Could heart drugs treat HIV?
Cholesterol-lowering statins may provide an alternative to antiretrovirals.
A study of six AIDS patients has revealed that statins can reduce levels of HIV and boost immune cell numbers. If the results can be repeated in large-scale trials, it's hoped that statins could provide an alternative to standard HIV treatments.
Statins are taken by millions of people to lower cholesterol levels and help protect against heart disease. And studies have shown that cultured cells with low levels of cholesterol in their membranes are less likely to succumb to HIV infection.
So, Carlos Martínez from the Spanish Council for Scientific Research and colleagues decided to study the effects of cholesterol-lowering statin drugs on HIV patients. Their results are reported in the Journal of Experimental Medicine1.
A one-month course of statin treatment caused the virus levels of human patients to drop by up to 20-fold. Levels began to rise when patients stopped taking the drug.
When mice, injected with HIV-infected human cells, were given the drugs, their virus levels fell, in some cases to undetectable levels.
Together, these results suggest that statins may prove useful against HIV in human patients, says Martínez.
HIV suppresses the immune system by infecting and killing the cells of which it consists. Martínez believes that statins prevent the virus from entering healthy cells in the first place.
It is hoped that the drugs could offer an alternative to the standard AIDS treatment, highly active antiretroviral therapy (HAART). This therapy is becoming less effective as drug-resistant HIV strains continue to emerge.
Resistant strains have limited the options for many HIV-infected patients, explains HIV researcher Eric Freed of the HIV Drug Resistance Program at the National Cancer Institute in Frederick, Maryland. "This makes the development of alternative treatments especially urgent."
Statins could also prove safer than antiretrovirals. HAART can trigger serious side-effects, such as liver damage, but statins are relatively free of such problems.
Martínez hopes that statins could also be used preventatively. His study shows that white blood cells taken from patients on statins are less likely to succumb to HIV infection.
Larger clinical trials should be forthcoming, says Martínez. But he cautions that such studies are difficult to set up. It is hard to find HIV-positive patients who are not already taking anti-HIV medication, he points out. One solution may be to concentrate on patients who have already become resistant to the standard treatments.
- del Real G., et al. J. Exp. Med., 200. 541 - 547 (2004).