In the present study, we identified a total of six peripheral immune phenotypes significantly associated with a low risk of AD, including four Treg cell-associated immune phenotypes (CD25++ CD45RA- CD4 not regulatory T cell % T cell, CD25++ CD45RA- CD4 not regulatory T cell % CD4+ T cell, Secreting CD4 regulatory T cell Absolute Count and Activated & secreting CD4 regulatory T cell Absolute Count), one monocyte-associated phenotype (HLA DR++ monocyte % monocyte), and one belonging to a dendritic cell subpopulation (HLA DR on myeloid Dendritic Cell). Here, CD4 is linked to Alzheimer disease.