Controlled attenuation parameter for non-invasive assessment of hepatic steatosis: does etiology affect performance?

Hepatic steatosis is an important parameter to assess in chronic liver disease patients. The controlled attenuation parameter (CAP) assesses liver steatosis using transient elastography.

To determine the accuracy of CAP for evaluation of hepatic steatosis in chronic hepatitis B virus (CHBV)-infected, chronic hepatitis C virus (CHCV)-infected, and non-alcoholic fatty liver disease (NAFLD) patients and to determine the influence of etiology on the diagnostic accuracy of CAP.

One hundred forty-six CHBV patients, 108 CHCV-infected patients and 63 patients with NAFLD, who underwent both liver biopsy and successful CAP measurements within the study period, were assessed. Area under the receiver operating characteristics was used to evaluate performance of CAP for diagnosing steatosis compared with biopsy.

Multivariate analysis found that CAP correlated with body mass index (odds ratio, 95% confidence interval = 4.09 [1.2-6.8] for CHBV; 4.7 [1.1-8.4] for CHCV, and 16.2 [9.1-24.5] for NAFLD patients respectively) and hepatic steatosis score on biopsy (odds ratio, 95% confidence interval = 30.7 [19.2-42.2] for CHBV; 24.2 [11.5-37.3] for CHCV, and 21.8 [10.1-45.0] for NAFLD patients respectively). Area under the receiver operating characteristics for CAP was 0.683 (0.601-0.757) for steatosis (S) ≥ 6%, 0.793 (0.718-0.856) for S > 33%, and 0.841 (0.771-0.896) for S > 66% respectively for CHBV-infected patients. There was no difference in accuracy of CAP for assessing liver fat among CHBV, CHCV, and NAFLD patients.

CAP is a novel, non-invasive tool that can detect and quantify steatosis accurately among CHBV, CHCV, and NAFLD patients, the accuracy being similar for all the three groups of patients.