IDDF2024-ABS-0177 Natural history and prognosis of chronic hepatitis B patients in the indeterminate phase

<h3>Background</h3> In chronic hepatitis B patients, an indeterminate phase exists outside the typical predefined phases. Our study investigates this indeterminate phase’s natural history and prognosis, focusing on antiviral treatment outcomes. <h3>Methods</h3> We conducted a retrospective cohort study to compare the risk of transitioning to the Immune Active phase in patients with indeterminate chronic hepatitis B and the incidence of adverse liver outcomes (hepatocellular carcinoma and/or cirrhosis) between untreated patients with indeterminate chronic hepatitis B (at baseline and throughout follow-up) and those who received treatment, following standard AASLD 2018 guidance. <h3>Results</h3> Inverse probability of treatment weighting (IPTW) was utilized to balance the groups of treated and untreated patients. Following IPTW adjustment, the 5-, 10-, and 12-year risk of transitioning to Immune Active was 11.8%, 12.3%, and 13.5% among treated patients (n=294), compared to 39.2%, 43.6%, and 44.8% among untreated patients (n=334), respectively (<i>P</i>&lt;0.001) (IDDF2024-ABS-0177 Figure 1). Furthermore, the cumulative incidence of hepatocellular carcinoma and/or cirrhosis was 2.6%, 6.7%, and 6.7% among treated patients (n=294), in contrast to 10.5%, 23.9%, and 36.8% among untreated patients (n=76), respectively (<i>P</i>=0.004) (IDDF2024-ABS-0177 Figure 2).In the multivariable analysis, antiviral therapy remained an independent predictor of a reduced risk of transitioning to Immune Active (aHR 0.238, 95% CI 0.162-0.351, <i>P</i>&lt;0.001) and of reducing the risk of hepatocellular carcinoma and/or cirrhosis (aHR 0.153, 95% CI 0.054 -0.434, <i>P</i>&lt;0.001). <h3>Conclusions</h3> The phase of indeterminate chronic hepatitis B patients changes frequently, and antiviral therapy can reduce the risk of transitioning to Immune Active as well as the incidence of developing hepatocellular carcinoma and/or cirrhosis.