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1.
J Virol ; 98(5): e0020724, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38639487

RESUMEN

To streamline standard virological assays, we developed a suite of nine fluorescent or bioluminescent replication competent human species C5 adenovirus reporter viruses that mimic their parental wild-type counterpart. These reporter viruses provide a rapid and quantitative readout of various aspects of viral infection and replication based on EGFP, mCherry, or NanoLuc measurement. Moreover, they permit real-time non-invasive measures of viral load, replication dynamics, and infection kinetics over the entire course of infection, allowing measurements that were not previously possible. This suite of replication competent reporter viruses increases the ease, speed, and adaptability of standard assays and has the potential to accelerate multiple areas of human adenovirus research.IMPORTANCEIn this work, we developed a versatile toolbox of nine HAdV-C5 reporter viruses and validated their functions in cell culture. These reporter viruses provide a rapid and quantitative readout of various aspects of viral infection and replication based on EGFP, mCherry, or NanoLuc measurement. The utility of these reporter viruses could also be extended for use in 3D cell culture, organoids, live cell imaging, or animal models, and provides a conceptual framework for the development of new reporter viruses representing other clinically relevant HAdV species.


Asunto(s)
Adenovirus Humanos , Genes Reporteros , Humanos , Infecciones por Adenovirus Humanos/virología , Adenovirus Humanos/genética , Adenovirus Humanos/fisiología , Línea Celular , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Células HEK293 , Carga Viral , Replicación Viral
2.
J Infect Dis ; 230(2): 394-402, 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-38716969

RESUMEN

BACKGROUND: Monoclonal antibodies (mAbs) represent a crucial antiviral strategy for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but it is unclear whether combination mAbs offer a benefit over single-active mAb treatment. Amubarvimab and romlusevimab significantly reduced the risk of hospitalizations or death in the ACTIV-2/A5401 trial. Certain SARS-CoV-2 variants are intrinsically resistant against romlusevimab, leading to only single-active mAb therapy with amubarvimab in these variants. We evaluated virologic outcomes in individuals treated with single- versus dual-active mAbs. METHODS: Participants were nonhospitalized adults at higher risk of clinical progression randomized to amubarvimab plus romlusevimab or placebo. Quantitative SARS-CoV-2 RNA levels and targeted S-gene next-generation sequencing was performed on anterior nasal samples. We compared viral load kinetics and resistance emergence between individuals treated with effective single- versus dual-active mAbs depending on the infecting variant. RESULTS: Study participants receiving single- or dual-active mAbs had similar demographics, baseline nasal viral load, symptom score, and symptom duration. Compared with single-active mAb treatment, treatment with dual-active mAbs led to faster viral load decline at study days 3 (P < .001) and 7 (P < .01). Treatment-emergent resistance mutations were more likely to be detected after amubarvimab plus romlusevimab treatment than with placebo (2.6% vs 0%; P < .001) and were more frequently detected in the setting of single-active compared with dual-active mAb treatment (7.3% vs 1.1%; P < .01). Single-active and dual-active mAb treatment resulted in similar decrease in rates of hospitalizations or death. CONCLUSIONS: Compared with single-active mAb therapy, dual-active mAbs led to similar clinical outcomes but significantly faster viral load decline and a lower risk of emergent resistance.


Asunto(s)
Anticuerpos Monoclonales Humanizados , Tratamiento Farmacológico de COVID-19 , SARS-CoV-2 , Carga Viral , Humanos , SARS-CoV-2/inmunología , SARS-CoV-2/efectos de los fármacos , Femenino , Masculino , Persona de Mediana Edad , Carga Viral/efectos de los fármacos , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/farmacología , Farmacorresistencia Viral , Antivirales/uso terapéutico , Antivirales/farmacología , COVID-19/inmunología , COVID-19/virología , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales/inmunología , Anciano , Adulto , Quimioterapia Combinada
4.
Bull Math Biol ; 86(9): 107, 2024 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-39003370

