1
|
The role of disturbance in invasive plant establishment in a changing climate: insights from a drought experiment. Biol Invasions 2021. [DOI: 10.1007/s10530-021-02478-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AbstractClimate change and disturbance are two major factors affecting the establishment of invasive species, yet few studies to date have assessed the individual and interactive effects of these two factors in a common setting. Disturbance has often been found to facilitate the establishment of invading species, while climate change may affect them positively or negatively through altering abiotic conditions, or indirectly by modifying species interactions. In a full-factorial field experiment in a semiarid temperate grassland in Central Hungary, we studied the effects of drought (40% rain exclusion throughout the year) and soil disturbance on the emergence, survival and aboveground biomass of four invasive plant species that represent different life forms and that are of concern in the region and at a broader scale. We added seeds of Ambrosia artemisiifolia (annual forb), Cenchrus incertus (annual grass), Asclepias syriaca (perennial forb) and Ailanthus altissima (deciduous tree) in drought and non-drought plots with and without soil disturbance. Ailanthus germinated poorly irrespective of treatments. Disturbance facilitated while drought suppressed seedling emergence in the other three species. Ambrosia was more sensitive to disturbance, while Cenchrus was more responsive to drought. Asclepias achieved substantial emergence in disturbed non-drought plots only, as drought strongly suppressed its emergence even in the presence of disturbance. Seedling survival and late-season aboveground biomass of Ambrosia and Cenchrus were positively affected by disturbance but were unaffected by drought, while no Asclepias seedling survived until late summer. Our results highlight that both drought and disturbance may considerably impact the establishment of invasive plants, with potential interactive effects, but responses may greatly differ among species and life stages. Overall, our findings in this study suggest that although drought may negatively affect seedling establishment, a drier climate may not suppress or eliminate invasive species if soil disturbance is present. They also highlight the importance of including disturbance in studies assessing the potential effects of climate change on plant invasions.
Collapse
|
2
|
Hadi R, Shin K, Reder N, Alpert L, Koch L, Choi WT, Swanson PE, Hart J, Westerhoff M. Utility of glutamine synthetase immunohistochemistry in identifying features of regressed cirrhosis. Mod Pathol 2020; 33:448-455. [PMID: 31391527 DOI: 10.1038/s41379-019-0346-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 07/13/2019] [Indexed: 02/07/2023]
Abstract
The prevailing view that cirrhosis is irreversible has been challenged. It has been proposed that varying degrees of fibrosis regression can be achieved if the injurious agent is removed. In the normal liver, glutamine synthetase immunostaining is present around central veins. In regressed cirrhosis, although fibrous bands between portal tracts and central veins may largely be resorbed, the abnormal portal tract-central vein adherence often remains. Hence, we hypothesized that aberrant glutamine synthetase positivity adjacent to portal tracts would help identify regressed cirrhosis. We performed glutamine synthetase immunohistochemistry on 49 liver specimens (16 regressed cirrhosis, 18 cirrhotic, and 15 normal livers). Qualification for regressed cirrhosis required the following histologic features: curved, delicate incomplete septa, portal tract-central vein adhesions, and portal tract "remnants" (portal tracts with no venous branch). Out of 16, 14 regressed cirrhosis cases had baseline cirrhosis established based on previous biopsy or signs of cirrhosis based on physical exam, laboratory, and radiological findings. All regressed cirrhosis cases (100%) had areas of aberrant glutamine synthetase positivity adjacent to portal tracts, indicating that portal tract-central vein approximation had occurred (p < 0.001 compared to all other categories). No normal cases had glutamine synthetase positivity adjacent to portal tracts, and half of cirrhosis cases had areas showing features of regression, with focal glutamine synthetase positivity adjacent to portal tracts. Overall, glutamine synthetase expression showed highly significant differences among the three categories (p < 0.001). This study shows that aberrant glutamine synthetase positivity adjacent to portal tracts is present in regressed cirrhosis and can be useful in identifying regressed cirrhosis when it is histologically suspected.
