Engineering interferons and interleukins for cancer immunotherapy.

Cytokines are a class of potent immunoregulatory proteins that are secreted in response to various stimuli and act locally to regulate many aspects of human physiology and disease. Cytokines play important roles in cancer initiation, progression, and elimination, and thus, there is a long clinical history associated with the use of recombinant cytokines to treat cancer. However, the use of cytokines as therapeutics has been limited by cytokine pleiotropy, complex biology, poor drug-like properties, and severe dose-limiting toxicities. Nevertheless, cytokines are crucial mediators of innate and adaptive antitumor immunity and have the potential to enhance immunotherapeutic approaches to treat cancer. Development of immune checkpoint inhibitors and combination immunotherapies has reinvigorated interest in cytokines as therapeutics, and a variety of engineering approaches are emerging to improve the safety and effectiveness of cytokine immunotherapy. In this review we highlight recent advances in cytokine biology and engineering for cancer immunotherapy.

B-Cell Therapies in Multiple Sclerosis.

B cells play a vital function in multiple sclerosis (MS) pathogenesis through an array of effector functions. All currently approved MS disease-modifying therapies alter the frequency, phenotype, or homing of B cells in one way or another. The importance of this mechanism of action has been reinforced with the successful development and clinical testing of B-cell-depleting monoclonal antibodies that target the CD20 surface antigen. Ocrelizumab, a humanized anti-CD20 monoclonal antibody, was approved by the Food and Drug Administration (FDA) in March 2017 after pivotal trials showed dramatic reductions in inflammatory disease activity in relapsing MS as well as lessening of disability progression in primary progressive MS. These and other clinical studies place B cells at the center of the inflammatory cascade in MS and provide a launching point for development of therapies that target selective pathogenic B-cell populations.

Distribution of therapeutic proteins into thoracic lymph after intravenous administration is protein size-dependent and primarily occurs within the liver and mesentery.

Therapeutic proteins can facilitate the targeting and treatment of lymphatic diseases (such as cancer metastases, infections and inflammatory diseases) since they are cleared via the lymphatics following interstitial (SC or IM) administration. However, therapeutic proteins are often administered intravenously (IV). Recently therapeutic proteins have been found to access the thoracic lymph in surprisingly high quantities after IV administration. The aim of this study was to determine, for the first time, the major sites of thoracic lymph access of therapeutic proteins, and the protein properties that enhance lymph access, after IV administration. In order to achieve this, novel methods were developed or optimized to collect hepatic, mesenteric or thoracic lymph from male SD rats. Four different sized PEGylated or non-PEGylated therapeutic proteins (native interferon α2b (IFN, 19kDa), PEGylated interferon α2b (IFN-PEG12, 31kDa), PEGylated interferon α2a (IFN-PEG40, 60kDa) or trastuzumab (150kDa)) were then administered via short IV infusion, and plasma and lymph concentrations of the proteins determined via ELISA. The recovery of the therapeutic proteins in the thoracic lymph duct, which collects lymph from most of the body, was significantly greater for trastuzumab, IFN-PEG40 and IFN-PEG12 (all >3% dose over 8h) when compared to native IFN (0.9% dose). Conversely, the thoracic lymph/plasma (L/P) concentration ratio and thus efficiency of extravasation and transport through the interstitium to lymph was highest for the smaller proteins IFN and IFN-PEG12 (at 90-100% vs 15-30% for trastuzumab and IFN-PEG40). The lower total recovery of IFN and IFN-PEG12 in thoracic lymph reflected more rapid systemic clearance and thus lower systemic exposure. For all therapeutic proteins, the majority (>80%) of lymph access occurred via the hepatic and mesenteric lymphatics. This lymphatic distribution pattern was supported by quantitative imaging of the lymph node distribution of IV administered Cy5 labelled trastuzumab. Optimizing the properties of IV administered therapeutic proteins represents a viable approach to better target and treat pathological states involving the lymphatics, particularly in the liver and mesentery. This includes cancer metastases, infections and inflammatory diseases. Successful development of the novel technique to collect hepatic lymph will also enable future work to evaluate tissue-specific lymph transport in health and disease.

