ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Tuesday, May 7, 1996 TAG: 9605070105
SECTION: NATIONAL/INTERNATIONAL PAGE: A-3 EDITION: METRO
DATELINE: WASHINGTON
SOURCE: Associated Press
Federal officials are moving swiftly to start new human research to see if a synthetic hormone used in popular injectable contraceptives increases the risk of AIDS virus infection. The action was prompted by monkey research that suggested the connection.
A study at the Aaron Diamond AIDS Research Center in New York City demonstrated that monkeys injected with progesterone were seven times more likely to become infected when exposed vaginally to simian immune deficiency virus, or SIV.
``It was a very striking result and one that we did not anticipate,'' said Dr. Preston Marx of the New York University School of Medicine, leader of the research team. A report on the findings was presented Monday to a meeting of clinical researchers.
Progesterone is a natural hormone, but a close synthetic chemical relative, progestin, is used in two injectable contraceptives that are widely sold in the United States.
Dr. Duane Alexander, director of the National Institute of Child Health and Human Development, which funded the monkey study, said his agency was ``moving as quickly as possible to follow up on these research findings.''
``We need to understand the transmission mechanism that is apparently at work in these cases and we need to determine whether it may be applicable to humans,'' Alexander said in a statement. Alexander noted that Marx used natural progesterone in his study and it is not known if the synthetic progestin, used in the contraceptives, will have the same effect.
Marx said a study is planned in which biopsies will be taken periodically from women volunteers to determine if progestin thins the vaginal lining.
Earlier animals studies, he said, found that progesterone can cause the lining of the vagina to become thinner. He said his team conducted the new study on monkeys to determine whether the change in the lining made it easier for virus to cross the mucous membrane barrier within the vagina and then infect cells in the circulating blood.
In the study, pellets of progesterone were implanted under the skin of 18 female rhesus monkeys. Ten other female monkeys received only a placebo.
All of the monkeys were then exposed vaginally to SIV, a virus that causes an AIDS-like disease in monkeys. SIV is closely related to HIV, the virus that causes AIDS in humans.
After 21 days, 14 of the 18 monkeys that received the progesterone were infected with SIV. Only one of the 10 monkeys in the placebo group was infected.
Marx said the study demonstrates that the thinning of the vaginal wall by progesterone increases the ability of the virus to cause infection in monkeys.
``The vaginal lining is a strong barrier against infection. That's the way it is supposed to function,'' he said. ``Progesterone will thin that barrier.''
Two contraceptives marketed in the United States, Depo-Provera and Norplant, contain synthetic hormones called progestins that mimic many of the effects of progesterone. About 1.5 million American women use Depo-Provera and about 1 million use Norplant.
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