Hepatitis B as an immune complex disease.

Evidence has accumulated which indicates that several of the extrahepatic syndromes associated with HBV infection--the prodromal arthritis-dermatitis syndrome, systemic necrotizing vasculitis, and glomerulonephritis--result from immune complex-mediated injury; however, our understanding of their pathogenesis remains incomplete. Other disorders--essential mixed cryoglobulinemia and polymyalgia rheumatica--have also been linked to HBV, but these associations are more controversial. In most patients with HBV infection, circulating immune complexes are of no pathogenetic importance, but may reflect normal mechanisms for immune clearance of viral antigens. Little insight has been gained into the factors which predispose to immune complex-mediated tissue injury in only a small proportion of patients with type B hepatitis, and few options are available for the management of patients with these extrahepatic disorders. Finally, circulating immune complexes do not appear to contribute to the pathogenesis of liver disease associated with HBV infection.