[Hepatitis B virus, extrahepatic immunologic manifestations and risk of viral reactivation].

Hepatitis B virus (HBV) infection is frequent with about 400 million individuals infected worldwide. Extrahepatic manifestations may be observed in up to 20% of patients infected with HBV, in both acute and chronic infections. The best-described manifestations are polyarteritis nodosa and glomerulonephritis. Besides manifestations related to HBV, patients presenting with primary autoimmune disorders and infected with HBV may exhibit reactivation of hepatitis B during immunosuppressive therapy that may be life-threatening. This article focuses on autoimmune manifestations related to HBV and its treatment, and on the risk of reactivation of HBV hepatitis in patients with primary autoimmune disorders treated with immunosuppressive agents.