Non-invasive assessments for the patients with NAFLD with obesity.

AIMS:In the diagnostic algorithm for NAFLD of the Japan Society of Ultrasonics in Medicine, Liver elastography is recommended in patients with intermediate risk based on FIB-4 and NAFLD fibrosis score (NFS).  However, obesity is a common reason for measurement failures of US elastography. We investigated the non-invasive assessments for patients who had difficulty in US elastography due to obesity.
METHODS: The subjects were 106 NAFLD patients with BMI >30 kg /m² who underwent liver biopsy at our hospital between 2015 and 2020 . Fibrosis markers and hepatic histopathology were evaluated retrospectively.
RESULTS: Brunt classification stage 0/1/2/3/4 were 29/28/23/13 cases, respectively.
The numbers of patients with NFS low(<-1.455)/intermediate (-1.455-0.676)/high((＞0.676) were 0/11/95, and FIB-4 low（＜1.3）/intermediate(1.3-2.67)/high(>2.67) were 73/22/11.
In 11 patients with intermediate NFS and low FIB-4, the numbers of stage 0/1/2 were 7/3/1 cases. In 11 patients with high NFS and high FIB-4, stage3/4 were 4/7 cases. In 84 patients with high NFS and low or intermediate FIB-4, stage0/1/2/3/4 were 22/25/12/19/6 cases. In this group, 29.8% had advanced fibrosis. As alternatives to elastography, APRI and type4collagen7S were evaluated. The AUROC values of APRI and type4collagen7S for diagnosis of advanced fibrosis in this group were 0.802 and 0.802.
Conclusion: In this study. NFS may be an overestimate as an indicator of liver fibrosis. In patients with high NFS and low or intermediate FIB-4, APRI and Type4collagen7S can be used to narrow down cases with advanced fibrosis.