Published online Mar 21, 2018. doi: 10.3748/wjg.v24.i11.1239
Peer-review started: January 17, 2018
First decision: January 25, 2018
Revised: February 10, 2018
Accepted: March 3, 2018
Article in press: March 3, 2018
Published online: March 21, 2018
Processing time: 58 Days and 1.3 Hours
The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide. NAFLD exhibits a wide spectrum, ranging from non-alcoholic fatty liver to non-alcoholic steatohepatitis (NASH) and ensuing cirrhosis and hepatocellular carcinoma. Although the evaluation of NAFLD/NASH depends on the histological findings, there is a limitation and an alternative method is required.
Several studies have attempted to estimate histological severity in NAFLD using various serum biomarkers, but the accuracy of these techniques remains unsatisfactory.
Recently, elevated serum autotaxin (ATX) has been implicated in fibrosis progression in chronic liver disease, especially hepatitis C. So, we examine the relationship between serum ATX concentrations and clinicopathological findings in NAFLD patients.
One hundred eighty-six NAFLD patients who had undergone liver biopsy between 2008 and 2017 were retrospectively enrolled. Serum samples were collected at the time of biopsy and ATX was measured by enzyme immunoassays. Sera obtained from 160 healthy, non-obese individuals were used as controls. Histological findings were graded according to an NAFLD scoring system and correlations with serum ATX were calculated by Spearman’s test. Diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve (AUC). Cut-off values were identified by the Youden index, and the nearest clinically applicable value to the cutoff was considered the optimal threshold for clinical convenience.
Serum ATX levels were significantly higher in NAFLD patients than in controls (0.86 vs 0.76 mg/L, P < 0.001) and correlated significantly with ballooning score and fibrosis stage (r = 0.36, P < 0.001 and r = 0.45, P < 0.001, respectively). Such tendencies were stronger in female patients. There were no remarkable relationships between ATX and serum alanine aminotransferase, lipid profiles, or steatosis scores. The AUC values of ATX for predicting the presence of fibrosis (≥ F1), significant fibrosis (≥ F2), severe fibrosis (≥ F3), and cirrhosis (F4), were all more than 0.70 in respective analyses.
Serum ATX levels may at least partially reflect histological severity in NAFLD.
In order to evaluate the severity of NAFLD, it is considered that a method that can simultaneously evaluate activity and fibrosis is necessary.