Jiang W, Luo Z, Stephenson S, et al. - Given that HIV infection is correlated with increased systemic microbial translocation, neuro-inflammation and sometimes neuronal injury, experts assessed if systemic lipopolysaccharide (LPS) penetrates into the brain and leads to neuro-inflammation in HIV. They measured plasma and cerebrospinal fluid (CSF) LPS levels as well as biomarkers of neuro-inflammation (white blood cell counts and 40 soluble markers) and neurofilament light chain (NfL). In HIV-infected patients, plasma LPS levels were directly associated with various markers of inflammation in both plasma and CSF, as well as with the degree of blood-brain barrier (BBB) permeability but not with CSF NfL. CSF LPS was undetectable in all samples, including three HIV-infected individuals with dementia. Such findings indicate that the extent of microbial translocation associates with neuro-inflammation and BBB permeability in HIV without direct penetration into the central nervous system.