Significant liver disease has been reported in chronic hepatitis B patients
with normal alanine aminotransferase (ALT). Liver biopsy (LB) is the
current gold standard for assessing hepatic inflammation and fibrosis in
patients with chronic HBV. However, associated risks have led to the
development of noninvasive models. Their utility in patients with normal
ALT is unknown. FIB-4 and aspartate aminotransferase (AST)-to-platelet
ratio index (APRI) were calculated for patients with chronic HBV infection
undergoing biopsy. The performance of each model and AUROC for predicting
significant fibrosis (Scheuer's score ≥ S2) were determined for the
entire cohort and stratified by elevated (≥50 U/L) and normal ALT.
Two-hundred and thirty-one liver biopsies were included. The number of
patient with normal ALT was 140, and 22.1% had significant fibrosis. The
AUROC curve for patients with normal ALT was 0.81 for FIB-4 and 0.80 for
APRI, compared with 0.71 for FIB-4 and 0.72 for APRI for those with mildly
elevated ALT level. The sensitivity, specificity, positive predictive value
(PPV) and negative predictive value (NPV) of FIB-4 were 0.63, 0.88, 0.61
and 0.93, for patients with normal ALT; the values for APRI were 0.40,
0.88, 0.33 and 0.93. Both FIB-4 and APRI are useful for identification of
those without significant fibrosis. However, because they have poor PPV, LB
will continue to be used for assessment of HBV-infected patients with
normal ALT and mildly elevated ALT.