MAPT and Alzheimer disease: CSF total-tau concentrations have been widely studied in people with Alzheimer's dementia, and age-adjusted thresholds have been proposed but challenged according to differences in methods and disease prevalence.33,34 In PLWH, CSF tau levels were found to be higher in patients with dementia, CNS opportunistic infections and blood–brain barrier impairment, with the highest concentrations in PLWH diagnosed with Alzheimer's dementia.27,35-38 CSF Tau levels found in this study were similar to what was reported by Gisslén et al. 35 in neuro-asymptomatic PLWH.