Effect of liver inflammation on accuracy of FibroScan device in assessing liver fibrosis stage in patients with chronic hepatitis B virus infection.

Background: Transient elastography (FibroScan) is a new and non-invasive test, which has been widely recommended by the guidelines of chronic hepatitis B virus (HBV) management for assessing hepatic fibrosis staging. However, some confounders may affect the diagnostic accuracy of the FibroScan device in fibrosis staging.

Aim: To evaluate the diagnostic value of the FibroScan device and the effect of hepatic inflammation on the accuracy of FibroScan in assessing the stage of liver fibrosis in patients with HBV infection.

Methods: The data of 416 patients with chronic HBV infection who accepted FibroScan, liver biopsy, clinical, and biological examination were collected from two hospitals retrospectively. Receiver operating characteristic (ROC) curves were used to analyze the diagnostic performance of FibroScan for assessing the stage of liver fibrosis. Any discordance in fibrosis staging by FibroScan and pathological scores was statistically analyzed. Logistic regression and ROC analyses were used to analyze the accuracy of FibroScan in assessing the stage of fibrosis in patients with different degrees of liver inflammation. A non-invasive model was constructed to predict the risk of misdiagnosis of fibrosis stage using FibroScan.

Results: In the overall cohort, the optimal diagnostic values of liver stiffness measurement (LSM) using FibroScan for significant fibrosis (≥ F2), severe fibrosis (≥ F3), and cirrhosis (F4) were 7.3 kPa [area under the curve (AUC) = 0.863], 9.7 kPa (AUC = 0.911), and 11.3 kPa (AUC = 0.918), respectively. The rate of misdiagnosis of fibrosis stage using FibroScan was 34.1% (142/416 patients). The group of patients who showed discordance between fibrosis staging using FibroScan and pathological scores had significantly higher alanine aminotransferase and aspartate aminotransferase levels, and a higher proportion of moderate to severe hepatic inflammation, compared with the group of patients who showed concordance in fibrosis staging between the two methods. Liver inflammation activity over 2 (OR = 3.53) was an independent risk factor for misdiagnosis of fibrosis stage using FibroScan. Patients with liver inflammation activity ≥ 2 showed higher LSM values using FibroScan and higher rates of misdiagnosis of fibrosis stage, whereas the diagnostic performance of FibroScan for different fibrosis stages was significantly lower than that in patients with inflammation activity < 2 (all < 0.05). A non-invasive prediction model was established to assess the risk of misdiagnosis of fibrosis stage using FibroScan, and the AUC was 0.701.

Conclusion: Liver inflammation was an independent risk factor affecting the diagnostic accuracy of FibroScan for fibrosis stage. A combination of other related non-invasive factors can predict the risk of misdiagnosis of fibrosis staging using FibroScan.