IGHE and Alzheimer disease: AD belongs to the group of “atopic” diseases, which show type I hypersensitive responses to antigens by IgE-mediated mast cell degranulation via cross-linking of the FC \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\upvarepsilon$$\end{document}ε R1A receptor and release of inflammatory mediators [40].