Have news about HIV? Send press releases, news tips and other announcements to news@poz.com.
April 10, 2008
Most U.K. Patients Start Treatment Without HIV Resistance Info
Nearly two thirds of HIV-positive people starting treatment for the first time in the United Kingdom did so without first finding out if they were infected with a drug-resistant strain of the virus, and one in 10 who did undergo pretreatment testing were found to have at least one mutation known to decrease the sensitivity of the virus to antiretroviral drugs. These new findings, presented at the 6th European HIV Drug Resistance Workshop and reported by the National AIDS Treatment Advocacy Project (NATAP), are similar to data from the United States, where approximately 10 percent of HIV-positive people are infected with drug-resistant strains of HIV.
There are at least two dangers stemming from starting a new regimen without first being tested for HIV drug resistance. First, if patients start treatment that includes one or more of the drugs to which the virus is resistant, the regimen may be less potent or durable. Second, because a less effective regimen may not completely suppress virus, there is an additional risk of HIV acquiring additional mutations, conferring resistance to the other drugs being used.
Anna Maria Geretti, MD, from the Royal Free and University College Medical School in London, and her colleagues studied the medical records of 3,344 people living with HIV who were enrolled in the UK CHIC cohort study. Included in the analysis were 1,175 people who received a genotypic resistance test and who had complete medical records. Eighty-four percent were men, 69 percent were white, and 15 percent were black African. The use of genotypic testing before starting antiretroviral therapy did increase over time, with only 13 percent who started treatment between 1999 and 2001 receiving a test, compared with 50 percent who started treatment between 2004 and 2006.
Ten percent of the people tested for pretreatment resistance were found to have at least one resistance mutation. Six and a half percent had resistance mutations to nucleoside reverse transcriptase inhibitors (NRTIs), 3.8 percent had non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance and 2 percent had protease inhibitor (PI) resistance.
In presenting their data, Geretti’s team recommended, “Selection of first-line [ARV treatment] should take into account the presence of transmitted drug resistance, together with tolerability and other recognized predictors of virological outcomes.”
