Non-invasive score system for fibrosis in chronic hepatitis: proposal for a model based on biochemical, FibroScan and ultrasound data

Background & Aims: We elaborate a non-invasive score system for liver fibrosis (NISF), exploring its diagnostic performance and comparing its accuracy to FibroScan in patients with chronic viral hepatitis (CH) and nonalcoholic fatty liver disease (NAFLD). Methods: Clinical, biochemical, elastographic and ultrasound parameters derived from patients with CH (n = 83) or NAFLD (n = 58), undergoing liver biopsy for fibrosis assessment, were prospectively collected as potential predictors of fibrosis. Each parameter was evaluated for its correlation with the liver biopsy (Gold Standard). Candidate predictors with good interobserver agreement and correlation with histological stages were combined into two algorithms (NISF) to predict fibrosis in chronic viral hepatitis and NAFLD. Results: The CH-NISF included six parameters: bluntness of liver edges, irregularity of left lobe surface, diameter of segment 4, liver stiffness measurement, platelet count and ALT values. The ability of the model to discriminate F3-F4 vs F0-F1 stages and F2 vs F0-F1 was high (AUROC of 0.95 and 0.83 respectively) and better than FibroScan alone, especially in intermediate stages (F2 vs F0-F1), AUROC 0.83 vs 0.57 (P = 0.003). The resulting algorithm is available as mathematical formula, nomogram or free online link. [http://health.mafservizi.it/NISF_Calculator/liver.htm] The NAFLD-NISF included liver stiffness, platelet count and AST levels, had good ability to discriminate F0-F1 vs F2-F3-F4 stages (AUROC 0.86), however, not significantly higher than FibroScan. Conclusions: CH-NISF can be proposed as preliminary and easily available staging tool, superior to FibroScan alone in predicting histological fibrosis, especially in intermediate stages. Further validations are needed to improve NISF accuracy in NAFLD.