1. Surface Antigen and Its Antibodies

1. Surface Antigen and Its Antibodies

Generally, the Surface Antigen can be detected in the patient's serum before the onset of hepatitis symptoms or biochemical abnormalities; in some cases, it can even be detected three months before the disease manifests. Most acute hepatitis B patients test positive for Surface Antigen at the time of onset, with the positivity rate dropping to around 25% after three months and further declining to about 6.4% after twelve months. This indicates that the Surface Antigen in acute hepatitis B is transient. If the Surface Antigen remains positive for several years, it suggests that the patient is not in the acute phase and may have progressed to chronic active hepatitis or chronic persistent hepatitis. The ratio of Surface Antigen is usually not strongly correlated with the severity of hepatitis or with the level of transaminases, so some patients may show no symptoms and have normal transaminase levels, yet still test positive for Surface Antigen for a long time, even maintaining high levels. Previously, such patients were considered healthy carriers, but recent extensive data show that most of them have varying degrees of liver damage. Therefore, whether the term "healthy carrier" is accurate still requires further discussion. In newly infected hepatitis B patients, surface antibodies are rarely detected at the same time as the Surface Antigen; if surface antibodies are detected, it indicates acute hepatitis B and suggests that the Surface Antigen will soon turn negative. In chronic active hepatitis patients, surface antibodies are usually not produced; even if detected, it does not necessarily indicate protective effects. Some reports suggest that the presence of surface antibodies at this stage may actually harm liver cells.