New lab test offers better prediction of HIV microbic...( July 9 2009 (BRONX NY) Scientists ...)

July 9, 2009 (BRONX, NY) Scientists at Albert Einstein College of Medicine of Yeshiva University have devised a laboratory test for predicting whether microbicides against HIV are safe for human use. The researchers have also discovered why several supposedly "safe" microbicides made women more susceptible to HIV infection. The study appears today in the online version of the Journal of Infectious Disease.

For years, scientists have been trying to develop a topical vaginal microbicide for preventing transmission of HIV, the virus that causes AIDS. A safe and effective microbicide would help protect women in settings where male condoms are not used a common situation in many cultures. The need for an HIV microbicide is especially urgent in Africa, where AIDS is the leading cause of death and where women account for six out of ten of those living with HIV.

Several microbicide gels have been assessed in clinical trials after passing laboratory and animal safety tests. But with just one exception, all the microbicides were found to be ineffective against HIV; and two of the gels nonoxynol-9 and cellulose sulfate actually increased the risk of HIV infection in women.

"Our goal was to develop assays that are predictive of safety before proceeding to clinical trials that typically cost millions of dollars, involve thousands of women, and take many years," says study leader Betsy C. Herold, M.D., professor of pediatrics, of microbiology & immunology, and of obstetrics & gynecology and women's health at Einstein.

In evaluating a microbicide's safety, researchers look primarily for signs that the chemical inflames cells of the vaginal lining, or epithelium. That could cause more harm than good: When the epithelium becomes inflamed, T cells flock to the damaged area which might actually encourage HIV infection, since T cells are the main targets of HIV.

Dr. Herold theorized that another mechanism may also comp
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