Antibody Trips Up Alzheimer’s a Bit

Alzheimers treatment trial found immunoglobulin to slightly alter plaque growth

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) The race to find a treatment for Alzheimer's disease has led to trying medications that work for other diseases. One particular medication has shown some positive signs of slowing down signs of Alzheimer's progression.

Researchers recently tested the use of antibodies — or by-products of the immune system that naturally occur in the blood to fight off bacteria and viruses — to treat mild to moderate Alzheimer’s disease.

These researchers found people given this immune system treatment had a slight reduction in the development of protein deposits in the brain that are associated with Alzheimer's disease.

"Talk to your doctor about Alzheimer’s treatments."

Norman Relkin, MD, PhD, of Weill Cornell Medical College and the Cornell Memory Disorders Programs, has been working on testing possible treatments for mild to moderate Alzheimer’s disease.

Dr. Relkin's Phase III clinical trial was part of the Gammaglobulin Alzheimer’s Partnership (GAP) Study. In this trial, the researchers set out to test whether antibodies from the immune system could help treat people with mild to moderate Alzheimer’s disease. 

Antibodies are part of the body's immune system, which work to fight off infections and inflammation in the body.

With Alzheimer's disease, there is a build-up of a certain type of plaque in the brain, which gets in the way of normal brain functioning. The researchers in this clinical trial set out to see if giving antibodies to a person with mild to moderate Alzheimer's disease could slow down mental decline and help patients maintain better thinking abilities over time. 

Immunoglobulin is an antibody found in the blood. It can be extracted from blood donors. Intravenous immunoglobulin (IVIG) therapy is a treatment in which immunoglobulin is fed through a tube with a needle directly into a vein.

IVIG is FDA-approved for treating certain, serious immune system problems and infections.

The GAP study recruited 390 people from 45 centers in Canada and the US and split them into the IVIG or the fake IV arms of the study. Each participant was given an IV treatment every two weeks for 18 months.

The researchers had the participants undergo blood tests and brain scans, as well as two widely used mental functioning tests.

The participants were also tested for a gene that has been associated with the risk for developing Alzheimer’s disease — APOE-e4.

The blood tests showed that the immunoglobulin worked its way into the brain and spinal cord.

Compared to participants receiving the fake IV, the IVIG participants had less Alzheimer’s-specific plaque on their brain scans after receiving 400 mg per kg every two weeks for 18 months.

"It is important to say that the GAP study results do not provide grounds for prescribing IVIG in Alzheimer’s disease," Dr. Relkin said in a press release.

However, Dr. Relkin went on to say that the discovery that IVIG affected the Alzheimer's-specific plaques and antibody levels in the blood and brain was noteworthy. This research shows that with IVIG, antibodies can travel through the bloodstream and reach the brains of people with Alzheimer's disease, Dr. Relkin said. 

He suggested further studies on IVIG would be necessary before it could be a recommended therapy for Alzheimer’s disease.

The participants were also taking existing Alzheimer’s disease medications while undergoing IVIG therapy for the trial.

IVIG is priced by the gram and can run between $1,000 and $10,000 per treatment, depending upon location and insurance coverage.

These trial results were presented at the Alzheimer’s Association International Conference in Boston, MA, July 13-18, 2013. This research has not been published in a peer-reviewed journal. As such, all findings should be considered preliminary.

This trial was supported by Baxter, the Alzheimer’s Disease Cooperative Study, the National Institute on Aging and the National Institutes of Health.

Review Date: 
July 16, 2013
Last Updated:
August 1, 2013