Macrocyclization of Interferon-Poly(α-amino acid) Conjugates Significantly Improves the Tumor Retention, Penetration, and Antitumor Efficacy.

Cyclization and polymer conjugation are two commonly used approaches for enhancing the pharmacological properties of protein drugs. However, cyclization of parental proteins often only affords a modest improvement in biochemical or cell-based in vitro assays. Moreover, very few studies have included a systematic pharmacological evaluation of cyclized protein-based therapeutics in live animals. On the other hand, polymer-conjugated proteins have longer circulation half-lives but usually show poor tumor penetration and suboptimal pharmacodynamics due to increased steric hindrance. We herein report the generation of a head-to-tail interferon-poly(α-amino acid) macrocycle conjugate circ-P(EG3Glu)20-IFN by combining the aforementioned two approaches. We then compared the antitumor pharmacological activity of this macrocycle conjugate against its linear counterparts, N-P(EG3Glu)20-IFN, C-IFN-P(EG3Glu)20, and C-IFN-PEG. Our results found circ-P(EG3Glu)20-IFN to show considerably greater stability, binding affinity, and in vitro antiproliferative activity toward OVCAR3 cells than the three linear conjugates. More importantly, circ-P(EG3Glu)20-IFN exhibited longer circulation half-life, remarkably higher tumor retention, and deeper tumor penetration in vivo. As a result, administration of the macrocyclic conjugate could effectively inhibit tumor progression and extend survival in mice bearing established xenograft human OVCAR3 or SKOV3 tumors without causing severe paraneoplastic syndromes. Taken together, our study provided until now the most relevant experimental evidence in strong support of the in vivo benefit of macrocyclization of protein-polymer conjugates and for its application in next-generation therapeutics.

Tissue and time specific expression pattern of interferon regulated genes in the chicken.

BACKGROUND: Type I interferons are major players against viral infections and mediate their function by the induction of Interferon regulated genes (IRGs). Recently, it became obvious that these cytokines have a multitude of additional functions. Due to the unique features of the chickens' immune system, available data from mouse models are not easily transferable; hence we performed an extensive analysis of chicken IRGs. RESULTS: A broad database search for homologues to described mammalian IRGs (common IRGs, cIRGs) was combined with a transcriptome analysis of spleen and lung at different time points after application of IFNα. To apply physiological amounts of IFN, half-life of IFN in the chicken was determined. Interestingly, the calculated 36 min are considerably shorter than the ones obtained for human and mouse. Microarray analysis revealed many additional IRGs (newly identified IRGs; nIRGs) and network analysis for selected IRGs showed a broad interaction of nIRGs among each other and with cIRGs. We found that IRGs exhibit a highly tissue and time specific expression pattern as expression quality and quantity differed strongly between spleen and lung and over time. While in the spleen for many affected genes changes in RNA abundance peaked already after 3 h, an increasing or plateau-like regulation after 3, 6 and 9 h was observed in the lung. CONCLUSIONS: The induction or suppression of IRGs in chickens is both tissue and time specific and beside known antiviral mechanisms type I IFN induces many additional cellular functions. We confirmed many known IRGs and established a multitude of so far undescribed ones, thus providing a large database for future research on antiviral mechanisms and additional IFN functions in non-mammalian species.

PEGylated interferon displays differences in plasma clearance and bioavailability between male and female mice and between female immunocompetent C57Bl/6J and athymic nude mice.

Gender and immune status can considerably impact on the pharmacokinetics (PK) of macromolecular and small molecule drugs. However, these effects are often not considered in drug development. We aimed to quantitatively evaluate effects of gender and immune status on the PK of PEGylated interferon in frequently used murine models. Chronically cannulated female athymic nude and female and male immunocompetent C57Bl/6J mice (n = 24 in total) received a single intravenous or subcutaneous (s.c.) dose of PEGylated interferon. Serial blood samples were taken for 48 h. Noncompartmental analysis and population PK modeling with covariate analysis were performed to evaluate the data. The PK of PEGylated interferon followed a three compartment disposition model with two sequential compartments for s.c. absorption. Female nude mice had significantly higher plasma clearance than C57Bl/6J mice (0.503 vs. 0.397 mL/h). Male mice had a slower absorption rate constant (0.138 h(-1)) and extent (46.2%) of s.c. absorption than female mice (0.274 in C57Bl/6J and 0.374 h(-1) in nude, 60.8% in both). Thus, gender and immune status significantly impacted on important PK parameters of PEGylated interferon in murine models commonly utilized in drug development. It is critical to take into account these differences when choosing animal models and conducting translational pharmacology research.

