[Letter to Colleagues from Peter Duesberg]

not address the more important occurrance of progressive immunodeficiency
and death in 25%-30% of the children of HIV infected mothers that is
unrelated to the use of psychoactive drugs during pregnancy.
The possible association of inhaled nitrates and Kaposi's sarcoma was
raised early in the AIDS epidemic. However, it is difficult to separate the use
of psychoactive drugs and promiscuity (leading to a greater chance of
exposure to another sexually transmitted pathogen). The fall in incidence of
KS has mirrored both a decline in drug use, a decline in promiscuity, and a
decline in many sexually transmitted diseases. The is some epidemiologic
evidence for a separate sexually transmited pathogen that causes KS.
possibly another retrovirus (Lancet 33*5- p.123, 1990), as well as in vitro
evidence for a role for the HIV tat protein and interleukin 6 in the growth of
KS cells (Science, 24, p.442, 1990). Duesberg does not discuss these other
possibilities, but focuses narrowly on nitrates.
Dr. Duesberg's asserts that the use of AZT has caused the increase in
lymphoma that is being seen as patients are living longer. While this
possiblity remains a concern, there is little evidence to incriminate AZT.
Animal studies of AZT have not shown an increase in lymphoma. Moreover,
patients with immunodeficencies (congenital, or after transplants) have a
propensity for the development of lymphoma that increases over time. The
increase in survival in AIDS patients due partly to AZT, and many other
improvements in medical care such as the use of prophylaxis for
pneumocystis most likely has led to the rise in lymphoma.
Dr. Duesberg's discussion of the possible mechanisms for
immunosuppression from iv drug use or malnutrition is very superficial.
Moreover, he does not address the common occurrence of AIDS in patients
who are well nourished and have not used drugs for many years. (The final
paragraph on page 9 is totally confusing as well as incomplete). His
discussion of alkvl nitrates is more interesting; however, the field of KS is
full of intriguing leads but few definite answers.
The discussion of AZT is very distorted. Hepatitis is rarely, if ever, a
side effect of AZT and few patients have significant central nervous system
problems taithough mild transient headaches are common). Hematologic
toxicity is mlore common in AIDS patients than asymptomatic HIV positives

but is less frequent 129% anemia) than the incidence quoted in the paper
since current practice is to use a lower dose of AZT than in the original drug
trial in 19S7.NEJM. 2:. p.1009. 1990). When AZT was given to
asymptomatic HIV positive patients in a placebo controlled trial. hematologic
toxicity (54.- was not greater than that seen in the placebo treated group