patients: four male, median age 43 years (29-52), median CD4 and CD8 count 150 (15-158) and 973 (354-1250) cell/mm3, respectively; median JCV-DNA and HIV-RNA in CSF/plasma pairs 9.540/1.503 cps/mL and 2.230/619 cp/mL, respectively. Overall, patients received between two and seven doses of pembrolizumab. After treatment, we observed JCV-DNA reduction and PD-1 down-regulation both in CSF and in plasma (high in circulating CD4 and CD8 at baseline), which remained stable at low levels in all patients. Three out of five patients showed stability of clinical picture and neuroimaging, while two others died. More data are needed in order to identify predictors of response to therapy.

In vitro Evaluation of Antiviral Efficacy of a Standardized Hydroalcoholic Extract of Poplar Type Propolis Against SARS-CoV-2.

Except for specific vaccines and monoclonal antibodies, effective prophylactic or post-exposure therapeutic treatments are currently limited for COVID-19. Propolis, a honeybee's product, has been suggested as a potential candidate for treatment of COVID-19 for its immunomodulatory properties and for its powerful activity against various types of viruses, including common coronaviruses. However, direct evidence regarding the antiviral activities of this product still remains poorly documented. VERO E6 and CALU3 cell lines were infected with SARS-CoV-2 and cultured in the presence of 12.5 or 25 µg/ml of a standardized Hydroalcoholic Extract acronym (sHEP) of Eurasian poplar type propolis and analyzed for viral RNA transcription, for cell damage by optical and electron microscopy, and for virus infectivity by viral titration at 2, 24, 48, and 72 h post-infection. The three main components of sHEP, caffeic acid phenethyl ester, galangin, and pinocembrin, were tested for the antiviral power, either alone or in combination. On both cell lines, sHEP showed significant effects mainly on CALU3 up to 48 h, i.e., some protection from cytopathic effects and consistent reduction of infected cell number, fewer viral particles inside cellular vesicles, reduction of viral titration in supernatants, dramatic drop of N gene negative sense RNA synthesis, and lower concentration of E gene RNA in cell extracts. Interestingly, pre-treatment of cells with sHEP before virus inoculation induced these same effects described previously and was not able to block virus entry. When used in combination, the three main constituents of sHEP showed antiviral activity at the same levels of sHEP. sHEP has a remarkable ability to hinder the replication of SARS-CoV-2, to limit new cycles of infection, and to protect host cells against the cytopathic effect, albeit with rather variable results. However, sHEP do not block the virus entry into the cells. The antiviral activity observed with the three main components of sHEP used in combination highlights that the mechanism underlying the antiviral activity of sHEP is probably the result of a synergistic effect. These data add further emphasis on the possible therapeutic role of this special honeybee's product as an adjuvant to official treatments of COVID-19 patients for its direct antiviral activity.

Virological and Immunological Outcomes of an Intensified Four-Drug versus a Standard Three-Drug Antiretroviral Regimen, Both Integrase Strand Transfer Inhibitor-Based, in Primary HIV Infection.

The optimal therapeutic approach for primary HIV infection (PHI) is still debated. We aimed to compare the viroimmunological response to a four- versus a three-drug regimen, both INSTI-based, in patients with PHI. This was a monocentric, prospective, observational study including all patients diagnosed with PHI from December 2014 to April 2018. Antiretroviral therapy (ART) was started, before genotype resistance test results, with tenofovir/emtricitabine and either raltegravir plus boosted darunavir or dolutegravir. Cumulative probability of virological suppression [VS] (HIV-1 RNA< 40 cp/mL), low-level HIV-1 DNA [LL-HIVDNA] (HIV-1 DNA < 200 copies/106PBMC), and CD4/CD8 ratio ≥1 were estimated using Kaplan−Meier curves. Factors associated with the achievement of VS, LL-HIVDNA, and CD4/CD8 ≥ 1 were assessed by a Cox regression model. We enrolled 144 patients (95.8% male, median age 34 years): 110 (76%) started a four-drug-based therapy, and 34 (24%) a three-drug regimen. Both treatment groups showed a comparable high probability of achieving VS and a similar probability of reaching LL-HIVDNA and a CD4/CD8 ratio ≥1 after 48 weeks from ART initiation. Higher baseline HIV-1 RNA and HIV-1 DNA levels lowered the chance of VS, whereas a better preserved immunocompetence increased that chance. Not statistically significant factors associated with LL-HIVDNA achievement were found, whereas a higher baseline CD4/CD8 ratio predicted the achievement of immune recovery. In PHI patients, the rapid initiation of either an intensified four-drug or a standard three-drug INSTI-based regimen showed comparable responses in terms of VS, viral reservoir size, and immunological recovery.

