Predictive value of cytokeratin-18 fragment levels for diagnosing steatohepatitis in patients with nonalcoholic fatty liver disease

Abstract

Objective: Several noninvasive markers have been developed to predict nonalcoholic steatohepatitis (NASH). We investigated the predictive value of the cytokeratin-18 fragment (CK18-F) level and FIB-4 index for diagnosing NASH in patients with nonalcoholic fatty liver disease (NAFLD).

Methods: A total of 246 patients histologically diagnosed with NASH (n = 185) or nonalcoholic fatty liver (n = 61) were enrolled. We analyzed weighted receiver operating characteristic (ROC) curves for the prediction of NASH and determined the relationship between the CK18-F level and the histological features of NASH. In addition, we investigated the predictive value of the combination of the CK18-F level and FIB-4 index for diagnosing NASH.

Results: The area under the ROC curve (AUROC) value of the CK18-F level was 0.77. With a CK18-F cutoff level of 260 U/L, the sensitivity and specificity for diagnosing NASH were 82.7 and 57.4%, respectively. Multiple comparisons showed that the CK18-F level did not differ among fibrosis stages but did significantly differ among hepatocyte ballooning grades. Overall, 95.7% (66/69) of patients with a FIB-4 index of ≥2.67 had NASH. In patients with a FIB-4 index of <2.67, the AUROC value of the CK18-F level for predicting NASH was 0.77 and a CK18-F cutoff level of 260 U/L resulted in a sensitivity and specificity of 82.4 and 56.9%.

Conclusions: The CK18-F level had a good predictive ability for diagnosing NASH in patients with NAFLD. Additionally, the combination of the CK18-F level and FIB-4 index accurately and noninvasively predicted NASH, even those with a low FIB-4 index.