Collapse
Affiliation(s)
- Rouba Hadi
- Department of Anatomic Pathology, University of Washington Medical Center, 1959 NE Pacific St, NE 110, Seattle, WA, 98195, USA.
| | - Kseniya Shin
- Department of Anatomic Pathology, University of Washington Medical Center, 1959 NE Pacific St, NE 110, Seattle, WA, 98195, USA
| | - Nicholas Reder
- Department of Anatomic Pathology, University of Washington Medical Center, 1959 NE Pacific St, NE 110, Seattle, WA, 98195, USA
| | - Lindsay Alpert
- Department of Anatomic Pathology, University of Chicago, A27 S Maryland Ave, Chicago, IL, 60637, USA
| | - Lisa Koch
- Department of Anatomic Pathology, University of Washington Medical Center, 1959 NE Pacific St, NE 110, Seattle, WA, 98195, USA
| | - Won-Tak Choi
- Department of Anatomic Pathology, University of California San Francisco, 505 Parnassus Avenue, Room M-552, San Francisco, CA, 94143, USA
| | - Paul E Swanson
- Department of Anatomic Pathology, University of Washington Medical Center, 1959 NE Pacific St, NE 110, Seattle, WA, 98195, USA
| | - John Hart
- Department of Anatomic Pathology, University of Chicago, A27 S Maryland Ave, Chicago, IL, 60637, USA
| | - Maria Westerhoff
- Department of Anatomic Pathology, University of Michigan Health System, NCRC building 35 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| |
Collapse
|
3
|
Abstract
The hepatitis C virus (HCV) is the most common blood-borne infection in the United States and is the most common cause of end-stage liver disease requiring liver transplant. Over the last 10 years, direct acting antiviral therapies have revolutionized HCV treatment, increasing the cure rates from less than 50% to more than 90% in those who reach access to care. This article is an overview for pathologists and clinicians covering the histologic findings of HCV as well as direct acting antiviral therapy.
Collapse
Affiliation(s)
- Maria Westerhoff
- University of Michigan, 1301 Catherine Street, 5231 Medical Science Building 1, Ann Arbor, MI 48104, USA.
| | - Joseph Ahn
- Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Mail Code L-461, Portland, OR 97239, USA
| |
Collapse
|
4
|
Burstow NJ, Mohamed Z, Gomaa AI, Sonderup MW, Cook NA, Waked I, Spearman CW, Taylor-Robinson SD. Hepatitis C treatment: where are we now? Int J Gen Med 2017; 10:39-52. [PMID: 28255252 PMCID: PMC5322849 DOI: 10.2147/ijgm.s127689] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Chronic hepatitis C infection affects millions of people worldwide and confers significant morbidity and mortality. Effective treatment is needed to prevent disease progression and associated complications. Previous treatment options were limited to interferon and ribavirin (RBV) regimens, which gave low cure rates and were associated with unpleasant side effects. The era of direct-acting antiviral (DAA) therapies began with the development of first-generation NS3/4A protease inhibitors in 2011. They vastly improved outcomes for patients, particularly those with genotype 1 infection, the most prevalent genotype globally. Since then, a multitude of DAAs have been licensed for use, and outcomes for patients have improved further, with fewer side effects and cure rates approaching 100%. Recent regimens are interferon-free, and in many cases, RBV-free, and involve a combination of DAA agents. This review summarizes the treatment options currently available and discusses potential barriers that may delay the global eradication of hepatitis C.
Collapse
Affiliation(s)
- Nicholas J Burstow
- Liver Unit, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Zameer Mohamed
- Liver Unit, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Asmaa I Gomaa
- National Liver Institute, Menoufiya University, Shbeen El Kom, Egypt
| | - Mark W Sonderup
- Division of Hepatology, Department of Medicine, Faculty of Health Sciences, University of Cape Town and Groote Schuur Hospital, Cape Town, Republic of South Africa
| | - Nicola A Cook
- Liver Unit, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Imam Waked
- National Liver Institute, Menoufiya University, Shbeen El Kom, Egypt
| | - C Wendy Spearman
- Division of Hepatology, Department of Medicine, Faculty of Health Sciences, University of Cape Town and Groote Schuur Hospital, Cape Town, Republic of South Africa
| | | |
Collapse
|
5
|
Wang LS, D'Souza LS, Jacobson IM. Hepatitis C-A clinical review. J Med Virol 2016; 88:1844-55. [PMID: 27097298 DOI: 10.1002/jmv.24554] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/10/2016] [Indexed: 12/18/2022]
Abstract
