Hepatitis B and C are two viruses that cause liver disease. Hepatitis B is a member of the Hepadnavirus family and is one of the smallest enveloped animal viruses. A third of the world’s population has been infected with the Hepatitis B virus at some point in their lives, and over 350 million people still carry the virus. Hepatitis B leads to liver cirrhosis if untreated.
It is often contracted through infectious blood or body fluids containing blood through sexual intercourse, blood transfusions, re-use of contaminated needles, or mother-child transmission during pregnancy. Similarly, Hepatitis C is a member of the Flaviviridae family. It is contracted through blood transmission often seen in re-use of contaminated needles of intravenous drug use. Hepatitis C virus affects approximately 3% of the world’s population.
When a person contracts Hepatitis B or C, clearance of the virus depends on whether there was a sufficiently strong immune response. The two immune cells most important for viral clearance are T helper cells and cytotoxic T cells. The T helper cells signal the rest of the immune system, for instance macrophages and cytotoxic T cells, to begin phagocytizing and destroying virus-infected cells, respectively. The cytotoxic T cells scan liver cells for any signs of infection by hepatitis B or C virions. If the T cell catches an infected liver cell, it signals a cascade that leads to the death of the liver cell. Thymic Protein A is known to assist the body in developing these key T cells and resisting viral infections by strenthening the immune response.
Hepatitis B and Hepatitis C are treated differently. Hepatitis C is currently treated with interferon, ribavirin, protease inhibitors or other anti-viral drugs. In contrast, Hepatitis B is not usually treated because it often resolves spontaneously. However, the virus has been contained by widespread-use of the Hepatitis B vaccine.