"We had hoped that a structured treatment interruption would be beneficial for people experiencing treatment failure due to multidrug-resistant HIV," Dr. Jody Lawrence of the University of California, San Francisco, who led the study, said in a statement.

"However, our results indicate that this strategy does not work and should be avoided by this group of HIV-infected individuals. Continuing therapy guided by HIV drug resistance testing proved to be a better approach."

The so-called drug holidays are being tried in a variety of HIV patients and some studies have suggested they can give patients a break from the side effects of the drugs without putting them at risk.

But this latest study suggested it was dangerous to do so in patients whose virus had evolved to resist the effects of the drugs.

Doctors considered interrupting treatment once resistance to the drugs has developed because, when the drugs are stopped, the AIDS virus tends to mutate back to a form that is sensitive to the highly active anti-retroviral therapy, known as HAART, used as the first line of treatment.

The Lawrence team found that in 64 percent of the 138 test patients whose treatment was interrupted for 16 weeks, the virus indeed reverted to a more sensitive form.

However, those people did not do as well as the 132 patients who were immediately switched to new medicines.

While AIDS progressed in 16 percent of the people who had a drug holiday, the disease got worse in only 9 percent of those who immediately received a different HAART cocktail.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, which sponsored the research, cautioned that the new study only included cases where the AIDS virus was detectable in the blood and the virus particles had become resistant to drugs.

"For individuals who are being successfully treated with anti-HIV medications, other studies have shown that cycles of treatment interruptions for shorter periods may be of potential benefit to conserve medications and reduce drug-related toxicities," Fauci said in a statement.

In a commentary, Dr. Bernard Hirschel of Cantonal University Hospital in Geneva, Switzerland, said the idea the AIDS virus, if left alone, will become more sensitive to drugs may be an illusion.

If there are 5,000 drug-resistant virus particles in each milliliter of blood, they may quickly become outnumbered by 100,000 drug-sensitive particles, but still remain and can linger for years, he said.

"Thus, it is hard to see what could be achieved by interrupting treatment for a few weeks," Hirschel wrote.

NEW YORK (Reuters Health) - The type of AIDS drugs used does not influence the risk of bone thinning in HIV patients, new research shows.

The findings are in agreement with a recent report that showed classic risk factors, not the treatment, were the primary cause of bone thinning in HIV patients.

In the new study, Dr. Dario Bruera, from the National University of Cordoba in Argentina, and others compared bone density in 111 HIV patients and 31 healthy subjects. The patients included 33 never treated with AIDS drugs, 36 treated for more than 1 year with one type of AIDS regimen, and 42 treated for more than 1 year with a different regimen.

The results are published in the medical journal AIDS.

At all bone sites tested, thinning was more evident in HIV patients than in healthy subjects, the investigators note. In contrast, all three groups patient with HIV showed similar amounts of bone thinning.

Osteoporosis, a severe form of bone thinning that raises the risk of fracture, was also more common among HIV patients than healthy subjects, but once again no differences were seen between the patient groups, the authors state.

So are there any factors that predict bone thinning in HIV patients? In the current study, the only factor linked to bone thinning was the duration of HIV infection. The longer a patient was infected with HIV, the more likely they would have low bone density.

The findings suggest that HIV itself, not the drugs used to treat it, has a harmful effect on bone metabolism, the researchers state.

SOURCE: AIDS, September 5, 2003.

Gay.com U.K.

SUMMARY: In a discovery that could lead to a new HIV treatment, U.S. researchers have established the function of a key HIV gene that attacks infection-fighting blood cells.

In a discovery that could lead to a new HIV treatment, U.S. researchers have established the function of a key HIV gene that attacks infection-fighting blood cells.

Scientists at the University of Utah and University of Rochester, N.Y., have discovered the method by which the viral gene, known as VPR, stops immune system cells from replicating and protecting the body from infection. The gene is capable of activating a dormant gene inside T-cells that prevents the cells from regenerating.

"We would like to find a method or a substance that would allow us to interfere with the ability of HIV to kill the white blood cells using this mechanism," said researcher Vincente Planelles of the University of Utah.

However, he warned that an effective treatment could take up to 10 years to develop, reported the Salt Lake Tribune.

The researchers published their study in the Journal of Biological Chemistry.

VPR had been in the headlines earlier this year, when researchers at the Mayo Clinic in Rochester reported that many HIV patients who never develop AIDS have damaged versions of the gene.

In these patients, called HIV nonprogressors, HIV kills the immune system, but T-cell supplies are replenished fast enough to protect the body from serious infection.

Gay.com U.K.

SUMMARY: Vitamin supplements often taken by HIV-positive people with lipodystrophy can have a negative effect on blood sugar levels, a new study suggests.

Vitamin supplements often taken by HIV-positive people with lipodystrophy can have a negative effect on blood sugar levels, a new study suggests.

A small pilot study of 10 patients, all of whom were on stable treatment with standard antiretroviral drugs, showed that while vitamin supplements can help cholesterol levels and midriff weight gain, metabolic problems were a potential side effect.

Lipodystrophy, which strikes many patients on HIV therapy, is an abnormal redistribution of body fat.

The two women and eight men were given supplements of vitamin E (800 IU per day), vitamin C (1000 milligrams daily) and N-acetylcysteine (NAC) (600 milligrams twice daily) for 24 weeks.

While total cholesterol and HDL ("good") levels showed no marked change, a trend towards lower LDL ("bad") cholesterol was noted.

"Even with the small study sample size, we were able to show some improvement of LDL cholesterol and waist-to-hip ratio, both being very promising findings," Dr. Grace McComsey told Reuters Health. She reported her findings in the Journal of Acquired Immune Deficiency Syndromes.

However, the patients' metabolism showed worsening resistance to insulin during the study, and fasting glucose levels increased.

This is "very concerning," McComsey said, "and reminds us that we should always investigate vitamins/herbals supplements prior to their use in HIV-infected subjects. We should never assume that high doses of vitamins are safe. They are not safe until clinical studies prove them to be safe."