RESUMEN

Human immunodeficiency virus (HIV) infects CD4+ cells and causes progressive immune function failure, and CD8+ cells lyse infected CD4+ cell via recognising peptide presented by human leukocyte antigens (HLA). Variations in HLA allele lead to observed different HIV infection outcomes. Within-host HIV dynamics involves virus replication within infected cells and lysing of infected cells by CD8+ cells, but how variations in HLA alleles determine different infection outcomes was far from clear. Here, we used mathematical modelling and parameter inference with a new analysis of published virus inhibition assay data to estimate CD8+ cell lysing efficiency, and found that lysing efficiency fall in the gap between low bound (0.1-0.2 day-1 (Elemans et al. in PLoS Comput Biol 8(2):e1002381, 2012)) and upper boundary (6.5-8.4 day-1 (Wick et al. in J Virol 79(21):13579-13586, 2005)). Our outcomes indicate that both lysing efficiency and viral inoculum size jointly determine observed different infection outcomes. Low lysing rate associated with non-protective HLA alleles leads to monostable viral kinetic to high viral titre and oscillatory viral kinetics. High lysing rate associated with protective HLA alleles leads monostable viral kinetic to low viral titre and bistable viral kinetics; at a specific interval of CD8+ cell counts, small viral inoculum sizes are inhibited but not large viral inoculum sizes remain infectious. Further, with CD8+ cell recruitment, HIV kinetics always exhibit oscillatory kinetics, but lysing rate is negatively correlated with range of CD8+ cell count. Our finding highlights role of HLA allele determining different infection outcomes, thereby providing a potential mechanistic explanation for observed good and bad HIV infection outcomes induced by protective HLA allele.


Asunto(s)
Alelos , Linfocitos T CD4-Positivos , Linfocitos T CD8-positivos , Infecciones por VIH , Antígenos HLA , Conceptos Matemáticos , Modelos Inmunológicos , Replicación Viral , Humanos , Infecciones por VIH/inmunología , Infecciones por VIH/genética , Infecciones por VIH/virología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD4-Positivos/inmunología , Antígenos HLA/genética , Antígenos HLA/inmunología , Replicación Viral/inmunología , VIH-1/inmunología , VIH-1/fisiología , Simulación por Computador , Carga Viral
5.
Proc Natl Acad Sci U S A ; 118(49)2021 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-34857628

RESUMEN

The within-host viral kinetics of SARS-CoV-2 infection and how they relate to a person's infectiousness are not well understood. This limits our ability to quantify the impact of interventions on viral transmission. Here, we develop viral dynamic models of SARS-CoV-2 infection and fit them to data to estimate key within-host parameters such as the infected cell half-life and the within-host reproductive number. We then develop a model linking viral load (VL) to infectiousness and show a person's infectiousness increases sublinearly with VL and that the logarithm of the VL in the upper respiratory tract is a better surrogate of infectiousness than the VL itself. Using data on VL and the predicted infectiousness, we further incorporated data on antigen and RT-PCR tests and compared their usefulness in detecting infection and preventing transmission. We found that RT-PCR tests perform better than antigen tests assuming equal testing frequency; however, more frequent antigen testing may perform equally well with RT-PCR tests at a lower cost but with many more false-negative tests. Overall, our models provide a quantitative framework for inferring the impact of therapeutics and vaccines that lower VL on the infectiousness of individuals and for evaluating rapid testing strategies.


Asunto(s)
COVID-19/diagnóstico , SARS-CoV-2/genética , COVID-19/virología , Prueba de Ácido Nucleico para COVID-19/métodos , Reacciones Falso Positivas , Humanos , Cinética , Pruebas Serológicas/métodos
6.
J Infect Dis ; 228(Suppl 2): S136-S143, 2023 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-37650233

RESUMEN

Understanding variant-specific differences in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral kinetics may explain differences in transmission efficiency and provide insights on pathogenesis and prevention. We evaluated SARS-CoV-2 kinetics from nasal swabs across multiple variants (Alpha, Delta, Epsilon, Gamma) in placebo recipients of the ACTIV-2/A5401 trial. Delta variant infection led to the highest maximum viral load and shortest time from symptom onset to viral load peak. There were no significant differences in time to viral clearance across the variants. Viral decline was biphasic with first- and second-phase decays having half-lives of 11 hours and 2.5 days, respectively, with differences among variants, especially in the second phase. These results suggest that while variant-specific differences in viral kinetics exist, post-peak viral load all variants appeared to be efficiently cleared by the host. Clinical Trials Registration. NCT04518410.


