Synergism between remdesivir and ribavirin leads to SARS-CoV-2 extinction in cell culture

BACKGROUND AND PURPOSE

There is a need for effective anti-COVID-19 treatments, mainly for individuals at risk of severe disease such as the elderly and the immunosuppressed. Drug repositioning has proved effective in identifying drugs that can find a new application for the control of coronavirus disease, in particular COVID-19. The purpose of the present study was to find synergistic antiviral combinations for COVID-19 based on lethal mutagenesis.

EXPERIMENTAL APPROACH

The effect of combinations of remdesivir and ribavirin on the infectivity of SARS-CoV-2 in cell culture has been tested. Viral populations were monitored by ultra-deep sequencing, and the decrease of infectivity as a result of the treatment was measured.

KEY RESULTS

Remdesivir and ribavirin exerted a synergistic inhibitory activity against SARS-CoV-2, quantified both by CompuSyn (Chou-Talalay method) and Synergy Finder (ZIP-score model). In serial passage experiments, virus extinction was readily achieved with remdesivir-ribavirin combinations at concentrations well below their cytotoxic 50 value, but not with the drugs used individually. Deep sequencing of treated viral populations showed that remdesivir, ribavirin, and their combinations evoked significant increases of the number of viral mutations and haplotypes, as well as modification of diversity indices that characterize viral quasi-species.

CONCLUSION AND IMPLICATIONS

SARS-CoV-2 extinction can be achieved by synergistic combination treatments based on lethal mutagenesis. In addition, the results offer prospects of triple drug treatments for effective SARS-CoV-2 suppression.

The HIV-1 reservoir landscape in persistent elite controllers and transient elite controllers

BACKGROUNDPersistent controllers (PCs) maintain antiretroviral-free HIV-1 control indefinitely over time, while transient controllers (TCs) eventually lose virological control. It is essential to characterize the quality of the HIV reservoir in terms of these phenotypes in order to identify the factors that lead to HIV progression and to open new avenues toward an HIV cure.METHODSThe characterization of HIV-1 reservoir from peripheral blood mononuclear cells was performed using next-generation sequencing techniques, such as full-length individual and matched integration site proviral sequencing (FLIP-Seq; MIP-Seq).RESULTSPCs and TCs, before losing virological control, presented significantly lower total, intact, and defective proviruses compared with those of participants on antiretroviral therapy (ART). No differences were found in total and defective proviruses between PCs and TCs. However, intact provirus levels were lower in PCs compared with TCs; indeed the intact/defective HIV-DNA ratio was significantly higher in TCs. Clonally expanded intact proviruses were found only in PCs and located in centromeric satellite DNA or zinc-finger genes, both associated with heterochromatin features. In contrast, sampled intact proviruses were located in permissive genic euchromatic positions in TCs.CONCLUSIONSThese results suggest the need for, and can give guidance to, the design of future research to identify a distinct proviral landscape that may be associated with the persistent control of HIV-1 without ART.FUNDINGInstituto de Salud Carlos III (FI17/00186, FI19/00083, MV20/00057, PI18/01532, PI19/01127 and PI22/01796), Gilead Fellowships (GLD22/00147). NIH grants AI155171, AI116228, AI078799, HL134539, DA047034, MH134823, amfAR ARCHE and the Bill and Melinda Gates Foundation.

A metagenome-wide association study of HIV disease progression in HIV controllers

Some HIV controllers experience immunologic progression with CD4⁺ T cell decline. We aimed to identify genetic factors associated with CD4⁺ T cell lost in HIV controllers. A total of 561 HIV controllers were included, 442 and 119 from the International HIV controllers Study Cohort and the Swiss HIV Cohort Study, respectively. No SNP or gene was associated with the long-term non-progressor HIV spontaneous control phenotype in the individual GWAS or in the meta-analysis. However, SNPs previously associated with natural HIV control linked to HLA-B (rs2395029 [p = 0.005; OR = 1.70], rs59440261 [p = 0.003; OR = 1.78]), MICA (rs112243036 [p = 0.011; OR = 1.45]), and PSORS1C1 loci (rs3815087 [p = 0.017; OR = 1.39]) showed nominal association with this phenotype. Genetic factors associated with the long-term HIV controllers without risk of immunologic progression are those previously related to the overall HIV controller phenotype.

Fitness-Dependent, Mild Mutagenic Activity of Sofosbuvir for Hepatitis C Virus

The concept of a mild mutagen was coined to describe a minor mutagenic activity exhibited by some nucleoside analogues that potentiated their efficacy as antiretroviral agents. In the present study, we report the mild mutagen activity of sofosbuvir (SOF) for hepatitis C virus (HCV). Serial passages of HCV in human hepatoma cells, in the presence of SOF at a concentration well below its cytotoxic concentration 50 (CC50) led to pre-extinction populations whose mutant spectra exhibited a significant increase of C→U transitions, relative to populations passaged in the absence of SOF. This was reflected in an increase in several diversity indices that were used to characterize viral quasispecies. The mild mutagenic activity of SOF was largely absent when it was tested with isogenic HCV populations that displayed high replicative fitness. Thus, SOF can act as a mild mutagen for HCV, depending on HCV fitness. Possible mechanisms by which the SOF mutagenic activity may contribute to its antiviral efficacy are discussed.

