Hepatitis delta in HIV-infected individuals in Europe.

BACKGROUND Hepatitis delta virus (HDV) infection results in the most aggressive form of chronic viral hepatitis. There is scarce information about the prevalence, epidemiology, virological profile and natural history of hepatitis delta in HIV patients. METHODS From 16,597 HIV patients enrolled in EuroSIDA, 1319 (7.9%) have ever reported serum hepatitis B virus (HBV) surface antigen (HBsAg)-positive. At last follow-up, 1084 (6.5%) patients were HBsAg-positive. The HDV substudy was carried out in 422 individuals for whom stored sera were available at the time they were HBsAg-positive. Anti-HDV immunoglobulin G was assessed using a commercial enzyme immunoassay (EIA) and serum HDV-RNA was quantified using a real-time PCR method. RESULTS A total of 61 of 422 HBsAg-positive carriers were anti-HDV-positive (prevalence: 14.5%). Hepatitis delta predominated in intravenous drug users and for this reason in south and/or east Europe. Serum HDV-RNA was detectable in 87% of tested anti-HDV-positive patients, with a median titer of 1.76×10(7) copies/ml. Overall, delta hepatitis patients showed lower serum HBV-DNA than the rest of HBsAg-positive carriers, although the inhibitory effect of HDV on HBV replication was not recognized in HBV genotype D patients. Whereas HDV was not associated with progression to AIDS, it significantly influenced the risk of death. CONCLUSION The prevalence of anti-HDV in chronic HBsAg-positive/HIV carriers in EuroSIDA is 14.5%. Most of these patients exhibit detectable HDV viraemia. Viral interference between HBV and HDV is manifested in all but HBV genotype D carriers in whom overt coreplication of both viruses occurs which might result in enhanced liver damage. Overall, delta hepatitis increases the risk of liver-related deaths and overall mortality in HIV patients.