Asunto(s)
COVID-19 , Humanos , Semivida , Cinética , SARS-CoV-2
7.
J Infect Dis ; 227(9): 1097-1103, 2023 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-36316804

RESUMEN

BACKGROUND: Yellow fever is a mosquito-borne zoonotic disease caused by yellow fever virus (YFV). Between 2017 and 2019, more than 504 human cases and 176 deaths were confirmed in the outskirts of São Paulo city. Throughout this outbreak, studies suggested a potential association between YFV viremia and mortality. METHODS: Viral ribonucleic acid was measured using reverse-transcription quantitative polymerase chain reaction in plasma samples collected at up to 5 time points, between 3 and 120 days after symptoms onset. RESULTS: Eighty-four patients with confirmed YFV infection were included. Most were males, median age was 42, and 30 (36%) died. Deceased patients were older than survivors (P = .003) and had a higher viremia across all time points (P = .0006). Mean values of viremia had a positive, statistically significant correlation with peak values of neutrophils, indirect bilirubin, aspartate transaminase, international normalized ratio, and creatinine. Finally, a Cox proportional hazards model adjusted for age and laboratory variables showed that viremia is independently associated with death, with a mean 1.84-fold increase (84%) in the hazard of death (P < .001) for each unit increase in mean log10 viremia. CONCLUSIONS: Our results raise the importance of monitoring YFV viremia and suggest a potential benefit of antiviral drugs or neutralizing monoclonal antibodies early in the course of this infection to improve disease outcomes.


Asunto(s)
Fiebre Amarilla , Masculino , Animales , Humanos , Femenino , Viremia , Cinética , Brasil/epidemiología , Virus de la Fiebre Amarilla , Anticuerpos Neutralizantes , Anticuerpos Antivirales
8.
J Infect Dis ; 228(3): 311-320, 2023 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-36722133

RESUMEN

BACKGROUND: Mathematical models explain how antivirals control viral infections. Hepatitis C virus (HCV) treatment results in at least 2 phases of decline in viremia. The first phase reflects clearance of rapidly produced virions. The second phase is hypothesized to derive from loss of infected cells but has been challenging to prove. METHODS: Using single-cell methods, we quantified the number of hepatitis C virus (HCV)-infected hepatocytes in liver biopsies taken before and within 7 days of initiating direct-acting antivirals (DAAs) in a double-blinded randomized controlled trial testing 2 (sofosbuvir-velpatasvir) versus 3 (sofosbuvir-velpatasvir-voxilaprevir) DAAs. RESULTS: We employed thousands of intrahepatic measurements in 10 persons with chronic genotype 1a HCV infection: median proportion of infected hepatocytes declined from 11.3% (range, 1.3%-59%) to 0.6% (range, <0.3%-5.8%), a loss of 75%-95% infected hepatocytes. Plasma viremia correlated with numbers of HCV-infected hepatocytes (r = 0.77; P < .0001). Second-phase plasma dynamics and changes in infected hepatocytes were indistinct (P = .16), demonstrating that second-phase viral dynamics derive from loss of infected cells. DAAs led to a decline in intracellular HCV RNA and interferon-stimulated gene expression (P < .05 for both). CONCLUSIONS: We proved that second-phase viral dynamics reflect decay of intrahepatic burden of HCV, partly due to clearance of HCV RNA from hepatocytes. CLINICAL TRIALS REGISTRATION: NCT02938013.


Asunto(s)
Hepatitis C Crónica , Hepatitis C , Humanos , Sofosbuvir/uso terapéutico , Antivirales/uso terapéutico , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Viremia/tratamiento farmacológico , Cinética , Lactamas Macrocíclicas/uso terapéutico , Hepatitis C/tratamiento farmacológico , ARN Viral , Genotipo
9.
J Med Virol ; 95(1): e28249, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36271515