Ledipasvir-sofosbuvir: interferon-/ribavirin-free regimen for chronic hepatitis C virus infection.

OBJECTIVES: To review the pharmacology, efficacy, and safety of ledipasvir-sofosbuvir for the treatment of chronic hepatitis C virus (HCV). DATA SOURCES: A literature search through clinicaltrials.gov, EMBASE, and PubMed was conducted (January 1966 to October 2014) using the terms ledipasvir, sofosbuvir, GS-5885, and GS-7977. References from retrieved articles and abstracts presented at recent meetings were reviewed for any additional material. The prescribing information was also reviewed. STUDY SELECTION/DATA EXTRACTION: Phase 1, 2, and 3 human and animal studies describing the pharmacology, pharmacokinetics, efficacy, and safety of ledipasvir and sofosbuvir for HCV were identified. DATA SYNTHESIS: Ledipasvir-sofosbuvir, a fixed-dose combination (FDC) tablet inhibiting nonstructural (NS) 5A and 5B proteins, without peginterferon and ribavirin is indicated for adult patients with genotype 1 HCV infection who are treatment naïve or experienced, with or without cirrhosis. Pivotal trials (n = 1952) have demonstrated that once-daily administration of ledipasvir-sofosbuvir for 12 or 24 weeks is effective at achieving sustained virological response (SVR) rates (94%-99%) in treatment-naïve patients (12 weeks), treatment-experienced patients without cirrhosis (12 weeks), and treatment-experienced patients with cirrhosis (24 weeks). Treatment-naïve patients without cirrhosis and baseline viral levels of less than 6 million IU/mL may be considered for 8 weeks of treatment. The most common adverse drug events (ADEs) associated with ledipasvir-sofosbuvir include headache, fatigue, insomnia, nausea, and diarrhea. CONCLUSIONS: Ledipasvir-sofosbuvir is the first interferon- and ribavirin-free FDC agent that has SVR rates much greater than 94%, with minimal ADEs, for the treatment of chronic HCV genotype 1 in naïve and treatment-experienced patients.

PEGylated recombinant human interferon-ω as a long-acting antiviral agent: structure, antiviral activity and pharmacokinetics.

Recombinant human interferon-ω (rhIFN-ω) exhibits a potent antiviral activity. Because of poor pharmacokinetics (PK) of rhIFN-ω, frequent dosing of rhIFN-ω is necessitated to achieve the sustained antiviral efficacy. PEGylation can efficiently improve the PK of rhIFN-ω while substantially decrease its bioactivity. The structure, antiviral activity and PK of the PEGylated rhIFN-ω were measured to establish their relationship with PEGylation sites, polyethylene glycol (PEG) mass and PEG structure. Accordingly, N-terminus and the lysine residues were selected as the PEGylation sites. PEGs with Mw of 20kDa and 40kDa were used to investigate the effect of PEG mass. Linear and branched PEGs were used to investigate the effect of PEG structure. PEGylation decreased the antiviral activity of rhIFN-ω and improved its PK. The PEGylation sites determine the bioactivity of the PEGylated rhIFN-ω and the conjugated PEG mass determines the PK. N-terminally PEGylated rhIFN-ω with 40kDa linear PEG maintains 21.7% of the rhIFN-ω antiviral activity with a half-life of 139.6h. Thus, N-terminally PEGylated rhIFN-ω with linear 40kDa PEG is a potential antiviral agent for long-acting treatment of the viral diseases.

