What are hepatitis B and C?
Both hepatitis B and C are viruses that lead to a chronic infection of the liver. They may result in cirrhosis of the liver and increased risk of primary hepatocellular carcinoma (liver cancer).
The hepatitis B virus causes a serious form of hepatitis that is spread through contact with infected blood. About 1.2 million people in the United States are infected. Hepatitis B may develop into a chronic form of the disease, with an increased risk for the development of cirrhosis and hepatocellular carcinoma.
Hepatitis C is the most serious form of hepatitis and affects 4 million people in the United States, with 30,00 new cases every year. The majority of people infected with hepatitis C develop chronic infections. If left untreated, hepatitis C may develop into cirrhosis, liver failure and hepatocellular carcinoma.
What determines whether hepatitis B and C will become a chronic disease?
Whether hepatitis B becomes chronic depends to a great extent on the patient’s age and immunological status at the time of infection. Newborns infected with hepatitis B have a chronicity rate of almost 100 percent. In young children, the rate decreases to about 70 percent. A healthy young adult would have a chronicity rate of less than 10 percent, unless he or she is taking steroids or has a chronic illness such as renal disease. These patients would be less likely to clear the infection.
The chronicity rate for hepatitis C is up to 75 to 85 percent. It does not clear spontaneously after chronic infection develops.
How are hepatitis B and C transmitted?
Both viruses are transmitted by contact with blood and other body fluids through sexual relations, injection drug use, sharing personal care items (tooth brush, razor, nail file or nail clipper) or direct contact with blood or body fluids of an infected person. Body piercing, using improperly sterilized equipment or tattooing with potentially contaminated needles or ink are also possible routes of transmission. Pregnant women can pass the virus to their babies.
What are the symptoms of hepatitis B and C?
Most people with hepatitis B or C have no visible signs or symptoms. Others experience anorexia, nausea, vomiting, severe fatigue, abdominal pain, mild fever, easy bruising or prolonged bleeding. Jaundice, dark urine and light stools are less common symptoms. More severe signs and symptoms of chronic liver disease or carcinoma may surface after many years of infection.
How are hepatitis B and C diagnosed?
Both viruses are diagnosed by blood tests. Eight separate assays can determine the stage of hepatitis B. Fortunately, only one blood sample is needed and all assays can be performed from the same sample. There are several assays for hepatitis C, which are also done on one sample of blood.
Are hepatitis B and C treatable?
In the acute stage, specific antiviral treatment has been attempted. Recent literature on the use of alfa-interferon and beta-interferon in acute hepatitis C is conflicting. There has been little information on treatment of acute hepatitis C because it is difficult to document. However, several anecdotal experiences have resulted in successful viral clearance if treated early in the disease course. The general consensus seems to be that early drug treatment leads to response of both alanine aminotransferase level (ALT, a liver enzyme) and viral load. Alfa-interferon has also been utilized in patients with hepatitis D and fulminant hepatitis due to either superinfection or co-infection with hepatitis B. Treatment of acute hepatitis B is generally not indicated, as most adults will clear the virus spontaneously.
Chronic hepatitis, on the other hand, is treatable. Alfa-interferon has been tested in multiple randomized controlled trials and is currently FDA-approved for the treatment of hepatitis B and C. Consensus interferon is approved for the treatment of hepatitis C.
The standard treatment for hepatitis B is interferon-alfa at a dose of 30 to 35 MU/week for 16 weeks. This treatment is effective for patients with well-compensated liver disease and evidence of viral replication. For patients not tolerating the side effects of the high dose of alfa-interferon, a smaller dose of 5 MU six days a week is generally better tolerated. Interferon is not indicated in patients with decompensated liver disease. The Food and Drug Administration recently approved a nucleoside analogue, lamivudine, for the treatment of hepatitis B patients with liver inflammation and evidence of hepatitis B viral replication. This therapy is effective in a small subset of patients with low viral levels, high aminotransferases, and short duration of disease. Seroconversion to eAg-negative status occurs in one third of the patients treated. It is taken daily for at least 12 months. Results are comparable to interferon, but lamivudine has significantly fewer side effects and should be used in patients who are not ideal candidates for interferon therapy.
The current standard of care for the treatment of chronic hepatitis C is combination therapy with interferon-alfa three times a week and ribavirin. Viral eradication with this regimen is 40 percent overall, but higher in patients with certain strains of the virus. Most patients are treated for six to 12 months, depending on virus characteristics, and the degree of liver fibrosis present. Patients with decompensated cirrhosis generally should not be treated because of the risk of worsening liver disease. Newer forms of interferon, requiring once-weekly injections, are undergoing clinical trials and will be FDA approved in 2001.
What is the goal of treatment for hepatitis B and C?
The goal of treatment for both hepatitis B and C is to reduce the level of viral replication and to alter the nature of the infection to a relatively inactive disease. The goal for treating hepatitis B is to stop active viral replication. Ultimately, converting the serological status to surface antigen negative with development of surface antibody titers is ideal. The goals of treating hepatitis C are threefold. The primary goal is sustained viral eradication. Secondary goals are to decrease progression of fibrosis, and to decrease the risk of developing liver cancer. In patients with extrahepatic manifestations of disease, there is an additional goal of relieving symptoms.
Are hepatitis B and C preventable?
There is a recombinant vaccine for hepatitis B available in the United States. It is more than 90 percent effective in providing long-term immunity after three doses. Patients who have been exposed to the virus and have not had the protective vaccine can receive hepatitis B immunoglobulin. This hyperimmune gamma-globulin has very high titer antibodies against hepatitis B surface antigen. Immunoglobulin may also be administered simultaneously with the vaccine in certain situations.
Currently there is no vaccine available to prevent hepatitis C. Because of its rapid mutation rate, a multivalent vaccine will be required and may take several years to develop and test before it can be routinely used.
What are the complications of hepatitis B and C?
Complications of hepatitis B and C include cirrhosis of the liver, portal hypertension with esophageal varices and hepatocellular cancer.
Will I eventually need a liver transplant?
Liver transplantation is reserved for patients with advanced symptomatic and irreversible liver disease. Patients with complications related to chronic hepatitis or cirrhosis should be referred to medical centers specializing in liver transplantation for evaluation. This should be done before the onset of terminal liver disease. Transplantation can dramatically prolong and improve quality of life for patients with advanced stages of this disease, which would otherwise be untreatable.