Laboratory based Non-Invasive Markers are Suboptimal in Detecting Advanced Fibrosis in Patients with Non-Alcoholic Steatohepatitis

Background and Aim: Hepatic fibrosis is a major determinant of clinical outcomes in patients with non-alcoholic steatohepatitis (NASH). We aimed to investigate the diagnostic performance of non-invasive tests in detecting advanced fibrosis (F3-4) in a large NASH cohort from central Ohio, the United States. Methods: Data of all patients with biopsy-proven NASH between 2014 and 2017 were collected. Diagnostic performance of aspartate aminotransferase (AST) to platelets ratio index (APRI), fibrosis-4 index (FIB-4) and NAFLD fibrosis score (NFS) were studied. Results: A total of 284 NASH patients were included, 27.82% of whom had F3-4. The cohort was predominantly female (60.92%) and White (88.38%) with a mean age of 50±13 years. The most common comorbidities were obesity (77.11%) and type 2 diabetes (49.65%). There was a significant difference in NFS between fibrosis stage F0-2 and F3-4 (-0.43±1.99 and 0.30±2.28, p=0.01). The sensitivity of APRI <1, FIB-4 <1.3, NFS <-1.455 were 28%, 64%, and 73.33%, respectively. The specificity of APRI ≥2, FIB-4 ≥3.25, NFS ≥0.675 were 93.1%, 84.73%, 74.26%, respectively. The negative predictive value of all three models ranged between 72.59% and 77.72%, and the positive predictive values were consistently low (<40.38%). The area under receiver operator curves of APRI, FIB-4, and NFS were 0.52, 0.55, and 0.59, respectively. Diagnostic performance of these models appeared to be better in older (>35 year) and male population. Conclusion: Overall APRI, FIB-4, NFS were suboptimal in detecting advanced fibrosis in our NASH cohort. Newer non-invasive tests with robust diagnostic accuracy are needed.