In the above diagnostic kit, the AD-specific microRNAs are miR-106b, miR-146b, miR-181a, miR-200a, miR-34a, miR-124b, miR-153, and miR-155, and the AD-specific antigens are Aβ1–42 monomer, Aβ1–42 oligomer, UCHL1, NLRP3, Tau, STAT3, SORL1, Clusterin, APOE3, APOE4, Nogo-A, NF-kB, IL-13, and Visfatin. The gene discussed is UCHL1; the disease is Alzheimer disease.