[A rare etiology for HBs-Ag negative acute hepatitis B--coinfection by hepatitis B and delta].

An unusual case of a 25-year-old male Italian is reported. The patient endured an acute hepatitis without detectable HBs-antigen by coinfection with hepatitis-B and Delta. Coincidently, a cured hepatitis-C was present. Firstly hepatitis-B-virus DNA could be demonstrated in a small quantity by serodiagnosis (6 pg/ml, hybridization technique). Subsequently, the identification of B-virus DNA was only possible in liver tissue (PCR-technique), but no longer by serodiagnosis. The probable enduring inhibition of hepatitis-B-virus replication by Delta virus resulted in a self limitation of the disease within 2 months (HDV-RNA negative, HBs-Ag and HBe-Ag negative; Anti-HBs negative, Anti-HBe and Anti-HBc positive). In spite of negativation of replication markers for hepatitis-B a subsequent reactivation of the infection was possible by viral material which persisted in liver tissue.