With an estimated prevalence of about 170 million people worldwide, chronic hepatitis C is an important cause of chronic liver disease associated with a substantial risk of cirrhosis and hepatocellular carcinoma. The recent past has borne witness to remarkable advancements in the treatment of chronic hepatitis C with the development of novel, effective, and well tolerated medications that have resulted in paradigm shifts in treatment approaches and may potentially affect the natural history of the disease. We provide a clinical review of current concepts and future developments in the management of chronic hepatitis C to aid in the understanding and individualization of chronic hepatitis C treatment. J. Med. Virol. 88:1844-1855, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Lan S Wang
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Texas Health Science Center at Houston, Houston, Texas
| | - Lionel S D'Souza
- Division of Digestive Diseases, Department of Medicine, Mount Sinai Beth Israel Medical Center, New York, New York
| | - Ira M Jacobson
- Division of Digestive Diseases, Department of Medicine, Mount Sinai Beth Israel Medical Center, New York, New York
| |
Collapse
|
6
|
Wells JT, Landaverde C, Gutierrez J, Lawitz E. Management of patients with hepatitis C virus resistance-associated variants to NS5A inhibitors: Where are we now? Clin Liver Dis (Hoboken) 2015; 6:82-85. [PMID: 31040995 PMCID: PMC6490661 DOI: 10.1002/cld.507] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 08/23/2015] [Accepted: 08/29/2015] [Indexed: 02/04/2023] Open
Affiliation(s)
- Jennifer T. Wells
- The Texas Liver Institute/University of Texas Health Science CenterSan AntonioTX
| | - Carmen Landaverde
- The Texas Liver Institute/University of Texas Health Science CenterSan AntonioTX
| | - Julio Gutierrez
- The Texas Liver Institute/University of Texas Health Science CenterSan AntonioTX
| | - Eric Lawitz
- The Texas Liver Institute/University of Texas Health Science CenterSan AntonioTX
| |
Collapse
|
7
|
Pipili C, Cholongitas E. Μanagement of patients with hepatitis B and C before and after liver and kidney transplantation. World J Hepatol 2014; 6:315-25. [PMID: 24868325 PMCID: PMC4033289 DOI: 10.4254/wjh.v6.i5.315] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 03/10/2014] [Accepted: 04/16/2014] [Indexed: 02/06/2023] Open
Abstract
New nucleos(t)ide analogues (NAs) with high genetic barrier to hepatitis B virus (HBV) resistance (such as entecavir, tenofovir) have improved the prognosis of patients with HBV decompensated cirrhosis and have prevented HBV recurrence after liver transplantation (LT). NAs are considered the most proper approach for HBV infection in patients under renal replacement therapy but their doses should be adjusted according to the patient's creatinine clearance. In addition, physicians should be aware of the potential nephrotoxicity. However, patients with chronic hepatitis C and decompensated cirrhosis can receive only one therapeutic option before LT, as well as for Hepatitis C virus (HCV) recurrence after LT, which is the combination of subcutaneous Peg-IFN and ribavirin. Generally, therapy for HCV after renal transplantation should be avoided. Although the optimal antiviral therapy for HCV infection has not been established, attention has turned to a new, oral direct acting antiviral treatment which marks a promising strategy in prognosis and in amelioration of these diseases.
Collapse
Affiliation(s)
- Chrysoula Pipili
- Chrysoula Pipili, Department of Nephrology, Laiki Merimna, 17343 Athens, Greece
| | | |
Collapse
|
8
|
Macarthur KL, Smolic R, Smolic MV, Wu CH, Wu GY. Update on the Development of Anti-Viral Agents Against Hepatitis C. J Clin Transl Hepatol 2013; 1:9-21. [PMID: 26357602 PMCID: PMC4521270 DOI: 10.14218/jcth.2013.007xx] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 05/14/2013] [Accepted: 05/14/2013] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) infects nearly 170 million people worldwide and causes chronic hepatitis, cirrhosis, and hepatocellular carcinoma. The search for a drug regimen that maximizes efficacy and minimizes side effects is quickly evolving. This review will discuss a wide range of drug targets currently in all phases of development for the treatment of HCV. Direct data from agents in phase III/IV clinical trials will be presented, along with reported side-effect profiles. The mechanism of action of all treatments and resistance issues are highlighted. Special attention is given to available trial data supporting interferon-free treatment regimens. HCV has become an increasingly important public health concern, and it is important for physicians to stay up to date on the rapidly growing novel therapeutic options.
