One of the major reasons that treatment for HIV/AIDS often doesn't work as well as it should is resistance to the drugs involved. Now, scientists at McGill University have revealed how mutations hidden in previously ignored parts of the HIV genome play an important role in the development of drug resistance in AIDS patients. Their study will be published Aug. 8 in the Journal of Biological Chemistry.
"HIV develops resistance very rapidly, and once that happens, drugs don't work as well as they theoretically should, or they stop working altogether," explained Dr. Matthias Götte, an associate professor in McGill's Department of Microbiology and Immunology. "Physicians routinely have the patient's virus tested for resistance in advance of treatment to help make the appropriate clinical decisions."
The study was conducted by a team of researchers led by Dr. Götte at McGill's Faculty of Medicine, with assistance from the B.C. Centre for Excellence in HIV/AIDS at the University of British Columbia (UBC). It was funded by the Canadian Institutes for Health Research (CIHR).
HIV genotype testing is now widely established in HIV drug resistance screening. However, for technical and economic reasons, the entire HIV genome is usually not sequenced.
"The focus has been on specific areas of the HIV genome where we expect these resistance-conferring mutations to occur," Dr. Götte said. "We focus on a particular sequence on an important gene from amino acid 1 to 300, and as such, we miss roughly a third of this gene. Until recently, most researchers believed that this hidden area was of little clinical significance."