A single intraventricular injection of anti-beta-amyloid significantly decreased beta-amyloid accumulation and general inflammation in brains of mice genetically engineered to develop early and late forms of Alzheimer’s disease, according to a presentation at the annual meeting of the American Association of Neurological Surgeons.

Researchers have previously demonstrated that antibodies injected into the periventricular region of the brain easily reach crucial areas affected by Alzheimer’s disease, but not without serious side effects. Removal of excessive cerebral beta-amyloid has been shown to be effective in the treatment of Alzheimer’s disease, but systemic passive immunization against beta-amyloid has been shown to be associated with serious inflammatory problems secondary to antibodies reacting to beta-amyloid in normal structures such as blood vessels.

In the current study, the injections were done in mice genetically engineered to develop Alzheimer’s disease at both an early and late stage of the disease. A single intraventricular injection of antibodies against beta-amyloid substantially reduced the amount of amyloid in the brain by approximately 70 percent, even in animals with a relatively severe stage of the disease. Associated inflammatory responses also were reduced.

Furthermore, there was no sign of serious inflammatory problems like meningoencephalitis or perivascular hemorrhage, which were seen in earlier studies when similar antibodies were injected systemically, such as with intranasal methods of delivery.

The outcome of this study suggests that periodic intraventricular administration of antibodies against beta-amyloid is a potentially useful method for rapid reduction of both pre-existing amyloid plaques and associated inflammation. In addition, this method of passive immunization may be safer than other methods used because there were no associated inflammatory side effects in the brain.

“The data reported in this study provide strong support for a new approach in the treatment of Alzheimer’s disease using a strategy involving injection of antibodies into the brain, without the serious side effects implicated in prior immunization strategies,” said Terry Lichtor, MD, PhD, presenter.