CLINICAL RELEVANCE OF THE DETECTION OF HEPATITIS-DELTA VIRUS-RNA IN SERUM BY RNA HYBRIDIZATION AND POLYMERASE CHAIN-REACTION

Hepatitis delta virus nucleic acid was detected by dot-blot hybridizat ion using RNA probe and reverse transcription/polymerase chain reactio n amplification in 223 serum samples from 66 patients with hepatitis D virus infection. Seven cases with chronic hepatitis D virus infection were treated with interferon: six for 3 months and one for 7.5 years. By using the primers located in the putative conserved regions, the t echnique of reverse transcription/polymerase chain reaction amplificat ion was 10(3) to 10(4) times more sensitive than that of dot-blot hybr idization. The main findings of this study are: (i) HDV RNA could be d etected in the absence of any other serological hepatitis D virus mark er in serum from acute hepatitis patients with IgM anti-HBc; (ii) high titer anti-HD antibodies (IgM and total anti-HD) persisted in patient s during short-term interferon treatment, and in one patient during lo ng-term interferon treatment, despite clearance of serum HDV RNA even after 3 years; (iii) total anti-HD alone was detected in the absence o f IgM anti-HD and serum HDV RNA. These observations indicate that the detection of HDV RNA by molecular techniques in serum is a useful, sen sitive and non-invasive technique for the early diagnosis and follow u p of hepatitis D virus infection, as well as for the monitoring of ant iviral therapy. In addition, total anti-HD antibody in the absence of HDV RNA may be the only residual marker of past infection. Finally, th e choice of the technique for hepatitis D virus detection is important for the optimal assessment of the clinical stage and monitoring of an tiviral therapy in hepatitis D virus-infected patients. (C) Journal of Hepatology.