RESUMEN

We describe the clinical and demographic characteristics, virological follow-up, and management of five confirmed monkeypox cases from New Delhi, India without any international travel history. The viral load kinetics and viral clearance were estimated in oropharyngeal swabs (OPS), nasopharyngeal swabs (NPS), EDTA blood, serum, urine, and various lesion specimens on every fourth day of follow-up ranging from 5 to 24 post onset day (POD) of illness. All five cases presented with mild to moderate-grade intermittent fever, myalgia, and lesions on the genitals, groins, lower limb, trunk, and upper limb. Four cases had non-tender firm lymphadenopathy. No secondary complications or sexually transmitted infections were recorded in these cases except for the presence of viral hepatitis B infection marker hepatitis B virus surface antigen (HBsAg) in one case. All the cases were mild and had a good recovery. A higher viral load was detected in lesion fluid (POD 9), followed by lesion roof (POD 9), urine (POD 5), lesion base (POD 5), and OPS/NPS (POD 5). The monkeypox virus (MPXV) DNA was detected in clinical samples from 5th to 24th POD. These monkeypox cases without international travel history suggest the underdiagnosed monkeypox infection in the community. This emphasizes the need for active surveillance of MPXV in the high-risk population such as men having sex with men and female sex workers.


Asunto(s)
Mpox , Trabajadores Sexuales , Enfermedades de Transmisión Sexual , Masculino , Humanos , Femenino , Mpox/diagnóstico , Mpox/epidemiología , Monkeypox virus/genética , India
10.
J Theor Biol ; 572: 111568, 2023 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-37393986

RESUMEN

The SARS-CoV-2 Omicron variant harbours many mutations in its spike protein compared to the original SARS-CoV-2 strain, which may alter its ability to enter cells, cell tropism, and response to interventions blocking virus entry. To elucidate these effects, we developed a mathematical model of SARS-CoV-2 entry into target cells and applied it to analyse recent in vitro data. SARS-CoV-2 can enter cells via two pathways, one using the host proteases Cathepsin B/L and the other using the host protease TMPRSS2. We found enhanced entry efficiency of the Omicron variant in cells where the original strain preferentially used Cathepsin B/L and reduced efficiency where it used TMPRSS2. The Omicron variant thus appears to have evolved to use the Cathepsin B/L pathway better but at the expense of its ability to use the TMPRSS2 pathway compared to the original strain. We estimated >4-fold enhanced efficiency of the Omicron variant in entry via the Cathepsin B/L pathway and >3-fold reduced efficiency via the TMPRSS2 pathway compared to the original or other strains in a cell type-dependent manner. Our model predicted that Cathepsin B/L inhibitors would be more efficacious and TMPRSS2 inhibitors less efficacious in blocking Omicron variant entry into cells than the original strain. Furthermore, model predictions suggested that drugs simultaneously targeting the two pathways would exhibit synergy. The maximum synergy and drug concentrations yielding it would differ for the Omicron variant compared to the original strain. Our findings provide insights into the cell entry mechanisms of the Omicron variant and have implications for intervention targeting these mechanisms.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Catepsina B/genética , Catepsina B/metabolismo , SARS-CoV-2/genética , Serina Endopeptidasas/genética , Internalización del Virus
11.
Eur J Clin Microbiol Infect Dis ; 42(8): 951-958, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37243828

RESUMEN

Detection of SARS-CoV-2 RNA in serum, viremia, has been linked to disease severity and outcome. The kinetics of viremia in patients receiving remdesivir has not been thoroughly studied and could help predict treatment response and outcome. We investigated the kinetics of SARS-CoV-2 viremia and factors associated with baseline viremia, viral clearance and 30-day mortality in patients receiving remdesivir. An observational study including 378 hospitalised patients (median age 67 years, 67% male) sampled with serum SARS-CoV-2 RT-PCR within ± 24 h of initiation of remdesivir treatment. Baseline viremia was present in 206 (54%) patients with a median Ct value of 35.3 (IQR = 33.3-37.1). In patients with baseline viremia, the estimated probability of viral clearance was 72% by day 5. Ct values decreased significantly during remdesivir treatment for viremic patients, indicating an increase in viral load. In total, 44 patients (12%) died within 30 days, and mortality was significantly associated with viremia at baseline (OR = 2.45, p = 0.01) and lack of viral clearance by day 5 (OR = 4.8, p = < 0.01). Viral clearance was not associated with any individual risk factor. Viremia appears to be a prognostic marker before and during remedesivir treatment. The resolution of viremia was similar to patients not receiving remdesivir in other studies, and the decrease in Ct values during treatment questions the antiviral capacity of remdesivir in vivo. Prospective studies are warranted to confirm our findings.


