IGHE and Alzheimer disease: In this pilot study, patients with treatment-refractory AD and total serum IgE levels >4,500 kU/L were treated with a total of 10 IA on days 1–5 (week 1) and days 29–33 (week 5) by using adsorption columns that contained polyclonal sheep antihuman immunoglobulin antibodies binding the different human immunoglobulins with similar affinity (referred to as panimmunoglobulin IA) (4).