In this study, we demonstrated that WBCs, RBCs, HT-22 cells, and primary cultured neuronal cells each express ABCA1, but only HT-22 and primary neuronal cells released exosomes with high ABCA1 expression, which indicates that evaluation of ABCA1-labeled exosomes may provide an approach to eliminate the interference of low miR-193b exosomes released by WBC and RBC, thereby increasing the specificity of AD diagnosis. Here, ABCA1 is linked to Alzheimer disease.