Reactivation of overt and occult hepatitis B infection in various immunosuppressive settings.

The aim of the study was to evaluate clinical and virological differences in HBV reactivation between patients with overt and occult HBV infection. Twenty-three consecutive patients with symptomatic HBV reactivation occurring during or after immunosuppressive therapy were enrolled in a retrospective study: 10 with reactivation of overt HBV infection (overt group) and 13 of occult HBV infection (occult group). Twenty-one patients were treated with nucleot(s)ide analogues after HBV reactivation. Regimens including rituximab or fludarabine were administered more frequently in the occult group (61% vs. 31%, respectively). HBV reactivation was severe frequently in the overt (40%) and occult groups (38.4%). Patients in the overt group showed higher HBV-DNA titers (1.1 × 10(8) ± 1.4 × 10(8) vs. 5.1 × 10(5) ± 6.8 × 10(5) IU; P < 0.005). Seven patients died during HBV reactivation, two in the overt and five in the occult group. Of these seven patients, two remained untreated and five had been treated with Lamivudine; of the 16 patients showing remission of HBV reactivation, four had been treated with Lamivudine, four with Entecavir, two with Telbivudine, and six with Lamivudine plus Adefovir. It is concluded that HBV reactivation is life-threatening in patients with diseases inhibiting the immune response and/or receiving immunosuppressive drugs. Supportive therapy without antiviral drugs or Lamivudine monotherapy may not be effective for treating patients with HBV reactivation.