RESUMEN
Combining peginterferon-alfa-2a (pegIFN) with a nucleotide analogue can result in higher rates of HBsAg loss than either therapy given alone. Here, we investigated the durability of the response to combination therapy in chronic hepatitis B (CHB) patients after 5 years of follow-up. In the initial study, 92 CHB patients (44 HBeAg-positive, 48 HBeAg-negative) with HBV DNA >100 000 c/mL (~20 000 IU/mL) and active hepatitis were treated for 48 weeks with pegIFN 180 µg/week and 10 mg adefovir dipivoxil daily. For the long-term follow-up (LTFU) study, patients were followed up for 5 years after the end of treatment. At year 5, 70 (32 HBeAg-positive, 38 HBeAg-negative) patients remained in the study. At year 5, 19% (6/32) of HBeAg-positive patients and 16% (6/38) of HBeAg-negative patients lost HBsAg, and no HBsAg seroreversion was observed. The 5-year cumulative Kaplan-Meier estimate for HBsAg loss was 17.2% for HBeAg-positive patients and 19.3% for HBeAg-negative patients. Fourteen of sixteen patients who lost HBsAg at any time point during follow-up developed anti-HBs antibodies (>10 IU/L). At year 5, in total 63% (20/32) of HBeAg-positive and 71% (27/38) of HBeAg-negative patients were retreated with nucleos(t)ide analogues during follow-up. The cumulative Kaplan-Meier estimate for retreatment was 60% of patients at year 5. At year 5 of follow-up, 18% of CHB patients treated with pegIFN/nucleotide analogue combination therapy had durable HBsAg loss and 88% of these had developed anti-HBs antibodies.
Asunto(s)
Adenina/análogos & derivados , Antivirales/uso terapéutico , Antígenos de Superficie de la Hepatitis B/sangre , Hepatitis B Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Organofosfonatos/uso terapéutico , Polietilenglicoles/uso terapéutico , Adenina/uso terapéutico , Adulto , Anciano , ADN Viral/sangre , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Proteínas Recombinantes/uso terapéutico , Respuesta Virológica Sostenida , Resultado del Tratamiento , Adulto JovenRESUMEN
Current treatment for chronic hepatitis B infection (CHB) consists of interferon-based therapy. However, for unknown reasons, a large proportion of patients with CHB do not respond to this treatment. Hence, there is a pressing need to establish response markers to select patients who will benefit from therapy and to spare potential nonresponders from unnecessary side effects of antiviral therapy. Here, we assessed whether HLA-C and KIR genotypes were associated with treatment outcome for CHB. Twelve SNPs in or near the HLA-C gene were genotyped in 86 CHB patients (41 HBeAg positive; 45 HBeAg negative) treated with peginterferon alfa-2a + adefovir. Genotyping of killer immunoglobin-like receptors (KIRs) was performed by SSP-PCR. One SNP in HLA-C (rs2308557) was significantly associated with combined response in HBeAg-positive CHB patients (P = 0.003). This SNP is linked to the HLA-C group C1 or C2 classification, which controls KIR binding. The combination of KIR2DL1 with its ligand HLA-C2 was observed significantly more often in HBeAg-positive patients with a combined response (13/14) than in nonresponders (11/27, P = 0.001). Patients with the KIR2DL1/C2 genotype had significantly higher baseline ALT levels (136 vs 50 U/L, P = 0.002) than patients without this combination. Furthermore, KIR2DL1-C2 predicted response independent of HBV genotype and ALT at baseline. HLA-C and KIR genotype is strongly associated with response in HBeAg-positive CHB patients treated with interferon-based therapy. In combination with other known response markers, HLA-C/KIR genotype could enable the selection of patients more likely to respond to interferon-based therapy.
