The aim of this study was to find the correlation of LSM,
aspartate transaminase to platelet ratio index (APRI) with
fibrosis as assessed by liver biopsy (LB), and predictors of discordance between LB and LSM.
METHODS: One hundred and eighty-five consecutive patients who underwent liver biopsy and transient elastography (TE) were enrolled.
Fibrosis was graded by two independent pathologists using the METAVIR classification. Area under receiver operating curves (AUROC) was used to evaluate the accuracy of transient elastography and APRI in diagnosing significant
fibrosis (F>2) and
cirrhosis (F4).
RESULTS: Predominant etiologies were
hepatitis B (46 %) and
hepatitis C (26 %). LSM was unsuccessful in ten patients (5 %) because of small intercostal space (n = 3) and
obesity (n = 7).
Fibrosis is significantly correlated with LSM (r = 0.901, p = 0.001) and APRI (r = 0.736, p = 0.001). There was a significant difference in median LSM value in patients with no
fibrosis (F0) in comparison to patients having mild
fibrosis [mild portal
fibrosis (F1) + fibrosis with few septa (F2)] (4.5 vs. 7.5 kPa, p = 0.001) and advanced
fibrosis [bridging
fibrosis that is spreading and connecting to other areas that contain
fibrosis (F3) + cirrhosis or advanced
scarring of the liver (F4)] (4.5 vs. 19.4 kPa, p = 0.001). Similarly, there was a significant difference in mean APRI value in patients with F0 in comparison to patients having mild
fibrosis (F1 + F2) (0.55 ± 0.31 vs. 1.09 ± 0.81, p = 0.001) and advanced
fibrosis (F3 + F4) (2.3 ± 1.3, p = 0.001). AUROC for diagnosis of significant
fibrosis was 0.98 (95 % confidence interval (CI) 0.963-0.999) for TE and 0.865 (95 % CI 0.810-0.920) for APRI. Optimal TE value was 10.0 kPa for diagnosis of significant
fibrosis and 14.7 kPa for
cirrhosis with specificity and sensitivity of 89 %, 98 % and 96 %, and 97 %, respectively. On multivariate analysis, total
bilirubin and histological activity index (HAI) were identified as an independent predictor of TE inaccuracy.
CONCLUSION: LSM is a reliable predictor of hepatic
fibrosis in Indian patients. LSM is superior to APRI for noninvasive diagnosis of hepatic
fibrosis and
cirrhosis, and high
bilirubin (10.5 mg/dL) and Ishak HAI grade (>11) were independent predictors of discordance between LB and LSM.