Evaluation of Fibrosis-4 Index, NAFLD Fibrosis Score, and Aspartate Aminotransferase to Platelet Ratio Index as Non-Invasive Indicators of Fibrosis in patients with NAFLD

Introduction: Multiple non-invasive scoring models have been internationally established and verified for assessing liver fibrosis risk in nonalcoholic fatty liver disease (NAFLD) patients. This study aimed to assess the performance of the Fibrosis-4 Index (FIB-4), the NAFLD Fibrosis Score (NFS), and the Aspartate Aminotransferase to Platelet Ratio Index (APRI) in individuals with NAFLD. Methods: We conducted a retrospective chart audit of 211 histologically confirmed NAFLD cases managed at Nanjing Second Hospital, Jiangsu Province, Jiangsu Province, with analysis focusing on clinical presentations, laboratory parameters, and hepatic histology. Liver fibrosis was graded according to the Scheuer classification system. Diagnostic accuracy of the non-invasive tests was evaluated, and revised fibrosis score thresholds were established to enable more effective comparisons of their performance and to assess their potential in ruling out hepatic fibrosis. Results: Among the cohort, fibrosis was staged as follows: 5.7 % showed no fibrosis (F0), 56.9 % had mild portal expansion (F1), 21.8 % exhibited periportal septa (F2), 10.9 % displayed architectural distortion without cirrhosis (F3), and 4.7 % presented with definite cirrhosis (F4).After threshold optimisation, the FIB-4 and NFS models reached AUROCs of 0.81 and 0.79 for identifying significant fibrosis, surpassing the 0.70 recorded for APRI. A significant difference in AUROCs was observed among the three scores. The three scoring systems demonstrated statistically significant variations in AUROC values when identifying advanced fibrosis and cirrhosis. For fibrosis exclusion, optimized cut-offs below conventional values were derived for FIB-4, NFS and APRI, maintaining similar diagnostic accuracy. Conclusion: Modification of the threshold values for FIB-4, NFS, and APRI may enhance their diagnostic performance in NAFLD patients.