Asunto(s)
Antivirales/uso terapéutico , Antígenos HLA-C/genética , Antígenos e de la Hepatitis B/sangre , Hepatitis B Crónica/tratamiento farmacológico , Hepatitis B Crónica/genética , Interferones/uso terapéutico , Receptores KIR2DL1/genética , Adulto , Biomarcadores/análisis , Quimioterapia Combinada/métodos , Femenino , Hepatitis B Crónica/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Resultado del TratamientoRESUMEN
Chronic hepatitis C virus (HCV) infection is a major cause of chronic liver disease and liver-related death. Recently, multiple regimens of different direct-acting antiviral agents (DAAs) have been registered. Although treatment with sofosbuvir (SOF) and simeprevir (SMV) is registered for the treatment of genotype 4 patients in some countries, data on efficacy of this combination are lacking. We aimed to assess the efficacy of SOF and SMV with or without RBV during 12 weeks in a real-life cohort of genotype 4 HCV patients. A retrospective multicentre observational study was conducted in 4 hospitals in Amsterdam, the Netherlands, including patients with advanced liver fibrosis or liver cirrhosis treated with SOF plus SMV with or without RBV during 12 weeks for a genotype 4 chronic HCV infection from 1 January 2015 to 1 August 2015. Sustained viral response (SVR) was established at week 12 after end of treatment. A total of 53 patients with genotype 4 HCV infection, treatment naïve and experienced, were included. SVR was achieved in 49 of 53 patients (92%). The four failures all had a virological relapse and did not receive ribavirin. Three were nonresponder to earlier interferon-based treatment, and one was treatment naive. In this real-life cohort of patients with HCV genotype 4 infection and advanced liver fibrosis/cirrhosis, we show that treatment with SOF and SMV is effective. The addition of RBV could be considered in treatment-experienced patients as recommended in guidelines.
Asunto(s)
Antivirales/uso terapéutico , Genotipo , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Cirrosis Hepática/patología , Simeprevir/uso terapéutico , Sofosbuvir/uso terapéutico , Adulto , Anciano , Femenino , Hepacivirus/clasificación , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/virología , Humanos , Cirrosis Hepática/virología , Masculino , Persona de Mediana Edad , Países Bajos , Inhibidores de Proteasas , Recurrencia , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
AIM: This study explores the potential role of a novel interferon-containing regimen for treatment of patients with chronic hepatitis C (CHC) and underlying haemophilia. METHODS: This trial (NCT01741545) was an open-label, non-randomized phase 3 study, which included adult haemophiliacs with hepatitis C virus (HCV). Patients with HCV genotypes (GT)-2 or -3 were treated with Lambda-IFN/ribavirin (RBV)/daclatasvir (DCV) for 12 weeks (cohort A). Patients with HCV GT-1b or -4 were treated with Lambda-IFN/RBV/DCV for 12 weeks, followed by Lambda-IFN/RBV for an additional 12 weeks (cohort B). The primary endpoint was the proportion of patients with a sustained virologic response at post-treatment follow-up week 12 (SVR12). Clinical development of Lambda-IFN was discontinued during this trial leading to study termination before a 24-week post-treatment follow-up was obtained for all participants. RESULTS: Overall, 51 patients were treated (cohort A, n = 12; cohort B, n = 39). The proportion of patients achieving SVR12 was 92% in cohort A and 90% in cohort B. Therapy was generally well tolerated. The most common adverse events (AEs) were related to elevations in serum transaminases and/or bilirubin. Five serious AEs, four discontinuations due to AEs, and no deaths were reported. The rate of grade 3-4 bilirubin elevations was 17-18% across cohorts. CONCLUSION: Lambda-IFN/RBV/DCV treatment demonstrated a high SVR rate and was generally well tolerated with a safety profile consistent with expectations for this special patient population. This study supports use of DCV as part of a combination treatment regimen for haemophiliacs with CHC.
