Background and Aims: The presence of advanced hepatic fibrosis is the prime marker for the prediction of liver-related complications in non-alcoholic fatty liver disease (NAFLD). Blood-based non-invasive tests (NITs) have been developed to evaluate fibrosis and identify patients at risk. Current guidelines propose monitoring the progression of NAFLD using repeated NITs at 2-3-year intervals. The aim of this study was to evaluate the association of changes in NITs measured at two time points with the progression of NAFLD.

Methods. We retrospectively included NAFLD patients with NIT measurements in whom the baseline hepatic fibrosis stage had been assessed by biopsy or transient elastography (TE). Subjects underwent follow-up visits at least 1 year from baseline to evaluate the progression of NAFLD. NAFLD progression was defined as the development of end-stage liver disease or fibrosis progression according to repeat biopsy or TE. The following NITs were calculated at baseline and follow-up: Fibrosis-4 (FIB-4), NAFLD fibrosis score (NFS), aspartate aminotransferase to platelet ratio index (APRI) and dynamic aspartate-to-alanine aminotransferase ratio (dAAR).

Results: One hundred and thirty-five patients were included with a mean follow-up of 12.6 +/- 8.5 years. During follow-up, 41 patients (30%) were diagnosed with progressive NAFLD. Change in NIT scores during follow-up was significantly associated with disease progression for all NITs tested except for NFS. However, the diagnostic precision was suboptimal with area under the receiver operating characteristics 0.56-0.64 and positive predictive values of 0.28-0.36 at sensitivity fixed at 90%.

Conclusions: Change of FIB-4, NFS, APRI, and dAAR scores is only weakly associated with disease progression in NAFLD. Our findings do not support repeated measurements of these NITs for monitoring the course of NAFLD.