HIV-positive people who have previously shown signs of drug resistance can have drug-resistant virus persist for years in the body despite successful antiretroviral treatments, Reuters Health reports. Doctors in Belgium studied 11 patients on successful anti-HIV drug regimens for an average of 59 months, all of whom had drug-resistant virus detected in their blood before beginning their successful treatment programs. After nearly five years of suppressing HIV to undetectable levels in their blood through anti-HIV drugs, 10 of the study subjects still had drug-resistant HIV in peripheral blood mononuclear cells.
"We were able to show that all drug-resistant HIV-1 variants that arise during therapy failure remain archived in the cells of the infected person for a very long period of time--at least seven years and most probably much longer," lead researcher Chris Verhofstede of Ghent University Hospital told Reuters Health. The resistance was detectable "even if drug pressure was removed or if a patient subsequently responded well to a new drug combination. These findings indicate that once resistance arises against an antiretroviral, the activity of this drug will remain reduced for several years and possibly lifelong, even after a withdrawal period of years."
The full study, titled "Drug-Resistant Variants That Evolve During Nonsuppressive Therapy Persist in HIV-1-Infected Peripheral Blood Mononuclear Cells After Long-Term Highly Active Antiretroviral Therapy," appears in the Journal of Acquired Immune Deficiency Syndromes.