Relating the outcome of HCV infection and different host SNP polymorphisms in a Majorcan population coinfected with HCV-HIV and treated with pegIFN-RBV

Hepatitis C virus (HCV) is one of the major causes of chronic hepatitis, cirrhosis, and hepatocellular carcinoma, and the development of HCV-related disease is accelerated in individuals coinfected with human immunodeficiency-1 virus (HIV). In the present study, we correlated different host single-nucleotide polymorphisms (SNPs) in the IL28B, CTLA4, LDLr, and HFE genes and mitochondrial DNA (mtDNA) haplogroups with the outcome of HCV infection and the response to pegylated-interferon plus ribavirin (pegIFN-RBV) treatment. Our study population consisted of 63 Majorcan patients coinfected with HCV and HIV and 59 anonymous unrelated controls. Whereas the population frequency of IL28B alleles was similar to that found in a North-American cohort of European descent, the frequency of the rs12979860 C allele was lower than that determined in other cohorts from Spain. The frequencies of CTLA4 and LDLr polymorphisms were comparable to those reported in other populations. Significant differences between cases and control cohorts occurred only for the H63D mutation of the HFE gene. There were no other differences in the frequencies of other polymorphisms or mtDNA haplogroups. The IL28B rs12979860 CC genotype was shown to be associated with a rapid virological response, and the spontaneous viral clearance rate for HCV was higher in patients with the CTLA4+49 G allele. There was no relationship between SNPs in the LDLr and HFE genes and mtDNA haplogroups and the response to treatment. Our results suggest that the host genetic background plays a significant role in the pegIFN-RBV response of patients coinfected with HCV and HIV (AU)

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Sustained virological response to pegylated interferon plus ribavirin leads to normalization of liver stiffness in hepatitis C virus-infected patients / Respuesta viral sostenida con interferón pegilado y ribavirina conduce a la normalización de la rigidez hepática en pacientes infectados por el virus de la hepatitis C

INTRODUCTION: Pegylated interferon plus ribavirin (Peg-IFN/RBV) therapy leads to improvements in liver stiffness measurements (LSM) in hepatitis C virus (HCV)-infected patients. However, the rate of LSM return to normal values in response to Peg-IFN/RBV is unclear. Thus, our aim was to assess the probability and factors associated with LSM normalization in HCV-infected patients receiving Peg-IFN/RBV. METHODS: This prospective observational longitudinal study included 160 HCV-infected patients, 111 (69%) with human immunodeficiency virus and receiving Peg-IFN/RBV, with baseline LSM ≥ 7kPa. The outcome variable was LSM normalization, i.e. a stable decrease in LSM below 7kPa after starting Peg-IFN/RBV. RESULTS: After starting Peg-IFN/RBV, 56 [35%, 95% confidence interval (95% CI): 28-42%] patients showed LSM normalization. The probability of LSM normalization was 21% (95% CI: 13.2-32.4%) at 12 months, and 51.3% (95% CI: 39.9-63.9%) at 24 months after Peg-INF/RBV initiation for individuals with sustained virological response (SVR), and 8.3% (95% CI: 4-16.6%) at 12 months and 11.3% (95% CI: 6-20.7%) at 24 months for those without SVR (p < 0.001). For individuals with LSM ≥7kPa 24 weeks after the pre-planned end of treatment, LSM normalizations were only observed among those with SVR. Achievement of SVR [Hazard ratio (HR, 95% CI): 6.84 (3.39-13.81)] and lack of baseline cirrhosis [HR (95% CI): 4.17 (1.69-10)] were independently associated with LSM normalization after starting Peg-IFN/RBV. CONCLUSIONS: LSM normalizations during Peg-IFN/RBV treatment are more likely, and occur earlier among patients with SVR. In addition, LSM normalizations continue 24 weeks after the scheduled end of therapy, but only among individuals who reach SVR

