Determinants of HIV Set-Point Viral Load

The HIV set-point viral load (spVL), which predicts how rapidly infected patients will progress to AIDS, varies by orders of magnitude among patients. To understand what contributes to this immense variability, investigators analyzed host and viral genetic data from 541 patients with chronic HIV infection before initiation of antiretroviral therapy. Linear mixed models were built to assess contributors to individual differences in spVL.

Polymorphisms in class I HLA genes (a host factor) accounted for 8.4% of the variance, whereas viral genetic diversity accounted for 29%. A joint model that included host and viral genetic factors showed that the viral genetic diversity explained almost all of the variance. Indeed, once viral genetic diversit…