Value of controlled attenuation parameter in fibrosis prediction in nonalcoholic steatohepatitis

BACKGROUND Liver stiffness measurement (LSM) tends to overestimate fibrosis stage in nonalcoholic fatty liver disease (NAFLD). Controlled attenuation parameter (CAP), provided by LSM device, has been introduced for noninvasive quantification of hepatic steatosis. AIM To determine the role of CAP values in predicting liver fibrosis stage by LSM in nonalcoholic steatohepatitis (NASH). METHODS One hundred eighty-four patients with biopsy proven NASH had LSM and CAP evaluated at baseline. Among them, 130 patients had 1-year follow up LSM and analyzed for the changes of LSM after pioglitazone or ursodeoxycholic acid (UDCA) treatment. RESULTS In Kleiner fibrosis stage F0-1, LSM values increased at higher CAP tertile (P = 0.001), and in F2, at middle and higher tertiles (P = 0.027). No difference across CAP tertiles was noticed in F3-4 (P = 0.752). Receiver operating characteristic curve for LSM cutoff in diagnosis of F >= 2 identified 8.05 kPa for lower CAP tertile, 9.35 kPa for middle, and 10.55 kPa for high tertile. When changes in proportion of significant fibrosis (F >= 2) were assessed among pioglitazone and UDCA treated patients considering CAP values, pioglitaame treated patients demonstrated decrease in proportion of high LSM. CONCLUSION In patient with NAFLD, interpretation of LSM in association with CAP scores may provide helpful information sparing unnecessary liver biopsy.