INTRODUCCIÓN: El retorno de la rigidez hepática (RH) a valores normales en respuesta al tratamiento de la infección por hepatitis C (VHC) con Peg-IFN/RBV no está claro. Por ello, evaluamos la probabilidad y los factores asociados con la normalización de la RH en pacientes tratados con Peg-IFN/RBV. MÉTODOS: Se incluyeron 160 pacientes infectados por VHC en este estudio longitudinal prospectivo, 111 (69%) de ellos por el virus de la inmunodeficiencia humana, con RH basal ≥ 7kPa y que recibieron Peg-IFN/RBV. La variable principal fue la disminución estable de la RH < 7kPa. RESULTADOS: Después de iniciar Peg-IFN/RBV, 56 (35%; intervalo de confianza del 95% [IC 95%]: 28-42%) pacientes normalizaron la RH. La probabilidad de la normalización de la RH fue del 21% (IC 95%: 13,2-32,4%) 12 meses y del 51,3% (IC 95%: 39,9-63,9%) 24 meses después de iniciar Peg-IFN/RBV en los pacientes con respuesta viral sostenida (RVS), y del 8,3% (IC 95%: 4-16,6%) 12 meses y del 11,3% (IC 95%: 6-20,7%) 24 meses en los sin RVS (p < 0,001). La normalización de la RH en los pacientes con ≥ 7kPa 24 semanas después de finalizar el tratamiento se observó solo en aquellos con RVS. La RVS (hazard ratio [HR]: 6,84; IC 95%: 3,39-13,81) y la ausencia de cirrosis [HR (95%IC): 4.17 (1.69-10)] se asociaron independientemente con la normalización de la RH después de iniciar Peg-IFN/RBV. CONCLUSIONES: La normalización de la RH durante la terapia con Peg-IFN/RBV es más probable y ocurre más temprano en los pacientes con RVS; además, continúa 24 semanas después del fin de tratamiento, pero solo en aquellos con RVS

What the infectious disease physician needs to know about pegylated interferon and ribavirin.

The treatment of chronic hepatitis C is rapidly evolving from triple therapy to regimens that do not require interferon or even ribavirin. However, pegylated interferon and ribavirin will remain the backbone of hepatitis C therapy for the time being. This review summarizes the pharmacokinetics of peginterferon and ribavirin with a particular emphasis on their side-effect profile and management. Finally, the continued role of peginterferon and ribavirin in future therapies will be discussed.

Metal ions guided self-assembly of therapeutic proteins for controllable release: from random to ordered aggregation.

PURPOSE: To make a comparative study on sustained delivery performance of rhIFN with random amorphous and spherical crystal-like ordered self-assemblies. METHODS: The rhIFN self-assemblies were identified in batch crystallization mode. Physico-chemical characteristics were compared, including morphology, XRD, FTIR, CD, biological potency, the dissolution behaviors in vitro and plasma pharmacokinetics in vivo. Moreover, molecular simulation was performed to better understand their binding site and mode. RESULTS: Here, we suggest that random amorphous and spherical ordered self-assemblies allow for long action without new molecular entities generation or carriers employed. By manipulating supersaturation, the ordered aggregates were self-organized at high concentration of Zn(II) (>100 mM) in pH 5.5-6.0, which was the first time that spherical semi-crystals of rhIFN can act as a depot source for the sustained delivery of biologically active proteins. The secondary structure and biological potency of rhIFN were unchanged after aggregation. Compared with that of the native rhIFN, both self-assemblies exhibited slower absorption and extended elimination profiles after s.c. administration, which were characterized as 4.75 ± 0.82 h and 10.58 ± 1.86 h of terminal half-life for random amorphous and spherical ordered self-assemblies, respectively. CONCLUSIONS: The work described here demonstrates the possibility of self-assemblies of biomacromolecules for controllable release application of therapeutic proteins.

Pharmacology and therapeutic potential of interferons.