Improving clinical laboratory efficiency: a time-motion evaluation of the Abbott m2000 RealTime and Roche COBAS AmpliPrep/COBAS TaqMan PCR systems for the simultaneous quantitation of HIV-1 RNA and HCV RNA.

BACKGROUND: Diagnostic laboratories need automation that facilitates efficient processing and workflow management to meet today's challenges for expanding services and reducing cost, yet maintaining the highest levels of quality. METHODS: Processing efficiency of two commercially available automated systems for quantifying HIV-1 and HCV RNA, Abbott m2000 system and Roche COBAS Ampliprep/COBAS TaqMan 96 (docked) systems (CAP/CTM), was evaluated in a mid/high throughput workflow laboratory using a representative daily workload of 24 HCV and 72 HIV samples. Three test scenarios were evaluated: A) one run with four batches on the CAP/CTM system, B) two runs on the Abbott m2000 and C) one run using the Abbott m2000 maxCycle feature (maxCycle) for co-processing these assays. Cycle times for processing, throughput and hands-on time were evaluated. RESULTS: Overall processing cycle time was 10.3, 9.1 and 7.6 h for Scenarios A), B) and C), respectively. Total hands-on time for each scenario was, in order, 100.0 (A), 90.3 (B) and 61.4 min (C). CONCLUSIONS: The interface of an automated analyzer to the laboratory workflow, notably system set up for samples and reagents and clean up functions, are as important as the automation capability of the analyzer for the overall impact to processing efficiency and operator hands-on time.

High Levels of TRIM5α Are Associated with Xenophagy in HIV-1-Infected Long-Term Nonprogressors.

Autophagy is a lysosomal-dependent degradative mechanism essential in maintaining cellular homeostasis, but it is also considered an ancient form of innate eukaryotic fighting against invading microorganisms. Mounting evidence has shown that HIV-1 is a critical target of autophagy that plays a role in HIV-1 replication and disease progression. In a special subset of HIV-1-infected patients that spontaneously and durably maintain extremely low viral replication, namely, long-term nonprogressors (LTNP), the resistance to HIV-1-induced pathogenesis is accompanied, in vivo, by a significant increase in the autophagic activity in peripheral blood mononuclear cells. Recently, a new player in the battle of autophagy against HIV-1 has been identified, namely, tripartite motif protein 5α (TRIM5α). In vitro data demonstrated that TRIM5α directly recognizes HIV-1 and targets it for autophagic destruction, thus protecting cells against HIV-1 infection. In this paper, we analyzed the involvement of this factor in the control of HIV-1 infection through autophagy, in vivo, in LTNP. The results obtained showed significantly higher levels of TRIM5α expression in cells from LTNP with respect to HIV-1-infected normal progressor patients. Interestingly, the colocalization of TRIM5α and HIV-1 proteins in autophagic vacuoles in LTNP cells suggested the participation of TRIM5α in the autophagy containment of HIV-1 in LTNP. Altogether, our results point to a protective role of TRIM5α in the successful control of the chronic viral infection in HIV-1-controllers through the autophagy mechanism. In our opinion, these findings could be relevant in fighting against HIV-1 disease, because autophagy inducers might be employed in combination with antiretroviral drugs.

Saliva Is a Valid Alternative to Nasopharyngeal Swab in Chemiluminescence-Based Assay for Detection of SARS-CoV-2 Antigen.

Diagnostic methods based on SARS-CoV-2 antigens detection are a promising alternative to SARS-CoV-2 RNA amplification. We evaluated the automated chemiluminescence-based Lumipulse® G SARS-CoV-2 Ag assay on saliva samples, using Simplexa™ COVID-19 Direct assay as a reference test. Analytical performance was established on a pool of healthy donors' saliva samples spiked with the 2019-nCoV/Italy-INMI1 isolate, whereas clinical performance was assessed on fresh saliva specimens collected from hospitalized patients with suspect or confirmed COVID-19 diagnosis. The limit of detection (LOD) was 0.65 Log TCID50/mL, corresponding to 18,197 copies/mL of SARS-CoV-2 RNA. Antigen concentrations and SARS-CoV-2 RNA were highly correlated (r = 0.99; p < 0.0001). Substantial agreement (80.3%) and significant correlation (r = -0.675; p = 0.0006) were observed between Lumipulse® G assay results and Ct values on clinical samples, with 52.4% sensitivity and specificity 94.1%. Sensitivity exceeded 90.0% when calculated on samples with Ct < 25, and specificity was 100% when excluding samples from recovered patients with previous COVID-19 diagnosis. Overall, chemiluminescence-based antigen assay may be reliably applied to saliva samples to identify individuals with high viral loads, more likely to transmit the virus. However, the low positive predictive value in a context of low SARS-CoV-2 prevalence underscores the need for confirmatory testing in SARS-CoV-2 antigen-positive cases.