< link rel="DCTERMS.isreplacedby" href="http://caltechgirlsworld.mu.nu/" /> Not Exactly Rocket Science: My last word on the HIV/AIDS debate

Thursday, January 13, 2005

My last word on the HIV/AIDS debate

So yesterday, Dean promised an earth-shattering revelation that would set on its ear all that you thought you knew about HIV and whether it causes AIDS. I applaud Dean for bringing forward his convictions, but we'll just have to agree to disagree.

Today he presents this graph:


And this one:


The graphs come from this paper by Peter Duesberg's group. The top graph is NEW (it can't be total, see here-- Ed.) AIDS cases in the US per 100,000 people and the bottom graph is millions of total HIV positive folks in the US. Don't worry about the difference in reporting. You could convert the top to pure number by multiplying any point by 2300-3000 since there were between 230 and 300 million people in the US during the time of the data. What's important here is the shape. And WRT the spike in the AIDS graph, see here for what the CDC says about how it changed it's criteria for diagnosis.

Dean and Dr. Bialy (you know what I think of him) say that these graphs mean that HIV can't cause AIDS since HIV remains relatively stable and AIDS is first increased and then decreased.

Initially you might say, "OK..." I say, "apples and oranges!"

Look, to believe Dean and Dr. Bialy you would have to believe that the only possible relationship between HIV and AIDS is specifically linear, that is, it can only be progresssive (HIV -> AIDS) without any susceptibility to intervention. I postulate that this is not so.

Mostly because I find it extremely telling that AIDS cases begin to drop off right at the same time that we were beginning to move beyond AZT. The first anti-retroviral drugs became available in the early 1990s, and the protease inhibitors first came out in the mid-1990s. Go look at the AIDS graph, I'll wait. These drugs have gotten progressively better at one thing: slowing the progress of HIV to AIDS.

AIDS is a clinical syndrome diagnosed after HIV positive status is attained and T-cell count drops below a certain threshold or one of a group of AIDS related illnesses is diagnosed (Kaposi's sarcoma, pneumocystis carinni pneumonia, etc), so by definition AIDS is at least related to HIV infection. This doesn't mean that people can't have all of the same symptoms and be HIV negative. So do those people have AIDS? Well, technically no, but clinically yes. They're certainly in the same sinking lifeboat, whatever the cause.

But I digress. The drug intervention is a confounding factor in these data that CANNOT be ignored. The effect of the drugs on the disease process is bringing about the very changes that folks like Dr. Bialy say are evidence that HIV is unrelated to AIDS.

He says
"If HIV is the cause of AIDS, and the number of infected individuals is constant, then, other things being unchanged, the number of cases must remain constant.

Although there are reasons why a virus might stop causing a disease (such as immunity, or drugs that confer resistance - although neither apply in this case), there is no defensible reason in the clear light of these data for thinking that HIV ever began to cause one in the first instance."

But this is patently false, because "other things" are changed. The efficacy of drug therapy is completely different. Dr. B would like to ignore that, but he can't.

Here's what I mean: I work in the Schizophrenia research field. Those of you who read this blog frequently already know that. However, because SZ, like AIDS, is devastating to patients, most are treated as quickly as possible with a regimen of anti-psychotics. AP's are potent drugs that have a great effect on brain function and MAY effect neuron survival, growth, etc. through any number of mechanisms that are currently being investigated, including by others in my own laboratory. Bottom line, when we see the brain of a SZ patient, we don't know what effects are drug mediated and what effects are disease mediated. Until we can tease that apart, we can't say for sure that SZ is related to lower cortical weight or fewer myelinating cells, or whether those things are a result of the drugs. ANY SZ researcher who discounts drug effects out of hand would be laughed right out of the university. If you don't believe me, you can go here and search the literature for yourself.

Back to the point. What are these drugs doing? Well, according to all of the peer-reviewed publications I can find, from studies all over the world, these drugs are INCREASING the amount of time between HIV+ notification and AIDS diagnosis. Because we only have 10 years with these drugs, this is all we can really say. It might even be a cure for some people. But only time and follow up exams will tell. Increased time before diagnosis + steady HIV infection numbers = decrease in NEW AIDS patients, compounded by the fact that patients who make it that far rarely have more than a 3-5 year life expectancy. And no, the drugs don't work for everyone, but that percentage of the HIV+ population is relatively small right now, even though some estimates indicate that it might be growing. Again, go here and search the literature for yourself.