Interferon (IFN) is widely recognised to be an integral part of the innate immune response to viral infection. Since its initial discovery in 1957 by Isaacs and Lindenmann, various IFN sub-types have been identified and there are now three distinct classes recognised-Type I (IFN-α and IFN-ß), Type II (IFN-γ) and Type III (IFN-λ), distinguished by their differing receptors. As well as displaying profound antiviral activity in vivo, IFN has anti-proliferative, cytotoxic and anti-tumoural roles. In an attempt to harness their immunomodulatory potential, investigators and clinicians have investigated the use of IFNs for the treatment of human diseases with considerable success. For example, IFN-α preparations are now a critical component in the treatment of chronic Hepatitis C infection and IFN-ß therapy is now the first line treatment for relapsing remitting multiple sclerosis. However, IFN therapy is also associated with significant morbidity and in some patients is poorly tolerated. In this review, we explore the scientific basis for IFN therapy and outline its therapeutic scope. We describe the commonly encountered side effects and attempt to explain the less well recognised pulmonary complications including emerging evidence of life threatening and irreversible pulmonary vascular pathology. Finally, we look to the future of interferon drug treatment, examining the potential for emerging therapies.

Perfiles de expresión génica en las primeras doce semanas de tratamiento en pacientes con hepatitis C crónica / Gene expression profiling in the first twelve weeks of treatment in chronic hepatitis C patients

Introducción Los perfiles de expresión génica (PEG) en las primeras semanas de tratamiento de pacientes con hepatitis C crónica pueden servir para evaluar la eficacia de la terapia basada en interferón. El objetivo de este trabajo fue estudiar los PEG de pacientes respondedores y no respondedores precoces antes y tras 12 semanas de tratamiento con peginterferón alfa y ribavirina. Métodos Estudio observacional donde se analizaron los PEG de 12 pacientes con hepatitis C crónica candidatos a recibir tratamiento con peginterferón alfa y ribavirina. Resultados De los 12 pacientes estudiados, seis mostraron una respuesta virológica precoz completa, mientras que seis no lograron controlar la viremia. En respondedores precoces, el tratamiento con peginterferón y ribavirina indujo un aumento de la expresión de un mayor número de genes de respuesta al interferón (ISG15, IFI6, IFI44L, IFI27, MX1, OASL, IRF7, IFIT3, IFITM1, EIF2AK2, HERC5 y APOBEC3A) que en no respondedores (ISG15, IFI44L, IFI27, IRF7, USP18) (p<0,05). En ambos grupos, se observaron cambios en los niveles de algunos genes hasta ahora escasamente descritos en el tratamiento de la hepatitis C.Conclusiones Los PEG descritos en este trabajo pueden ayudar a comprender mejor la patogénesis de la infección, así como las bases fisiológicas de la respuesta al tratamiento. Así, el mayor efecto del tratamiento sobre la expresión de genes de respuesta al interferón observado en respondedores podría explicar su mejor control de la carga viral (AU)

Introduction: Gene expression profiling in the first weeks of treatment of patients with chronic hepatitis C may contribute to better evaluate the response to interferon-based therapy. The objective of this study was to evaluate the gene expression profiles of early responders and non-responders before, and after12 weeks of treatment with peginterferon alfa and ribavirin. Methods: Gene expression profiles were analysed in 12 patients with chronic hepatitis C, and scheduled for treatment with peginterferon alpha and ribavirin. Results: Of the 12 patients studied, six showed a complete early virological response, while six failed tocontrol viremia. In early responders, treatment with peginterferon and ribavirin induced an increasedexpression of a larger number of interferon-induced genes (ISG15, IFI6, IFI44L, IFI27, MX1, OASL, IRF7,IFIT3, IFITM1, EIF2AK2, HERC5 and APOBEC3) than in non-responders (ISG15, IFI44L, IFI27, IRF7, USP18)in the first twelve weeks of treatment (P<0.05). In both groups, there were changes in the levels of certaingenes poorly described in the treatment of hepatitis C so far (AU)

Tratamiento actual de la hepatitis B: ¿dónde encajan los nuevos análogos de los núcleos(t)idos? / Current treatment of hepatitis B infection: where do the new nucleos(t)ide analogues fit in?

