Long-term nonprogressors (LTNPs), are individuals infected with HIV, who maintain a CD4 count greater than 500 without antiretroviral therapy with a detectable viral load.
[1] Many of these patients have been HIV positive for 30 years without progressing to the point of needing to take medication in order not to develop AIDS.
[citation needed] They have been the subject of a great deal of research, since an understanding of their ability to control HIV infection may lead to the development of immune therapies or a therapeutic vaccine.
[citation needed] Long-term nonprogressors typically have viral loads under 10,000 copies /mL blood,[3] do not take antiretrovirals, and have CD4+ counts within the normal range.
The Argentinian patient took antiretroviral therapy only while pregnant, but her viral load was nevertheless reported to be undetectable years after treatment discontinuation.