Phase II Study of Intravenous Immunoglobulin (IVIg) for Alzheimer's Disease

1. Diagnosis of probable Alzheimer's disease (AD) of mild to moderate severity (as determined by a Mini Mental State Examination (MMSE) score of 14 - 26 inclusive).

2. Ability to give informed consent, designate a decision-maker or have an already recognized decision-maker (such as a legal guardian or health care proxy).

3. Ability to comply with testing and infusion regimen.

4. An able caregiver willing to participate (such as a spouse, child, other relative, close friend, aide or other professional caregiver closely involved in helping the patient take care of himself/herself).

5. Venous access suitable for repeated infusion and phlebotomy.

6. On stable doses of approved AD medications for at least 3 months.

7. As applicable, on stable doses of psychoactive medications (e.g. antidepressants, antipsychotics) for at least 6 weeks.

8. Neuroimaging performed after symptom onset consistent with the patient's diagnosis.

9. Clinical laboratory values within normal limits or if abnormal, judged clinically insignificant by the Principal Investigator.

10. Women who want to take part in this study must either be post-menopausal, surgically sterilized or agree to avoid becoming pregnant during the entire period of their participation in this study

1. Non-Alzheimer dementia.

2. Active renal disease.

3. Abnormally high serum viscosity levels.

4. Immunoglobulin A (IgA) deficiency.

5. Untreated congestive heart failure, unstable angina or a history of recent myocardial infarction.

6. Unstable arrhythmia.

7. Untreated or poorly controlled hypercholesterolemia.

8. Untreated or poorly controlled hypertension.

9. Poorly controlled diabetes.

10. Thrombosis (central or peripheral) in the past year.

11. Modified Hachinski score > 5.

12. Active cancer diagnosis, except basal cell carcinoma.

13. Active autoimmune or neuroimmunologic disorder.

14. History of IVIg treatment in past 6 months.

15. Untreated major depression or other major psychiatric disorders.

16. Known coagulopathy or platelet counts < 100,000.

17. Positive serology for Hepatitis B or C, or HIV.

18. Active migraines or frequent headaches (3 or more times per week).

19. Taking immunosuppressive drugs.

20. Chronic (more than thrice weekly) use of non-steroidal anti-inflammatory drugs (NSAIDs), excluding aspirin 81 milligrams daily.

21. Received an investigational treatment for AD within 3 months of study entry.

22. A history of or current disorder or disease that in a physician co-investigator's judgment may impede the subject's participation in the study, pose immoderate risk to the patient or confound the results of the study