Short Course of IVIG May Slow Brain Atrophy and Conversion to Dementia in Persons with MCI Stage Alzheimer’s Disease

An exploratory controlled, randomized, double-blind study was conducted by investigators at the Sutter Neuroscience Institute in Sacramento to determine whether a single course of intravenous immune globulin (IVIG) influences the rate of brain atrophy and cognitive function in mild cognitive impairment (MCI) due to Alzheimer’s disease (AD). Fifty participants aged 50 years to 84 years with amnestic MCI were administered 0.4 g/kg of 10% IVIG or 0.9% saline every two weeks for a total of five infusions (2 g/kg total dose). Brain magnetic resonance imaging (MRI) was completed at baseline, 12 months and 24 months; average annualized percentage change in ventricular volume was computed as a measure of brain atrophy. Cognitive testing was completed at baseline and every four months thereafter.

At 12 months post-treatment, subjects in the IVIG group experienced significantly less brain atrophy (-5.87%) than those in the placebo control group (8.14%) (p=0.037, adjusted for MCI status); at 24 months, the relative reduction in brain atrophy in the IVIG group no longer reached statistical significance. Participants stratified into the late MCI stage who received IVIG performed better on AD Assessment Scalecognitive subscale (ADAS-Cog; p=0.011) and Mini-Mental State Examination (MMSE; p-0.004) at one year; however, these differences were no longer present after two years. While after two years there was no difference in conversion to AD dementia between the IVIG and control groups, after one year there were fewer conversions from late MCI to AD dementia in the IVIG group (33.3%) when compared with the control group (58.3%).

This study provides limited evidence that a short course of IVIG given in the MCI stage of AD reduces brain atrophy, slows cognitive decline in late MCI and delays conversion to AD dementia for at least one year; however, its effect appears to wane by two years.