 Participants received 12 infusions of 0.1 gkg, 0.25 gkg, or 0.4 gkg body weight octagam 10 at 2-week intervals 3 days or 6 infusions of 0.2 gkg, 0.5 gkg, or 0.8 gkg body weight octagam 10 at 4-week intervals 5 days. The effect of the infusions on the reduction of Aβ peptide in CSF and the increase of Aβ peptide in blood plasma was evaluated. 