Hepatitis B surface antigen (HBsAg) – fibrinogen interaction

Abstract

Deparaffinized sections of hepatitis B surface antigen (HBsAg) positive liver biopsies, when incubated in a human fibrinogen solution, reveal a strong labeling of ground-glass hepatocytes with fibrinogen. This implies an interaction between HBsAg and fibrinogen. The binding of fibrinogen to HBsAg is thought to be mediated by the protein moiety of HBsAg since its binding capacity is destroyed by trypsin digestion, and to occur through formation of disulfide bridges because the binding can be disrupted by the reducing effect of 2-mercapto-ethanol. Not all ground-glass hepatocytes exhibit fibrinogen binding. The reason for this is at present unclear. No relationship between serum HBsAg [hepatitis B e antigen] positivity and binding of HBsAg to fibrinogen was observed. Preincubation in a fibrinogen solution did not alter the immunoreactivity of HBsAg. Evidently, there is a striking analogy between the interaction of HBsAg with polymerized human serum albumin and its interaction with fibrinogen.