Asunto(s)
COVID-19 , Humanos , Masculino , Anciano , Femenino , SARS-CoV-2 , Cinética , Viremia/tratamiento farmacológico , ARN Viral , Tratamiento Farmacológico de COVID-19 , Antivirales/uso terapéutico
12.
J Formos Med Assoc ; 122(8): 766-775, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36934018

RESUMEN

BACKGROUND: COVID-19 rebound is usually reported among patients experiencing concurrent symptomatic and viral rebound. But longitudinal viral RT-PCR results from early stage to rebound of COVID-19 was less characterized. Further, identifying the factors associated with viral rebound after nirmatrelvir-ritonavir (NMV/r) and molnupiravir may expand understanding of COVID-19 rebound. METHODS: We retrospectively analyzed clinical data and sequential viral RT-PCR results from COVID-19 patients receiving oral antivirals between April and May, 2022. Viral rebound was defined by the degree of viral load increase (ΔCt ≥ 5 units). RESULTS: A total of 58 and 27 COVID-19 patients taking NMV/r and molnupiravir, respectively, were enrolled. Patients receiving NMV/r were younger, had fewer risk factors for disease progression and faster viral clearance rate compared to those receiving molnupiravr (All P < 0.05). The overall proportion of viral rebound (n = 11) was 12.9%, which was more common among patients receiving NMV/r (10 [17.2%] vs. 1 [3.7%], P = 0.16). Of them, 5 patients experienced symptomatic rebound, suggesting the proportion of COVID-19 rebound was 5.9%. The median interval to viral rebound was 5.0 (interquartile range, 2.0-8.0) days after completion of antivirals. Initial lymphopenia (<0.8 × 109/L) was associated with viral rebound among overall population (adjusted odds ratio [aOR], 5.34; 95% confidence interval [CI], 1.33-21.71), and remained significant (aOR, 4.50; 95% CI, 1.05-19.25) even when patients receiving NMV/r were considered. CONCLUSION: Our data suggest viral rebound after oral antivirals may be more commonly observed among lymphopenic individuals in the context of SARS-CoV-2 Omicron BA.2 variant.


Asunto(s)
Antivirales , COVID-19 , Humanos , Antivirales/uso terapéutico , Estudios Retrospectivos , SARS-CoV-2
13.
J Virol ; 95(14): e0049220, 2021 06 24.
Artículo en Inglés | MEDLINE | ID: mdl-33910953

RESUMEN

Whereas the mode of action of lamivudine (LAM) against hepatitis B virus (HBV) is well established, the inhibition mechanism(s) of interferon alpha (IFN-α) is less completely defined. To advance our understanding, we mathematically modeled HBV kinetics during 14-day pegylated IFN-α-2a (pegIFN), LAM, or pegIFN-plus-LAM (pegIFN+LAM) treatment of 39 chronically HBV-infected humanized uPA/SCID chimeric mice. Serum HBV DNA and intracellular HBV DNA were measured frequently. We developed a multicompartmental mathematical model and simultaneously fit it to the serum and intracellular HBV DNA data. Unexpectedly, even in the absence of an adaptive immune response, a biphasic decline in serum HBV DNA and intracellular HBV DNA was observed in response to all treatments. Kinetic analysis and modeling indicate that the first phase represents inhibition of intracellular HBV DNA synthesis and secretion, which was similar under all treatments with an overall mean efficacy of 98%. In contrast, there were distinct differences in HBV decline during the second phase, which was accounted for in the model by a time-dependent inhibition of intracellular HBV DNA synthesis, with the steepest decline observed during pegIFN+LAM treatment (1.28/day) and the slowest (0.1/day) during pegIFN monotherapy. Reminiscent of observations in patients treated with pegIFN and/or LAM, a biphasic HBV decline was observed in treated humanized mice in the absence of an adaptive immune response. Interestingly, combination treatment did not increase the initial inhibition of HBV production but rather enhanced second-phase decline, providing insight into the dynamics of HBV treatment response and the mode of action of IFN-α against HBV. IMPORTANCE Chronic hepatitis B virus (HBV) infection remains a global health care problem, as we lack sufficient curative treatment options. Elucidating the dynamics of HBV infection and treatment response at the molecular level could facilitate the development of novel, more effective HBV antivirals. Currently, the only well-established small animal HBV infection model available is the chimeric uPA/SCID mice with humanized livers; however, the HBV inhibition kinetics under pegylated IFN-α-2a (pegIFN) in this model system have not been determined in sufficient detail. In this study, viral kinetics in 39 humanized mice treated with pegIFN and/or lamivudine were monitored and analyzed using a mathematical modeling approach. We found that the main mode of action of IFN-α is blocking HBV DNA synthesis and that the majority of synthesized HBV DNA is secreted. Our study provides novel insights into HBV DNA dynamics within infected human hepatocytes.