Toll-like receptor agonists enhance HIV-specific T cell response mediated by plasmacytoid dendritic cells in diverse HIV-1 disease progression phenotypes

BACKGROUND

Plasmacytoid dendritic cells (pDCs) sense viral and bacterial products through Toll-like receptor (TLR)-7 and -9 and translate this sensing into Interferon-α (IFN-α) production and T-cell activation. The understanding of the mechanisms involved in pDCs stimulation may contribute to HIV-cure immunotherapeutic strategies. The objective of the present study was to characterize the immunomodulatory effects of TLR agonist stimulations in several HIV-1 disease progression phenotypes and in non HIV-1 infected donors.

METHODS

pDCs, CD4 and CD8 T-cells were isolated from 450 ml of whole blood from non HIV-1 infected donors, immune responders (IR), immune non responders (INR), viremic (VIR) and elite controller (EC) participants. pDCs were stimulated overnight with AT-2, CpG-A, CpG-C and GS-9620 or no stimuli. After that, pDCs were co-cultured with autologous CD4 or CD8 T-cells and with/without HIV-1 (Gag peptide pool) or SEB (Staphylococcal Enterotoxin B). Cytokine array, gene expression and deep immunophenotyping were assayed.

FINDINGS

pDCs showed an increase of activation markers levels, interferon related genes, HIV-1 restriction factors and cytokines levels after TLR stimulation in the different HIV-disease progression phenotypes. This pDC activation was prominent with CpG-C and GS-9620 and induced an increase of HIV-specific T-cell response even in VIR and INR comparable with EC. This HIV-1 specific T-cell response was associated with the upregulation of HIV-1 restriction factors and IFN-α production by pDC.

INTERPRETATION

These results shed light on the mechanisms associated with TLR-specific pDCs stimulation associated with the induction of a T-cell mediated antiviral response which is essential for HIV-1 eradication strategies.

FUNDING

This work was supported by Gilead fellowship program, the Instituto de Salud Carlos III (Fondo Europeo de Desarrollo Regional, FEDER, "a way to make Europe") and the Red Temática de Investigación Cooperativa en SIDA and by the Spanish National Research Council (CSIC).

Hepatitis C virus fitness can influence the extent of infection-mediated epigenetic modifications in the host cells

Introduction

Cellular epigenetic modifications occur in the course of viral infections. We previously documented that hepatitis C virus (HCV) infection of human hepatoma Huh-7.5 cells results in a core protein-mediated decrease of Aurora kinase B (AURKB) activity and phosphorylation of Serine 10 in histone H3 (H3Ser10ph) levels, with an affectation of inflammatory pathways. The possible role of HCV fitness in infection-derived cellular epigenetic modifications is not known.

Methods

Here we approach this question using HCV populations that display a 2.3-fold increase in general fitness (infectious progeny production), and up to 45-fold increase of the exponential phase of intracellular viral growth rate, relative to the parental HCV population.

Results

We show that infection resulted in a HCV fitness-dependent, average decrease of the levels of H3Ser10ph, AURKB, and histone H4 tri-methylated at Lysine 20 (H4K20m3) in the infected cell population. Remarkably, the decrease of H4K20m3, which is a hallmark of cellular transformation, was significant upon infection with high fitness HCV but not upon infection with basal fitness virus.

Discussion

Here we propose two mechanisms ─which are not mutually exclusive─ to explain the effect of high viral fitness: an early advance in the number of infected cells, or larger number of replicating RNA molecules per cell. The implications of introducing HCV fitness as an influence in virus-host interactions, and for the course of liver disease, are warranted. Emphasis is made in the possibility that HCV-mediated hepatocellular carcinoma may be favoured by prolonged HCV infection of a human liver, a situation in which viral fitness is likely to increase.

Efficacy decrease of antiviral agents when administered to ongoing hepatitis C virus infections in cell culture

We report a quantification of the decrease of effectiveness of antiviral agents directed to hepatitis C virus, when the agents are added during an ongoing infection in cell culture vs. when they are added at the beginning of the infection. Major determinants of the decrease of inhibitory activity are the time post-infection of inhibitor administration and viral replicative fitness. The efficacy decrease has been documented with antiviral assays involving the combination of the direct-acting antiviral agents, daclatasvir and sofosbuvir, and with the combination of the lethal mutagens, favipiravir and ribavirin. The results suggest that strict antiviral effectiveness assays in preclinical trials may involve the use of high fitness viral populations and the delayed administration of the agents, relative to infection onset.

SARS-CoV-2 Mutant Spectra at Different Depth Levels Reveal an Overwhelming Abundance of Low Frequency Mutations

Populations of RNA viruses are composed of complex and dynamic mixtures of variant genomes that are termed mutant spectra or mutant clouds. This applies also to SARS-CoV-2, and mutations that are detected at low frequency in an infected individual can be dominant (represented in the consensus sequence) in subsequent variants of interest or variants of concern. Here we briefly review the main conclusions of our work on mutant spectrum characterization of hepatitis C virus (HCV) and SARS-CoV-2 at the nucleotide and amino acid levels and address the following two new questions derived from previous results: (i) how is the SARS-CoV-2 mutant and deletion spectrum composition in diagnostic samples, when examined at progressively lower cut-off mutant frequency values in ultra-deep sequencing; (ii) how the frequency distribution of minority amino acid substitutions in SARS-CoV-2 compares with that of HCV sampled also from infected patients. The main conclusions are the following: (i) the number of different mutations found at low frequency in SARS-CoV-2 mutant spectra increases dramatically (50- to 100-fold) as the cut-off frequency for mutation detection is lowered from 0.5% to 0.1%, and (ii) that, contrary to HCV, SARS-CoV-2 mutant spectra exhibit a deficit of intermediate frequency amino acid substitutions. The possible origin and implications of mutant spectrum differences among RNA viruses are discussed.

