The Optimal Cutoffs of Liver Stiffness Measurement for Staging Fibrosis in On-treatment Patients With Chronic Hepatitis B.

Background & aims: Liver stiffness measurement (LSM) cutoffs for diagnosis of liver fibrosis in untreated patients with chronic hepatitis B (CHB) have been well-established. However, the applicability and the optimal LSM cutoffs for patients undergoing antiviral therapy remain unclear.

Methods: Adults with CHB who had LSM and liver biopsy on the same day during antiviral therapy were enrolled from 2 clinical studies and their extension observations (NCT01938820, NCT01943617, NCT01938781, and NCT03777969). Liver fibrosis was evaluated according to the METAVIR and Ishak scoring system. The performance of LSM measured by vibration-controlled transient elastography (VCTE) devices was estimated using the area under the receiver operating characteristic curve (AUROC).

Results: A total of 754 patients were enrolled and randomly divided into derivation and validation sets in a ratio of 2:1. Among them, 75.9% of patients (572/754) were male, with a median age of 42.1 years (interquartile range [IQR], 34.0-49.0 years). The median treatment duration was 1.5 years (IQR, 1.0-2.5 years). The cutoffs of LSM for diagnosis of ≥F2, ≥F3, and F4 during antiviral treatment were 7.6 kPa, 7.6 kPa, and 9.0 kPa, respectively, with a sensitivity of 57.5%, 79.2%, and 74.4%, and a specificity of 86.1%, 73.0%, and 77.2%. The area under the receiver operating characteristic curve (AUROC) for diagnosing ≥F2, ≥F3, and F4 were 0.753 (95% confidence interval [CI], 0.712-0.790), 0.818 (95% CI, 0.778-0.848), and 0.815 (95% CI, 0.755-0.846), respectively.

Conclusion: The optimal cutoffs for diagnosing ≥F2/F3 and F4 in on-treatment patients with CHB were 7.6 kPa and 9.0 kPa. These cut-offs could be reliably and repeatedly applied for long-term monitoring of patients with CHB under antiviral therapy.