Asunto(s)
Antivirales/uso terapéutico , Hemofilia A/complicaciones , Hepatitis C Crónica/tratamiento farmacológico , Imidazoles/uso terapéutico , Interferón-alfa/uso terapéutico , Interleucinas/uso terapéutico , Polietilenglicoles/uso terapéutico , Ribavirina/uso terapéutico , Adulto , Antivirales/efectos adversos , Carbamatos , Esquema de Medicación , Quimioterapia Combinada , Genotipo , Hemofilia A/diagnóstico , Hepacivirus/genética , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/virología , Humanos , Imidazoles/efectos adversos , Interferones , Interleucinas/efectos adversos , Interleucinas/genética , Persona de Mediana Edad , Polietilenglicoles/efectos adversos , Pirrolidinas , ARN Viral/sangre , Proteínas Recombinantes/uso terapéutico , Recurrencia , Resultado del Tratamiento , Valina/análogos & derivados , Adulto JovenRESUMEN
Achievement of a sustained virologic response (SVR) after peginterferon (PEG-IFN) and ribavirin (RBV) treatment is considered to be a marker for the cure of chronic hepatitis C virus (HCV) infection. Long-term follow-up of patients with SVR after treatment with a direct acting antiviral has not yet been described. We used a randomized placebo-controlled, double-blind, two-period phase 1b trial that was conducted in 40 HCV genotype 1 (treatment-naïve and treatment-experienced)-infected patients. Nineteen patients achieved SVR after treatment with the HCV protease inhibitor narlaprevir followed by PEG-IFN/RBV. In these patients, HCV-RNA tests were scheduled at 3, 6, 12 and 24 months after end of treatment. Patients were followed for a median of 27 months (range 15-32) after end of treatment with a median number of follow-up visits of 4 (range 3-8). All patients remained HCV-RNA negative over time. SVR achieved following narlaprevir and PEG-IFN/RBV-therapy was durable up to 32 months after the end of treatment.
Asunto(s)
Antivirales/administración & dosificación , Dipéptidos/administración & dosificación , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/administración & dosificación , Polietilenglicoles/administración & dosificación , Ribavirina/administración & dosificación , Sulfonas/administración & dosificación , Adulto , Anciano , Ciclopropanos , Método Doble Ciego , Quimioterapia Combinada/métodos , Femenino , Estudios de Seguimiento , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/virología , Humanos , Interferón alfa-2 , Leucina/análogos & derivados , Masculino , Persona de Mediana Edad , Placebos/administración & dosificación , Prolina/análogos & derivados , ARN Viral/sangre , Proteínas Recombinantes/administración & dosificación , Resultado del Tratamiento , Urea , Carga ViralRESUMEN
Narlaprevir, a hepatitis C virus (HCV) NS3/4A serine protease inhibitor, has demonstrated robust antiviral activity in a placebo-controlled phase 1 study. To study evolutionary dynamics of resistant variants, the NS3 protease sequence was clonally analysed in thirty-two HCV genotype 1-infected patients following treatment with narlaprevir. Narlaprevir monotherapy was administered for one week (period 1) followed by narlaprevir/pegylated interferon-alpha-2b combination therapy with or without ritonavir (period 2) during two weeks, interrupted by a washout period of one month. Thereafter, all patients initiated pegylated interferon-alpha-2b/ribavirin combination therapy. Longitudinal clonal analysis was performed in those patients with NS3 mutations. After narlaprevir re-exposure, resistance-associated mutations at position V36, T54, R155 and A156 were detected in five patients in >95% of the clones. Narlaprevir retreatment resulted in a 2.58 and 5.06 log10 IU/mL viral load decline in patients with and without mutations, respectively (P=<0.01). After treatment, resistant variants were replaced with wild-type virus within 2-24 weeks in three patients. However, the R155K mutation was still observed 3.1 years after narlaprevir dosing in two patients in 5% and 45% of the viral population. Resistant variants could be detected early during treatment with narlaprevir. A slower viral load decline was observed in those patients with resistance-associated mutations detectable by direct population sequencing. These mutations disappeared within six months following treatment with the exception of R155K mutation, which persisted in two patients.
