de Almeida SM, et al. - Researchers aimed at analyzing the impact of HIV subtype on neprilysin (NEP)-mediated cleavage of Aβ by comparing cerebrospinal fluid (CSF) and serum levels of NEP between HIV+ (27 patients with HIV-1B and 26 with HIV-1C), healthy HIV- controls (n = 13), and patients with Alzheimer disease (n = 24). HIV subtype was noted to have an influence on NEP. Lower ratio of NEP/Aβ-40 on serum was noted on HIV1-C than HIV1-B. These results were in line with the results of CSF Aβ-42 levels decreased in HIV1-C compared with HIV1-B, indicating higher amyloid β deposit on HIV1-C than HIV1-B.