Multidrug Resistance May Be Lifelong

HIV-positive people infected with virus that is resistant to all three widely used classes of antiretroviral drugs will likely keep that resistance for life, and the virus may never revert back to its original, more drug-susceptible wild-type strain, according to data presented at the Seventh International Congress on Drug Therapy in HIV Infection. Canadian researchers studied 31 HIV-positive adults diagnosed during primary infection. Six patients had three-class resistant virus, while 10 others were resistant to at least one anti-HIV drug. The six multidrug-resistant patients were followed from two to seven years, during which time genetic tests showed that the genetic mutations in their viral infections conveying resistance to the drugs scarcely changed over time. The only specific change seen was that a mutation conveying resistance to Epivir and Emtriva faded; all other genetic mutations persisted. One patient kept exactly the same pattern of mutations conveying resistance to protease inhibitors and nonnucleoside reverse transcriptase inhibitors for seven years. The clinical consequences of infection with multidrug-resistant virus were widely varied, the researchers say, varying from repeated treatment failure to long-term nonprogression. But regardless of the outcome, it is likely that the virus will never become more susceptible to anti-HIV drugs, the researchers conclude.