Dynamics of cell-free viral burden in HIV-1-infected patients

Whereas previous cross-sectional studies have shown a 1-2 log increase in cell-free HIV-1 RNA viral burden associated with disease progression, recent longitudinal studies reveal a less dynamic association. We addressed this conundrum in a cohort of 17 rapid and 20 slow progressors. Initial levels of serum viral RNA from the rapid progressors were 1 log unit higher than those from the slow progressors. Serum RNA increased by >0.5 log in 10 of the rapid progressors (increase group), but the remaining seven showed a <0.5 log increase (static group). Patients whose serum RNA increased had lower amounts of serum RNA at study entry but not at follow-up compared with the static group. There was a trend toward lower CD4 counts in the static group at follow-up. These data suggest that the timing of specimen evaluation can influence interpretation of viral RNA dynamics in HIV disease.