Vaccine breakthrough infections with SARS-CoV-2 Alpha mirror mutations in Delta Plus, Iota, and Omicron

Replication of SARS-CoV-2 in the human population is defined by distributions of mutants that are present at different frequencies within the infected host and can be detected by ultra-deep sequencing techniques. In this study, we examined the SARS-CoV-2 mutant spectra of amplicons from the spike-coding (S-coding) region of 5 nasopharyngeal isolates derived from patients with vaccine breakthrough. Interestingly, all patients became infected with the Alpha variant, but amino acid substitutions that correspond to the Delta Plus, Iota, and Omicron variants were present in the mutant spectra of the resident virus. Deep sequencing analysis of SARS-CoV-2 from patients with vaccine breakthrough revealed a rich reservoir of mutant types and may also identify tolerated substitutions that can be represented in epidemiologically dominant variants.

SARS-CoV-2 Point Mutation and Deletion Spectra and Their Association with Different Disease Outcomes

Mutant spectra of RNA viruses are important to understand viral pathogenesis and response to selective pressures. There is a need to characterize the complexity of mutant spectra in coronaviruses sampled from infected patients. In particular, the possible relationship between SARS-CoV-2 mutant spectrum complexity and disease associations has not been established. In the present study, we report an ultradeep sequencing (UDS) analysis of the mutant spectrum of amplicons from the nsp12 (polymerase)- and spike (S)-coding regions of 30 nasopharyngeal isolates (diagnostic samples) of SARS-CoV-2 of the first COVID-19 pandemic wave (Madrid, Spain, April 2020) classified according to the severity of ensuing COVID-19. Low-frequency mutations and deletions, counted relative to the consensus sequence of the corresponding isolate, were overwhelmingly abundant. We show that the average number of different point mutations, mutations per haplotype, and several diversity indices was significantly higher in SARS-CoV-2 isolated from patients who developed mild disease than in those associated with moderate or severe disease (exitus). No such bias was observed with RNA deletions. Location of amino acid substitutions in the three-dimensional structures of nsp12 (polymerase) and S suggest significant structural or functional effects. Thus, patients who develop mild symptoms may be a richer source of genetic variants of SARS-CoV-2 than patients with moderate or severe COVID-19. IMPORTANCE The study shows that mutant spectra of SARS-CoV-2 from diagnostic samples differ in point mutation abundance and complexity and that significantly larger values were observed in virus from patients who developed mild COVID-19 symptoms. Mutant spectrum complexity is not a uniform trait among isolates. The nature and location of low-frequency amino acid substitutions present in mutant spectra anticipate great potential for phenotypic diversification of SARS-CoV-2.

Guanosine inhibits hepatitis C virus replication and increases indel frequencies, associated with altered intracellular nucleotide pools

In the course of experiments aimed at deciphering the inhibition mechanism of mycophenolic acid and ribavirin in hepatitis C virus (HCV) infection, we observed an inhibitory effect of the nucleoside guanosine (Gua). Here, we report that Gua, and not the other standard nucleosides, inhibits HCV replication in human hepatoma cells. Gua did not directly inhibit the in vitro polymerase activity of NS5B, but it modified the intracellular levels of nucleoside di- and tri-phosphates (NDPs and NTPs), leading to deficient HCV RNA replication and reduction of infectious progeny virus production. Changes in the concentrations of NTPs or NDPs modified NS5B RNA polymerase activity in vitro, in particular de novo RNA synthesis and template switching. Furthermore, the Gua-mediated changes were associated with a significant increase in the number of indels in viral RNA, which may account for the reduction of the specific infectivity of the viral progeny, suggesting the presence of defective genomes. Thus, a proper NTP:NDP balance appears to be critical to ensure HCV polymerase fidelity and minimal production of defective genomes.

A Two-Level, Intramutant Spectrum Haplotype Profile of Hepatitis C Virus Revealed by Self-Organized Maps

RNA viruses replicate as complex mutant spectra termed viral quasispecies. The frequency of each individual genome in a mutant spectrum depends on its rate of generation and its relative fitness in the replicating population ensemble. The advent of deep sequencing methodologies allows for the first-time quantification of haplotype abundances within mutant spectra. There is no information on the haplotype profile of the resident genomes and how the landscape evolves when a virus replicates in a controlled cell culture environment. Here, we report the construction of intramutant spectrum haplotype landscapes of three amplicons of the NS5A-NS5B coding region of hepatitis C virus (HCV). Two-dimensional (2D) neural networks were constructed for 44 related HCV populations derived from a common clonal ancestor that was passaged up to 210 times in human hepatoma Huh-7.5 cells in the absence of external selective pressures. The haplotype profiles consisted of an extended dense basal platform, from which a lower number of protruding higher peaks emerged. As HCV increased its adaptation to the cells, the number of haplotype peaks within each mutant spectrum expanded, and their distribution shifted in the 2D network. The results show that extensive HCV replication in a monotonous cell culture environment does not limit HCV exploration of sequence space through haplotype peak movements. The landscapes reflect dynamic variation in the intramutant spectrum haplotype profile and may serve as a reference to interpret the modifications produced by external selective pressures or to compare with the landscapes of mutant spectra in complex in vivo environments. IMPORTANCE The study provides for the first time the haplotype profile and its variation in the course of virus adaptation to a cell culture environment in the absence of external selective constraints. The deep sequencing-based self-organized maps document a two-layer haplotype distribution with an ample basal platform and a lower number of protruding peaks. The results suggest an inferred intramutant spectrum fitness landscape structure that offers potential benefits for virus resilience to mutational inputs.