Asunto(s)
Antivirales/farmacología , Virus de la Hepatitis B/fisiología , Hepatitis B/tratamiento farmacológico , Hepatitis B/virología , Interferón-alfa/farmacología , Animales , Preescolar , ADN Viral/sangre , Modelos Animales de Enfermedad , Femenino , Virus de la Hepatitis B/efectos de los fármacos , Humanos , Lactante , Cinética , Lamivudine/farmacología , Trasplante de Hígado , Masculino , Ratones SCID , Modelos Teóricos , Polietilenglicoles/farmacología , Proteínas Recombinantes/farmacología , Albúmina Sérica/metabolismo , Quimera por Trasplante
14.
Int J Mol Sci ; 24(1)2022 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-36613566

RESUMEN

The understanding of the kinetics of gene expression in cells infected by viruses is currently limited. As a rule, the corresponding models do not take viral microRNAs (miRNAs) into account. Such RNAs are, however, operative during the replication of some viruses, including, e.g., herpesvirus. To clarify the kinetics of this category (with emphasis on the information available for herpesvirus), I introduce a generic model describing the transient interplay of cellular mRNA, protein, miRNA and viral miRNA. In the absence of viral miRNA, the cellular miRNA is considered to suppress the populations of mRNA and protein due to association with mRNA and subsequent degradation. During infection, the viral miRNA suppresses the population of cellular miRNA and via this pathway makes the mRNA and protein populations larger. This effect becomes appreciable with the progress of intracellular viral replication. Using biologically reasonable parameters, I investigate the corresponding mean-field kinetics and show the scale of the effect of viral miRNAs on cellular miRNA and mRNA. The scale of fluctuations of the populations of these species is illustrated as well by employing Monte Carlo simulations.


Asunto(s)
MicroARNs , Virus , MicroARNs/genética , MicroARNs/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Virus/genética , Virus/metabolismo , ARN Viral/genética , ARN Viral/metabolismo
15.
Immunol Rev ; 285(1): 55-71, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30129199

RESUMEN

The advent of powerful direct-acting antiviral agents (DAAs) has revolutionized the treatment of hepatitis C. DAAs cure nearly all patients with short duration, oral treatments. Significant efforts are now underway to optimize DAA-based treatments. We discuss the potential role of interferon in this optimization. Clinical studies present compelling evidence that DAAs perform better in treatment-naive individuals than in individuals who previously failed treatment with interferon, a surprising correlation because interferon and DAAs are thought to act independently. Recent mathematical models explore a mechanistic hypothesis underlying this correlation. The hypothesis invokes the action of interferon at the cellular, individual, and population levels. Strong interferon responses prevent the productive infection of cells, reduce viral replication, and impede the development of resistance to DAAs in infected individuals and improve cure rates elicited by DAAs in treated populations. The models develop descriptions of these processes, integrate them into a comprehensive framework, and capture clinical data quantitatively, providing a successful test of the hypothesis. Individuals with strong endogenous interferon responses thus present a promising subpopulation for reducing DAA treatment durations. This review discusses the conceptual advances made by the models, highlights the new insights they unravel, and examines their applicability to optimize DAA-based treatments.


