Maybe HIV doesn't cause AIDS. Crazy notion - or is it?
I was at a lecture a couple of days ago by Kary Mullis, 1993 Nobel
Chemistry Laureate (inventor of PCR). He proposed a very interesting
alternative hypothesis for the AIDS epidemic whereby AIDS may be due not to
HIV infection as such, but due to infection by retrovirii or other infectious
agents in general.
It goes something like this:
If you are infected by some pathogen every so often, your immune system leaps
into action to deal with it (clonal expansion, lots of plasma cell division,
that sort of thing). All well and good, but if one of the plasma cells
involved harbours a lysogenic retrovirus (normally dormant, but replicates
during cell division since it is incorporated into the chromosome), then you
will produce lots of copies of the virus as an unfortunate byproduct of
producing lots of plasma cells. That virus may be non-pathogenic in small
quantities, but when your blood is suddenly awash with it, your immune system
will attempt to destroy it, i.e. you will get two responses - one to wipe out
your flu infection or whatever and one to wipe out the virus produced as a
result of wiping out the flu infection.
Now, if you are reasonably healthy, not many of your cells will harbour
a retrovirus. If, say, 50 of your million plasma cells (arbitary figures) have
a retrovirus, you will only elicit an *extra* immune response if one of those
50 is selected for clonal expansion, so you'll only put an extra strain on the
immune system occasionally.
If *all* of your plasma cells harbour a retrovirus, then you put an
extra strain on your immune system *every* time it deals with an infection. An
immune response will lead to a second immune response, which will lead to a
third immune response and so on.
Mullis suggested that this perpetual immune system activation resulted in
breakdown of the immune system, i.e. AIDS.
This is not necessarily linked to HIV infection, since HIV alone may be
completely non-pathogenic at normal levels. It is only it's synergistic action
when present alongside hundreds of other infections that it becomes a problem.
Even then, it is not HIV itself that is the problem, but the overall level of
infection.
This increase in the number of non-pathogenic (if present on their own) virii
in an individual could have arisen from the San-Francisco bath-house scene
(lots of partners, lots of contact, warm & damp environment, lots of
opportunity for infection), since if one individual caught something it would
spread like wildfire. In such a scenario, AIDS may have hit the gay community
first because they were more gregarious than the heterosexual community -
heterosexuals with hundreds of partners who each had hundreds of partners who
each had hundreds of partners would be just as likely to spontaneously
initiate an AIDS epidemic.
In such a scenario, all AIDS sufferers would probably have HIV (along with
anything else you care to mention), but not everyone with HIV will necessarily
develop AIDS, since HIV alone is insufficient to cause it. Blood-to-blood
contact would still spread AIDS because the blood of an AIDS sufferer would
contain many, many *different* infectious agents. This would explain
increasing CDC figure for the latency of the virus (what is it, 12 years or so
at the moment?) since an HIV+ person may have no chance of developing AIDS
whatsoever.
This would also mean that money spent researching an anti-HIV drug is money
down the tubes. An awful lot of governments may have been funding the wrong
thing, but the scientific and political establishment has become blinkered -
too much money is now at stake. Scientists have vested interests and don't
want to admit that they're wrong.
I'm not saying that I necessarily believe this hypothesis, but it does
adequately explain the data available and I believe it warrants further
investigation - I can't see NIH or anyone like that agreeing though, so such
research will probably never get funded.
What do other people think?
__________________________________________________
Richard Burge | e-mail:
King's College London | R.Burge at bay.cc.kcl.ac.uk
______________________|___________________________
