A Skin Test for Alzheimer's Disease

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Alkon's test is just one in a number of new approaches to early detection, including measuring molecules linked to the disease in blood and cerebrospinal fluid, as well as new brain-imaging markers that can detect signs of Alzheimer's, such as buildup of the protein beta-amyloid--a hallmark of the disease. "A number of these tests have been successful in separating Alzheimer's patients from normal subjects, but most of them have not as yet compared those with AD to those with other neurological diseases, such as ALS," says Gilman.

The new research is "interesting and promising, but we need to know how specific it will turn out to be," he says. "There is a history of tests that are in the news and then disappear quietly."

Alkon says that the skin test can distinguish between other types of neurological diseases, such as Parkinson's, Huntington's, and Lewy body disease--a finding that he aims to confirm in larger clinical trials. He also hopes to confirm the test's ability to diagnose Alzheimer's early on--within four years of when a patient first notices memory problems. Clinical diagnosis within this period can be hit or miss, with accuracy rates as low as 55 percent.

Alkon is also planning a small clinical trial of an experimental drug called bryostatin, originally tested as an anticancer drug, for Alzheimer's. At low concentrations, the drug activates PKCs. Developing drugs that target PKCs has been somewhat difficult because some can trigger the formation of tumors. But Alkon says that he has identified structural variations in these molecules that predict which ones potentially cause tumors. His team has developed a number of novel PKC-activating compounds, which he eventually hopes to test in clinical trials.