Impaired response to HAART in HIV-infected individuals with high autonomicnervous system activity

Neurotransmitters can accelerate HIV-1 replication in vitro, leading us to examine whether differences in autonomic nervous system (ANS) activity migh t promote residual HIV-1 replication in patients treated with highly active antiretroviral therapy. Patients who showed constitutively high levels of ANS activity before highly active antiretroviral therapy experienced poorer suppression of plasma viral load and poorer CD4(+) T cell recovery over 3- 11 months of therapy. ANS activity was not related to demographic or behavi oral characteristics that might influence pathogenesis. However, the ANS ne urotransmitter norepinephrine enhanced replication of both CCR5- and CXCR4- tropic strains of HIV-1 in vitro via chemokine receptor up-regulation and e nhanced viral gene expression, suggesting that neural activity may directly promote residual viral replication.