So far, we’ve concentrated on information about current treatments that will help manage your disease and your life now that you have been diagnosed with hepatitis, and to protect your loved ones and others from contracting the virus. Now we’re going to talk about new treatments that may be available to help you in the future.
The search for new treatments for hepatitis B and hepatitis C has been slow and sometimes frustrating. But new treatments are being tried.
Any one of the ideas being pursued by researchers today could be the next breakthrough in treating hepatitis. Yet the fact is that while some will work better than others, some may not work at all, and no one can pick the winners until all of the research information is studied.
How better diagnosis can improve treatment?
As well as new treatments, researchers are working on new types of tests that can give your doctor more information about both the virus that has infected you and how your body is reacting to the infection. Together, this information can steer you and your doctor toward the best treatments for you.
For example, people whose blood shows evidence that the hepatitis B virus is actively reproducing, as opposed to just being present in the blood, seem less likely to be cured by interferon treatment. In much the same way, certain strains (slightly different versions of the same virus) of hepatitis C can be attacked more easily by interferon than others.
Researchers have also found that people whose bodies are producing large numbers of immune cells, called cytolytic cells or sometimes called killer cells, seem to have the best ability to clear the hepatitis B virus from their systems. More research may provide more information about these viruses.
Learning more about prevention
Researchers are also looking into better ways of preventing infection.
Specific anti-hepatitis B immune globulin (HBIG) treatment and hepatitis B vaccination have proved effective at preventing that virus from taking hold in the body. (See Chapter 4.) Today’s hepatitis B vaccine is effective at preventing infection. In fact, some studies have suggested that the vaccine, if given at the right time, may assist people who are already infected to clear the virus from their systems. This treatment technique is called therapeutic vaccination, and researchers are trying to figure out how to get it to work in more patients.
But unfortunately hepatitis C presents vaccine developers with a moving target. Once in the body, hepatitis C can literally change its coat in a process known as mutation. A mutation is a permanent change to the virus’s genetic makeup. This change also affects the virus’s outer coat, or capsule. (Because the coat around the virus is what helps the body detect and then attack it, clearing the virus from the body is a little like a game of hide and seek.)
Hepatitis C mutates even more than hepatitis B. So much so, in fact, that the body ends up having to fight many, many slightly different forms, or strains, of hepatitis C. This has made producing a vaccine for hepatitis C difficult. (See illustration below.)
A vaccine against the virus would probably need to protect against many strains at once, or you would need several vaccines. Research in the related problem of figuring out how to protect people from the many strains of the flu or the AIDS virus, other organisms that mutate a lot, many offer some clues that will help with hepatitis C as well.
New treatments now being tested
Interferon alone, and in combination with Ribavirin (Hep C) have helped some patients with hepatitis. But the fact is that treatment doesn’t always work. Again, mutation seems to be part of the problem. Just as the mutated hepatitis C virus can hide from the immune system, viruses can also develop mutations that help them escape the effects of drug treatments like interferon and interferon/Ribavirin. One of the key goals for hepatitis research is the creation of treatments that so overwhelm the virus that it can’t mutate its way out of trouble.
Unfortunately, the body creates problems for treatment as well. Along with producing antibodies against the virus, the body may produce antibodies against some forms of interferon, blocking the drug’s action. Researchers are investigating ways of changing interferon slightly, so that it still works but antibodies can’t attack it.
Other drugs may also be necessary to treat hepatitis B and hepatitis C. Interferon acts by strengthening the immune system and keeping the virus from infecting healthy cells.
A new group of antiviral drugs, called nucleoside analogs, destroys viral reproduction by inserting themselves into the virus’s genes.
Another family of drugs, called the protease inhibitors, interferes with the packing of viral genes into new viruses. Many hepatitis researchers have taken hope from the fact that protease inhibitors designed against the AIDS virus have worked, suggesting this is a good way to fight a virus. Because protease inhibitors must be tailored to a specific virus, those used against HIV, the virus that causes AIDS, won’t work against hepatitis B or hepatitis C. Remember, the AIDS virus is not in any way related to the hepatitis B and C viruses, but because HIV is also a virus, many of the discoveries from AIDS research also apply to other viruses, including the hepatitis viruses. Because so much attention has been given to AIDS research over the last few years, many discoveries about viruses are coming out of this field.
Another area of focus for viral hepatitis which comes from AIDS research is combination therapy. This type of therapy uses a mixture of different drugs all at once, in the hope of preventing HIV from developing resistance to any of them. In theory, it’s impossible for a virus to develop enough mutations quickly enough to survive combination therapy, provided that it’s hit with a high enough dose of enough drugs at once.
Even better, combination therapy has had some practical success. It has eliminated any detectable HIV from some patients’ systems. (Remember, there is no cure for HIV yet, so this is the closest scientists have come to providing a cure for this viral disease.) It’s too early to tell whether these patients will show signs of the AIDS virus in the blood again later, or whether some virus still lurks somewhere in the body. But most researchers agree that combination therapy is likely at least to extend HIV patients’ lives.
Hope on the horizon: Future treatments
In the more distant future, a completely new type of therapy is coming that may revolutionize viral hepatitis treatment. Called gene therapy, it’s actually a group of treatments that rely on putting new DNA into a patient’s tissues.
One type of gene therapy being planned for viral hepatitis is called antisense therapy. Most people think of gene therapy as being a way to put a good gene (one that works) into a cell that has a bad gene (one that doesn’t work), but antisense is a completely different approach that aims to just shut off bad genes (in this case, those of a virus). In antisense, the patient is given a man-made copy of DNA that is exactly matched to a gene that the virus needs to reproduce itself. The antisense DNA attaches to the viral gene (or to another molecule that the cell uses to make proteins), interfering with its workings, and preventing the virus from surviving.
The next step
The sheer number of new approaches being tried in viral hepatitis therapy is encouraging. The fact that researchers are using new knowledge to aim these approaches more effectively is even better.
Q U I Z
Q. What is a therapeutic vaccine?
A. One that helps a person already infected with the virus clear it from his or her body.
Q. Why is there no vaccine yet for hepatitis C?
A. Hepatitis C exists as many strains and mutates quickly. Researchers haven’t yet discovered a vaccine that can protect against more than one strain of hepatitis C at one.
Q. What are two reasons that treatments like interferon used alone may fail in viral hepatitis?
A. The virus can mutate and become resistant to the drug, or the body may make an antibody that interferes with the drug’s action.