Biopsy rate and nonalcoholic steatohepatitis (NASH) in patients with nonalcoholic fatty liver disease (NAFLD)

Background:Licensed therapies for nonalcoholic fatty liver disease (NAFLD) do not yet exist, but clinical trials are testing treatment options. Inclusion criteria often require liver biopsy showing fibrosis (F2/3) or cirrhosis (F4) and nonalcoholic steatohepatitis (NASH). However, histological criteria pose a serious obstacle for recruitment. Aims:Characterize the relevance of liver biopsies in the selection of patients with NAFLD. Methods:Patients between 2013 and 2018 with the ICD-10 code K76.0 were analyzed. Fibrosis was defined by the NASH clinical research network (CRN) fibrosis staging system, NASH by a NAFLD activity score (NAS) >= 4. Predictive factors were determined by logistic regression. Results:Liver biopsy was performed in 87/638 (13.6%) patients (49% female, age 52.5 +/- 14.0, BMI 30.4 +/- 5.9 kg/m(2)). Fibrosis stage F0/F1/F2/F3/F4 was observed inN = 7/47/7/17/9, an NAS >= 4 inN = 27. Fibrosis stage F2/F3 and F4 along with NAS >= 4 was found in 1.7% and 0.5% of cases. Liver stiffness measurement, LSM (OR 2.3 per doubling of value; CI 1.3-4.4,p = .005) and FIB-4 (OR 2.3 per doubling of value; CI 1.2-4.4,p = .012) were significant predictors for fibrosis >= F2. Predictive factors for NASH were not identified. Conclusion:The biopsy rate in NAFLD patients is low and fibrosis >= F2 along with NAS >= 4 only present in a few cases. Transient elastography and FIB-4 are useful to select patients at risk for fibrosis for liver biopsy.