Promising Therapy for Alzheimer's

In what may prove to be a landmark development, a new clinical study has provided encouraging evidence that antibodies derived from human plasma can capture the beta-amyloid protein in blood and exert positive effects on the thinking abilities of patients with Alzheimer's disease (AD).

Intravenous immunoglobulin (IVIg) has been found to contain antibodies that latch onto beta-amyloid proteins in the blood. Prior studies have shown that these antibodies can draw beta-amyloid out of the nervous system and reduce the burden of amyloid on the brain. However, AD patients were found to have lower levels of anti-amyloid antibodies in their blood than cognitively normal individuals their age. Later on, researchers discovered that IVIg contained antibodies to several forms of beta-amyloid, including those thought to play a central role in the development of AD.

In the phase I trial, eight AD patients were treated with IVIg and, to date, seven have undergone cognitive testing after six months of therapy. The testing showed that cognitive function not only stopped declining in all seven patients but also improved in six of the seven.

"If these results are confirmed in larger, controlled trials, we might have a safe Alzheimer's treatment capable of clearing the amyloid protein away,” observed senior researcher Dr. Marc E. Weksler, professor of geriatric medicine at Weill Cornell Medical College (New York, NY, USA).

The AD patients on the study had mild-to-moderate AD and averaged 74 years of age. They received one to four IVIg infusions per month at varying doses. Since the researchers wanted to track circulating levels of beta-amyloid and beta-amyloid antibodies, patients also underwent regular blood tests, as well as spinal taps to collect samples of spinal fluid. Patients were also given standard tests of memory and cognition to assess ongoing changes in their mental function. The study findings were presented at the annual meeting of the American Academy of Neurology in Miami (FL, USA) in April 2005.

In spite of the encouraging results, the scientists and doctors involved remained cautious. "Right now, we'd advise doctors against treating Alzheimer's patients with IVIg,” they stated. "There's still too much we don't know--especially the treatment's long-term effectiveness. We need to confirm these findings in larger, controlled trials before we can say anything definite.”





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Weill Cornell Medical Center