Acoustic radiation force impulse elastography and liver fibrosis risk scores in severe obesity

ABSTRACT Objective: Identifying significant fibrosis is crucial to evaluate the prognosis and therapeutic interventions in patients with nonalcoholic fatty liver disease (NAFLD). We assessed the performance of acoustic radiation force impulse (ARFI) elastography, APRI, FIB-4, Forns, NFS and BARD scores in determining liver fibrosis in severe obesity. Subjects and methods: A prospective study included 108 patients undergoing bariatric surgery. Liver biopsy specimens were obtained intraoperatively and classified according to the NAFLD Activity Score. Patients were assessed with serological markers and shear wave velocity of the liver was measured with the Siemens S2000 ultrasound system preoperatively. Optimal cut-off values were determined using the area under the receiver operating characteristic curves (AUROC). Results: In the entire cohort prevalence of NAFLD was 80.6%, steatohepatitis 25.9% and significant fibrosis 19.4%. The best tests for predicting significant fibrosis were FIB-4 and Forns scores (both AUROC 0.78), followed by APRI (AUROC 0.74), NFS (AUROC 0.68), BARD (AUROC 0.64) and ARFI (AUROC 0.62). ARFI elastography was successful in 73% of the patients. Higher body mass index (BMI) correlated with invalid ARFI measurements. In patients with BMI < 42 kg/m2, ARFI showed 92.3% sensitivity and 82,6% specificity for the presence of significant fibrosis, with AUROC 0.86 and cut-off 1.32 m/s. Conclusions: FIB-4 and Forns scores were the most accurate for the prediction of significant fibrosis in bariatric patients. Applicability and accuracy of ARFI was limited in individuals with severe obesity. In patients with BMI < 42 kg/m2, ARFI elastography was capable for predicting significant fibrosis with relevant accuracy.

Aspartate aminotransferase-to-platelet ratio index for fibrosis and cirrhosis prediction in chronic hepatitis C patients

In chronic hepatitis C (CHC), liver biopsy is the gold standard method for assessing liver histology, however it is invasive and can have complications. Non-invasive markers have been proposed and aspartate aminotransferase (AST)-to-platelet ratio index (APRI) has been shown as an easy and inexpensive marker of liver fibrosis. This study evaluated the diagnostic performance of APRI for significant fibrosis and cirrhosis prediction in CHC patients. This study included treatment-naive CHC patients who had undergone liver biopsy from January 2000 to August 2006. All histological slides were reviewed according to the METAVIR system. APRI was calculated based on laboratory results performed within four months from the biopsy. Twenty-eight (56 percent) patients had significant fibrosis (F2-F4) and 13 (26 percent) had cirrhosis (F4). The area under ROC curves of APRI for predicting significant fibrosis and cirrhosis were 0.92 (0.83-1.00) and 0.92 (0.85-1.00), respectively. Using cut-off values recommended by prior studies, significant fibrosis could be identified, in accordance with liver biopsy, in 44 percent and cirrhosis in 66 percent of patients. APRI could identify significant fibrosis and cirrhosis at a high degree of accuracy in studied patients.