Immunoadsorption for Treatment of Alzheimer's Disease

Inclusion Criteria: * 55-85 years of age * Diagnosis of Alzheimer's disease * Presence of agAAB against alpha1-adrenoceptor * Mini mental state examination (MMSE) score between 19 and 26 * Written informed consent given Exclusion Criteria: * Haemanalysis: * Presence of autoantibodies against the N-methyl-D-aspartate (NMDA) receptor * Defective blood coagulation at time of inclusion * Severe protein deficiency disorders * manifest Vitamin/Folic acid deficiency (substitution allowed) * Active infectious disease, or signs of ongoing infection with C-reactive protein (CRP) \>10mmol/L * Impaired renal function (serum creatinine \>220 μmol/L) * Any disease requiring immunosuppressive drugs or therapeutic antibodies * Non curative treated malignant disease or another life-threatening disease with poor prognosis (survival less than 2 years), except for basal-cell carcinoma * Unstable angina pectoris, atrioventricular block (AV block) 2./3. degree or symptomatic sick sinus syndrome without implanted pacemaker, history of myocardial infarct, bypass or other revascularization measures, valvular heart defect (≥ 2. Degree) * Severely reduced left ventricular systolic function (LVEF \< 30%) and/or heart failure symptoms according to New York Heart Association (NYHA) class III/IV * Clinical manifestation of arterial disease, vascular surgery: No Arteria Carotis Interna (ACI) Stenosis \> 60%, peripheral artery occlusive disease (PAOD) \> IIb, NASCET, no clinical manifest apparent stroke in anamnesis, MRI: no diffusion disorder, no expired territorial stroke * Endocrine disorder excluding diabetes mellitus * Severe hepatic damages (CHILD-Score \< 4) * Severe mental disorders (bipolar disorder, schizophrenia, depression) requiring treatment * Alcohol or drug abuse * Drug therapy against dementia since less than 3 months * Psychopharmacological drug therapy since less than 3 months * Dialysis requirement * MRI contraindications (e.g. heart pacemaker) * Legal tutelage * Previous treatments with IA or immunoglobulin * Inability to undergo the study procedure (IA on five consecutive days with subsequent Immunoglobulin G (IgG) substitution) * treatment with angiotensin-converting-enzyme inhibitors (ACE inhibitors) during the IA (angiotensin receptor blockers (AT-blockers) possible) * Participation in any other clinical/interventional study within less than 30 days prior to screening date