Akt Phosphorylation of Hepatitis C Virus NS5B Regulates Polymerase Activity and Hepatitis C Virus Infection

Hepatitis C virus (HCV) is a single-stranded RNA virus of positive polarity [ssRNA(+)] that replicates its genome through the activity of one of its proteins, called NS5B. This viral protein is responsible for copying the positive-polarity RNA genome into a negative-polarity RNA strand, which will be the template for new positive-polarity RNA genomes. The NS5B protein is phosphorylated by cellular kinases, including Akt. In this work, we have identified several amino acids of NS5B that are phosphorylated by Akt, with positions S27, T53, T267, and S282 giving the most robust results. Site-directed mutagenesis of these residues to mimic (Glu mutants) or prevent (Ala mutants) their phosphorylation resulted in a reduced NS5B in vitro RNA polymerase activity, except for the T267E mutant, the only non-conserved position of all those that are phosphorylated. In addition, in vitro transcribed RNAs derived from HCV complete infectious clones carrying mutations T53E/A and S282E/A were transfected in Huh-7.5 permissive cells, and supernatant viral titers were measured at 6 and 15 days post-transfection. No virus was rescued from the mutants except for T53A at 15 days post-transfection whose viral titer was statistically lower as compared to the wild type. Therefore, phosphorylation of NS5B by cellular kinases is a mechanism of viral polymerase inactivation. Whether this inactivation is a consequence of interaction with cellular kinases or a way to generate inactive NS5B that may have other functions are questions that need further experimental work.

Amino Acid Substitutions Associated with Treatment Failure for Hepatitis C Virus Infection

Despite the high virological response rates achieved with current directly acting antiviral agents (DAAs) against hepatitis C virus (HCV), around 2% to 5% of treated patients do not achieve a sustained viral response. The identification of amino acid substitutions associated with treatment failure requires analytical designs, such as subtype-specific ultradeep sequencing (UDS) methods, for HCV characterization and patient management. Using this procedure, we have identified six highly represented amino acid substitutions (HRSs) in NS5A and NS5B of HCV, which are not bona fide resistance-associated substitutions (RAS), from 220 patients who failed therapy. They were present frequently in basal and posttreatment virus of patients who failed different DAA-based therapies. Contrary to several RAS, HRSs belong to the acceptable subset of substitutions according to the PAM250 replacement matrix. Their mutant frequency, measured by the number of deep sequencing reads within the HCV quasispecies that encode the relevant substitutions, ranged between 90% and 100% in most cases. They also have limited predicted disruptive effects on the three-dimensional structures of the proteins harboring them. Possible mechanisms of HRS origin and dominance, as well as their potential predictive value for treatment response, are discussed.

Dissimilar Conservation Pattern in Hepatitis C Virus Mutant Spectra, Consensus Sequences, and Data Banks

The influence of quasispecies dynamics on long-term virus diversification in nature is a largely unexplored question. Specifically, whether intra-host nucleotide and amino acid variation in quasispecies fit the variation observed in consensus sequences or data bank alignments is unknown. Genome conservation and dynamics simulations are used for the computational design of universal vaccines, therapeutic antibodies and pan-genomic antiviral agents. The expectation is that selection of escape mutants will be limited when mutations at conserved residues are required. This strategy assumes long-term (epidemiologically relevant) conservation but, critically, does not consider short-term (quasispecies-dictated) residue conservation. We calculated mutant frequencies of individual loci from mutant spectra of hepatitis C virus (HCV) populations passaged in cell culture and from infected patients. Nucleotide or amino acid conservation in consensus sequences of the same populations, or in the Los Alamos HCV data bank did not match residue conservation in mutant spectra. The results relativize the concept of sequence conservation in viral genetics and suggest that residue invariance in data banks is an insufficient basis for the design of universal viral ligands for clinical purposes. Our calculations suggest relaxed mutational restrictions during quasispecies dynamics, which may contribute to higher calculated short-term than long-term viral evolutionary rates.

Viral fitness: history and relevance for viral pathogenesis and antiviral interventions

The quasispecies dynamics of viral populations (continuous generation of variant genomes and competition among them) has as one of its frequent consequences variations in overall multiplication capacity, a major component of viral fitness. This parameter has multiple implications for viral pathogenesis and viral disease control, some of them unveiled thanks to deep sequencing of viral populations. Darwinian fitness is an old concept whose quantification dates back to the early developments of population genetics. It was later applied to viruses (mainly to RNA viruses) to quantify relative multiplication capacities of individual mutant clones or complex populations. The present article reviews the fitness concept and its relevance for the understanding of the adaptive dynamics of viruses in constant and changing environments. Many studies have addressed the fitness cost of escape mutations (to antibodies, cytotoxic T cells or inhibitors) as an influence on the efficacy of antiviral interventions. Here, we summarize the evidence that the basal fitness level can be a determinant of inhibitor resistance.

