Long-term nonprogressor
Long-term nonprogressors (LTNPs) are individuals infected with HIV, who maintain a CD4 cell count greater than 500, without antiretroviral therapy with a detectable viral load. 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. 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.