Asunto(s)
Antivirales/uso terapéutico , Hepacivirus/fisiología , Hepatitis C/inmunología , Interferones/inmunología , Modelos Inmunológicos , Animales , Protocolos Clínicos , Hepatitis C/terapia , Humanos , Interferones/uso terapéutico , Selección de Paciente , Resultado del Tratamiento
16.
J Viral Hepat ; 28(2): 383-392, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33074571

RESUMEN

Hepatitis B virus RNA (HBV RNA)-containing particles are encapsidated pre-genomic RNA (pgRNA) detectable in chronically infected patients in addition to virions (HBV DNA) that have been suggested as a marker of the treatment efficacy. This makes promising the use of core protein allosteric modulators, such as RG7907, which disrupt the nucleocapsid assembly and profoundly reduce HBV RNA. Here, we developed a multiscale model of HBV extending the standard viral dynamic models to analyse the kinetics of HBV DNA and HBV RNA in 35 patients treated with RG7907 for 28 days. We compare the predictions with those obtained in patients treated with the nucleotide analog tenofovir. RG7907 blocked 99.3% of pgRNA encapsidation (range: 92.1%-99.9%) which led to a decline of both HBV DNA and HBV RNA. As a consequence of its mode of action, the first phase of decline of HBV RNA was rapid, uncovering the clearance of viral particles with half-life of 45 min. In contrast, HBV DNA decline was predicted to be less rapid, due to the continuous secretion of already formed viral capsids (t1/2  = 17 ± 6 h). After few days, both markers declined at the same rate, which was attributed to the loss of infected cells (t1/2  â‰… 6 ± 0.8 days). By blocking efficiently RNA reverse transcription but not its encapsidation, nucleotide analog in contrast was predicted to lead to a transient accumulation of HBV RNA both intracellularly and extracellularly. The model brings a conceptual framework for understanding the differences between HBV DNA and HBV RNA dynamics. Integration of HBV RNA in viral dynamic models may be helpful to better quantify the treatment effect, especially in viral-suppressed patients where HBV DNA is no longer detectable.


Asunto(s)
Virus de la Hepatitis B , ARN Viral , ADN Viral , Virus de la Hepatitis B/genética , Humanos , Virión , Replicación Viral
17.
J Viral Hepat ; 28(2): 410-419, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33185325

RESUMEN

HBV-DNA levels are low or even undetectable in the majority HDV-infected patients. The impact of PEG-IFNα on HBV-DNA kinetics in HDV-infected patients has not been studied in detail. We analysed data of a prospective treatment trial where 120 HDV-RNA-positive patients were randomized to receive PEG-IFNα-2a plus tenofovir-disoproxil-fumarate (PEG-IFNα/TDF, n = 59) or placebo (PEG-IFNα/PBO; n = 61) for 96 weeks. At week 96, HBV-DNA was still quantifiable in 71% of PEG-IFNα/PBO-treated patients but also in 76% of PEG-IFNα/TDF-treated patients, despite low HBV-DNA baseline values. Surprisingly, a transient HBV-DNA increase between weeks 12 and 36 was observed in 12 in PEG-IFNα/TDF-treated and 12 PEG-IFNα/PBO-treated patients. This increase was positively associated with HBsAg loss [(P = 0.049, odds ratio (OR) 5.1] and HDV-RNA suppression (P = 0.007, OR 4.1) at week 96. Biochemical markers of cell death (M30 and ALT) were higher during the HBV-DNA peak but no distinct systemic immune pattern could be observed by screening 91 soluble inflammatory markers. In conclusion, an early increase in HBV-DNA during PEG-IFNα-2a therapy occurred in more than 20% of patients, even in TDF-treated patients. This transient HBV-DNA rise may indicate PEG-IFNα-induced cell death and lead to long-term HDV-RNA suppression and HBsAg loss.


Asunto(s)
Antígenos de Superficie de la Hepatitis B , Hepatitis D , Antivirales/uso terapéutico , ADN Viral , Virus de la Hepatitis B/genética , Hepatitis D/tratamiento farmacológico , Humanos , Interferón-alfa/uso terapéutico , Polietilenglicoles/uso terapéutico , Estudios Prospectivos , ARN , Resultado del Tratamiento
18.
Br J Clin Pharmacol ; 87(9): 3425-3438, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33373059

