Researchers May Have Key To Predicting Alzheimer's — But Do You Really Want To Know?

Hard questions arise on screening for incurable diseases, like Alzheimer's

By Marielle Segarra, WBUR intern

If you could find out with relative certainty that you’ll get a disease that is currently incurable would you want to know?

Relatives of people with Alzheimer’s Disease may begin asking themselves this question in light of new research that could form the basis of an accurate blood test for the disease.

A Scripps Research Institute study published in the journal Cell this month has identified two antibodies that may be markers for Alzheimer’s.

The levels of these antibodies were three times higher in the blood of those with Alzheimer’s Disease than they were in the blood of healthy participants or participants with Parkinson’s Disease.

Typically, antibodies are difficult to identify because they must be located through antigens that trigger them. But the study pioneered a new method, using synthetic molecules, rather than their antigens, to measure antibodies.

If developed further, the test could prove more accurate than any others already in use.

But how could knowing your status affect you when there is no cure?

In a 2009 study, researchers at the Boston University School of Medicine tried to measure how people reacted psychologically to tests predicting their risk of developing Alzheimer’s Disease. The Risk Evaluation and Education for Alzheimer’s Disease (REVEAL) Study used a blood test that looked for a gene that signals an increased risk for the disease, says Denise Lautenbach, Genetic Counselor and REVEAL Project Manager.

Study participants were all told their risk levels for developing Alzheimer’s. One group of participants was evaluated based on each person’s family history, sex, and age. The other participants were evaluated based on the gene blood test and the same factors as the others.

The study found no differences in levels of depression, anxiety, or test-related distress between people who were given the blood test and people who were not, either at the time of the test or in the year following.

But the blood test they used is not 100 percent accurate, Lautenbach says. It can only tell people that they may be likely to develop the disease.

The uncertainty could leave room for hope for some that they will beat the test.

“Just gathering more information about the chance of developing Alzheimer’s Disease doesn’t seem to cause harmful psychological reactions as we’ve seen in our tightly controlled study population,” Lautenbach says. But perhaps that might be different if you learned that you definitely will or will not get this disease.”

If the research at the Scripps Institute does mark the beginning of a yes- or no- answer about Alzheimer’s Disease, those at risk will have to ask whether they want to know for sure.

(While there is no cure, and no fully effective treatment, knowing you’ll get the disease may help you prepare a bit. FDA-approved drugs temporarily slow worsening of symptoms for about 6 to 12 months, on average, for about half of the individuals who take them, according to Alzheimer’s experts and medications are available for memory loss, anxiety, depression and sleep disruption.)

If the test proves accurate, it could effectively function like the test for Huntington’s Disease, a genetic degenerative disorder that can be identified by the a blood test for a certain gene.

The Scripps study, led by Dr. Thomas Kodadek, had 18 participants: 6 healthy, 6 with Alzheimer’s, and 6 with Parkinson’s Disease, which is also a degenerative brain disorder. Although researchers say the results are preliminary, they also say their model – testing for antibodies using synthetic molecules – could be used to predict many diseases that could be treated or cured if found early, such as cancer.

They say the new test for Alzheimer’s could also help scientists ultimately find a cure, by ensuring more accurate trials.

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