News (Updated August 21, 2004)
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By Maggie Fox, Health and Science Correspondent
WASHINGTON, Aug 16 (Reuters) - Statin drugs that lower cholesterol levels and reduce the risk of heart disease may also help slow down the AIDS virus, Spanish researchers reported on Monday.Statins alone given to HIV-infected patients suppressed the virus and helped replenish immune cells known as T-cells -- two key measures of health in patients with the virus.
The drugs seem to stop the virus from infecting cells by stopping them from opening the cell membrane, and stop the virus from getting out of already infected cells, the team at the Spanish Council for Scientific Research in Madrid reported.
"Our results indicate that statins might be suitable antiretroviral drugs for more accessible AIDS treatment," the researchers report in Monday's issue of the Journal of Experimental Medicine.
Human immunodeficiency virus causes AIDS by infecting immune system cells. The virus injects its genetic material into the cells and forces them to become virus factories, pumping out more copies of the virus.
Eventually the immune system is destroyed and patients die of a range of illnesses such as pneumonia. There is no cure and more than 25 million people have died of AIDS globally.
Drugs called highly active antiretroviral therapy or HAART can suppress the virus and allow the immune system to function, but they are expensive and have side-effects.
One side-effect is called lipodystrophy, a series of metabolic changes that can raise cholesterol levels and cause a redistribution of body fat.
Patients with lipodystrophy are often given statins. Immunologist Gustavo del Real and colleagues wanted to see if the statins may themselves affect the course of infection.
They first tested HIV-infected cells in a lab dish and then in mice. "Results suggest that HIV-1 entry into and exit from the host cell require actin cytoskeleton rearrangement and adequate cholesterol levels in host and viral membranes," they wrote in their report.
The cytoskeleton is the structure of the cell itself.
Then they tested six people infected with HIV who had not yet begun HAART therapy. They got lovastatin for a month.
Levels of the virus, measured by genetic material, fell and T-cell count went up. When the patients stopped taking the statin the viral levels rebounded, the researchers reported.
"The data suggest that statins can inhibit HIV-1 replication in
chronically infected individuals, and support future clinical studies of statins
as possible antiretroviral agents," the researchers concluded.
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Wed Aug 18, 5:08 PM ET
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WASHINGTON (AFP) - A new method of screening for HIV/AIDS and hepatitis C is making the US blood supply safer, according to a study.
Nucleic acid-amplification testing has detected the virus in instances where its concentration is too small to be picked up by other screening methods, the study by the National Institutes of Health, published in the August 19 issue of the New England Journal of Medicine, showed.
The new state-of-the-art testing method has helped prevent the transmission of HIV/AIDS in five different cases and hepatitis C in 56 cases, on average, per year between 1999 and 2002, according to the study.
The test "enhances the safety of the nation's blood supply by further reducing these risks (of transmitting HIV and hepatitis C)," said Barbara Alving, acting director of the National Heart, Lung, and Blood Institute.
The test is carried out on around 98 percent of the blood collected in the United States.
Researchers said nucleic acid-amplification testing had reduced the risk of HIV/AIDS and hepatitis infections to about one in two million units of blood, compared with one in 1.5 million for HIV and one in 276,000 for hepatitis when less comprehensive screening methods were used.
The new test has also proved effective in detecting emerging viruses. In 2003, it detected traces of the West Nile virus in blood from nearly 1,000 donors, whose donations were then discarded.
Thu Aug 19, 2004 11:18 AM ET
NEW YORK (Reuters Health) - Even a couple brief sessions with a counselor may
help prevent cases of HIV and other sexually transmitted diseases among people
at greatest risk, new research suggests.
Health officials found that among patients at public STD clinics in five U.S. cities, those who received one-on-one counseling had lower rates of HIV and other sexually transmitted infections over the next year than did patients who received the "educational messages" typically provided with HIV testing.
Most importantly, and unexpectedly, the study authors report, counseling had the biggest effect on the two groups at greatest risk for future STDs -- teenagers and patients who had an STD at the start of the study.
