Controlled attenuation parameter for noninvasive assessment of hepatic steatosis using Fibroscan®: validation in chronic hepatitis B.

BACKGROUND AND AIM: The controlled attenuation parameter (CAP) using transient elastography (TE) was validated in chronic hepatitis C to evaluate hepatic steatosis; however, limited data are available on chronic hepatitis B (CHB). Therefore, we assessed the accuracy and the efficacy of CAP for the detection of steatosis in CHB. METHODS: Consecutive CHB patients underwent liver biopsy and liver stiffness measurements (LSM) with simultaneous CAP determination using the M probe of the TE. The area under the receiver operating characteristics curve (AUROC) was used to evaluate the performance of CAP in diagnosing steatosis compared with biopsy. RESULTS: A total of 340 patients were included: 60 % were male, the median age was 37 years; the body mass index (BMI) was ≥ 28 kg/m(2) for 14 % of the subjects; and the distribution of the steatosis grade was S0 58.2 %, S1 34.2 %, S2 5.0 % and S3 2.6 %. The median (range) of CAP was 218 (100-400) dB/m, and CAP correlated with the BMI (ρ = 3.622) and steatosis grade (ρ = 29.203) according to a multivariate analysis (both P < 0.001). CAP could detect the different grades of steatosis: ≥ S1 with AUROC of 0.81 at a cutoff of 224 dB/m, ≥ S2 with AUROC of 0.90 at a cutoff of 236 dB/m and ≥ S3 with AUROC of 0.97 at a cutoff of 285 dB/m. Furthermore, the LSM and fibrosis and activity grades on biopsy did not influence the CAP performance. CONCLUSIONS: CAP presented excellent diagnostic performance for severe steatosis with high sensitivity and specificity in Chinese patients with CHB.

Controlled attenuation parameter for non-invasive assessment of hepatic steatosis in Chinese patients.

AIM: To evaluate the performance of a novel non-invasive controlled attenuation parameter (CAP) to assess liver steatosis. METHODS: This was a multi-center prospective cohort study. Consecutive patients (aged ≥ 18 years) who had undergone percutaneous liver biopsy and CAP measurement were recruited from three Chinese liver centers. Steatosis was categorized as S0: < 5%; S1: 5%-33%; S2: 34%-66%; or S3: ≥ 67%, according to the nonalcoholic fatty liver disease (NAFLD) activity score. The FibroScan(®) 502 equipped with the M probe (Echosens, Paris, France) was used to capture both CAP and liver stiffness measurement values simultaneously. Receiver operating characteristic curves were plotted, and the areas under the curves were calculated to determine the diagnostic efficacy. The accuracy of the CAP values at the optimal thresholds was defined by maximizing the sum of sensitivity and specificity (maximum Youden index). RESULTS: A total of 152 patients were recruited, including 52 (34.2%) patients with NAFLD and 100 (65.8%) with chronic hepatitis B (CHB) virus infection. After adjustment, the steatosis grade (OR = 37.12; 95%CI: 21.63-52.60, P < 0.001) and body mass index (BMI, OR = 6.20; 95%CI: 2.92-9.48, P < 0.001) were found independently associated with CAP by multivariate linear regression analysis. CAP was not influenced by inflammation, fibrosis or aetiology. The median CAP values and interquartile ranges among patients with S0, S1, S2 and S3 steatosis were 211 (181-240) dB/m, 270 (253-305) dB/m, 330 (302-360) dB/m, and 346 (313-363) dB/m, respectively. The cut-offs for the CAP values in all patients with steatosis ≥ 5%, ≥ 34% and ≥ 67% were 253 dB/m, 285 dB/m and 310 dB/m, respectively. The areas under the curves were 0.92, 0.92 and 0.88 for steatosis ≥ 5%, ≥ 34% and ≥ 67%, respectively. No significant differences were found in the CAP values between the NAFLD group and the CHB group in each steatosis grade. CONCLUSION: CAP appears to be a promising tool for the non-invasive detection and quantification of hepatic steatosis, but is limited by BMI.