Where Does Rebounding HIV Come from When Treatment Is Stopped?

In almost all infected patients, HIV rebounds when antiretroviral therapy (ART) is stopped. The source of rebounding virus is thought to be latently infected resting memory T cells in blood. Now, investigators have found evidence that virus may emerge from multiple sources.

Twelve HIV-infected patients with virologic suppression on ART stopped therapy under close supervision; plasma HIV RNA was measured three times weekly, and ART was reinitiated as soon as viremia was detected. The median time to HIV rebound was 14 days (range, 5–29 days). CD4 counts declined from a median of 561 to 452 cells/mm³, but quickly returned to baseline following ART resumption; all patients again achieved an undetectable viral load. No patient had clinical sympto…