Extrahepatic Manifestations of Chronic Hepatitis B Infection

Abstract

Hepatitis B virus (HBV) is responsible for over 350 million chronic carriers, 50% of whom will die prematurely from cirrhosis and hepatocellular carcinoma associated with T cell-mediated cytopathic immune clearance of the virus occurring over lifetime. Around 20% of acute and chronic HBV carriers are experiencing a great range of extrahepatic manifestations related to complex immunological mechanisms. Extrahepatic manifestations are due to circulating immune complexes or possibly local inflammation triggered by viral antigens and activating the complement cascade. Their mechanism and severity are unrelated to progression of liver disease. The exact viral trigger antigens remain elusive and the most likely candidates could be hepatitis B e antigen. The spectrum of the lesion includes acute infection serum sickness, vasculitis including, polyarteritis nodosa and the most affected organs are skin, large joints, muscles, and kidneys. Prompt awareness of these extrahepatic manifestations is now of paramount importance, since well-tolerated nucleoside analogues devoid of resistance are capable of inhibiting HBV replication and have proven not only lifesaving but remarkably also curative, like for PAN, turning as the most prophetic illustration of HBV cure.