Rare haplotype load as marker for lethal mutagenesis

RNA viruses replicate with a template-copying fidelity, which lies close to an extinction threshold. Increases of mutation rate by nucleotide analogues can drive viruses towards extinction. This transition is the basis of an antiviral strategy termed lethal mutagenesis. We have introduced a new diversity index, the rare haplotype load (RHL), to describe NS5B (polymerase) mutant spectra of hepatitis C virus (HCV) populations passaged in absence or presence of the mutagenic agents favipiravir or ribavirin. The increase in RHL is more prominent in mutant spectra whose expansions were due to nucleotide analogues than to multiple passages in absence of mutagens. Statistical tests for paired mutagenized versus non-mutagenized samples with 14 diversity indices show that RHL provides consistently the highest standardized effect of mutagenic treatment difference for ribavirin and favipiravir. The results indicate that the enrichment of viral quasispecies in very low frequency minority genomes can serve as a robust marker for lethal mutagenesis. The diagnostic value of RHL from deep sequencing data is relevant to experimental studies on enhanced mutagenesis of viruses, and to pharmacological evaluations of inhibitors suspected to have a mutagenic activity.

Abstract P4-20-01: Implications of financial modeling in breast cancer clinical research from 1990 to 2010

SUMMARY: Over the past two decades significant progress has been made in breast cancer treatment resulting in a substantial improvement in patients' outcome. But we have to think about who promotes all this research and the consequences of the type of fundingThis project aims to evaluate the implication of finance in clinical research and the variance according to the type of funding.

OBJETIVES: To evaluate the financial evolvement of breast cancer clinical trials in the past two decades, regarding the phase of development design of the studies, the collaboration between Academy (Acad) and Industry (Ind), the sample size, the study results and the statistical analyses conducted.

METHODS: A systematic review was performed using MEDLINE to identify breast cancer randomized clinical trials published between January1990 and December2010. Studies that involved chemotherapy, endocrine and/or targeted therapies, wherethe primary endpoint was considered adequate to support a drug approval in oncology according to the FDA and EMA (U.S. Food and Drug Administration and European Medicines Agency, respectively), were included.

RESULTS:Data were evaluated 2,211 and 472 met selection criteria comprised in the methodology During the first decade the Acad was the main breast cancer research promoter being replaced by the Inv. throughout the second decade (p <0.0001). Thirty nine percent of the studies evaluated were phase III (39% Acad, 61% Ind), 15% were phase II (30% Acad, 70% Ind) and the remaining 47% were not classified by authors (65% Acad 35% Ind). As for the primary endpoint, 25% of the phase III trials evaluated progression free survival, 15% overall response rate, 1% time to progression and only 5% examined overall survival. Sixty five percent of the trials were national (60% Acad 40% Ind) and 35% international (25% Acad 75% Ind). Single-center studies accounted for 11% of the trial (65% Acad 35% Ind). Most of the national trials were developed by the US. Fifty four percent of the studies were conducted by research groups (67% supported by Ind. and 33% Acad.). The Ind sponsored 26% of the studies in the first decade and 50% during the second. The median number of patients enrolled by research groups was 892 in contrast with 409 included by other organizations. The primary endpoint was achieved in 19% of the Acad trials and 21% of the Ind trials. Only 53% of the studies declared intention to treat based analysis in their statistical workout.

RESULTS  ACADEMY(%)INDUSTRY (%)PPROMOTION OF THE STUDY1990-2000121(26)68(14)0,0001 2001-2010105(22)178(38)0,0001STUDY DESIGNUNICENTRIC TRIALS34(7)18(4)0,007 MULTICENTRIC TRIALS191(40)228(48)  NATIONAL TRIALS183(39)122(26)0,0001 INTERNATIONAL TRIALS42(9)124(26)  COOPERATIVE GROUP95(20)160(34)  NOT COOPERATIVE GROUP130(28)86(18) STATISTICAL ANALYSISINTENT OF TREAT86(18)163(35)  NOT DECLARATED140(30)83(18) 

CONCLUSIONS:There is a significant tendency towards the promotion of research by the pharmaceutical industries during the last two decades, leading a change in the clinical trials design and the endpoints.

Citation Format: Jerez Y, Lopez-Tarruella S, Marquez-Rodas I, Perez S, Ocaña A, Echavarria I, Lobo M, Gallego I, Torres G, Ortega L, Garcia G, Palomero I, Gonzalez Del Val R, Massarrah T, Esteban M, Del Monte-Millan M, Martin M. Implications of financial modeling in breast cancer clinical research from 1990 to 2010 [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-20-01.

Lethal Mutagenesis of Hepatitis C Virus Induced by Favipiravir

Lethal mutagenesis is an antiviral approach that consists in extinguishing a virus by an excess of mutations acquired during replication in the presence of a mutagen. Here we show that favipiravir (T-705) is a potent mutagenic agent for hepatitis C virus (HCV) during its replication in human hepatoma cells. T-705 leads to an excess of G → A and C → U transitions in the mutant spectrum of preextinction HCV populations. Infectivity decreased significantly in the presence of concentrations of T-705 which are 2- to 8-fold lower than its cytotoxic concentration 50 (CC50). Passaging the virus five times in the presence of 400 μM T-705 resulted in virus extinction. Since T-705 has undergone advanced clinical trials for approval for human use, the results open a new approach based on lethal mutagenesis to treat hepatitis C virus infections. If proven effective for HCV in vivo, this new anti-HCV agent may be useful in patient groups that fail current therapeutic regimens.

