Among 167 participants, 38.3% were late presenters (LPs) (presenting for care with a CD4+ T-cell count < 350 cells/mm3 or after an AIDS-defining event), and 21.6% were late presenters with advanced disease (LPs-AD) (presenting for care with a CD4+ T-cell count < 200 cells/mm3 or after an AIDS-defining event). This evidence concerns the gene CD4 and Alzheimer disease.