Overview
HDV is an RNA virus that infects only in the presence of HBV, affecting about 13% of HBsAg carriers. In Italy, prevalence ranges from 3.2% to 9.3%. It increases the risk of cirrhosis, fulminant hepatitis, and HCC, particularly in high-risk groups (HIV, HCV, drug users, dialysis patients). Until 2020, pegIFN was the only therapy; since 2022, bulevirtide (BLV) has been available, blocking viral entry into hepatocytes and reducing HDV RNA and liver stiffness, with efficacy in 45-48% of patients, though the optimal treatment duration remains uncertain. The gut microbiota and bile acids also play a role in fibrosis and cirrhosis progression: dysbiosis, typical in cirrhotic patients, alters bile acid metabolism and increases intrahepatic toxicity.
Eligibility
Inclusion Criteria:
- Patients with chronic HDV-related hepatitis or compensated liver cirrhosis (Child-Pugh class A)
- Positive HDV RNA within the 24 weeks prior to enrollment
- Ongoing antiviral therapy for HBV at the time of enrollment
- First prescription of Bulevirtide 2 mg issued within 30 days prior to enrollment
- Caucasian ethnicity
- Age ≥18 years
- Normocaloric omnivorous diet
- No intake of antibiotics, probiotics, or prebiotics in the month prior to enrollment
- Signed informed consent
Exclusion Criteria:
- Decompensated liver cirrhosis (Child-Pugh Score B or C)
- Patients without HBV-HDV-related infection/hepatitis/cirrhosis
- Age ≤18 years
- Pregnant or breastfeeding women
- Concomitant diseases with short life expectancy (solid or hematologic neoplasms, heart failure NYHA III/IV, COPD GOLD C-D)
- Conditions (celiac disease, chronic inflammatory bowel diseases) or use of medications (antibiotics, probiotics, prebiotics) capable of altering gut microbiota composition