Asunto(s)
Antivirales/uso terapéutico , Dipéptidos/uso terapéutico , Evolución Molecular , Hepacivirus/efectos de los fármacos , Hepatitis C Crónica/tratamiento farmacológico , Inhibidores de Proteasas/uso terapéutico , Sulfonas/uso terapéutico , Proteínas no Estructurales Virales/genética , Adulto , Ciclopropanos , Quimioterapia Combinada/métodos , Femenino , Hepacivirus/genética , Humanos , Interferón alfa-2 , Interferón-alfa/uso terapéutico , Leucina/análogos & derivados , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Polietilenglicoles/uso terapéutico , Prolina/análogos & derivados , Proteínas Recombinantes/uso terapéutico , Ribavirina/uso terapéutico , Análisis de Secuencia de ADN , Urea , Carga ViralRESUMEN
IDX375 is a potent and selective palm-binding nonnucleoside inhibitor of the hepatitis C virus (HCV) genotype 1 polymerase. This first-in-human study evaluated the safety, tolerability, and pharmacokinetics of IDX375 in healthy volunteers, as well as its antiviral activity in HCV-infected patients. IDX375, as a choline salt, was administered for 1 day to 40 healthy male volunteers (25- to 200-mg IDX375-equivalent single ascending doses and a 200-mg twice-daily [BID] dose) and three patients chronically infected with HCV genotype 1 (200 mg BID only). IDX375 was well absorbed and well tolerated by all of the study participants. A single-day 200-mg BID dose resulted in exposure-related anti-HCV activity with maximal 0.5 to 1.1 log(10) reductions in plasma HCV RNA. These observations support further clinical investigations of IDX375.
Asunto(s)
Antivirales/farmacología , Antivirales/farmacocinética , Hepacivirus/efectos de los fármacos , Hepatitis C/virología , Lactamas/farmacología , Lactamas/farmacocinética , Compuestos Organofosforados/farmacología , Compuestos Organofosforados/farmacocinética , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Adulto , Antivirales/efectos adversos , Antivirales/uso terapéutico , Inhibidores Enzimáticos/efectos adversos , Inhibidores Enzimáticos/farmacocinética , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Femenino , Hepacivirus/genética , Hepatitis C/tratamiento farmacológico , Humanos , Lactamas/efectos adversos , Lactamas/uso terapéutico , Masculino , Persona de Mediana Edad , Compuestos Organofosforados/efectos adversos , Compuestos Organofosforados/uso terapéutico , ARN Viral/sangre , Carga Viral/efectos de los fármacosRESUMEN
BACKGROUND: Bacterial contamination of platelet concentrates (PCs) still remains a significant problem in transfusion with potential important clinical consequences, including death. The International Society of Blood Transfusion Working Party on Transfusion-Transmitted Infectious Diseases, Subgroup on Bacteria, organised an international study on Transfusion-Relevant Bacteria References to be used as a tool for development, validation and comparison of both bacterial screening and pathogen reduction methods. MATERIAL AND METHODS: Four Bacteria References (Staphylococcus epidermidis PEI-B-06, Streptococcus pyogenes PEI-B-20, Klebsiella pneumoniae PEI-B-08 and Escherichia coli PEI-B-19) were selected regarding their ability to proliferate to high counts in PCs and distributed anonymised to 14 laboratories in 10 countries for identification, enumeration and bacterial proliferation in PCs after low spiking (0·3 and 0·03 CFU/ml), to simulate contamination occurring during blood donation. RESULTS: Bacteria References were correctly identified in 98% of all 52 identifications. S. pyogenes and E. coli grew in PCs in 11 out of 12 laboratories, and K. pneumoniae and S. epidermidis replicated in all participating laboratories. The results of bacterial counts were very consistent between laboratories: the 95% confidence intervals were for S. epidermidis: 1·19-1·32 × 10(7) CFU/ml, S. pyogenes: 0·58-0·69 × 10(7) CFU/ml, K. pneumoniae: 18·71-20·26 × 10(7) CFU/ml and E. coli: 1·78-2·10 × 10(7) CFU/ml. CONCLUSION: The study was undertaken as a proof of principle with the aim to demonstrate (i) the quality, stability and suitability of the bacterial strains for low-titre spiking of blood components, (ii) the property of donor-independent proliferation in PCs, and (iii) their suitability for worldwide shipping of deep frozen, blinded pathogenic bacteria. These aims were successfully fulfilled. The WHO Expert Committee Biological Standardisation has approved the adoption of these four bacteria strains as the first Repository for Transfusion-Relevant Bacteria Reference Strains and, additionally, endorsed as a project the addition of six further bacteria strain preparations suitable for control of platelet contamination as the next step of enlargement of the repository.
