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About Just out. (Portland, OR) 1983-2013 | View Entire Issue (May 2, 1997)
Ju st o u t T may 2 , 1 9 9 7 ▼ 1 3 REASONS FOR HOPE here is much confusion about what happens inside the bodies of people with HIV before they develop AIDS. In the early 1980s when AIDS was It was once believed that HIV was a “latent stage” that led to first encountered, it was seen as a collection of diseases that were occurring in people the disease called AIDS—we now know that isn ’t true whose immune system was seriously damaged. It ▼ was several years before it was discovered that a virus, now known as HIV (human immunodefi by The Boston AIDS Writers Group ciency virus), caused this damage. Had research ers known in the beginning what they know now, infected a cell, CD4 cells get other cells to fight and the virus take place in the lymph system, there would be no “syndrome” known as AIDS, the germs with antibodies, and marshal another where most T cells are housed. As HIV gains the instead it would be referred to as the late stages of kind of cell, called a CD8 cell, to kill the infected upper hand, the architecture of the system is HIV disease. As tests showed that people with slowly destroyed. We know that cancer patients cells. Therefore, losing CD4 cells impairs the HIV appeared healthy for years before the dis who receive radiation therapy have similar dam body’s ability to fight illness. One reason HIV eases now known as opportunistic infections be may be so difficult to fight is that it infects these age, and it makes them more likely to get other gan, it was believed that HIV stayed in the body CD4 cells, and the immune system then needs to infections. Other casualties to the virus are the for years, doing little, in what was called the spleen— which in part helps filter out infections— wipe out many of its own officers. “latent stage.” There seemed to be no reason to and the thymus. There are two basic kinds of CD4 cells: those, treat a virus that clinicians believed was dormant. Finally, with so much going on, many re called “memory cells,” that are programmed to In recent years researchers have discovered searchers believe that HIV begins to disrupt the recognize specific invaders, and those, called that there is no latent stage, and that the virus communication between the immune cells. The “naive cells,” that are ready to fight new illnesses begins damaging the immune system earlier than immune system communicates through chemical the body hasn’t seen before. Losing too many was first thought. When HIV first enters the body messengers, which can be disrupted by HIV. The memory cells leaves the body defenseless against it reproduces at an astounding rate. The immune result is that cells respond ineffectively. diseases it has recognized and fought before. system recognizes the threat and fights back; that At the same time that the immune system Losing too many naive cells leaves the system first fight sometimes causes flu-like symptoms. The immune system’s response is amazingly suc cessful at reducing the amount of virus in the body. Actually, this response against the virus is more powerful than any of the strong antiviral combinations now available, but for reasons not completely understood, the immune system doesn’t finish the job by eliminating all of the virus. What follows is nothing like the image of HI V quietly lying dormant, to emerge years later as AIDS. Instead, what goes on inside the body is like a war of major proportions. The immune system itself becomes the main battlefield in this fight for survival. On the one side, HIV hijacks T cells and converts them into virus-producing fac tories that turn out billions of new copies of the virus every day. On the other side, the immune system eliminates huge numbers of copies of the virus, killing its own infected cells in the process. It is a war that the immune system cannot win on its own. So far there is only one known way for a person with HIV to keep this infection manage without a way to fight new diseases. Interestingly, weakens, the virus itself multiplies faster and able: through help from powerful antiviral thera it is the naive cells that fight things like the infects new types of cells. Eventually the virus is pies. There is, however, debate over when is the common cold, since each cold virus is different. able to enter cells with ease, by using entrances best time to start that antiviral treatment. The Unfortunately, while reducing viral load usu (receptors) not available to it earlier. In addition, reason many researchers now believe it is best to ally increases the number of CD4 cells, it now because the virus is not always exact when it start early, is their understanding of the hidden appears that if all the memory cells which recog makes copies of itself, many variations of the damage being done before the immune system nize a specific invader have been killed, taking virus develop. The cells which are set to look for becomes so weak that it can’t stop opportunistic antivirals will not bring back those particular and kill HIV may not recognize all of these infections. cells. And if all the naive cells are lost, then the variations as the virus they are supposed to hunt body may never be able to cope with an infection down. Therefore the immune system is open to it has not seen before, or relearn to fight illnesses attack even as more “naive” cells are needed to T he D amage D one it “forgot.” learn to recognize the new variations. These