NIH Consens State Sci Statements. 2002;19(3):1-46.
To provide health care providers, patients, and the general public with a responsible assessment of currently available data regarding the management and treatment of hepatitis C.
A non-Federal, nonadvocate, 12-member panel representing the fields of infectious diseases, gastroenterology, medical oncology, molecular genetics, geriatrics, internal medicine, and the public. In addition, experts in these same fields presented data to the panel and to a conference audience of approximately 300.
Presentations by experts; a systematic review of the medical literature provided by the Agency for Healthcare Research and Quality; and an extensive bibliography of hepatitis C research papers, prepared by the National Library of Medicine. Scientific evidence was given precedence over clinical anecdotal experience.
Answering predefined questions, the panel drafted a statement based on the scientific evidence presented in open forum and the scientific literature. The draft statement was read in its entirety on the final day of the conference and circulated to the experts and the audience for comment. The panel then met in executive session to consider these comments and released a revised statement at the end of the conference. The statement was made available on the World Wide Web at http://consensus.nih.gov immediately after the conference. This statement is an independent report of the panel and is not a policy statement of the NIH or the Federal Government.
The incidence of newly acquired hepatitis C infection has diminished in the United States. This decline is largely due to a decrease in cases among IDUs for reasons that are unclear and, to a lesser extent, to testing of blood donors for HCV. The virus is transmitted by blood and such transmission now occurs primarily through injection drug use, sex with an infected partner or multiple partners, and occupational exposure. The majority of infections become chronic, and therefore the prevalence of HCV infections is high, with about 3 million Americans now estimated to be chronically infected. HCV is a leading cause of cirrhosis, a common cause of HCC and the leading cause of liver transplantation in the United States. The disease spectrum associated with HCV infection varies greatly. Various studies have suggested that 3 to 20 percent of chronically infected patients will develop cirrhosis over a 20-year period, and these patients are at risk for HCC. Persons who are older at the time of infection, patients with continuous exposure to alcohol, and those co-infected with HIV or HBV demonstrate accelerated progression to more advanced liver disease. Conversely, individuals infected at a younger age have little or no disease progression over several decades. The diagnosis of chronic hepatitis C infection is often suggested by abnormalities in ALT levels and is established by EIA followed by confirmatory determination of HCV RNA. Several sensitive and specific assays are now partly automated for the purposes of detecting HCV RNA and quantifying the viral level. Although there is little correlation between viral level and disease manifestations, these assays have proven useful in identifying those patients who are more likely to benefit from treatment and, particularly, in demonstrating successful response to treatment as defined by an SVR. Liver biopsy is useful in defining baseline abnormalities of liver disease and in enabling patients and healthcare providers to reach a decision regarding antiviral therapy. Noninvasive tests do not currently provide the information that can be obtained through liver biopsy. Information on the genotype of the virus is important to guide treatment decisions. Genotype 1, most commonly found in the United States, is less amenable to treatment than genotypes 2 or 3. Therefore, clinical trials of antiviral therapies require genotyping information for appropriate stratification of subjects. Recent therapeutic trials in defined, selected populations have clearly shown that combinations of interferons and ribavirin are more effective than monotherapy. Moreover, trials using pegylated interferons have yielded improved SVR rates with similar toxicity profiles. However, results continue to show that the SVR rate is less common in patients with genotype 1 infections, higher HCV RNA levels, or more advanced stages of fibrosis. Genotype 1 infections require therapy for 48 weeks, whereas shorter treatment is feasible in genotype 2 and 3 infections. In genotype 1, the lack of an early virologic response (< 2 log decrease in HCV RNA) is associated with failure to achieve an SVR. The SVR is lower in patients with advanced liver disease than in patients without cirrhosis. Ongoing trials are exploring the usefulness of combination therapy in various populations. Preliminary experience in IDUs, individuals co-infected with HIV, children, and other special groups suggests similar responses are achievable in these populations. Patients with acute hepatitis C may be treated, but specific recommendations for antiviral treatment must await further evaluation of the rate of spontaneous clearance of the virus and determination of the optimal time to initiate treatment. Preventive measures beyond blood-banking practices include prompt identification of infected individuals, awareness of the potential for perinatal transmission, implementation of safe-injection practices, linkage of drug users to drug treatment programs, and implementation of community-based education and support programs to modify risk behavior. Some of these measures have been successfully implemented in the control of HIV infections, and it stands to reason that they would be valuable for reducing HCV transmission. Future advances in the diagnosis and management of hepatitis C require continued vigilance concerning the transmission of this infection, extending treatment to populations not previously evaluated in treatment trials, and the introduction of more effective therapies.