Collapse
Affiliation(s)
| | | | | | - Catherine H. Wu
- Department of Medicine, Division of Gastroenterology-Hepatology, University of Connecticut Health Center, Farmington, CT, USA
| | - George Y. Wu
- Department of Medicine, Division of Gastroenterology-Hepatology, University of Connecticut Health Center, Farmington, CT, USA
| |
Collapse
|
9
|
Analysis of boceprevir resistance associated amino acid variants (RAVs) in two phase 3 boceprevir clinical studies. Virology 2013; 444:329-36. [PMID: 23876458 DOI: 10.1016/j.virol.2013.06.029] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/10/2013] [Accepted: 06/25/2013] [Indexed: 12/23/2022]
Abstract
BACKGROUND We investigated the frequency of RAVs among patients failing to achieve SVR in two clinical trials. We also investigated the impact of interferon responsiveness on RAVs and specific baseline RAVs relationship with boceprevir treatment failure. METHODS Data are from 1020 patients enrolled into either SPRINT-2 or RESPOND-2; patients received a 4-week PR lead-in prior to receiving boceprevir or placebo. RAVs were analyzed via population-based sequence analysis of the NS3 protease gene (success rate of >90% at a virus level of ≥ 10,000IU/mL) RESULTS: The high SVR rate in patients who received boceprevir resulted in a low rate of RAVs; 7% was detected at baseline in all patients, which rose to 15% after treatment. However, RAVs were detected in 53% of patients that failed to achieve SVR, which declined to 22.8% 6-14 months following cessation of boceprevir therapy. Baseline RAVs alone were not predictive of virologic outcome; poor interferon responsiveness was highly predictive of non-SVR. RAVs were more frequently detected in poor interferon responders. CONCLUSIONS We detected no association between the presence of baseline amino acid variants at boceprevir resistance-associated loci and outcome in the context of good IFN response.
Collapse
|
10
|
Yaseen AlSabbagh ME, Davitkov P, Falck-Ytter Y. Protease inhibitors in combination with pegylated interferon and ribavirin for adult patients with chronic hepatitis C virus. Hippokratia 2013. [DOI: 10.1002/14651858.cd010587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | - Perica Davitkov
- Case Western Reserve University; 4th floor; 2103 Cornell Rd Cleveland OH USA 44106
| | - Yngve Falck-Ytter
- VA Medical Center; Division of Gastroenterology; 10701 East Boulevard Cleveland OH USA 44106
| |
Collapse
|
11
|
Direct-acting antivirals for the treatment of chronic hepatitis C: open issues and future perspectives. ScientificWorldJournal 2013; 2013:704912. [PMID: 23844410 PMCID: PMC3687480 DOI: 10.1155/2013/704912] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Accepted: 05/06/2013] [Indexed: 12/14/2022] Open
Abstract
Currently, two direct-acting antivirals (DAAs) show well-established efficacy against hepatitis C virus (HCV), namely, first-wave protease inhibitors telaprevir and boceprevir. Most clinical trials have examined DAAs in combination with standard of care (SOC) regimens. Future therapeutic drugs were divided into three categories. They are second-wave protease inhibitors, second-generation protease inhibitors, and polymerase inhibitors. Second-wave protease inhibitors are more improved form and can be administered once a day. Oral drug combinations can be favored because interferon (IFN) not only has to be given as intradermal injection, but also can cause several serious side effects. Combination of drugs with different mechanisms shows a good sustained virological response (SVR). But several mutations are associated with viral resistance to DAAs. Therefore, genotypic resistance data may provide insights into strategies aimed at maximizing SVR rates and minimizing resistance. Combined drug regimens are necessary to prevent the emergence of drug-resistant HCV. Many promising DAA candidates have been identified. Of these, a triple regimen containing sofosbuvir shows promise, and treatment with daclatasvir plus asunaprevir yields a high SVR rate (95%). Oral drug combinations will be standard of care in the near future.
Collapse
|
12
|
Schaefer EAK, Chung RT. Anti-hepatitis C virus drugs in development. Gastroenterology 2012; 142:1340-1350.e1. [PMID: 22537441 DOI: 10.1053/j.gastro.2012.02.015] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 01/23/2012] [Accepted: 02/03/2012] [Indexed: 02/07/2023]
Abstract
Development of robust cell culture models for hepatitis C viral infection has greatly increased our understanding of this virus and its life cycle. This knowledge has led to the development of many drugs that target specific elements of viral replication, including viral proteins and host factors required for replication. The NS3/4A serine protease inhibitors were the first of these to be used in the clinic, and reagents that target other elements of the viral lifecycle are in advanced stages of clinical development. These include new NS3/4A protease inhibitors, NS5B RNA-dependent RNA polymerase inhibitors, NS5A inhibitors, and host-directed antivirals, such as cyclophilin inhibitors. Alternative interferons with possibly improved tolerability, specifically interferon-λ1 (interleukin-29), are also under development. These new reagents against hepatitis C virus should lead to highly effective, well-tolerated, and likely interferon-sparing therapies in the next several years.
