CD4 and Alzheimer disease: Regarding T-cells count in AD, although several studies aimed to evaluate the immune system in people with dementia found no change at any stage of disease progression for total T cells (CD3), CD4 or CD8 T cells [38,39], according to our results, other reports have demonstrated how disease progression in AD seems to parallel with an increase of CD4+ T cells in the advanced stages of the disease [24,40].