ANNOUNCER: One of the biggest questions facing people with HIV is when to begin therapy to fight the disease-what's known as HAART, or highly active anti-retroviral therapy.
KATHLEEN SQUIRES, MD: Well, right now, the decision about starting HAART or antiretroviral therapy is a complicated one. And the reason for that is that the drugs are very effective in controlling viral replication but they do have side effects and toxicities and complications. So really when you think about HIV infection and when to treat, you're balancing the risks of progressive HIV infection versus the complications, toxicities of the drugs.
ANNOUNCER: One of the first questions to ask when deciding when to start anti-HIV therapy is: Is the patient ready? If not, the patient may have trouble sticking to his or her medication schedule.
PETER REISS, MD: What we've learned over the last few years is that-and it's, in fact, pretty obvious-is that they will only remain effective if the patient actually takes them. And taking them means taking them day-in, day-out basically for the rest of his or her life. Well, you can probably imagine that this is not an easy task.
ANNOUNCER: Doctors also use two measures of the progression of HIV in helping a patient decide when to start therapy. Tests can determine just how much HIV is circulating in a patient's blood, what's called the viral load. Tests can also determine how badly the virus has decimated its primary target, white blood cells known as T-cells, or CD4 cells.
KATHLEEN SQUIRES, MD: We have the two things that we measure, CD4 cell counts and viral loads and what we have found is that you can't really depend on one or the other. It's putting the two of them together, tracking them over time, because each individual patient has their own course in terms of dropping the level of cd4 cell counts or rising viral load and their symptoms. How long they've been infected. So we put everything sort of into an equation and try our best to figure out when is the best time to intervene.
ANNOUNCER: Some numbers, however, are calls to action. An uninfected person will usually have a T-cell count of 600 or higher. Most doctors would agree, a count of 200 or below means it's definitely time to start therapy.
ANDREW CARR, MD: The evidence suggests that once your T-cells count is approaching 200, that the risks of something serious happening, are really starting to increase.
KATHLEEN SQUIRES, MD: It's very clear that for people who present with advanced disease, who have very low CD4 cell counts or T4 counts, and have developed an opportunistic infection, those people need immediate therapy.
What's not so clear is when you were defined earlier in the disease, where your CD4 cell counts are more intact, meaning in the 300-500 range, and have modest viral loads. There again, the risk benefit analysis is something that really comes into play.
ANNOUNCER: It's in that gray zone where clinicians and their patients must weigh the advantages and disadvantages of early treatment.
KATHLEEN SQUIRES, MD: It is clear that ongoing, unchecked viral replication does affect the immune system and will cause progressive deterioration in the immune system. We do know that when we start therapy, we can get some "reconstitution" or rebuilding of the immune system. So the major reason that people really push early therapy is to try and preserve as much immunologic function as possible.
ANDREW CARR, MD: The advantages of starting treatment early is clearly preventing progression, keeping people well and truly away from illness.
KATHLEEN SQUIRES, MD: In terms of reasons to start therapy, it is clear that if you don't start drugs until patients have advanced disease-again, maybe they've developed an opportunistic infection or they have a low CD4 cell count, their response to therapy is simply not as good.
ANNOUNCER: Clinicians say there are also reasons to delay the start of anti-retroviral therapy.
KATHLEEN SQUIRES, MD: In the mid-90s, when it became clear that combination cocktail HAART based regimens were making a dramatic difference in patient's lives, the feeling was that you start everybody on drugs as soon as you make the diagnosis of the infection.
It's now clear that while the drugs are very effective by themselves can not eradicate the infection. And what's also clear is as we use these drugs longer, there are side effects. There are toxicities. There are complications. So there has been a rethinking and decision to perhaps wait later in the disease process because the drugs still can give patients a very marked advantage once they're started.
ANNOUNCER: Deciding when to start anti-retroviral therapy is usually a difficult decision. But doctors have become adept at helping patients weigh many factors, to help determine when they should start this life-prolonging treatment.