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 cutoff 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%.