Asunto(s)
Plaquetas/microbiología , Transfusión Sanguínea , Infecciones Bacterianas/prevención & control , Técnicas de Tipificación Bacteriana/métodos , Técnicas Bacteriológicas , Bancos de Muestras Biológicas , Transfusión de Componentes Sanguíneos/métodos , Plaquetas/citología , Escherichia coli/metabolismo , Humanos , Cooperación Internacional , Klebsiella pneumoniae/metabolismo , Garantía de la Calidad de Atención de Salud/métodos , Reproducibilidad de los Resultados , Staphylococcus epidermidis/metabolismo , Streptococcus pyogenes/metabolismoRESUMEN
In a cohort of 95 chronic hepatitis B patients, who were treated with peg-interferon and adefovir for 1 year, and who had 15% HBsAg loss (overall), no association was found between IL28B polymorphisms and HBeAg seroconversion or HBsAg clearance. These findings suggest that any association with outcome, if present, is less than that seen in chronic hepatitis C. Additional studies are needed to enlarge sample size and to refine our understanding of IL28B biology in the context of chronic hepatitis B response to immunomodulatory and direct antiviral therapy.
Asunto(s)
Adenina/análogos & derivados , Antivirales/uso terapéutico , Variación Genética , Antígenos e de la Hepatitis B/inmunología , Hepatitis B Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Interleucinas/genética , Organofosfonatos/uso terapéutico , Polietilenglicoles/uso terapéutico , Adenina/uso terapéutico , Estudios de Cohortes , ADN Viral/metabolismo , Quimioterapia Combinada , Etnicidad/genética , Estudios de Seguimiento , Virus de la Hepatitis B/genética , Hepatitis B Crónica/genética , Hepatitis B Crónica/inmunología , Humanos , Interferones , Polimorfismo de Nucleótido Simple/genética , Estudios Prospectivos , Proteínas Recombinantes/uso terapéutico , Resultado del TratamientoRESUMEN
Chronic hepatitis B affects approximately 400 million people in the world with a substantial disease burden like liver cirrhosis and hepatocellular carcinoma (HCC). Treatment for chronic hepatitis B has improved dramatically in the last decade, resulting in more patients achieving a state of inactive disease. Currently two treatment strategies are available; treatment with peginterferon (peg-IFN) or nucleos(t)ide analogues with the aim to suppress hepatitis B virus (HBV) DNA to subsequently avoid the development of cirrhosis and HCC. Unfortunately, treatment with peg-IFN can be suboptimal with important adverse effects and nucleos(t)ide analogues provoke resistance. At present, no new promising compounds attacking the HBV life cycle are in development. However, for prediction of sustained response or treatment failure, data from the long-term large peg-IFN trials provide important response markers. For the future the focus is to achieve HBsAg loss and anti-HBs conversion which is the closest the treatment can get to a cure. This review summarizes the current treatment options with their response rates and discusses future strategies for chronic hepatitis B treatment.
