HEPATITIS

What Is Hepatitis? The liver is a major organ in the body and performs many important functions. For instance, it plays a major role in the conversion of the foods that we eat into forms that the body can use, such as a multitude of specific proteins, glucose and various lipids (fatty substances). It also plays an important role as a filter. The liver detoxifies potentially harmful substances (such as drugs), plays a key role in disposing of alcohol (ethanol) and excretes many compounds into the bile, so that they can be eliminated in the feces. Hepatitis is a condition in which there is inflammation of the liver, due to one of many causes (see below). Inflammation can lead to injury to liver cells and even their death. Any injury to the liver can result in a decrease in its ability to perform the functions mentioned above, and also many other functions not mentioned above. One result of these various impairments of liver function is that an individual with hepatitis often feels quite sick and lethargic. Hence the old saying "Is life worth living? It depends on the liver."

What Causes Hepatitis? Most cases are due to viruses which cause viral hepatitis. There are six main hepatitis viruses involved; hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), hepatitis E virus (HEV) and hepatitis G virus (HGV). HAV and HEV are transmitted through the fecal-oral route. This means that eating or drinking contaminated food or water may result in hepatitis. HBV and HDV are both transmitted through any exchange of body fluids (e.g. blood, semen, saliva), for example by unprotected sexual intercourse, use of contaminated needles and blood transfusions. HDV does not occur on its own, since it needs the presence of HBV for its survival. Transmission from mother to child is also another significant mode of transmission in the case of HBV. HCV causes at least 80% of hepatitis resulting from blood transfusions. Sexual transmission and vertical transmission from mother to infant can occur, but in contrast to HBV, are relatively rare. HGV makes up 10% of cases that are not explained by HAV through HEV and is transmitted by blood. It is not as well characterized as the other hepatitis viruses and little is currently known about it. There are many other less common causes of hepatitis, some caused by other viruses and other not due to viruses; these include mononucleosis, yellow fever, the herpes simplex virus, long term alcohol or drug use, certain drugs or an overactive immune system.

What Are The Signs And Symptoms Of Hepatitis? There are two forms of hepatitis, acute and chronic. Each of these forms can produce different signs and symptoms. Acute hepatitis is mainly viral-related and is caused by any of the hepatitis viruses (A,B,C,D,E,G). Symptoms usually come on suddenly and usually last only a few weeks. Some of the signs and symptoms include flu-like symptoms (loss of appetite, malaise, nausea, vomiting, and often fever) in the first 3 to 10 days. In the case of HBV infection, one may experience hives and joint pain. After the first week, the urine may darken and there may be signs of jaundice (yellow discoloration of the skin and whites of the eyes). After this, the flu-like symptoms may improve; however, the jaundice will usually stay until the 2nd to 4th week and slowly fade as the recovery period begins. Rarely, acute hepatitis can be fatal. Major causes of chronic hepatitis include HBV and HCV. The other hepatitis viruses are not known to cause chronic hepatitis. Non-viral causes include drugs such as isoniazid, methyldopa, nitrofurantoin, and acetaminophen. Many cases of chronic hepatitis have causes which are not well understood; these are commonly referred to as "idiopathic" hepatitis (idiopathic = of unknown cause). There are indications that at least some of these cases may be related to an autoimmune reaction in the liver, in which the body's immune system attacks its own liver cells. One-third of those who have chronic hepatitis develop signs and symptoms similar to acute hepatitis. However, the remaining two-thirds (especially those due to HCV) often have no signs or symptoms. Thus it can be very difficult to recognize chronic hepatitis before significant liver damage occurs.

With What Can Hepatitis Be Confused? Hepatitis can be confused with influenza, due to the development of flu-like symptoms, making it difficult to distinguish between these two conditions. Other conditions with which hepatitis can be confused are the presence of one or more tumours in the liver, obstruction of the common bile duct, (often due to the presence of a gall stone in it) and a variety of diseases that cause jaundice.

How Is Hepatitis Diagnosed? Viral hepatitis is diagnosed through special blood tests. Hepatitis A, C and G are diagnosed by blood tests that detect specific antibodies, proteins produced by the immune system in an attempt to destroy the individual hepatitis viruses. HBV is diagnosed by identifying a component at the surface of the virus known as HBV surface antigen. HDV cannot be diagnosed without the diagnosis of HBV, since HDV requires the presence of hepatitis B. Other blood tests often performed are measurements of bilirubin (the yellow pigment that causes jaundice) and of specific enzymes that can indicate the degree of liver injury.

What Is The Likely Outcome Of Hepatitis? Most cases of acute viral hepatitis resolve after four to eight weeks. Hepatitis A is the most likely to resolve, except for rare cases which are fatal. Chronic hepatitis, most likely caused by HCV, can lead to cirrhosis (fibrosis) of the liver in 20% of cases. This may take decades before any signs appear. Liver cancer is a risk, especially if cirrhosis caused by HCV has occurred; tumours rarely develop in cases where there is no cirrhosis. However, chronic hepatitis caused by HBV can result in liver cancer, even without the development of cirrhosis.

What Can You Do To Prevent Hepatitis? Although hepatitis is a serious and potentially fatal disease, it is preventable. Taking precautions to avoid contaminated food and water can prevent the transmission of HAV and HEV. Avoiding unprotected sex, avoiding sharing needles and screening donated blood can decrease the risk for transmitting HBV, HCV, HDV, and HGV. There are currently vaccinations for HAV and HBV which are safe and effective. There is currently no vaccine for HCV or any of the other hepatitis viruses. The use of vaccines is known as active protection, as the vaccinated individual produces the antibodies to the vaccine. In some cases, where contact with a hepatitis virus (e.g. HAV or HBV) is known to have occurred, injections of immune globulin obtained from other individuals can offer protection. This is known as passive protection, as the antibodies are not made by the affected individual, but are supplied from a donor and administered by injection. For further information about vaccination and use of immune globulin, consult your physician.

How Is Hepatitis Treated? In the case of acute viral hepatitis, there is no special treatment. However, it is recommended that you see a physician if you experience any of the sign and symptoms related to hepatitis, in order to rule out other causes and also to determine if there are any complications. It is not required to stay in bed or to make changes in diet, such as taking vitamin supplements. What is recommended is to eat what you can tolerate and stay comfortable. For many patients, appetite usually returns after the first few days with the resolution of jaundice after the 2nd to 4th week. Corticosteroids, such as prednisone, are not recommended in acute cases. In chronic hepatitis, treatment involves stopping all drugs which may have caused the hepatitis. If autoimmune hepatitis is suspected, drugs which decrease the inflammatory reaction, such as corticosteroids, are generally prescribed. In chronic viral hepatitis, corticosteroids are not used since they allow for enhanced reproduction of the virus. Interferon, a drug that suppresses viral reproduction, is used in cases of HBV and HCV. Other drug treatments (e.g Rebetron [ribavarin] and a modified form of interferon [PEG-interferon], which has a longer duration of action than interferon) are currently being studied. The last option is a liver transplant in end-stage liver disease. It has been observed that liver transplants have generally better outcomes when liver disease is due to the hepatitis C virus, as compared with the hepatitis B virus.