Types of Hepatitis
Hepatitis is a term used to describe inflammation of the liver that can be caused by viruses, alcohol, or some medications. In the U.S., the three most common viruses that cause hepatitis are hepatitis A virus, hepatitis B virus, and hepatitis C virus.
Hepatitis A virus usually causes a self-limited acute hepatitis that does not result in chronic liver injury. It is usually transmitted by consuming contaminated food and water or by direct contact with an infected person. Good hygiene and proper sanitation as well as vaccination can help to prevent hepatitis A virus.
Unlike hepatitis A virus, hepatitis B virus can cause both acute and long-term or chronic infection which may lead to chronic liver inflammation and progressive scarring or fibrosis in the liver. Hepatitis B virus can be transmitted through blood, unprotected sex, unsterile or contaminated needles, and from an infected woman to her newborn child during childbirth. In parts of the world with a high rate of chronic hepatitis B infection such as Southeast Asia and sub-Saharan Africa, this virus virus is the primary cause of liver cancer, now among the top leading cause of cancer deaths worldwide. The best way to prevent hepatitis B is by vaccination. However, if you contract hepatitis B virus, several effective medications are now available that can stop the virus from replicating and causing liver damage
Hepatitis C virus almost always results in chronic infection and therefore can result in longstanding inflammation and scarring in the liver. Hepatitis C is commonly transmitted through infected blood, and contaminated or unsterile needles. Hepatitis C virus is the leading cause for liver transplant in the U.S. As a blood-borne virus, the best way to prevent hepatitis C is by avoiding behaviors that can cause its spread, such as injection drug use. There is no vaccine for hepatitis C virus, but there several highly effective treatments are now available.
Stages of Fibrosis
The liver is an important organ of your body that clears toxins and helps you digest food and nutrients. The hepatitis B virus lives in your liver and can cause damage resulting in acute or chronic inflammation. Scarring develops in the liver as part of the wound healing process. As the liver becomes more damaged, this scarring, or fibrosis, increases and is categorized into five different stages. A Stage F0 describes a liver that has no scarring. In stage F1, there is mild scarring starting around the edges of the liver lobule, which is the smallest working unit of the liver. In stage F2, we see that scarring has progressed and extends beyond the edges of the lobule, indicating significant fibrosis. At stage F3, the fibrosis has advanced to where bridges of scarring extend from one lobule to the next.
This stage, also called “bridging fibrosis” eventually leads to stage F4 fibrosis or cirrhosis where extensive scarring throughout the liver results in the liver taking on a hardened “nodular” appearance rather than the smooth appearance of a liver without cirrhosis. Once cirrhosis or F4 has developed, many changes can develop in the blood circulation into and around the liver, resulting in an increased risk of serious complications such as bleeding from varices (enlarged veins) in the esophagus, ascites (accumulation of fluid in the abdominal cavity) or hepatic encephalopathy (altered mental status due to the buildup of ammonia in the brain due to shunting of blood away from the liver). Patients with cirrhosis are also at increased risk of liver cancer.
The goal of treatment in chronic hepatitis B and C is to stop the virus from multiplying, stop liver damage and inflammation and stop or reverse the scarring that leads to F4 fibrosis or cirrhosis.