In patients with AD, laboratory test results showed a proportion of eosinophils of 8.22 ± 3.24%, of IgE of 4843.9 ± 4236.3 IU/mL (range 1284 to 13,600), and of eosinophil cationic protein of 84.6 ± 44.5 mg/mL (range 26.7 to 122). Here, IGHE is linked to Alzheimer disease.