[Electrodiagnostic criteria for childhood Guillain-Barre syndrome. Eight years' experience]

INTRODUCTION. The Guillan-Barre syndrome is the most frequent case of acute flacid paralysis in children. The diagnostic criteria differ according to the demyelinating or axonal variant and the prevalence by geographical area. The electro-myographic study permits identifying variants, evaluating the prognosis and predicting the evolution, is in addition an objective tool for the monitoring. AIM. To describe the electromyographic characteristics of the Guillain-Barre syndrome evaluated in hospital and its classification by physiopathological pattern. PATIENTS AND METHODS. All the cases diagnosed between 2005 and 2012 are included. Studies of motor and sensitive nervous conduction and F waves in 14 girls and 11 boys between 1 and 13 years of age. RESULTS. 19 cases of acute inflammatory demyelinating polyneuropathy (AIDP) and five of acute motor axonal neuropathy (AMAN) were diagnosed. The electromyogram was performed between 1 and 30 days after the beginning of symptoms. In AIDP cases, multifocal demyelination, four of them with the preserved sural and 13 with alteration and absence of F wave were objectified. In the cases of AMAN, four had low amplitude potential and in one of them they were not evoked. CONCLUSIONS. The demyelinating form of the illness is the most frequent although the high number of AMAN cases stands out, probably related to the population object of study. The evolution was favorable in three cases of motor axonal neuropathy and in 15 accute demyelinating polyneuropathy. In four cases the symptoms became chronic; three of them with persistent demyelination a similar occurrence in other studies with children.

Long-term results of vagal nerve stimulation for adults with medication-resistant epilepsy who have been on unchanged antiepileptic medication

PURPOSE

Several studies suggest that vagal nerve stimulation (VNS) is an effective treatment for medication-resistant epileptic patients, although patients' medication was usually modified during the assessment period. The purpose of this prospective study was to evaluate the long-term effects of VNS, at 18 months of follow-up, on epileptic patients who have been on unchanged antiepileptic medication.

METHODS

Forty-three patients underwent a complete epilepsy preoperative evaluation protocol, and were selected for VNS implantation. After surgery, patients were evaluated on a monthly basis, increasing stimulation 0.25mA at each visit, up to 2.5mA. Medication was unchanged for at least 18 months since the stimulation was started. The outcome was analysed in relation to patients' clinical features, stimulation parameters, epilepsy type, magnetic resonance imaging (MRI) results, and history of prior brain surgery.

RESULTS

Of the 43 operated patients, 63% had a similar or greater than 50% reduction in their seizure frequency. Differences in the responder rate according to stimulation intensity, age at onset of epilepsy, duration of epilepsy before surgery, previous epilepsy surgery and seizure type, did not reach statistical significance. Most side effects were well tolerated.

CONCLUSIONS

62.8% of our series of 43 medication-resistant epileptic patients experienced a significant long-term seizure reduction after VNS, even in a situation of on unchanged medical therapy. Patient characteristics predictive of VNS responsiveness remain subject to investigation. Controlled studies with larger sample sizes, on VNS for patients with medication-resistant epilepsy on unchanged medication, are necessary to confirm VNS efficacy for drug-resistant epilepsy, and to identify predictive factors.

Ribavirin can be mutagenic for arenaviruses

Arenaviruses include several important human pathogens, and there are very limited options of preventive or therapeutic interventions to combat these viruses. An off-label use of the purine nucleoside analogue ribavirin (1-β-d-ribofuranosyl-1-H-1,2,4-triazole-3-carboxamide) is the only antiviral treatment currently available for arenavirus infections. However, the ribavirin antiviral mechanism action against arenaviruses remains unknown. Here we document that ribavirin is mutagenic for the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) in cell culture. The mutagenic activity of ribavirin on LCMV was observed under single- and multiple-passage regimes and could not be accounted for by a decrease of the intracellular GTP pool promoted by ribavirin-mediated inhibition of inosine monophosphate dehydrogenase (IMPDH). Our findings suggest that the antiviral activity of ribavirin on arenaviruses might be exerted, at least partially, by lethal mutagenesis. Implications for antiarenavirus therapy are discussed.

[Psychogenic non-epileptic seizures in an epilepsy surgery unit]

INTRODUCTION

The psychogenic non-epileptic seizures (PNES) represent a significant percentage of patients in different units of epilepsy surgery. AIMS. To analyze the characteristics of patients with PNES and compared with epileptic patients, to analyze the early response to the application of placebo and to discuss the multidisciplinary approach to these patients.

PATIENTS AND METHODS

408 patients, candidates for epilepsy surgery in the last nine years, were retrospectively evaluated. All patients were studied with scalp electroencephalography, magnetic resonance imaging, interictal single photon emission computed tomography and video-EEG.

RESULTS

Patients were ascribed to the following diagnostic groups: epileptics (90.2%), patients with PNES and/or without seizures or signs of epilepsy (6.4%) and patients for whom no seizures were recorded, but showed signs of epilepsy (3.4%). There were no differences between patients with PNES and epileptic respect to age, average frequency, distribution of seizures or drug treatment, but the time of onset was earlier in PNES. Patients with PNES (n = 15) revealed the presence of epilepsy or irritative manifestations in 10 cases. Most (n = 13) were women and only five had a history of mild psychiatric disorders that were not present in the group of patients exclusively with PNES. In four cases was carried out an induction with placebo, which was positive.

CONCLUSION

A multidisciplinary approach is required for the proper evaluation and treatment of patients with PNES.

