Background

Nonalcoholic fatty liver disease (NAFLD) is common in the general population but identifying patients with high-risk nonalcoholic steatohepatitis (NASH) who are candidates for pharmacologic therapy remains a challenge.

Purpose

To develop a score to identify patients with high-risk NASH, defined as NASH with an NAFLD activity score (NAS) of 4 or greater and clinically significant fibrosis (stage 2 [F2] or higher).

Materials and Methods

This was a cross-sectional secondary analysis of data prospectively collected between April 2017 and March 2019 for a group of patients with NAFLD in Japan (Japan NAFLD, the derivation data set) with contemporaneous two-dimensional shear-wave elastography and biopsy-proven NAFLD (age range, 20–89 years). Three US markers (liver stiffness [LS, measured in kilopascals], attenuation coefficient [AC, measured in decibels per centimeter per megahertz], and dispersion slope [DS, measured in meters per second per kilohertz]) were determined, together with aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and the AST-to-ALT ratio. The best-fit multivariate logistic regression model for identifying patients with high-risk NASH was determined. Diagnostic performance was assessed by using the area under the receiver operating characteristic curve (AUC). The findings were validated in an independent data set (Korea NAFLD; age range, 20–78 years).

Results

The Japan NAFLD data set included 111 patients (mean age, 53 years ± 18 [standard deviation]; 57 men), 84 (76%) with NASH. The Korea NAFLD data set included 102 patients (mean age, 48 years ± 18; 43 men), 55 (36%) with NASH. The most predictive model (LAD NASH score) combined LS, AC, and DS. Performance was satisfactory in both the derivation sample (AUC, 0.86; 95% CI: 0.79, 0.93) and the validation sample (AUC, 0.88; 95% CI: 0.80, 0.95). The LAD NASH score showed a positive predictive value of 86.5% and a negative predictive value of 87.5% for high-risk NASH in the derivation sample.

Conclusion

A score combining three US markers may be useful for noninvasive identification of patients with high-risk nonalcoholic steatohepatitis for inclusion in clinical trials and pharmacologic therapy.

© RSNA, 2021

Online supplemental material is available for this article.

See also the editorial by Lockhart in this issue.

中文翻译：

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用于识别高危 NASH 患者的多参数美国：推导和验证研究

背景

非酒精性脂肪性肝病 (NAFLD) 在普通人群中很常见，但确定适合药物治疗的高危非酒精性脂肪性肝炎 (NASH) 患者仍然是一个挑战。

目的

开发一个评分来识别高危 NASH 患者，定义为 NAFLD 活动评分 (NAS) 为 4 或更高且有临床意义的纤维化（2 期 [F2] 或更高）的 NASH。

材料和方法

这是对 2017 年 4 月至 2019 年 3 月期间前瞻性收集的一组日本 NAFLD 患者（日本 NAFLD，推导数据集）的横断面二次分析，同时进行了二维剪切波弹性成像和活检证实的 NAFLD （年龄范围，20-89 岁）。与天冬氨酸氨基转移酶一起测定了三个美国标志物（肝脏硬度 [LS，以千帕为单位测量]、衰减系数 [AC，以每厘米每兆赫兹的分贝测量] 和分散斜率 [DS，以米每秒每千赫兹为单位测量]） (AST) 和丙氨酸氨基转移酶 (ALT) 水平以及 AST 与 ALT 的比率。确定了用于识别高危 NASH 患者的最佳拟合多元逻辑回归模型。通过使用受试者工作特征曲线下面积（AUC）评估诊断性能。这些发现在一个独立的数据集（韩国 NAFLD；年龄范围，20-78 岁）中得到了验证。

结果

日本 NAFLD 数据集包括 111 名 NASH 患者（平均年龄，53 岁 ± 18 [标准差]；57 名男性），84 名（76%）。韩国 NAFLD 数据集包括 102 名 NASH 患者（平均年龄，48 岁 ± 18；43 名男性），55 名（36%）。最具预测性的模型（LAD NASH 评分）结合了 LS、AC 和 DS。衍生样本 (AUC, 0.86; 95% CI: 0.79, 0.93) 和验证样本 (AUC, 0.88; 95% CI: 0.80, 0.95) 的性能令人满意。LAD NASH 评分在衍生样本中对高危 NASH 的阳性预测值为 86.5%，阴性预测值为 87.5%。

结论

结合三个美国标志物的评分可能有助于无创识别高危非酒精性脂肪性肝炎患者，以纳入临床试验和药物治疗。

© 北美放射学会，2021

本文提供在线补充材料。

另请参阅本期 Lockhart 的社论。