To derive an optimal liver stiffness measurement cut point to discriminate METAVIR fibrosis stage F4 and to validate both METAVIR fibrosis stage F3-F4 and F4 cut points in a separate cohort.

Patients at Boston Children's Hospital with liver stiffness measurement from 2006 to 2016 and liver biopsy ≤12 months before screening were eligible. Patients enrolled 2006-2011 were used to calibrate liver stiffness measurement cut points and those enrolled 2011-2016 for validation. Diagnostic performance was assessed by receiver operating curve analysis.

In total, 267 subjects were enrolled (97 calibration, 170 validation). The cohorts were similar with 54% male, aged 0-29 years (median 13 years), and liver diseases including 21% autoimmune, 19% viral, 11% nonalcoholic fatty liver, 9% cholestatic, and 9% primary sclerosing cholangitis. Cut points to discriminate F3-F4 and F4 were >8.6 kPa and >11.5 kPa with 81% and 84% accuracy, respectively. Applied to the validation cohort, accuracy was 67% and 75%, respectively. In 44 fasted subjects, the accuracy was 73% and 80%, respectively.

This study validates previously determined liver stiffness measurement cut points of 8.6 kPa and 11.5 kPa to predict METAVIR F3-F4 and F4 fibrosis in children and young adults in separate cohorts. With increasing data on the utility and validity of liver stiffness measurement in children, transient elastography may help identify patients with greater risk of advanced fibrosis and those who need liver biopsy assessment and/or surveillance for the complications of cirrhosis in a variety of liver disorders.