A quantitative system for monitoring blood-circulating viral protein R of human immunodeficiency virus-1 detected a possible link with pathogenic indices.

We developed a detergent-free enzyme-linked immunosorbent assay (ELISA) for HIV-1 viral protein R (Vpr), an accessory protein of human immunodeficiency virus type-1 (HIV), and detected soluble Vpr in approximately 22% of HIV patients who were receiving combination antiretroviral therapy (cART) and were free of plasma HIV RNA. Notably, the levels of CD8-positive cell count, soluble intercellular adhesion molecule-1 (sICAM-1) and C-C motif chemokine ligand 2 (CCL2), all of which are markers of chronic inflammation in HIV patients, were higher in Vpr-positive patients than in Vpr-negative patients. Because sICAM1 and CCL2 are associated with an increased risk of HIV-associated neurocognitive disorder, we propose that an established Vpr-ELISA would be useful for monitoring the risk of HIV complications during latent HIV-1 infection.