Hair Samples Determine HIV Drug Treatment Success

Researchers and scientists have used hair samples for years for reasons ranging from DNA analysis to drug testing. Now, researchers at the University of California in San Francisco have determined yet another way hair samples can help – this time in the fight against the HIV/AIDS epidemic.

In an article published recently in AIDS, researchers have determined that hair samples from HIV-infected patients that indicate high levels of antiretrovirals is directly correlated to how well a patient will respond to their drug therapy. According to the lead investigator of the study, Monica Gandhi, an assistant professor at UCSF, “High levels of antiretrovirals in hair correlated with success in HIV viral suppression in treatment and did so better than any of the other variables usually considered to predict response.”

In the past, doctors had several different ways to determine if patients were taking their antiretroviral drugs on a consistent basis, including asking the patients, counting out remaining pills or investing in costly medicine dispensers. Unfortunately, each of these methods relies solely on the patient and, historically, they have not been a good measure of how successful a drug treatment would be.

Another way to determine how well the treatment has been going is through a blood draw and a measure of the plasma for the medication levels. However, Gandhi points out that the blood draw is good only in determining medicine levels from hours previous to the draw and is not a good indicator of drug treatment successor or a good predictor of how well the virus is suppressed. Gandhi goes on to note that medicine levels vary drastically from day to day and could simply be a reflection of a patient correctly taking their pills in preparation for their visit to the clinic.

On the flip side, hair samples are able to give accurate readings of medicine and drug levels that reflect their consumption over a period of weeks as opposed to a period of a few days. Ruth Greenblatt, a professor of clinical pharmacy at UCSF and a co-author of the study, states, “Hair sampling for antiretroviral levels could become a new standard to look at how much drug a patient is getting—an equivalent in HIV clinical care of measuring hemoglobin A1C, the method used in diabetes to monitor average blood glucose levels.”

Researchers in the study took ten hair strands from HIV-infected patients on drug treatments and stored them wrapped in foil and in a plastic bag until they could be analyzed. Gandhi explains, “This is a painless, bloodless, biohazard-free, method of collecting a stable specimen from HIV patients that may allow for the monitoring of levels of antiretroviral drugs absorbed over time and the prediction of treatment success. Our next step is to test this method in resource-limited settings where blood collection and viral load monitoring may be expensive and difficult. Not only could this method help in measuring pill-taking, but its strong correlation with viral suppression could allow its use as an inexpensive, non-invasive method of monitoring treatment success in particularly challenging settings.”