IGHE and Alzheimer disease: Multivariate logistic and linear regression analyses were performed to identify independent determinants of disease severity, considering age, sex, eosinophil counts, total IgE, food allergies, and baseline immunoglobulin levels.<h4>Results</h4>The prevalence of hypogammaglobulinemia among the 1850 screened children with AD was 10.8% (200/1850).