Division of Gastroenterology, Department of Medicine, Brooke Army Medical Center, Fort Sam Houston, TX 78234, USA.
Aliment Pharmacol Ther. 2011 Jul;34(2):214-8. doi: 10.1111/j.1365-2036.2011.04695.x. Epub 2011 May 18.
The non-alcoholic fatty liver disease (NAFLD) activity score (NAS) is a scoring system designed by the Nonalcoholic Steatohepatitis (NASH) Clinical Research Network (CRN) to encompass the spectrum of NAFLD and evaluate histological changes. However, the NAS and the correlation between the NAS and a diagnosis of NASH have not been validated outside the NASH CRN.
To validate the NAS outside the NASH CRN.
This study retrospectively examined liver biopsies from adults with NAFLD or steatohepatitis obtained from January 2003 to May 2010. Biopsy specimens were evaluated twice in a blinded manner by a single hepatopathologist, once to determine a diagnosis (steatohepatitis or steatosis/not-steatohepatitis), and a second time to determine the NAS.
A total of 386 liver biopsies were evaluated. Mean age of patients at time of biopsy was 49.9±10.2years. NASH was found in 51% of the patients. For NAS ≥5 as a diagnosis of steatohepatitis and NAS <5 for not-steatohepatitis, the sensitivity was 57%, specificity: 95%, negative predictive value (NPV): 68% and positive predictive value (PPV): 93%. Lowering the NAS to ≥4 as a diagnosis of steatohepatitis increased the sensitivity to 85% with a decrease in specificity to 81%; NPV: 84%, PPV: 82% and Cohen's kappa 0.658.
The NAFLD activity score is a valid scoring system encompassing the spectrum of NAFLD with an excellent level of agreement between the histological diagnosis and the NAFLD activity score. A NAFLD activity score ≥4 has optimal sensitivity and specificity for predicting steatohepatitis, and is the recommended value for admission into an interventional trial for NASH.
非酒精性脂肪性肝病（NAFLD）活动评分（NAS）是由非酒精性脂肪性肝炎（NASH）临床研究网络（CRN）设计的一种评分系统，旨在涵盖 NAFLD 的范围并评估组织学变化。然而，NAS 及其与 NASH 诊断之间的相关性尚未在 NASH CRN 之外得到验证。
在 NASH CRN 之外验证 NAS。
本研究回顾性分析了 2003 年 1 月至 2010 年 5 月期间从患有 NAFLD 或脂肪性肝炎的成年人中获得的肝活检标本。由一名肝病理学家以盲法两次评估活检标本，一次用于确定诊断（脂肪性肝炎或脂肪变性/非脂肪性肝炎），另一次用于确定 NAS。
共评估了 386 份肝活检标本。活检时患者的平均年龄为 49.9±10.2 岁。51%的患者存在 NASH。对于 NAS≥5 作为脂肪性肝炎的诊断，NAS<5 作为非脂肪性肝炎的诊断，敏感性为 57%，特异性为 95%，阴性预测值（NPV）为 68%，阳性预测值（PPV）为 93%。将 NAS 降低至≥4 作为脂肪性肝炎的诊断，敏感性提高至 85%，特异性降低至 81%；NPV：84%，PPV：82%，Cohen's kappa 0.658。
NAFLD 活动评分是一种有效的评分系统，涵盖了 NAFLD 的范围，组织学诊断与 NAFLD 活动评分之间具有极好的一致性。NAFLD 活动评分≥4 对预测脂肪性肝炎具有最佳的敏感性和特异性，是纳入 NASH 干预试验的推荐值。
