Hair used to 'manage' Aids

2009-03-11 14:08

New York - A hair sample analysis could be more effective than a blood test in determining if anti-Aids drugs are effective in patients, researchers said.

Dr Monica Gandhi, of the University of California, San Francisco, said blood levels may not reflect how well the patient is adhering to treatment, and other factors such as diet and medications can cause variability.

But hair samples reflect drug exposure over time.

"We ... plan to test this method in resource-limited settings, such as in India or Africa, where blood collection and (HIV) monitoring may be expensive and difficult," said Gandhi, who reported the findings in the journal Aids.

She and her team measured anti-Aids drug levels in hair samples from 224 women who were starting a new antiretroviral regimen. Sampling required 10-20 hair strands, clipped close to the scalp.

Hair drug levels

As hair levels of the drugs increased, so did the likelihood that HIV levels were successfully reduced, the report shows.

If hair drug levels are high, but HIV levels continue to rise, it suggests that the virus may have become resistant to the antiretroviral agents being used, Gandhi said.

If hair drug levels fall and HIV levels increase, it suggests that either the patient is not adhering with treatment or is using a new drug that is reducing the absorption of the antiretroviral drug.

Gandhi's group also plans to examine the relationship between drug levels in hair and side effects of the antiretroviral drugs.

The purpose would be to see if some patients can lower their dose of antiretroviral drugs to reduce rate of side effects, while still having a treatment response, the investigator explained.