为医疗保健提供者、患者及普通大众提供关于丙型肝炎管理与治疗的现有数据的负责任评估。
一个由12名成员组成的非联邦、非倡导性小组,代表传染病、胃肠病学、医学肿瘤学、分子遗传学、老年医学、内科医学及公众领域。此外,这些领域的专家向该小组及约300人的会议听众展示了数据。
专家发言;医疗保健研究与质量局提供的医学文献系统综述;以及国立医学图书馆编制的丙型肝炎研究论文广泛参考文献。科学证据优先于临床轶事经验。
小组根据公开论坛上展示的科学证据及科学文献,回答预先设定的问题,起草了一份声明。声明草案在会议最后一天全文宣读,并分发给专家和听众征求意见。然后小组召开执行会议审议这些意见,并在会议结束时发布了一份修订声明。会议结束后,该声明立即在万维网(http://consensus.nih.gov)上提供。本声明是小组的独立报告,并非美国国立卫生研究院或联邦政府的政策声明。
美国新感染丙型肝炎病毒的发病率有所下降。这种下降主要是由于注射吸毒者中病例数减少,原因不明,在较小程度上是由于对献血者进行丙型肝炎病毒检测。该病毒通过血液传播,目前主要通过注射吸毒、与感染伴侣或多个伴侣发生性行为以及职业暴露传播。大多数感染会转为慢性,因此丙型肝炎病毒感染的患病率很高,目前估计约有300万美国人慢性感染。丙型肝炎病毒是肝硬化的主要病因,是肝细胞癌的常见病因,也是美国肝移植的主要病因。与丙型肝炎病毒感染相关的疾病谱差异很大。各种研究表明,3%至20%的慢性感染患者在20年内会发展为肝硬化,这些患者有患肝细胞癌的风险。感染时年龄较大、持续接触酒精的患者以及同时感染艾滋病毒或乙型肝炎病毒的患者,肝病进展会加速。相反,年轻时感染的个体在几十年内几乎没有或没有疾病进展。慢性丙型肝炎病毒感染的诊断通常由丙氨酸转氨酶水平异常提示,并通过酶免疫测定法确诊,随后进行丙型肝炎病毒RNA的确认测定。目前有几种敏感和特异的检测方法部分实现了自动化,用于检测丙型肝炎病毒RNA和定量病毒水平。虽然病毒水平与疾病表现之间几乎没有相关性,但这些检测方法已被证明有助于识别那些更可能从治疗中获益的患者,特别是有助于证明对持续病毒学应答所定义的治疗成功反应。肝活检有助于确定肝病的基线异常,并使患者和医疗保健提供者能够就抗病毒治疗做出决定。目前非侵入性检测无法提供通过肝活检可获得的信息。病毒基因型信息对于指导治疗决策很重要。在美国最常见的1型基因型,比2型或3型基因型更难治疗。因此,抗病毒治疗的临床试验需要基因型信息以便对受试者进行适当分层。在特定选定人群中的近期治疗试验清楚地表明,干扰素和利巴韦林联合使用比单一疗法更有效。此外,使用聚乙二醇化干扰素的试验提高了持续病毒学应答率,且毒性特征相似。然而,结果继续表明,1型基因型感染患者、丙型肝炎病毒RNA水平较高或纤维化程度较晚期的患者中,持续病毒学应答率较低。1型基因型感染需要治疗48周,而2型和3型基因型感染采用较短疗程治疗是可行的。在1型基因型中,缺乏早期病毒学应答(丙型肝炎病毒RNA下降<2 log)与未实现持续病毒学应答相关。晚期肝病患者的持续病毒学应答率低于无肝硬化患者。正在进行的试验正在探索联合治疗在不同人群中的有效性。在注射吸毒者、同时感染艾滋病毒的个体、儿童及其他特殊群体中的初步经验表明,这些人群也可获得类似的反应。急性丙型肝炎患者可以接受治疗,但抗病毒治疗的具体建议必须等待对病毒自发清除率的进一步评估以及确定开始治疗的最佳时间。除了血库操作之外的预防措施包括及时识别感染个体、认识围产期传播的可能性、实施安全注射操作、将吸毒者与戒毒治疗项目联系起来,以及实施基于社区的教育和支持项目以改变危险行为。其中一些措施已在控制艾滋病毒感染方面成功实施,有理由认为它们对于减少丙型肝炎病毒传播也将是有价值的。丙型肝炎诊断和管理的未来进展需要对这种感染的传播持续保持警惕,将治疗扩展到以前未在治疗试验中评估的人群,并引入更有效的疗法。