Association of hepatitis delta virus infection and hepatocellular carcinoma, hepatic decompensation, all-cause and liver-related death in a national cohort.

Background: Hepatitis Delta Virus (HDV) infection is the most severe form of chronic hepatitis. However, studies on outcomes and causes of death in a United States-born population, with primarily horizontal transmission of HDV, are lacking. The aim of this study was to conduct a national study of patients with hepatitis D to understand the natural history and outcomes compared to patients with hepatitis B virus (HBV). infection.

Methods: In a national cohort of 4,817 HBV infected veterans tested for HDV (99.6% US-born, 3.3% HDV positive) over a 23-year period, we used multivariable models to identify the factors associated with a composite outcome of hepatocellular carcinoma (HCC), decompensation, and liver-related mortality (LRM), as well as all-cause mortality of patients with HDV compared to HBV mono-infection.

Results: HDV coinfection (vs. HBV monoinfection) was associated with a significantly higher incidence of composite liver-related outcomes at both 5 (23.84 vs. 7.98, p<0.001), and 10 years (19.14 vs. 10.18, p<0.001) respectively. The most common cause of death was liver-related (33.8% for HDV vs. 24.7% for HBV), followed by non-hepatic malignancies, (15.6 vs. 14.8%),cardiac (11.7 vs. 15.2%), and lung disease (5.2 vs. 3.7%). In multivariable models, HDV was associated with an increased risk of composite liver outcomes (aHR 2.57, 95% CI 1.87-3.52, p<0.001), and all-cause mortality (aHR 1.52, 95% CI 1.20-1.93, p<0.001).

Conclusion: In a predominantly U.S born cohort of Veterans, HDV co-infection was associated with an increased risk of liver-related outcomes and all-cause mortality. Our findings support widespread testing for early identification of HDV.