La aparición de los análogos de nucleós(t)idos ha sido uno de los avances más importantes en el tratamiento de la hepatitis crónica por infección del virus de la hepatitis B. Los primeros antivirales empleados presentaban una eficacia limitada por la tasa de resistencias elevada pero en los últimos años han aparecido nuevas moléculas (tenofovir, entecavir) con mayor potencia antiviral y menor tasa de resistencias, y por ello las guías clínicas más actuales los consideran de primera elección. No obstante, el interferón todavía puede tener un papel relevante en el tratamiento de la hepatitis B en pacientes seleccionados. Además, en determinadas circunstancias como la insuficiencia renal, el embarazo o la inmunodepresión no se ha definido con exactitud el papel de los nuevos antivirales orales.En esta revisión se analizan estos aspectos, así como algunas peculiaridades del manejo de los pacientes tratados con análogos de nucleós(t)idos (AU)

Introducción La aparición de los análogos de nucleósidos y nucleótidos ha sido uno de los avances más importantes en el tratamiento de la hepatitis crónica por infección del virus de la hepatitis B (VHB). El primer fármaco de administración oral que se aprobó fue la lamivudina en 1998, y posteriormente se han incluido otros 4 (adefovir, tenofovir, entecavir y telbivudina). También hay una combinación de emtricitabina y tenofovir (Trubada®), aprobada para el tratamiento de la infección por el virus de la inmunodeficiencia humana (VIH), y con eficacia demostrada frente al VHB. El VHB es un virus ADN que se replica casi exclusivamente en los hepatocitos, aunque se han detectado bajos niveles de replicación en otros tejidos como páncreas, riñón y linfocitos. Una vez que el virus entra en la célula hepática, la cápside se transporta hasta el núcleo donde se libera el ADN viral que formará el ADNccc (ADN circular covalentemente cerrado) a partir del cual se sintetizan los ARNm que, una vez pasan al citoplasma, dirigen la síntesis de las diferentes proteínas que darán lugar a las nuevas partículas virales. El HBcAg polimeriza alrededor del complejo de ribonucleoproteínas que contiene el genoma en forma de ARN para constituir las cápsides inmaduras. En éstas, a partir del ARN y mediante la polimerasa viral, que tiene acción transcriptasa inversa similar a la del VIH, se sintetizan las nuevas cadenas de ADN, con la consiguiente maduración de las partículas virales que pueden seguir 2 caminos: volver al núcleo para replecionar el ADNccc o bien (AU)

Predictive baseline criteria of primary therapeutic failure in chronic hepatitis C genotype 1

Background and aims: more than half of patients with genotype 1 chronic hepatitis C (CHC) do not achieve a sustained viral response (SVR) to current antiviral therapy due to primary non-response, relapse or intolerance. Factors related to each of these unfavorable outcomes are different and the last two may be partially prevented. Our aim was to identify basal criteria to predict the risk of primary failure. Patients and methods: we included 251 consecutive patients (152 males) from a single centre, infected with HCV genotype 1 and not previously treated. SVR was achieved in 141 patients and primary failure in 110. Results: high vs. low viral load (> 400,000 IU/mL, OR = 6.17; 95% CI: 2.50-15.23), high serum GGT (> 60 IU/mL, OR = 4.25; 95% CI: 2.49-7.24), low serum cholesterol (< 178 mg/dL, OR = 2.93; 95% CI: 1.75-4.92) and older age (> 47 yrs., OR = 1.79; 95% CI: 1.08-2.96) were associated to the risk of primary failure in the lineal logistic regression analysis. From the 58 patients carrying all the first three negative criteria, 46 (79.3%) were primary non-responders. Conclusions: the negative basal profile identified in this study is based on easily available data and provides information about the risk of primary therapeutic failure, and may help to decide whether antiviral therapy should be offered to a single patient(AU)

Cinética viral durante el primer mes de tratamiento en pacientes con hepatitis crónica C genotipo 1 / Viral kinetics during the first month of treatment in patients with genotype 1 chronic hepatitis C

