DETERMINATION OF HEPATITIS-DELTA VIRUS-RNA BY POLYMERASE CHAIN-REACTION IN ACUTE AND CHRONIC DELTA-INFECTION

The objective of this study was to evaluate the usefulness of hepatiti s delta virus (HDV) RNA detection by polymerase chain reaction (PCR) i n acute and chronic D hepatitis and to correlate with HDV-RNA detectio n by dot blot and hepatic delta antigen. Serum samples from 33 patient s with acute hepatitis B surface antigen (HBsAg)-positive hepatitis (1 5 with hepatitis B and D coinfection, 8 with HDV superinfection, and 1 0 with acute hepatitis B), 85 patients with chronic HBsAg-positive hep atitis (73 with chronic D hepatitis and 12 with chronic B hepatitis), and consecutive serum samples from nine patients with chronic D hepati tis treated with interferon alfa-2b were studied. HDV-RNA was detected by PCR in 93% of the patients with hepatitis B and D coinfection, in 100% of the patients with hepatitis D superinfection, and in 1 of the 10 patients with acute hepatitis B who subsequently seroconverted to t otal antibody to hepatitis delta antigen (HDAg), whereas HDV RNA was f ound by dot blot technique in 60% of the hepatitis B and D coinfection cases, in 62.5% of the patients with hepatitis D superinfection, and in none of the acute hepatitis B cases. In chronic D hepatitis, HDV-RN A tested positive by PCR assay in 97% of patients with intrahepatic HD Ag, in one patient with undetectable hepatic HDAg, and in none of the patients with chronic hepatitis B. In the treated patients, HDV-RNA wa s observed to become negative by PCR only in the three patients who ha d a persistent response to interferon. The results of this study show that HDV-RNA determination by PCR assay is a reliable tool for the dia gnosis of delta infection and a clear improvement over other methods f or the evaluation of HDV replication and response to antiviral therapy .