De Arka, Keisham Amarjit, Mishra Saurabh, Mehta Manu, Verma Nipun, Premkumar Madhumita, Taneja Sunil, Das Ashim, Singh Virendra, Duseja Ajay
Department of Hepatology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
J Clin Exp Hepatol. 2022 Mar-Apr;12(2):440-447. doi: 10.1016/j.jceh.2021.06.008. Epub 2021 Jun 15.
The FibroScan-AST (FAST) score was recently described to detect patients with nonalcoholic steatohepatitis (NASH) having elevated nonalcoholic fatty liver disease (NAFLD) activity score (NAS ≥ 4) and significant fibrosis (≥ F2) on liver biopsy (NASH+ NAS ≥ 4 + F ≥ 2).
The aim of this study was to validate the FAST score in Indian patients with NAFLD and to derive optimal cut-offs.
Sixty patients with biopsy-proven NAFLD [men: 38 (63.3%), age 40 (32-52) years] with all parameters for assessing the FAST score within 3 months of liver histology were retrospectively analysed.
Histological NASH was present in 17 patients (28.3%), while 11 (18.3%) patients had NASH + NAS ≥ 4 + F ≥ 2. The area under the curve (AUROC) of the FAST score for discriminating NASH + NAS ≥ 4 + F ≥ 2 was 0.81. Using cut-offs by Newsome , the rule-out cut-off (FAST: ≤ 0.35) had a negative predictive value (NPV) of 0.88 [sensitivity: 0.91, specificity: 0.14, negative likelihood ratio (LR): 0.64], while the rule-in cut-off (FAST: ≥ 0.67) had a positive predictive value (PPV) of 0.33 (sensitivity: 0.73, specificity: 0.67, positive LR: 2.22). Fifteen (25%) patients were correctly classified as per histology, while 28 (46.67%) patients fell in the grey zone. On recalculating the optimal cut-offs for our patients, the rule-out cut-off (FAST: ≤ 0.55) had an NPV of 0.95 (sensitivity: 0.90, specificity: 0.45, negative LR: 0.21), while the optimal rule-in cut-off (FAST: ≥ 0.78) had a PPV of 0.70 (sensitivity: 0.64, specificity 0.94, positive LR: 10.39). With these cut-offs, 27 (45%) patients fell in the grey zone and 29 (48.3%) were correctly classified as per histology, performing better than the cut-offs by Newsome ( < 0.001).
The FAST score demonstrates good AUROC for detecting NASH with significant fibrosis and inflammation on histology. Cut-offs should be recalibrated based on prevalence of disease.
India has a high burden of NAFLD with an estimated 25 million patients at potential risk for significant liver disease. Liver biopsy remains the gold standard for diagnosing NASH, although its application in routine clinical practice is limited. Noninvasive tests for the simultaneous detection of steatosis, inflammation and fibrosis are thus the need of the hour. The FAST score has been recently suggested for the noninvasive detection of NASH with significant fibrosis (≥ F2) and inflammation (NAS ≥ 4) on liver biopsy. We validated the utility of the FAST score for detecting NASH with significant fibrosis and inflammation on liver biopsy in Indian patients with NAFLD. This noninvasive, easy-to-use and nonproprietary FAST score can correctly classify disease severity in more than 50% patients. However, our results suggest that cut-offs should be recalibrated based on the anticipated prevalence of NASH + NAS ≥ 4 + F ≥ 2 in the given population.
最近有人描述了FibroScan-AST（FAST）评分，用于检测非酒精性脂肪性肝炎（NASH）患者，这些患者经肝活检显示非酒精性脂肪性肝病（NAFLD）活动评分升高（NAS≥4）且有显著纤维化（≥F2）（NASH + NAS≥4 + F≥2）。
本研究的目的是验证FAST评分在印度NAFLD患者中的有效性，并得出最佳临界值。
对60例经活检证实为NAFLD的患者[男性：38例（63.3%），年龄40（32 - 52）岁]进行回顾性分析，这些患者在肝组织学检查后3个月内具备评估FAST评分的所有参数。
17例患者（28.3%）存在组织学NASH，而11例（18.3%）患者为NASH + NAS≥4 + F≥2。FAST评分用于鉴别NASH + NAS≥4 + F≥2的曲线下面积（AUROC）为0.81。采用纽瑟姆提出的临界值，排除临界值（FAST：≤0.35）的阴性预测值（NPV）为0.88[敏感性：0.91，特异性：0.14，阴性似然比（LR）：0.64]，而纳入临界值（FAST：≥0.67）的阳性预测值（PPV）为0.33（敏感性：0.73，特异性：0.67，阳性LR：2.22）。15例（25%）患者根据组织学检查被正确分类，而28例（46.67%）患者处于灰色地带。重新计算我们患者的最佳临界值后，排除临界值（FAST：≤0.55）的NPV为0.95（敏感性：0.90，特异性：0.45，阴性LR：0.21），而最佳纳入临界值（FAST：≥0.78）的PPV为0.70（敏感性：0.64，特异性0.94，阳性LR：10.39）。采用这些临界值时，27例（45%）患者处于灰色地带，29例（48.3%）患者根据组织学检查被正确分类，其表现优于纽瑟姆提出的临界值（P < 0.001）。
FAST评分在检测组织学上有显著纤维化和炎症的NASH方面显示出良好的AUROC。应根据疾病患病率重新校准临界值。
印度NAFLD负担沉重，估计有2500万患者有发生严重肝病的潜在风险。肝活检仍是诊断NASH的金标准，但其在常规临床实践中的应用有限。因此，当下需要用于同时检测脂肪变性、炎症和纤维化的非侵入性检查。最近有人提出FAST评分用于非侵入性检测肝活检显示有显著纤维化（≥F2）和炎症（NAS≥4）的NASH。我们验证了FAST评分在印度NAFLD患者肝活检中检测有显著纤维化和炎症的NASH的效用。这种非侵入性、易于使用且非专利的FAST评分可以正确分类超过50%患者的疾病严重程度。然而，我们的结果表明，应根据给定人群中NASH + NAS≥4 + F≥2的预期患病率重新校准临界值。