RESUMEN

AIMS: We propose the use of in silico mathematical models to provide insights that optimize therapeutic interventions designed to effectively treat respiratory infection during a pandemic. A modelling and simulation framework is provided using SARS-CoV-2 as an example, considering applications for both treatment and prophylaxis. METHODS: A target cell-limited model was used to quantify the viral infection dynamics of SARS-CoV-2 in a pooled population of 105 infected patients. Parameter estimates from the resulting model were used to simulate and compare the impact of various interventions against meaningful viral load endpoints. RESULTS: Robust parameter estimates were obtained for the basic reproduction number, viral release rate and infected-cell mortality from the infection model. These estimates were informed by the largest dataset currently available for SARS-CoV-2 viral time course. The utility of this model was demonstrated using simulations, which hypothetically introduced inhibitory or stimulatory drug mechanisms at various target sites within the viral life-cycle. We show that early intervention is crucial to achieving therapeutic benefit when monotherapy is administered. In contrast, combination regimens of two or three drugs may provide improved outcomes if treatment is initiated late. The latter is relevant to SARS-CoV-2, where the period between infection and symptom onset is relatively long. CONCLUSIONS: The use of in silico models can provide viral load predictions that can rationalize therapeutic strategies against an emerging viral pathogen.


Asunto(s)
Tratamiento Farmacológico de COVID-19 , SARS-CoV-2 , Simulación por Computador , Humanos , Pandemias , SARS-CoV-2/efectos de los fármacos , Carga Viral
19.
Eur J Clin Microbiol Infect Dis ; 40(2): 435-439, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32914220

RESUMEN

PURPOSE: Data on the efficacy, dosing and safety of letermovir for the compassionate therapeutic use of CMV infections are limited. METHODS: Clinical and virological efficacy of letermovir was assessed in a retrospective single-centre study of patients who received letermovir for the compassionate therapeutic use of CMV infections. RESULTS: Letermovir initiation yielded prompt treatment response in 7 out of 9 patients (77.7%). CONCLUSION: Letermovir may be an effective and well tolerated option in the compassionate treatment of CMV infections, although recurrence of CMV and emergence of resistance may be issues.


Asunto(s)
Acetatos , Antivirales , Infecciones por Citomegalovirus/tratamiento farmacológico , Quinazolinas , Acetatos/uso terapéutico , Anciano , Antivirales/uso terapéutico , Ensayos de Uso Compasivo , Citomegalovirus/efectos de los fármacos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Quinazolinas/uso terapéutico , Estudios Retrospectivos , Resultado del Tratamiento
20.
Dig Dis ; 39(1): 52-57, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32777784

RESUMEN

BACKGROUND: Abnormal liver function has been reported in patients with COVID-19 infection. The aim of our study was to report on the prevalence of liver injury in our cohort, to evaluate the association of mild versus severe liver injury with mortality in COVID-19 patients and to scrutinize the temporal pattern of viral detection and liver injury. METHODS: We present data from a German cohort of 147 SARS-CoV-2 infected patients. The patients were divided into 3 groups according to their liver status during treatment. The first group included patients without elevated alanine aminotransferase or bilirubin, the third group patients meeting the biochemical criteria of acute liver failure (ALF), and the second group all other patients. RESULTS: Liver injury was detected in 75 (50.7%) and 93 (63%) patients by admission and during treatment, respectively. ALF was associated with the male sex, younger age, and higher BMI. Mortality was associated with the presence of ALF (OR = 9.423, 95% CI: 2.410-36.858) in contrast to milder liver injury (OR 1.101, 95% CI: 0.435-2.791). In 30% of patients with mild liver injury and in 50% of ALF patients, peak liver injury was observed at a time point when the virus was no longer detectable in the respiratory tract. CONCLUSION: Mild liver injury was not associated with worse outcome in our cohort, and the pattern of liver injury did not fit well to the theory of SARS-CoV-2 directly causing liver impairment. Instead, severe liver injury in our cohort was associated multiple-organ failure and acute vascular events.


Asunto(s)
Alanina Transaminasa/sangre , Bilirrubina/sangre , COVID-19 , Fallo Hepático Agudo , Pruebas de Función Hepática , SARS-CoV-2/aislamiento & purificación , Adulto , COVID-19/complicaciones , COVID-19/diagnóstico , COVID-19/mortalidad , Estudios de Cohortes , Correlación de Datos , Femenino , Alemania/epidemiología , Hospitalización/estadística & datos numéricos , Humanos , Fallo Hepático Agudo/sangre , Fallo Hepático Agudo/epidemiología , Fallo Hepático Agudo/etiología , Fallo Hepático Agudo/virología , Pruebas de Función Hepática/métodos , Pruebas de Función Hepática/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Prevalencia , Índice de Severidad de la Enfermedad
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