δ‐Infection and suppression of hepatitis B virus replication in chronic HBsAg carriers

The presence of hepatitis B virus DNA and anti‐δ was examined in a longitudinal study of 24 patients known to be δ‐infected during the course from acute to chronic hepatitis B virus infection. Fifteen patients (63%) were hepatitis B virus DNA positive in the first serum sample. Eleven of 14 patients, who cleared hepatitis B virus DNA, did so following or at the same time as onset of δ‐infection. Duration of hepatitis B virus DNA positivity in these 11 patients was shorter than in 11 anti‐δ‐negative controls matched according to duration of preceding hepatitis B virus DNA positivity, but the difference was not statistically significant. Considering only patients positive for IgM anti‐δ in the last serum sample (eight patients), a statistically significant shorter duration of hepatitis B virus DNA positivity was found in δ‐infected patients than in the controls (p < 0.02). The study indicates that the δ‐agent may have the capacity to inhibit hepatitis B virus replication and that a chronic δ‐infection may lead to a termination of the period of active viral replication.