SIGNIFICANCE OF LOW HDV REPLICATION LEVELS DURING THE NATURAL-HISTORYOF HDV INFECTION - LONG-TERM FOLLOW-UP

The use of genetic amplification of the hepatitis delta virus (HDV) ge nome reveals the existence of different HDV replicative behaviours dur ing the natural history of chronic HDV infection. While some of the pa tients (8/19, 42%) presented high and long-term maintained levels of H DV replication, as detected by slot-blot hybridization, others showed fluctuations from positive to negative, and in 5/7 (71%) polymerase ch ain reaction (PCR) demonstrated the presence of the HDV genome. Finall y, 4 patients were persistently slot-blot-negative and in 3 of them HD V-RNA was detected by PCR in all samples tested. The correlation obser ved between the low levels of HDV replication and the ALT values, as w ell as the reactivation observed in one of the patients, suggests that PCR is useful in the virological surveillance of HDV infection, and i ndicates its usefulness in evaluating the effectiveness of antiviral t herapy for chronic hepatitis D.