Mycoplasma: CRI Plans Doxycycline Treatment Study
New York's Community Research Initiative (CRI), one of thepioneers of community-based AIDS research, is developing a trial
to see whether the antibiotic doxycycline can help certain
patients with an ARC diagnosis -- and whether a blood test for
mycoplasma infection can predict who might benefit. This trial
will test the hypothesis of Luc Montagnier, M. D. -- one of the
discoverers of the AIDS virus -- that mycoplasma infection might
be an important cofactor in the development of AIDS.
Background
Mycoplasmas are organisms between viruses and bacteria in
complexity. They are known to cause some human diseases, and
they can be controlled with certain antibiotics. During the last
several years, Shyh-Ching Lo, M. D., and other researchers at the
U. S. Armed Forces Institute of Pathology found a mycoplasma
which appeared to be a previously unknown species in organs of 22
of 34 persons who had died of AIDS, and reported evidence that
this mycoplasma may be causing organ failures. (For more
information on this work, see AIDS TREATMENT NEWS #95, January
19, 1990.) In laboratory tests, the antibiotics most active
against this mycoplasma appear to be doxycycline and
ciprofloxicin (see Lo, SC and others, Sixth International
Conference, abstract #Th.B. 536).
At a special meeting organized at the Sixth International
Conference on AIDS last month in San Francisco, Dr. Montagnier
reported laboratory studies supporting a hypothesis that
mycoplasma might be a major cofactor in the development of AIDS
-- not just an opportunistic infection. His team found
mycoplasma in the blood of about one third of AIDS patients; the
organisms are hard to detect, so they may be present in others,
too.
Also, the researchers found that antibiotics which inhibited
the mycoplasma prevented HIV from killing cells in the
laboratory, although the drugs did not affect HIV directly. Dr.
Montagnier speculated that HIV might become more destructive
later in the disease than early after infection, because of later
mycoplasma infection. An abstract by Dr. Montagnier and others
(#1072, accepted for publication-only at the Conference, without
a talk or a poster presentation) reported that doxycycline
protected cells against destruction by HIV, even though the virus
continued to multiply within the already-infected cells. HIV
cultures treated with tetracycline lost their ability to kill
cells even after the tetracycline was removed, suggesting that a
tetracycline-susceptible contaminant in the culture (probably a
mycoplasma) enabled the HIV to kill the cells.
Dr. Montagnier has given high priority to further
investigation of the possible role of mycoplasma in AIDS, and has
assigned 15 people, half of his unit, to work on it.
For more information on this research, see the interview
with Dr. Montagnier by Martin Delaney of Project Inform,
published in The Advocate, July 3, 1990.
The CRI Study
The treatment study now being planned by the Community
Research Initiative will randomize 150 patients with an ARC
diagnosis to one of three daily doses of doxycycline: 50, 100,
or 200 mg twice a day. Researchers will monitor patients'
clinical status and do the usual blood work; in addition, a
special laboratory will test blood samples for mycoplasma, at
baseline and at three-month intervals. Because clinical
evaluations can be subjective, the mycoplasma test results will
be blinded; a Data Safety Monitoring Board will examine the
unblinded data after six months, in order to halt the study if
the results are dramatic enough to justify that step.
The CRI has raised about half of the $300,000 required for
this study; it wants to have at least two thirds of the funding
before beginning, to assure that the trial can be completed.
Doxycycline is a generic drug, as its patent has expired;
therefore pharmaceutical companies have no incentive to fund
research. Federal agencies are not yet ready to conduct a
treatment trial for mycoplasma, although they may do a prevalence
study by analyzing blood and tissue samples.
This CRI study is important for several reasons:
* Even before mycoplasma became an issue, some physicians
have prescribed doxycycline empirically for people with HIV who
had unknown illnesses. The rationale is that many people with
AIDS have opportunistic infections which have not been diagnosed
(as has been shown by autopsy studies); doxycycline is fairly
safe, and effective against many disease-causing organisms, so it
could be worth trying when attempts to diagnose a problem have
failed. The doxycycline trial will provide the best available
data to guide empirical use of the antibiotic by persons with HIV
-- whether or not mycoplasma is important.
* The study will test Dr. Montagnier's hypothesis that
mycoplasma infection may be a major cofactor in AIDS. It will
show whether the available mycoplasma blood test is helpful in
guiding the use of doxycycline, and whether testing for
mycoplasma has prognostic value.
* Doxycycline is readily available, very well known in human
use, and inexpensive. Therefore if the study does find a
positive result, it could have rapid impact on AIDS treatment in
the United States and elsewhere.
If you can help in the fundraising or otherwise in the
development of this study, call Bernard Bihari, M. D., Executive
Director, Community Research Initiative, 212/481-1050.
source: AIDS Treatment News




