IGHE and Alzheimer disease: At the molecular level, AD pathogenesis involves multiple key immune pathways: Th2 cell-mediated IL-4 and IL-13 signaling triggering inflammation and IgE production (38), Langerhans cell-mediated responses through antigen presentation and cytokine secretion (39), autoimmune responses including IgE autoantibody production and autoreactive T cell activation (40), and Th2/Th17 cytokine imbalance mediated through JAK signaling (41).