Asunto(s)
Antivirales/uso terapéutico , Hepatitis B Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Humanos , Interferón alfa-2 , Proteínas RecombinantesRESUMEN
Prophylactic anti-D is a very safe and effective therapy for the suppression of anti-D immunization and thus prevention of haemolytic disease of the foetus and newborn. However, migration from countries with low health standards and substantial cuts in public health expenses have increased the incidence of anti-D immunization in many "developed" countries. Therefore, this forum focuses on prenatal monitoring standards and treatment strategies in pregnancies with anti-D alloimmunization. The following questions were addressed, and a response was obtained from 12 centres, mainly from Europe.
Asunto(s)
Antígenos de Grupos Sanguíneos/inmunología , Isoanticuerpos/administración & dosificación , Complicaciones Hematológicas del Embarazo/terapia , Isoinmunización Rh/terapia , Sistema del Grupo Sanguíneo Rh-Hr/inmunología , Femenino , Sangre Fetal/inmunología , Hemoglobina Fetal/análisis , Humanos , Isoanticuerpos/sangre , Isoanticuerpos/inmunología , Embarazo , Complicaciones Hematológicas del Embarazo/sangre , Complicaciones Hematológicas del Embarazo/inmunología , Complicaciones Hematológicas del Embarazo/prevención & control , Isoinmunización Rh/inmunología , Isoinmunización Rh/prevención & control , Globulina Inmune rho(D)RESUMEN
A critical aspect of blood transfusion is the timely provision of high quality blood products. This task remains a significant challenge for many blood services and blood systems reflecting the difficulty of balancing the recruitment of sufficient donors, the optimal utilization of the donor's gift, the increasing safety related restrictions on blood donation, a growing menu of specialized blood products and an ever-growing imperative to increase the efficiency of blood product provision from a cost perspective. As our industry now faces questions about our standard practices including whether or not the age of blood has a negative impact on recipients, it is timely to take a look at our collective inventory management practices. This International Forum represents an effort to get a snap shot of inventory management practices around the world, and to understand the range of different products provided for patients. In addition to sharing current inventory management practices, this Forum is intended to foster an exchange of ideas around where we see our field moving with respect to various issues including specialty products, new technologies, and reducing recipient risk from blood transfusion products.
Asunto(s)
Bancos de Sangre/organización & administración , Inventarios de Hospitales/organización & administración , Adulto , Américas , Asia , Bancos de Sangre/estadística & datos numéricos , Conservación de la Sangre/métodos , Conservación de la Sangre/normas , Conservación de la Sangre/estadística & datos numéricos , Transfusión Sanguínea/normas , Transfusión Sanguínea/estadística & datos numéricos , Niño , Criopreservación , Envejecimiento Eritrocítico , Europa (Continente) , Humanos , Recién Nacido , Registros Médicos , Encuestas y Cuestionarios , Factores de TiempoRESUMEN
Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) serves as a template for viral replication and plays a role in persistence of HBV infection. The origin and significance of cccDNA in plasma however, is not well understood. A sensitive, specific, and reproducible real-time PCR for detection and quantitation of cccDNA in plasma of chronic hepatitis B patients was developed and validated. Four HBV DNA reference panels, and 96 plasma samples of chronic hepatitis B patients were analyzed. Results were compared with total HBV DNA levels, individual ALT levels and the Histology Activity Index (HAI). This cccDNA assay had a lower limit of detection at 15 copies/PCR, a lower limit of quantitation at 91 copies/PCR and a correlation coefficient (R) of 0.98 (P < 0.0001). cccDNA was detected in two of four international panels. Significant correlation was found between cccDNA and total HBV DNA levels in both panels (R = 0.96, and R = 0.43) and in samples of the chronic hepatitis B patients (R = 0.88, P < 0.0001). In 57% of these samples cccDNA was detectable. Mean level of cccDNA was 0.16% of total HBV load. Plasma cccDNA levels were higher in HBeAg positive samples than in HBeAg negative samples (4.91 log copies/ml vs. 3.88 log copies/ml, P < 0.0001). Levels of total HBV DNA and HBV genotype did not influence cccDNA detection. ALT levels and HAI-score were not correlated with plasma cccDNA levels. These findings suggest that cccDNA levels in plasma are not the result of increased hepatocyte degeneration, but indicate that other mechanisms might be responsible.