Overall, the researchers found, counseling prevented STDs in a number of higher-risk groups that studies have suggested are hard to reach, including injection-drug users and people who have been tested for HIV in the past.
These findings suggest that counseling has the potential to help most STD clinic patients, according to the researchers, led by Omotayo O. Bolu of the Centers for Disease Control and Prevention in Atlanta.
They report the findings in the journal Sexually Transmitted Diseases.
The study also found that brief contact with a counselor -- a 20-minute session at the time of an HIV test, and another one when the test results were available -- appeared to work as well as four sessions of "enhanced" counseling. Both types of counseling aimed to arm patients with a plan to reduce their STD risk.
The study involved more than 4,300 patients who were followed for a year after receiving either STD counseling or two five-minute talks with a doctor about STD prevention. During the year, 13 percent contracted chlamydia, gonorrhea, syphilis or HIV.
Patients who received counseling, however, were less likely to develop a new STD, particularly when it came to teenagers and individuals who had an STD at the study's start. For these patients, the researchers estimate that counseling prevented eight to 10 percent of STD cases that would otherwise have occurred.
SOURCE: Sexually Transmitted Diseases, August 2004.
Wed Aug 18, 2004 05:16 PM ET
NEW YORK (Reuters Health) - Less that 0.1 percent of blood and tissue donors in
the United States had positive screening tests for HIV between 2000 and 2002,
according to a new study. And the rate of hepatitis C virus was just over 1
percent.
The findings from two studies reported in The New England Journal of Medicine help clarify the risk of transmitting HIV and other viruses with tissue and blood donation in the U.S.
Both studies indicate that nucleic acid amplification testing, which measures genetic material, can help reduce the risk of these infections.
In the first study, Dr. Shimian Zou, from the American Red Cross in Rockville, Maryland, and colleagues analyzed data from 11,391 tissue donors at various centers between 2000 and 2002 to assess the probability of undetected HIV, hepatitis B virus, hepatitis C virus, and human T-lymphotropic virus. These rates were compared with those seen in first-time blood donors.
The researchers determined that the rate of positive screening tests was 0.093 percent for HIV, 0.299 percent for hepatitis B virus, 1.091 percent for hepatitis C virus, and 0.068 percent for human T-lymphotropic virus.
Based on these findings, the probability of viral infection at the time of tissue donation ranged from 1 in 34,000 for hepatitis B virus to 1 in 128,000 for human T-lymphotropic virus. The probability of HIV infection at tissue donation was 1 in 55,000.
The rates for these four infections among tissue donors are lower than in the general population, the investigators point out. However, tissue donors are more likely than blood donors to have undetected viremia at the time of donation.
"The addition of nucleic acid-amplification testing to the screening of tissue donors should reduce the risk of these infections among recipients of donated tissues," the investigators note.
In the second study, Dr. Susan L. Stramer, from the American Red Cross in Gaithersburg, Maryland, and colleagues used nucleic acid-amplification testing to evaluate the rate of HIV and hepatitis C virus infections among donors without detectable antibodies in their blood. More than 37 million units of blood were screened.
Twelve units were confirmed as containing HIV RNA, yielding a rate of 1 contaminated unit per 3.1 million donations. Only two of these units were identified when HIV p24 antigen testing was used. The rate for hepatitis C virus was 1 contaminated unit per 230,000 donations.
Specimens from first-time donors were 3.3- and 4.1-times more likely than those from repeat donors to test positive for hepatitis C virus and HIV, respectively. Testing in 67 hepatitis C virus RNA-positive donors revealed an average period of 35 days between the donation and the appearance of antibodies in the blood.
"Nucleic acid-amplification testing has helped prevent the transmission of approximately 5 HIV-1 infections and 56 hepatitis C virus infections annually and has reduced the residual risk of transfusion-transmitted HIV-1 and hepatitis C virus to approximately 1 in 2 million blood units," the researchers comment.
SOURCE: The New England Journal of Medicine, August 19, 2004.