Ability of Cytokeratin-18 Fragments and FIB-4 Index to Diagnose Overall and Mild Fibrosis Nonalcoholic Steatohepatitis in Japanese Nonalcoholic Fatty Liver Disease Patients

Background: Several laboratory markers used in lieu of liver biopsy are reportedly useful in the diagnosis of nonalcoholic steatohepatitis (NASH). In the present study, we investigated the diagnostic impact of various non-invasive markers for predicting NASH.

Methods: A total of 229 nonalcoholic fatty liver disease (NAFLD) patients who underwent liver biopsy were enrolled for the study. The diagnostic ability of various markers to diagnose NASH from NAFLD was investigated.

Results: A total of 140 patients were histologically diagnosed with NASH. Of these, 104 had degree 0-2 fibrosis (F0-2), and 36 had degree 3-4 fibrosis (F3-4). Multiple logistic regression analysis identified hyaluronic acid (HA) (OR 1.014; 95% CI 1.002-1.026; p = 0.024), FIB-4 index (OR 2.097; 95% CI 1.177-3.735; p = 0.012), and cytokeratin-18 fragments (CK-18F) (OR 1.002; 95% CI 1.001-1.002; p < 0.001) as factors independently associated with the diagnosis of NASH. The areas under the receiver operating characteristic curves (AUROCs) of HA, FIB-4 index, and CK-18F for the diagnosis of NASH were 0.77, 0.76, and 0.72, respectively. In addition, FIB-4 index (OR 1.907; 95% CI 1.063-3.419; p = 0.03) and CK-18F (OR 1.002; 95% CI 1.001-1.002; p < 0.001) could differentiate between NASH and NAFL, even when NASH patients with advanced fibrosis (F3-4) were excluded. AUROCs of FIB-4 index and CK-18F for the diagnosis of NASH with mild fibrosis (F0-2) from NAFLD were 0.70 and 0.70, respectively.

Conclusions: FIB-4 index and CK-18F have good diagnostic abilities not only for NASH overall, but also for NASH with mild fibrosis.