Discussion on Hepatitis B, January 22, 1985

Discussion on Hepatitis B, January 22, 1985

The viral morphology of hepatitis B typically includes three forms: ① spherical particles; ② tubular particles; ③ Dane particles (lipoprotein envelope). This disease has four antigen-antibody systems: ① surface antigen and its antibody: HBsAg (antigen), HBsAb (antibody); ② core antigen and its antibody: HBcAg (antigen), HBcAb (antibody); ③ e antigen and its antibody: HBeAg (antigen), HBeAb (antibody); ④ δ antigen and δ antibody. Clinically, surface antigen (HBsAg) and antibody (HBsAb) are commonly used for diagnosis. The former is sometimes referred to as the Australian antigen, while the latter is called the cooperative antigen. The incubation period for hepatitis B is 3–6 months, meaning that after oral infection with the virus, it takes 96–180 days for HBsAg in the blood to become positive, followed by another 30 days or so for serum transaminase levels to rise. When symptoms and jaundice appear, surface antigen levels usually decrease and eventually disappear. This state can persist for several months or even years. Acute-phase symptoms are more severe, and patients carrying surface antigen generally have a better prognosis; conversely, those with milder acute symptoms tend to fare worse.

The antibody against hepatitis B surface antigen (HBsAb) can be detected 2–10 weeks after the onset of acute infection and can persist for several months or longer. The detection of this antibody indicates past infection with hepatitis B virus and subsequent recovery, potentially conferring immunity against reinfection. There are two main types of antibody responses: ① primary antibody response, commonly seen in symptomatic hepatitis B cases, which can only be detected shortly after the surface antigen disappears, or even weeks after the hepatitis symptoms have subsided. ② secondary antibody response, which appears earlier than the primary response, generally within 1–4 weeks after infection, with higher titers, known as the memory response. This suggests a strong resistance to the hepatitis B virus.