Comparison of the liver stiffness measurement by transient elastography with the liver biopsy

AIM: To compare the liver stiffness (LS) measurement by transient elastography (TE) to the liver biopsy (LB)-considered the "gold standard" in the evaluation of patients with chronic hepatitis C. METHODS: During a period of 12 mo, we evaluated 199 consecutive patients with chronic hepatitis due to hepatitis C virus (HCV), in which LB and LS assessments (by means of TE) were performed during the same session. RESULTS: Out of 199 patients, a valid measurement of the LS could not be obtained in 8. The mean value of LS in the cohort of 191 valid measurements was 8.45 4.96 kPa, ranging from 2.3 to 38 kPa. The mean value of LS in patients with significant fibrosis at biopsy (161 patients with F ≥ 2 according to Metavir) was 9.02±5.15 kPa, significantly higher than in patients with no or mild fibrosis (30 patients with F < 2 Metavir): 5.39 ± 1.81 kPa (P < 0.0001). For a cut-off value of 6.8 kPa, the LS had a PPV of 98%, a NPV of 30.1%, a sensitivity of 59.6% and a specificity of 93.3% for the presence of significant fibrosis (at least F2 Metavir), with a diagnostic performance of 77.3% (AUROC 0.773). Using this cut-off value, we reached the best discrimination between absence of fibrosis/ mild fibrosis (F < 2 Metavir) and the presence of moderate to severe fibrosis (F ≥ 2 Metavir). CONCLUSION: In patients with chronic hepatitis due to HCV, a cut-off value of 6.8 kPa measured by TE can differentiate between significant fibrosis and absent or mild fibrosis, with a PPV of 98%, a NPV of 30.1%, a sensitivity of 59.6%, a specificity of 93.3%, and a diagnostic performance of 77.3%.