Collapse
Affiliation(s)
- Esperance A K Schaefer
- Massachusetts General Hospital, Department of Medicine, Gastrointestinal Unit, Boston, USA.
| | | |
Collapse
|
13
|
McGovern BH. Editorial commentary: Hepatitis C virus and the infectious disease physician: a perfect match. Clin Infect Dis 2012; 55:414-7. [PMID: 22491341 DOI: 10.1093/cid/cis378] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
|
14
|
Fusco DN, Chung RT. New protease inhibitors for HCV--help is on the way. J Hepatol 2011; 54:1087-9. [PMID: 21232563 DOI: 10.1016/j.jhep.2010.12.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 12/23/2010] [Accepted: 12/29/2010] [Indexed: 12/21/2022]
|
15
|
Kwo PY, Lawitz EJ, McCone J, Schiff ER, Vierling JM, Pound D, Davis MN, Galati JS, Gordon SC, Ravendhran N, Rossaro L, Anderson FH, Jacobson IM, Rubin R, Koury K, Pedicone LD, Brass CA, Chaudhri E, Albrecht JK. Efficacy of boceprevir, an NS3 protease inhibitor, in combination with peginterferon alfa-2b and ribavirin in treatment-naive patients with genotype 1 hepatitis C infection (SPRINT-1): an open-label, randomised, multicentre phase 2 trial. Lancet 2010; 376:705-16. [PMID: 20692693 DOI: 10.1016/s0140-6736(10)60934-8] [Citation(s) in RCA: 567] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Peginterferon plus ribavirin achieves sustained virological response (SVR) in fewer than half of patients with genotype 1 chronic hepatitis C virus infection treated for 48 weeks. We tested the efficacy of boceprevir, an NS3 hepatitis C virus oral protease inhibitor, when added to peginterferon alfa-2b and ribavirin. METHODS In part 1 of this trial, undertaken in 67 sites in the USA, Canada, and Europe, 520 treatment-naive patients with genotype 1 hepatitis C virus infection were randomly assigned to receive peginterferon alfa-2b 1.5 mug/kg plus ribavirin 800-1400 mg daily for 48 weeks (PR48; n=104); peginterferon alfa-2b and ribavirin daily for 4 weeks, followed by peginterferon alfa-2b, ribavirin, and boceprevir 800 mg three times a day for 24 weeks (PR4/PRB24; n=103) or 44 weeks (PR4/PRB44; n=103); or peginterferon alfa-2b, ribavirin, and boceprevir three times a day for 28 weeks (PRB28; n=107) or 48 weeks (PRB48; n=103). In part 2, 75 patients were randomly assigned to receive either PRB48 (n=16) or low-dose ribavirin (400-1000 mg) plus peginterferon alfa-2b and boceprevir three times a day for 48 weeks (low-dose PRB48; n=59). Randomisation was by computer-generated code, and study personnel and patients were not masked to group assignment. The primary endpoint was SVR 24 weeks after treatment. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00423670. FINDINGS Patients in all four boceprevir groups had higher rates of SVR than did the control group (58/107 [54%, 95% CI 44-64], p=0.013 for PRB28; 58/103 [56%, 44-66], p=0.005 for PR4/PRB24; 69/103 [67%, 57-76], p<0.0001 for PRB48; and 77/103 [75%, 65-83], p<0.0001 for PR4/PRB44; vs 39/104 [38%, 28-48] for PR48 control). Low-dose ribavirin was associated with a high rate of viral breakthrough (16/59 [27%]), and a rate of relapse (six of 27 [22%]) similar to control (12/51 [24%]). Boceprevir-based groups had higher rates of anaemia (227/416 [55%] vs 35/104 [34%]) and dysgeusia (111/416 [27%] vs nine of 104 [9%]) than did the control group. INTERPRETATION In patients with untreated genotype 1 chronic hepatitis C infection, the addition of the direct-acting antiviral agent boceprevir to standard treatment with peginterferon and ribavirin after a 4-week lead-in seems to have the potential to double the sustained response rate compared with that recorded with standard treatment alone. FUNDING Merck.