Torsion of the fallopian tube and acute pelvic pain: an unusual presentation of genital tuberculosis

A case of a genital tuberculosis found during laparoscopic evaluation for recurrent acute pelvic pain is presented. The symptoms of genital tuberculosis can vary greatly, and a laparoscopic approach is effective for making the diagnosis. Clinicians should consider tuberculosis as a differential diagnosis when encountering clinical presentations of pelvic pain and ascites.

Analysis of the candidate tumor suppressor Ris-1 in primary human breast carcinomas

Frequent chromosome 3 losses have been described in several tumors types, which strongly suggest the presence of one or several tumor suppressor genes. Recently, a novel candidate tumor suppressor gene termed Ris-1 (for Ras-induced senescence 1) has been identified at chromosomal position 3p21.3. Ris-1 has been proposed to participate in anti-tumor responses that resemble cellular senescence and that are elicited by oncogenes such as Ras. To analyze the role of Ris-1 as a putative tumor suppressor gene in human breast cancer, we have performed a real-time quantitative analysis of its mRNA expression in 60 patients. Moreover, we carried out a first approach to evaluate the most common inactivation mechanism that can affect expression levels of tumor suppressor genes (mutation, promoter hypermethylation and allelic losses). Furthermore, a correlation study between expression as well as inactivating mechanisms of Ris-1 and several clinico-pathological parameters of the tumors was designed, with the objective of appraising the prognostic value of Ris-1 status. Decreased expression of Ris-1 was observed in 23% of the cases and overexpressed Ris-1 was detected in 15% of the primary breast tumors. Our data showed high frequency of LOH (30%) at one of the markers used. Nevertheless, a polymorphism related with the expression levels was described. Statistically significant correlations were found between decreased Ris-1 expression and negative progesterone receptors, as well as between overexpressing Ris-1 tumors and high histological grade. Despite all these data, we conclude that the suggested role of Ris-1 as tumor suppressor gene is not evident, at least in breast cancer. Future and larger series studies in different tumor types are necessary to clarify Ris-1 function in human cancer.

[Bladder hemangioma after radiotherapy]

OBJECTIVES

Bladder hemangiomas are exceptional benign tumours representing 0.6% bladder tumours. Most times they present as solitary, unique lesions; radiological signs are very similar to urothelial neoplasias making differential diagnosis or at least diagnostic suspicions very difficult due to its low incidence. We perform a bibliographic review and comment on its clinical and pathological characteristics, as well as on diagnostic methods and latest modifications in therapy.

METHODS

We present a case of bladder haemangioma secondary to pelvic radiotherapy, being this presentation unique among approximately 100 cases described in the literature.

RESULTS

From cystoscopy we suspected the lesion could be an endothelial neoplasia based on its vascular appearance. We performed transurethral resection and electrocoagulation of the lesion because it was small and unique. Pathology report confirmed it was a bladder hemangioma secondary to radiotherapy, being this an exceptional presentation. There has been no relapse up to date.

CONCLUSION

We think that resection and electrocoagulation of unique, solitary bladder hemangiomas is a therapeutic option to be taken into consideration in the management of this kind of benign tumours.

Analysis of genetic and epigenetic processes that influence p14ARF expression in breast cancer

The INK4a/ARF locus encodes two unrelated cell cycle-regulatory proteins that both function in tumor suppression, p16INK4a and p14ARF. In human tumors including breast cancer, alterations affecting selectively p14ARF have been poorly analysed. We have performed a comprehensive analysis of the inactivation mechanisms (mutation, homozygous and hemizygous deletion, and promoter hypermethylation) in a large series of 100 primary breast carcinomas. RT-PCR showed expression variable of the p14ARF transcript, with 17% demonstrating overexpression and 26% demonstrating decreased expression. No detectable alterations were observed in the majority of cases with overexpressed p14ARF mRNA, but 77% of tumors with decreased expression presented at least one of these genetic/epigenetic alterations. Nevertheless, a statistically significant correlation was observed between decreased p14ARF expression and several poor prognostic parameters.

Foreign bodies in granulomatous cutaneous lesions of patients with systemic sarcoidosis

OBJECTIVE

To assess the presence of foreign material in the granulomatous cutaneous lesions of patients with systemic sarcoidosis.

DESIGN AND SETTING

Observational study reevaluating histological specimens at a university referral hospital.

PATIENTS

Sixty-five patients diagnosed as having sarcoidosis who developed granulomatous cutaneous involvement.

MAIN OUTCOME MEASURES

To detect the presence of polarizable foreign particles in cutaneous biopsy specimens and to evaluate the association with clinical features of the patients.

RESULTS

Granulomatous cutaneous involvement was demonstrated in 65 (15.3%) of 425 patients with systemic sarcoidosis. In 14 (22%) of the 65 patients, the cutaneous biopsy specimen showed foreign particles in polarized light. The skin lesions corresponded to 3 different clinical patterns: an admixture of papules and infiltration of previously undetected minute scars (n = 6); scar sarcoidosis (n = 4); and subcutaneous nodules (n = 4). The lesions were located most frequently in the extremities, involving the knees in 10 patients.

CONCLUSIONS

The presence of polarizable foreign body material in granulomatous cutaneous lesions is not infrequent in patients with systemic sarcoidosis. Inoculation of foreign matter from a previous inapparent minor trauma may induce granuloma formation in individuals with sarcoidosis.