Objective: to identify predictive factors of response to pegylatedinterferon alpha-2b and ribavirin in patients with genotype 1chronic hepatitis C. Viral kinetics were studied in weeks 2 and 4.Methods: a prospective and consecutive study of patients withgenotype 1 chronic hepatitis C referred to our Hepatology Clinicbetween January 2004 and October 2006 for antiviral treatment.Baseline data were recorded and viremia levels were determinedhours before the weekly dose of pegylated interferon by qualitativeand quantitative PCR.Results: 57 patients were included in the study, although 3 ofthese were excluded during follow up; 65% were male (n = 35),with a mean age of 42 (26-65) years. Baseline viremia levels were> 800,000 IU/mL in 67% (n = 36). Liver biopsy was performedin 86% (n = 46), 22% (n = 12) had advanced fibrosis. Forty werenaïve, 4 relapsing and 10 non-responders. Ribavirin dose wasmodified in one patient alone due to adverse effects. End treatmentresponse and sustained virological response (SVR) were 59and 41%, respectively. A univariate analysis revealed a statisticallysignificant association of SVR with baseline viremia (p = 0.006),baseline GGT (p = 0.025), and a reduction in viremia >= 2 logs at2, 4 and 12 weeks (p = 0.001). The extent of viremia reduction atweek 2 was associated with 100% SVR, and at 4 weeks the positivepredictive values was 84% and the negative predictive valueswas 96.5%. A subanalysis of the naïve group yielded analogousresults.Conclusions: in our study, a reduction in viremia >= 2 logs2 weeks after treatment could ensure SVR. At 4 weeks, mostnon-responders could be identified(AU)

Objetivo: identificar qué factores predicen la respuesta al interferónpegilado alfa-2b y ribavirina en pacientes con hepatitiscrónica C genotipo 1. Se estudió la cinética viral en la semana 2 y4.Métodos: se evaluaron de forma prospectiva y consecutiva alos pacientes con hepatitis crónica C genotipo 1 remitidos a nuestraconsulta de hepatología entre enero de 2004 y octubre de2006, para tratamiento antiviral. Se recogieron datos basales y laviremia se determinó horas antes de la dosis semanal de interferónpegilado por PCR cualitativa y cuantitativa.Resultados: cincuenta y siete pacientes fueron incluidos aunque3 fueron excluidos durante el seguimiento. Un 65% fueronvarones (n = 35) con edad media de 42 (26-65) años. La viremiabasal fue > 800.000 UI/ml en 67% (n = 36). Se realizó biopsiahepática en 86% (n = 46), 22% (n = 12) tenían fibrosis avanzada.40 fueron naïves, 4 recidivantes y 10 no respondedores. La dosisde ribavirina se modificó por efecto secundario sólo en un paciente.La RFT y la RVS fueron de 59 y 41%, respectivamente. Elanálisis univariante mostró asociación estadísticamente significativacon RVS de la viremia basal (p = 0,006), GGT basal (p =0,025) y el descenso en la viremia >= 2 logaritmos a las 2, 4 y 12semanas (p = 0,001). El descenso de la viremia en la semana 2 seasoció con 100% de RVS y a las 4 semanas el VPP fue 84% y elVPN 96,5%. Se realizó un subanálisis en el grupo de pacientesnaïves con resultados superponibles.Conclusiones: en nuestro estudio el descenso de la viremia >= 2 logaritmos a las 2 semanas de tratamiento aseguró la RVS. Alas 4 semanas, identificamos a la gran mayoría de los pacientes norespondedores(AU)

Respuesta virológica temprana e implicaciones en el tratamiento antiviral / No disponible

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Mathematical modeling of HCV infection and treatment.

In the last decade, viral kinetic modeling has played an important role in the analysis of HCV RNA decay after the initiation of antiviral therapy. Models have provided a means of evaluating the antiviral effectiveness of therapy and of estimating parameters, such as the rate of virion clearance and the rate of loss of HCV-infected cells, and they have suggested mechanisms of action for both interferon-alpha and ribavirin. The inclusion of homeostatic proliferation of infected and uninfected hepatocytes in existing viral kinetic models has allowed prediction of most observed HCV RNA profiles under treatment, for example, biphasic and triphasic viral decay and viral rebound to baseline values after the cessation of therapy. In addition, new kinetic models have taken into consideration the different pharmacokinetics of standard and pegylated forms of interferon and have incorporated alanine aminotransferase kinetics and aspects of immune responses to provide a more comprehensive picture of the biology underlying changes in HCV RNA during therapy. Here, we describe our current understanding of the kinetics of HCV infection and treatment.