Collapse
Affiliation(s)
- Paul Y Kwo
- Department of Medicine, Division of Gastroenterology/Hepatology, Indiana University School of Medicine, Indianapolis, IN 46202-5121, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Viral response to specifically targeted antiviral therapy for hepatitis C and the implications for treatment success. CANADIAN JOURNAL OF GASTROENTEROLOGY = JOURNAL CANADIEN DE GASTROENTEROLOGIE 2010; 24:385-90. [PMID: 20559582 DOI: 10.1155/2010/125435] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Currently, hepatitis C virus (HCV) antiviral therapy is characterized by long duration, a multitude of side effects, difficult administration and suboptimal success; clearly, alternatives are needed. Collectively, specifically targeted antiviral therapy for HCV (STAT-C) molecules achieve rapid viral suppression and very high rapid virological response rates, and improve sustained virological response rates. The attrition rate of agents within this class has been high due to various toxicities. Regardless, several STAT-C molecules are poised to become the standard of care for HCV treatment in the foreseeable future. Optimism must be tempered with concerns related to the rapid development of drug resistance with resulting HCV rebound. Strategies including induction dosing with interferon and ribavirin, use of combination high-potency STAT-C molecules and an intensive emphasis on adherence to HCV antiviral therapy will be critical to the success of this promising advance in HCV therapy.
Collapse
|
17
|
Smolic R, Smolic M, Andorfer JH, Wu CH, Smith RM, Wu GY. Inhibition of hepatitis C virus replication by single-stranded RNA structural mimics. World J Gastroenterol 2010; 16:2100-8. [PMID: 20440850 PMCID: PMC2864835 DOI: 10.3748/wjg.v16.i17.2100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To examine the effect of hepatitis C virus (HCV) structural mimics of regulatory regions of the genome on HCV replication.
METHODS: HCV RNA structural mimics were constructed and tested in a HCV genotype 1b aBB7 replicon, and a Japanese fulminant hepatitis-1 (JFH-1) HCV genotype 2a infection model. All sequences were computer-predicted to adopt stem-loop structures identical to the corresponding elements in full-length viral RNA. Huh7.5 cells bearing the BB7 replicon or infected with JFH-1 virus were transfected with expression vectors generating HCV mimics and controls. Cellular HCV RNA and protein levels were quantified by real-time polymerase chain reaction and Western blotting, respectively. To evaluate possible antisense effects, complementary RNAs spanning a mimic were prepared.
RESULTS: In the BB7 genotype 1b replicon system, mimics of the polymerase (NS-5B), X and BA regions inhibited replication by more than 90%, 50%, and 60%, respectively. In the JFH-1 genotype 2 infection system, mimics that were only 74% and 46% identical in sequence relative to the corresponding region in JFH-1 inhibited HCV replication by 91.5% and 91.2%, respectively, as effectively as a mimic with complete identity to HCV genotype 2a. The inhibitory effects were confirmed by NS3 protein levels. Antisense RNA molecules spanning the 74% identical mimic had no significant effects.
CONCLUSION: HCV RNA structural mimics can inhibit HCV RNA replication in replicon and infectious HCV systems and do so independent of close sequence identity with the target.
Collapse
|
18
|
Schulze Zur Wiesch J, Lohse AW. Results of the IDEAL trial: "Mirror, mirror on the wall ... which's the fairest peg-interferon of them all?". Hepatology 2009; 50:2034-7. [PMID: 19937677 DOI: 10.1002/hep.23376] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
|
19
|
Perales C, Agudo R, Tejero H, Manrubia SC, Domingo E. Potential benefits of sequential inhibitor-mutagen treatments of RNA virus infections. PLoS Pathog 2009; 5:e1000658. [PMID: 19911056 PMCID: PMC2771356 DOI: 10.1371/journal.ppat.1000658] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Accepted: 10/18/2009] [Indexed: 02/06/2023] Open
Abstract
Lethal mutagenesis is an antiviral strategy consisting of virus extinction associated with enhanced mutagenesis. The use of non-mutagenic antiviral inhibitors has faced the problem of selection of inhibitor-resistant virus mutants. Quasispecies dynamics predicts, and clinical results have confirmed, that combination therapy has an advantage over monotherapy to delay or prevent selection of inhibitor-escape mutants. Using ribavirin-mediated mutagenesis of foot-and-mouth disease virus (FMDV), here we show that, contrary to expectations, sequential administration of the antiviral inhibitor guanidine (GU) first, followed by ribavirin, is more effective than combination therapy with the two drugs, or than either drug used individually. Coelectroporation experiments suggest that limited inhibition of replication of interfering mutants by GU may contribute to the benefits of the sequential treatment. In lethal mutagenesis, a sequential inhibitor-mutagen treatment can be more effective than the corresponding combination treatment to drive a virus towards extinction. Such an advantage is also supported by a theoretical model for the evolution of a viral population under the action of increased mutagenesis in the presence of an inhibitor of viral