FibroScan–aspartate aminotransferase score in an Asian cohort of non‐alcoholic fatty liver disease and its utility in predicting histological resolution with bariatric surgery

Abstract

Background and Aim The FibroScan–aspartate aminotransferase (FAST) score was developed for identifying patients with non‐alcoholic steatohepatitis, who also have an elevated non‐alcoholic fatty liver disease (NAFLD) activity score (NAS) ≥ 4 and significant fibrosis (F ≥ 2). We aimed to validate it in our NAFLD cohort and assess if it correlates with the histological changes after bariatric surgery. Methods Patients with NAFLD, including those undergoing bariatric surgery, were included. The FAST score was calculated using liver stiffness measure, controlled attenuation parameter, and aspartate aminotransferase. Calibration and discrimination of the model were assessed by calibration plots and area under the receiver operating characteristic curve, respectively. Sensitivity and specificity were assessed at the rule‐out and rule‐in cutoffs (≤0.35 and ≥0.67), respectively. Changes in the NAS and FAST scores were compared in the bariatric cohort 1 year after surgery. Results The cohort composed of 309 patients, of which 48 patients underwent repeat liver biopsy at 1 year. The model showed good discrimination with area under the receiver operating characteristic curve of 0.79 (0.74–0.84); however, it was not satisfactorily calibrated (Hosmer–Lemeshow test, P = 0.008). The sensitivity and specificity at the rule‐out and rule‐in cutoffs were 0.90 and 0.84, respectively. A significant correlation was seen between the 1‐year reduction in the NAS and FAST scores (r = 0.38, P = 0.009). A significant reduction in the median FAST score was seen in patients who had ≥2‐point reduction in NAS after bariatric surgery. Conclusion FibroScan–aspartate aminotransferase score demonstrated good discrimination for fibrotic non‐alcoholic steatohepatitis in our cohort. However, a miscalibration resulted in overprediction. The score correlated well with the histological response to interventions for NAFLD.

FibroScan-AST (FAST) Score for Nonalcoholic Steatohepatitis – Validation in an Indian Cohort

“…Our findings are further corroborated by a recent study, reporting an AUROC of 0.79 with the FAST score for detecting NASH + NAS $4 + F $ 2 in Indian patients with NAFLD. 33 Using the cut-offs proposed by Newsome et al 6 in our cohort, we found that the rule-out cut-off (FAST: #0.35) had an NPV of 0.88 with a negative LR of 0.64. 6 However, the rule-in cut-off (FAST: $0.67) had a PPV of only 0.33 with a positive LR of 2.23.…”

“…The PPVs of the rule-in cut-off (FAST: $0.67) in these 3 cohorts were 0.33, 0.63 and 0.54, respectively. 6 Similarly, Anand et al 33 recently reported poor PPV (0.43) and positive LR (2.53) with these cut-offs in their cohort of Indian patients with NAFLD where the proportion of NASH + NAS $ 4 + F $ 2 was 23%.…”

“…Preliminary evidence from paired biopsies in a cohort of 48 patients who underwent bariatric surgery suggested a good correlation between FAST score and improvement in NAS on histology at 1 year after surgery. 33 One of the vexing issues with predictive models having two different threshold values is the problem of the grey zone. Indeed, 45% of our patients fell in the grey zone despite using optimised cut-offs.…”

A metagenomic study identifies a Prevotella copri enriched microbial profile associated with non‐alcoholic steatohepatitis in subjects with obesity

“…Moreover, because weight loss after bariatric surgery may induce a significant improvement of NAFLD metabolic profile and liver histopathology, 26 there is a growing need of non‐invasive biomarkers to assess the liver response to therapeutic interventions, including bariatric surgery. It is thus important to assess whether this P. copri dominant microbiome cluster, alone or in combination with other non‐invasive diagnostic methods, 27 may be used as a biomarker to assess metabolic and histological improvement in NASH patients after bariatric surgery.…”

Endoscopic Bariatric Treatment with Duodenal-Jejunal Bypass Liner Improves Non-invasive Markers of Non-alcoholic Steatohepatitis

“…These are fairly similar to the reductions seen at 72 weeks in a recent double-blind phase 2 trial in patients with biopsy-confirmed NASH for the highest daily dose of 0.4 mg semaglutide used there, namely − 39 dB/m, 0.52, 0.42, and 0.72, respectively [3]. In bariatric surgery, studies with a varying proportion of gastric bypass found that CAP was reduced by 62 to 75 dB/m and mean or median LSM by a factor of 0.7 to 0.8 [32][33][34][35]. However, a direct comparison of bariatric surgery, DJBL, and GLP-1 agonists has not yet been conducted and merits a prospective trial with special attention to modulation of glucose homeostasis.…”