本美国胃肠学会（AGA）临床实践更新专家评论的目的是为临床医生提供关于非侵入性测试（NITs）在非酒精性脂肪性肝病（NAFLD）患者评估和管理中的使用指导。NAFLD影响全球近30%的人口，并且是末期肝病和与肝脏相关的卫生资源利用的增长原因。然而，只有少数NAFLD患者经历与肝脏相关的结果。因此，对临床医生来说，对初步评估时的预后进行评估并识别那些具有疾病进展和负面临床结果风险增加的患者至关重要。同样重要的是，长期评估疾病轨迹，特别是对当前可用治疗方法的反应。评估预后和疾病监测的参考标准是肝组织活检标本的组织学检查。然而，肝活检及其解读存在许多限制，限制了它们在常规实践中的使用。NITs的使用有助于对NAFLD患者进行风险分层和疾病进展的长期评估。这个临床更新根据对利用NITs管理NAFLD的文献综述提供最佳实践建议。因此，结合可用证据和基于专家共识的意见，并未对证据的强度和质量进行正式评级，用于制定这些最佳实践建议。该专家评论由AGA学会临床实践更新委员会和AGA执委会委托和批准，旨在为AGA会员提供关于高度临床重要性的主题的及时指导，并通过Gastroenterology的标准程序进行内部同行评审和外部同行评审。这些建议是根据已发表文献和专家意见的综述而得出的。由于没有进行系统综述，这些最佳实践建议不带有正式的证据质量评级或所表述考虑因素的强度。最佳实践建议1：NITs可用于风险分层评估NAFLD患者的诊断评估。最佳实践建议2：纤维化4指数得分<1.3与晚期肝纤维化强负预测值相关，并可能有助于排除NAFLD患者中的晚期肝纤维化。最佳实践建议3：将两种或更多对合并血清生物标志物和/或成像生物标志物进行组合的NITs优先用于NAFLD患者的分级和风险分层，其纤维化4指数得分>1.3。最佳实践建议4：遵循制造商规定使用NITs（例如，不适用于腹水患者或使用起搏器的患者），可最小化不一致结果和不良事件的风险。最佳实践建议5：应将NITs与相关临床数据（如体格检查、生化标志物、放射学和内镜检查）结合考虑解读，以优化在识别患有晚期纤维化患者方面的阳性预测值。最佳实践建议6：对NIT结果具有不确定性或不一致性的患者，与其他临床、实验室或放射学发现冲突的患者，或疑似其他肝病因素的患者应考虑进行肝活检。最佳实践建议7：使用NITs进行连续长期监测以评估疾病进展或回归可以为临床管理提供信息（即对生活方式改变或治疗干预的反应）。最佳实践建议8：对于NITs结果提示存在晚期纤维化（F3）或肝硬化（F4）的NAFLD患者应考虑进行肝并发症的监测（如按巴韦诺标准进行肝细胞肝癌筛查和静脉曲张筛查）。对于NITs提示存在晚期肝纤维化（F3）或（F4）的NAFLD患者，应进行串行肝硬度测量、振动控制的瞬时弹性成像或磁共振弹性成像监测，以鉴定其与临床显著门静脉高压和临床失代偿相关性的关联。版权所有©2023 The Authors. Elsevier Inc.保留所有权利。

The purpose of this American Gastroenterological Association (AGA) Clinical Practice Update Expert Review is to provide clinicians with guidance on the use of noninvasive tests (NITs) in the evaluation and management of patients with nonalcoholic fatty liver disease (NAFLD). NAFLD affects nearly 30% of the global population and is a growing cause of end-stage liver disease and liver-related health care resource utilization. However, only a minority of all patients with NAFLD experience a liver-related outcome. It is therefore critically important for clinicians to assess prognosis and identify those with increased risk of disease progression and negative clinical outcomes at the time of initial assessment. It is equally important to assess disease trajectory over time, particularly in response to currently available therapeutic approaches. The reference standard for assessment of prognosis and disease monitoring is histologic examination of liver biopsy specimens. There are, however, many limitations of liver biopsies and their reading that have limited their use in routine practice. The utilization of NITs facilitates risk stratification of patients and longitudinal assessment of disease progression for patients with NAFLD. This clinical update provides best practice advice based on a review of the literature on the utilization of NITs in the management of NAFLD for clinicians. Accordingly, a combination of available evidence and consensus-based expert opinion, without formal rating of the strength and quality of the evidence, was used to develop these best practice advice statements.This Expert Review was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. These best practice advice statements were drawn from a review of the published literature and from expert opinion. Because systematic reviews were not performed, these best practice advice statements do not carry formal ratings of the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: NITs can be used for risk stratification in the diagnostic evaluation of patients with NAFLD. BEST PRACTICE ADVICE 2: A Fibrosis 4 Index score <1.3 is associated with strong negative predictive value for advanced hepatic fibrosis and may be useful for exclusion of advanced hepatic fibrosis in patients with NAFLD. BEST PRACTICE ADVICE 3: A combination of 2 or more NITs combining serum biomarkers and/or imaging-based biomarkers is preferred for staging and risk stratification of patients with NAFLD whose Fibrosis 4 Index score is >1.3. BEST PRACTICE ADVICE 4: Use of NITs in accordance with manufacturer's specifications (eg, not in patients with ascites or pacemakers) can minimize risk of discordant results and adverse events. BEST PRACTICE ADVICE 5: NITs should be interpreted with context and consideration of pertinent clinical data (eg, physical examination, biochemical, radiographic, and endoscopic) to optimize positive predictive value in the identification of patients with advanced fibrosis. BEST PRACTICE ADVICE 6: Liver biopsy should be considered for patients with NIT results that are indeterminate or discordant; conflict with other clinical, laboratory, or radiologic findings; or when alternative etiologies for liver disease are suspected. BEST PRACTICE ADVICE 7: Serial longitudinal monitoring using NITs for assessment of disease progression or regression may inform clinical management (ie, response to lifestyle modification or therapeutic intervention). BEST PRACTICE ADVICE 8: Patients with NAFLD and NITs results suggestive of advanced fibrosis (F3) or cirrhosis (F4) should be considered for surveillance of liver complications (eg, hepatocellular carcinoma screening and variceal screening per Baveno criteria). Patients with NAFLD and NITs suggestive of advanced hepatic fibrosis (F3) or (F4), should be monitored with serial liver stiffness measurement; vibration controlled transient elastography; or magnetic resonance elastography, given its correlation with clinically significant portal hypertension and clinical decompensation.Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.