But what about the first part of the graph? Supposedly conversion from HIV to AIDS takes 3-20 years. If AIDS was first reported in 1981, why are there so many cases of AIDS so early?

Umm. Duh. Because HIV didn't just magically appear on Jan 1, 1981. It was out there, circulating and being transmitted. Remember, no one knew to look for it, if anyone saw a patient that would later be described as an AIDS patient before 1981, he or she was a sad statistic known as "undiagnosed immune failure", and the Dr. who treated that patient probably never saw another one like that until AIDS exploded, as epidemics tend to do. And none of those patients probably had any effective drug treatment. Anyone who got AIDS before we knew how it was transmitted (roughly 1983) would be converting between 1986 and 2003, most of them probably in the early portion of that window since they would be untreated. The CDC didn't even keep records on AIDS diagnoses until 1985.

This isn't earthshaking, or mind-altering, or any of the other things Dean promised yesterday. It's more of the same, with misinterpreted statistics (I've already pointed out how this crew likes to do that, see the bit about AZT and pregnant moms in my post on Duesberg), and logical faults.

I believe that there's more to AIDS than HIV, but by the same token, that doesn't mean that HIV is totally unrelated to AIDS. In fact, I believe the vast majority of AIDS cases are directly due to HIV infection. We can toss examples back and forth of people with AIDS but not HIV, HIV but no symptoms, drug abusers with and without HIV, etc. But it boils down to this: The NUMBER ONE thing associated with AIDS symptoms (notice I did not say diagnosis) is HIV infection. Whether that's causative or correlative is certainly up for discussion. But to my mind there is no good evidence that HIV doesn't cause AIDS, and plenty of evidence that treating HIV decreases AIDS.

But hey, make up your own mind. I already have.

Update: jenks over at The MUSC tiger fisks hell out of Dr. Bialy's premise and gets a mistake I overlooked! Pay particular attention to the graph of HIV infections, People living with AIDS, and new AIDS cases.

Update II: edited to be PERFECTLY CLEAR that I did not misinterpret the AIDS graph. My argument was based on my interpretation of the graph as representing new AIDS cases, and the only point I made WRT total AIDS cases actually reinforces the interpretation of the graph as showing new AIDS cases. I also stated my position more clearly. That and I was less willing to leave room for argument with those of you still on the fence.

3 Comments:

At Thursday, January 13, 2005 4:35:00 PM, Blogger Jared said...

Dean, you're backtracking! The cofactors don't equate to a cause. The graphs on your site aren't showing the data used to make your point: new AIDS cases does not represent total AIDS cases. Environmental factors affect the presentation of AIDS, but this is vastly different from causing it.

 
At Thursday, January 13, 2005 6:26:00 PM, Blogger Caltechgirl said...

This comment has been removed by a blog administrator.

 
At Thursday, January 13, 2005 6:49:00 PM, Blogger silvermine said...

Yep -- what Jared said.

The "no one else believe in cofactors" thing is a strawman. Because if anyone can honestly say that they think that HIV turns into AIDS 100% of the time, they aren't paying attention. No one thinks that, and anyone who studies disease wouldn't think that.

Every disease has a typhoid Mary -- a carrier who carries the virus, infects others, but doesn't get sick themselves. Anyone worth their salt in microbiology knows this.

They DO know of people who don't get AIDS, and they know exactly why. It's genetic. One of the co-factors for geting AIDS from HIV is having a certain protein on the outside of your CD4 T cells. There are some people who have a mutation in this protein, and HIV can no longer use it as a receptor. If they have two copies of the mutation, HIV can't touch them.

Duesberg & company have set up a series of strawmen. They are not proof. They're easily parried.

Just saying that "people don't believe cofactors are involved" only proves those people are stupid, not that everything they believe is wrong.

 

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