Wild type p73 overexpression and high-grade malignancy in breast cancer

The overexpression of wild type p73 is the most frequent alteration of p73 in malignancies. We investigated, in 70 breast carcinomas, p73 mRNA expression and its relationship to p53 mutations, determined by an immunohistochemical method, and loss heterozygosity (LOH) status of the 1p36 region, together with its possible implication in the pathogenesis of breast carcinomas. LOH, amplifying DNA by PCR using 5 markers, of 1p36 region (one intragenic to p73 gene) was found in 17% of cases but no significant correlation was observed with p73 overexpression. p53 positive immunostaining was present in 33% of breast carcinomas, and these exhibited a statistically significant relation with p73 overexpressed tumors. Overexpression of p73 mRNA was observed in 19 tumors (27%). The analysis of cases with p73 overexpression and cases with normal mRNA expression, in terms of age and pathologic characteristics of the tumors showed a significant association of p73 overexpression and tumors with lymph node metastases, vascular invasion and higher pathologic stage. These results suggest that p73 overexpression is a molecular alteration that could be implicated in the tumorigenesis of breast carcinomas and, eventually, in a poor clinical behavior.

[Skin reactions to interferon alpha in a series of 92 patients with multiple sclerosis]

BACKGROUND

A significant proportion of multiple sclerosis patients develop cutaneous reactions by interferon beta 1b (IFN-beta). The am of this study was to describe clinically and histologically the cutaneous reactions by IFN-beta.

PATIENTS AND METHODS

A series of 92 patients with multiple sclerosis in treatment with IFN-beta was followed. Cutaneous biopsy was performed in cases with persistent lesions.

RESULTS

9 out of 92 patients presented eritematous plaques, 4 cutaneous ulcers and 1 sclerodermiform plaques. Vascular thrombosis was demonstrated in 2 cases.

CONCLUSIONS

In patients with multiple sclerosis treated with IFN-beta the persistent skin lesions are more frequent in female patients. Generally is not necessary to stop the treatment.

Loss of heterozygosity in BRCA1 and BRCA2 markers and high-grade malignancy in breast cancer

Loss of heterozygosity (LOH) in loci of the 17q21 and 13q12-13 regions can collaborate in the inactivation of BRCA1, BRCA2, and possibly other genes implicated in the pathogenesis of breast carcinomas. We investigate allelic losses in microsatellites of the BRCA1 and BRCA2 regions, and their correlations with seven pathologic parameters in 140 breast carcinomas. Those cases showing LOH in the region of the RB gene, 13q14, were excluded from the study. The LOH analysis was performed by amplifying DNA by PCR, using four markers of the 17q21 region (D17S856, D17S855, D17S1323, and D17S1327) and four markers of the 13q12-13 region (D13S290, D13S260, D13S310, and D13S267). LOH in the BRCA1 region was found in 47% of tumors, correlating significantly with estrogen receptor content (p = 0.025), progesterone receptors (p = 0.004), higher grade (p = 0.0008), peritumoral vessel invasion (p = 0.001), and lymph node metastases (p = 0.002). When we excluded the cases with LOH in the BRCA2 region and those not informative for it, the significance disappeared. In the BRCA2 region, a rate of LOH of 51% was found; it correlated significantly with estrogen receptor content (p = 0.002), progesterone receptors (p = 0.03), peritumoral vessel invasion (p = 0.005), higher grade (p = 0.002), and lymph node metastases (p = 0.001). When cases with BRCA1 losses and those not informative were excluded, again the significance disappeared. Concomitant losses in the BRCA1 and BRCA2 regions were found in 32% of cases, correlating significantly with lymph node metastases (p = 0.0002), estrogen receptor content (p = 0.003), progesterone receptors (p = 0.001), histologic grade (p = 0.01), and peritumoral vessel invasion (p = 0.0004). These results suggest that concomitant losses in both regions could have a functional effect, influencing the presence of a poor tumor pathophenotype in breast carcinomas.

Hepatocellular carcinoma. A study of 50 autopsy cases with detection of hepatitis B surface antigen in fixed tissues

Fifty patients who died of hepatocellular carcinoma (HCC) were autopsied at the Ciudad Sanitaria "1 degree de Octubre" and the Hospital de la Cruz Roja (Madrid) from 1974 to 1980. Formalin fixed paraffin-embedded autopsy tissue of liver and tumor from the 50 HCC and liver tissue from 50 liver cirrhosis (LC) and from 50 autopsy of non cirrhotic control cases were examined for the presence of cytoplasmic hepatitis B surface antigen (HBsAg). The study was carried out using orcein staining, immunoperoxidase technique (IP) and indirect immunofluorescence (IF). In livers with HCC the HBsAg was detected in the cytoplasm of the hepatocytes in 10 cases (20%) with the orcein staining and in 11 (22%) with the IP and IF techniques. In one case (2%) HBsAg was found in the cytoplasm of tumor cells with the three methods--In four cases (8%) of LC and 2 (4%) control cases cytoplasmic positive cells were found. In 41 patients with HCC HBsAg was studied in the serum by radio-immunoassay (RIA) (13 cases) and immunodiffussion (28 cases). 5 patients (12,1%) were positive and 36 (72%) were negative. In the 5 serum positive HBsAg HCC the staining methods for cytoplasmic HBsAg were positive (100%). In 36 serum negative HBsAg HCC the staining method were positive in 2 cases. The results let us to conclude that HBV is a probable important etiologic factor of HCC in our milieu. 54% of the patients with HCC had a previous history of alcohol abuse; however, histologic features compatible with an alcoholic etiology were found in only 5 cases. Nevertheless we consider that the described histopathologic findings do not exclude excess alcohol consumption as a possible etiologic factor for HCC in our series.