Smoldering in the sanctuary: HIV-associated brain injury in the ART era.

Although combination antiretroviral therapy (ART) has dramatically reduced the incidence of severe HIV-associated neurological disease, the central nervous system (CNS) remains a viral sanctuary in which inflammation and brain injury persist despite systemic viral suppression. Here, we synthesize evidence that ongoing HIV-associated brain injury is sustained not primarily by unchecked viral replication but by persistent viral transcription from defective proviruses, immune-mediated synaptic dysfunction driven by bystander activation, and long-lived microglial reprogramming shaped by epigenetic "training." We highlight how emerging single-cell multiomics and "liquid biopsy" approaches are redefining our understanding of the CNS reservoir at high resolution. We further discuss the growing emphasis on biologically anchored, molecularly defined disease subtypes as a means to disentangle HIV-specific pathology from the confounding overlap of aging and multimorbidity, which have increased in the ART era. Finally, we underscore the necessity of human-centered translational studies to validate preclinical findings, outlining how these molecular insights pave the way for precision therapeutics and CNS-targeted cure strategies.