replication. The model suggests that benefits of the sequential treatment are due to the involvement of a mutagenic agent, and to competition for susceptible cells exerted by the mutant spectrum. The results may impact lethal mutagenesis-based protocols, as well as current antiviral therapies involving ribavirin. RNA viruses are associated with many important human and animal diseases such as AIDS, influenza, hemorrhagic fevers and several forms of hepatitis. RNA viruses mutate at very high rates and, therefore, can adapt easily to environmental changes. Viral mutants resistant to antiviral inhibitors are readily selected, resulting in treatment failure. The simultaneous administration of three or more inhibitors is a means to prevent or delay selection of resistant mutants. A new antiviral strategy termed lethal mutagenesis is presently under investigation. It consists of the administration of mutagenic agents to elevate the mutation rate of the virus above the maximum level compatible with virus infectivity, without mutagenizing the host cells. Since low amounts of virus are extinguished more easily, the combination of a mutagen and inhibitor was more efficient than a mutagen alone in driving virus to extinction. Here we show that foot-and-mouth disease virus replicating in cell culture can be extinguished more easily when the inhibitor guanidine is administered first, followed by the mutagenic agent ribavirin, than when both drugs are administered simultaneously. Interfering mutants that contribute to extinction were active in the presence of ribavirin but not in the presence of guanidine. This observation provides a mechanism for the advantage of the sequential versus the combination treatment. This unexpected effectiveness of a sequential treatment is supported by a theoretical model of virus evolution in the presence of the inhibitor and the mutagen. The results can have an application for future lethal mutagenesis protocols and for current antiviral treatments that involve the antiviral agent ribavirin when it acts as a mutagen.
Collapse
Affiliation(s)
- Celia Perales
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Rubén Agudo
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Hector Tejero
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense de Madrid, Madrid, Spain
| | | | - Esteban Domingo
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
- Centro de Astrobiología (CSIC-INTA), Madrid, Spain
- * E-mail:
| |
Collapse
|
20
|
McGovern BH, Nagami EH, Birch CE, Bowen MJ, Reyor LL, Chung RT, Kim AY. Rate of sustained virologic response in relation to baseline hepatitis C virus (HCV) RNA level and rapid virologic clearance in persons with acute HCV infection. J Infect Dis 2009; 200:877-81. [PMID: 19673649 DOI: 10.1086/605444] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Treatment of acute hepatitis C virus (HCV) infection leads to a sustained virologic response (SVR) in the vast majority of patients, although the clinical predictors of these favorable responses are not well understood. In chronic infection, the most potent predictor of a SVR is complete viral suppression after 4 weeks of treatment, also known as a rapid virologic response (RVR). However, few patients with HCV genotype 1 infection and high-level viremia ever achieve this benchmark. In 2 separate cohorts of patients with acute HCV infection, we demonstrate that rapid virologic clearance and low-level viremia (HCV RNA level, <400,000 IU/mL) are highly prevalent, regardless of HCV genotype.
Collapse
Affiliation(s)
- Barbara H McGovern
- Lemuel Shattuck Hospital, 170 Morton Street, Jamaica Plain, MA 02130, USA.
| | | | | | | | | | | | | |
Collapse
|
21
|
Goto K, Watashi K, Inoue D, Hijikata M, Shimotohno K. Identification of cellular and viral factors related to anti-hepatitis C virus activity of cyclophilin inhibitor. Cancer Sci 2009; 100:1943-50. [PMID: 19659609 PMCID: PMC11159858 DOI: 10.1111/j.1349-7006.2009.01263.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We have so far reported that an immunosuppressant cyclosporin A (CsA), a well-known cyclophilin (CyP) inhibitor (CPI), strongly suppressed hepatitis C virus (HCV) replication in cell culture, and that CyPB was a cellular cofactor for viral replication. To further investigate antiviral mechanisms of CPI, we here developed cells carrying CsA-resistant HCV replicons, by culturing the HCV subgenomic replicon cells for 4 weeks in the presence of CsA with G418. Transfection of total RNA from the isolated CsA-resistant cells to naïve Huh7 cells conferred CsA resistance, suggesting that the replicon RNA itself was responsible for the resistant phenotype. Of the identified amino acid mutations, D320E in NS5A conferred the CsA resistance. The replicon carrying the D320E mutation was sensitive to interferon-alpha, but was resistant to CsA and other CPIs including NIM811 and sanglifehrin A. Knockdown of individual CyP subtypes revealed CyP40, in addition to CyPA and CyPB, contributed to viral replication, and CsA-resistant replicons acquired independence from CyPA for efficient replication. These data provide important evidence on the mechanisms underlying the regulation of HCV replication by CyP and for designing novel and specific anti-HCV strategies with CPIs.