Asunto(s)
ADN Circular/sangre , ADN Viral/sangre , Virus de la Hepatitis B/genética , Hepatitis B Crónica/virología , Plasma/virología , Reacción en Cadena de la Polimerasa/métodos , Adulto , ADN Circular/genética , ADN Viral/genética , Antígenos de Superficie de la Hepatitis B/sangre , Humanos , Persona de Mediana Edad , Sensibilidad y Especificidad , Carga ViralRESUMEN
Serial monotherapy and add-on regimes for treatment of chronic hepatitis B virus (HBV) infection may induce the accumulation of viral resistance mutations in patients, reducing the options for ongoing viral suppression. The induction of antiviral resistance by serial application of polymerase inhibitors does not necessarily imply that the subsequent combined use of the drugs will fail. Some HIV strains resistant to one polymerase inhibitor show increased susceptibility to another polymerase inhibitor. After failure of sequential lamivudine and adefovir monotherapy, two patients with hepatitis B changed to treatment with lamivudine plus adefovir and had renewed suppression of HBV. To study the mutational history of resistant HBV subpopulations in the two patients, a part of the HBV polymerase gene was amplified, cloned, sequenced, and analyzed for the presence of mutations, in sequential plasma samples. In both patients serial monotherapy caused the replacement in all HBV clones of wild-type virus by classical lamivudine resistant mutants (L180M and M204V/I), which were replaced subsequently by adefovir resistant mutants (A181V and N236T). When finally lamivudine was added to adefovir, the A181V adefovir mutation persisted in all clones and lamivudine-related mutations did not reappear. During 18 months of combination therapy, HBV-DNA levels decreased 10,000, respectively, 1,000-fold, despite the earlier resistance to lamivudine and adefovir. Although clinically insufficient, this effect indicates that HBV polymerase resistance mutations may be antagonistic, which is relevant if chronic HBV infection is to be treated by a combination of polymerase inhibitors.
Asunto(s)
Adenina/análogos & derivados , Antivirales/uso terapéutico , Farmacorresistencia Viral , Virus de la Hepatitis B/efectos de los fármacos , Lamivudine/uso terapéutico , Organofosfonatos/uso terapéutico , Adenina/farmacología , Adenina/uso terapéutico , Adulto , Sustitución de Aminoácidos , Antivirales/farmacología , Análisis Mutacional de ADN , ADN Viral/genética , Quimioterapia Combinada , Virus de la Hepatitis B/genética , Hepatitis B Crónica/tratamiento farmacológico , Humanos , Lamivudine/farmacología , Masculino , Mutación Missense , Organofosfonatos/farmacología , Análisis de Secuencia de ADN , Carga ViralRESUMEN
Chronic hepatitis C virus (HCV) infection is a major cause of liver cirrhosis and hepatocellular carcinoma. HCV is endemic in most parts of the world, with an estimated 170 million people infected worldwide and 3-4 million new cases each year. HCV-related end-stage liver disease is now the main indication for liver transplantation in the USA and Western Europe. Unfortunately, no vaccine or immunoglobulin is available to prevent HCV infection. Currently, HCV treatment consists of the combined administration of pegylated interferon and ribavirin for a period of 24-48 weeks, resulting in complete viral eradication in 40-80% of patients, depending on genotype, viral load and patient characteristics. This therapy is often accompanied with side-effects that affect compliance and reduce treatment outcomes. Recently, reliable in vitro culture systems have been developed which accelerated antiviral therapy research. Many new specifically targeted antiviral therapies for hepatitis C (STAT-C) and treatment strategies are evaluated in clinical trials. These new antiviral agents are expected to improve treatment significantly with potentially shorter treatment duration. The most promising antiviral agents will be reviewed.