The presence of HBsAg in the blood indicates that you are infected with the Hepatitis B virus (HBV). Blood levels of the virus (or more precisely of the viral DNA), enzyme DNA-polymerase and HBeAg serve to estimate the amount of viral replication. When body gets infected with HBV there are 3 possibilities:
1. THe HBV-infection can cause acute hepatitis but the body’s immune system struggles against the infection and can completely clean the virus from the body. At the beginning of the infection, all serological signs of acute viral infection are positive: HBV-DNA, DNA-polymerase, HBsAg and HBeAg. Then, the immune system starts to fight the virus, which can be confirmed by detecting antibodies against viral antigens (Anti-HBs, Anti-HBc-IgM and Anti-HBe). HBV does not damage the liver directly when the immune responds. Rather the immune system itself can damage the liver - this is evidenced with biochemical signs of liver damage such as increased transaminase-enzymes (SGPT and GOT) and increased total bilirubin. After a few months, all the signs of viral replication and liver damage disappear and only the signs of a former HBV-infection and life-long immunity remain (Anti-HBc-IgG). This happens in 90% of all cases of Hepatitis B.
2. HBV, the Hepatitus B virus can infect the liver without an immune system response. When the immune system does not fight the virus it is called tolerance. In this case, there are signs of viral presence (positive HBs-Ag, HBe-Ag, HBV-DNA and DNA-polymerase) but there are no signs of an immune response (no antibodies are detected). The HBV virus does not damage the liver, so there are no signs of liver damage present. Technically, people who experience this reaction to Hepatitis B are termed HBV-carriers. Hep B carriers do not experience the illness and liver damage, but they can transmit the virus to other people. This happens in 2% of cases.
3. In the third possibility (8% of cases), Hepatitis B can infect the liver. The immune system response may fight the virus, but not efficiently enough to wipe it out completely. So, in this case, an acute infection with Hep B is not overcome but develops into a chronic infection , or chronic hepatitis B. Chronic hepatitis is a serious condition because usually ends with cirrhosis of the liver or cancer. In cases of chronic hepatitis, serological signs of viral replication are present as well as an immune response and liver damage that last longer than 6 months. Generally there are 2 types of chronic hepatitis: chronic persistent and chronic active. The active form of chronic Hep B is characterized by a faster evolution and worse prognosis than the persistent form.
An HBV-infection can’t be transmitted via kissing. HBV, however, can be transmitted via unprotected sex and direct “blood to blood” contact.
Anti-HCV is an antibody against the Hepatitis C virus (HCV). The presence of Anti-HCV can indicate these 3 possibilities: acute infection, chronic infection or immunity after an infection has passed . Unlike HBV, however, HCV causes chronic liver inflammation in 80% of cases and only 20% result in complete recovery and immunity for life.