newly Some of the damage has consequences that are Meanwhile, theCD8 cells, which like soldiers trained cells won’t be looking for the original now understood, and some of it has consequences do much of the killing of enemy infected cells, do variations, making the immune system’s response no one has been able to clearly define. Probably not work as well as the HIV infection progresses. very inefficient. the best known damage caused by HIV is re It may be the lack of CD4 cells—the officers that flected in the slow but consistent reduction in the give them the orders to kill. In addition, there is S topping the D amage number of a kind of white blood cell called the T- evidence that HIV directly infects and kills CD8 helper cells, or CD4 cells, that for many years was cells. Another possibility is that the CD8 cells are One way to slow the damage, or at least the best way to know one’s status. Everyone knew reproducing so often that they prematurely age prevent it from speeding up too much, is to stay that when CD4 cells fell below 200, people began and weaken, coming to resemble the cells of a healthy. By staying healthy one can prevent in getting opportunistic infections, but until recently much older person. Whatever the cause of the fections from invading the body, or at least stop it was not clear what was going on before that problem, it is clear that without effective CD8 them from gaining a foothold. Adding more in time. cells, or effective antivirals to keep the virus at fections may further tax an already overworked HIV reduces the number of CD4 cells—the bay, continued deterioration of the immune sys immune system. In addition, when the immune officers of the immune system’s disease-fighting tem is assured. system fights infection, it also increases the amount army. When they have determined that a germ has The great battles between these immune cells of virus being produced. Staying healthy involves D am age control T ombard LO\*/E R Proudly Serving The Greater Portland Metro Area 503/286-1330 W2 Located in Historic St. Johns 8 3 0 2 N. LOMBARD • PORTLAND, OREGON 9 7 2 0 3 Fm nfm m f! any number of things from watching what you eat, exercising and getting plenty of rest to making sure that contact is limited with friends who have colds or other infections. It also includes practic ing safer sex, since many infections other than HIV, from herpes to Kaposi’s sarcoma, are sexu ally transmitted and tax the immune system. If, however, you want to stop the damage and not just slow it down, you will need to use antiviral medications. Antivirals may stop the continuing damage if they are used together in combinations that reduce the amount of virus to very low levels using the most sensitive viral load tests (meaning they measure as low as 400 or 500 copies of the virus). It is hoped that once such drugs get the amount of virus down to an undetectable level, it is unlikely to go back up. However, this means taking medicine on time, all the time and in the right amounts. Already there is some evidence from people who started antivirals very early in the illness, when their immune systems were fairly intact, that the body can repair the damage caused by HIV. There is a series of tests that determines how well the immune system works. Early results from these tests show that people who start antiviral therapy early can recover the small amounts of immune function they may have lost. But people whose systems are more damaged before they begin therapy usually do not recover all the way. This does not mean that people with very low levels of CD4 cells should give up, however, because the majority of people with counts lower than 50 have been dramatically helped by power ful antiviral combinations. But if people start very early when little damage is done, it may be pos sible to avoid the damage altogether. There is even a chance that if antiviral combinations are used early enough the virus may be cleared by the body, although tests to determine this will not be completed for a few years. P ros and C ons That said, it would be logical to ask why people don’t just take an antiviral combination right away, as soon as they know that they are infected with HIV. One of the reasons to wait is the side effects of the drugs— some of which can be severe. There are those who are early in the disease and want to wait for better drugs, afraid that using the ones we have now might preclude them from using better ones later. And there are people who are simply not ready to take medicines every day, on time, for the rest of their lives. The best argument for waiting is that it is not yet known whether taking these powerful drugs for long periods will have serious implications. But even taking this into account, many researchers now believe that the earlier one starts, the better. The message is simple: There is no latent stage. From the beginning HIV is running rampant and— if it remains untreated— will cause damage which can’t be felt or seen. There are now ways to control that damage. The Boston AIDS Writers Group consists o f Robert Folan-Johnson and Lou Pesce o f ACT UP Boston; David Scondras, Robert Krebs, Derek Libby and Larry Bresslour o f Search for a Cure; and Jeff Terry. For more information, write Search fo r a Cure, 58 Burbank St., Boston, MA 02115; phone (617) 536-2474; or e-mail lbresslour@sfac.org. STEPHEN D. YEW, D .M .D . A GENTLE APPROACH TO DENTISTRY Hours: Tuesday - Saturday 8 am-5 pm 700 N. Hayden Island Drive, Suite 330 Phone: 289-1215
