Short-lived 'blips' don't mean virus has gained resistance, study says
WEDNESDAY, Feb. 16 (HealthDay News) -- Sudden, temporary increases ("blips") in the amount of HIV in the blood generally don't mean the AIDS-causing virus is developing resistance to drugs, says a Johns Hopkins University study.
"These results should provide relief to hundreds of thousands of HIV-positive patients in the United States currently taking drug therapy, called highly active anti-retroviral therapy, or HAART, and reassure them that their medications have not failed," senior study author and infectious disease specialist Dr. Robert Siliciano said in a prepared statement.
"Physicians and patients now have a much better idea of when to worry about these blips and when not to worry," added Siliciano, a professor at Johns Hopkins University School of Medicine and an investigator at the Howard Hughes Medical Institute.
He and his colleagues concluded that many of these blips are mathematical variations that stem from the test used to measure the amount of HIV in the body -- called viral load. Unless the blip is higher than 200 copies per milliliter of blood, or is evident in repeated tests, it does not indicate that the virus has mutated and become drug-resistant, the researchers said.
For this study, the Hopkins team performed a detailed genetic analysis of multiple blood samples from 10 people with HIV. The blood samples were collected every two to three days over a period of three months. Blips occurred in nine of the 10 patients, with a median viral load of 79 copies per milliliter of blood.
The blips typically lasted less than three days and weren't related to any demographic (age, gender) or clinical (illness, vaccination, differences in antiretroviral drug regimens) factors. No new HIV mutations were found.
"The lack of any consistency among the tests performed on blood samples confirms that there is no danger from these blips in viral load. These blips can be attributed to random statistical artifact inherent in measurements of very low amounts of virus," study lead author Dr. Richard Nettles, an assistant professor at Hopkins, said in a prepared statement.
The study appears online Feb. 16 in the Journal of the American Medical Association.
SOURCE: Johns Hopkins Medicine, news release, Feb. 11, 2005
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