Collapse
Affiliation(s)
- Kaku Goto
- Laboratory of Human Tumor Viruses, Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | | | | | | | | |
Collapse
|
22
|
WEISS JJ, BRÄU N, STIVALA A, SWAN T, FISHBEIN D. Review article: adherence to medication for chronic hepatitis C - building on the model of human immunodeficiency virus antiretroviral adherence research. Aliment Pharmacol Ther 2009; 30:14-27. [PMID: 19416131 PMCID: PMC3102513 DOI: 10.1111/j.1365-2036.2009.04004.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Treatment of hepatitis C virus (HCV) infection with pegylated interferon/ribavirin achieves sustained virological response in up to 56% of HCV mono-infected patients and 40% of HCV/human immunodeficiency virus (HIV)-co-infected patients. The relationship of patient adherence to outcome warrants study. AIM To review comprehensively research on patient-missed doses to HCV treatment and discuss applicable research from adherence to HIV antiretroviral therapy. METHODS Publications were identified by PubMed searches using the keywords: adherence, compliance, hepatitis C virus, interferon and ribavirin. RESULTS The term 'non-adherence' differs in how it is used in the HCV from the HIV literature. In HCV, 'non-adherence' refers primarily to dose reductions by the clinician and early treatment discontinuation. In contrast, in HIV, 'non-adherence' refers primarily to patient-missed doses. Few data have been published on the rates of missed dose adherence to pegylated interferon/ribavirin and its relationship to virological response. CONCLUSIONS As HCV treatment becomes more complex with new classes of agents, adherence will be increasingly important to treatment success as resistance mutations may develop with suboptimal dosing of HCV enzyme inhibitors. HIV adherence research can be applied to that on HCV to establish accurate methods to assess adherence, investigate determinants of non-adherence and develop strategies to optimize adherence.
Collapse
Affiliation(s)
- J. J. WEISS
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY, USA
| | - N. BRÄU
- Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA
,Veterans Affairs Medical Center, Infectious Disease Section, Bronx, NY, USA
| | - A. STIVALA
- Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA
| | - T. SWAN
- Treatment Action Group, New York, NY, USA
| | - D. FISHBEIN
- Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA
| |
Collapse
|
23
|
Hepatocellular carcinoma in HIV-infected patients comes of age: The convergence of epidemiology and treatment effectiveness. J Hepatol 2009; 50:655-8. [PMID: 19243854 DOI: 10.1016/j.jhep.2009.01.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|
24
|
Potter M, Klein MB. Co-infections and co-therapies: treatment of HIV in the presence of hepatitis C and hepatitis B. ACTA ACUST UNITED AC 2009. [DOI: 10.2217/17584310.3.2.189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An increasing number of people are chronically infected with HIV and HCV, and/or HBV owing to shared routes of transmission. With the advent of HAART, liver disease secondary to hepatitis co-infections has emerged as a leading cause of morbidity and mortality in HIV-infected persons. There is increasing need to manage dual infection, but treatment is complicated by co-morbidities, overlapping toxicities, drug activities and resistance. A model of treatment that builds on the lessons learned from the treatment of HIV has evolved to maximize success of treating dual infections. This review will address current strategies for the management of HIV in the setting of HCV and HBV co-infection and discuss future treatment directions and challenges.
Collapse
Affiliation(s)
- Martin Potter
- Department of Medicine, Divisions of Infectious Diseases/Immunodeficiency, Royal Victoria Hospital, McGill University Health Centre, Montréal, Québec, Canada
| | - Marina B Klein
- Department of Medicine, Divisions of Infectious Diseases/Immunodeficiency, Royal Victoria Hospital, McGill University Health Centre, Montréal, Québec, Canada
- Montreal Chest Institute, 3650 Saint Urbain Street, Montréal, Quebec H2X 2P4, Canada
| |
Collapse
|
25
|
Meanwell NA, Kadow JF, Scola PM. Chapter 20 Progress towards the Discovery and Development of Specifically Targeted Inhibitors of Hepatitis C Virus. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2009. [DOI: 10.1016/s0065-7743(09)04420-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
|