Blood Test Might Predict Alzheimer's

Plasma phospholipid profile associated with memory impairment in next few years

(RxWiki News) It's been difficult to develop a treatment for early Alzheimer's disease without being able to predict who might get it. Researchers may have just found a way to tell who could be at risk for the disease.

The number of people with Alzheimer’s disease could hit 115 million by 2050. Without a good way to predict who will get the disease, little can be done to prevent it in people at risk.

A research team just announced that they have developed a blood test that might predict, with 90 percent certainty, who will get memory impairment that can lead to Alzheimer’s disease in the next few years.

"Talk to your doctor if you have signs of memory loss."

The research team was led by Howard J. Federoff, from the Department of Neuroscience, Georgetown University Medical Center in Washington, DC.

People initially included in the study were 525 people aged 70 and older who lived in the community — not in assisted living or nursing homes.

When the people were given memory testing, 46 people were identified as having early memory loss or mild Alzheimer’s disease (AD group), and 28 others developed memory loss or mild Alzheimer’s disease in the next two years (converter group).

The researchers compared 53 people who did not develop memory loss or Alzheimer’s during the study (control group) with 53 people with memory loss or Alzheimer’s disease (AD group). Included in the AD group were 18 people from the converter group.

Blood was drawn and analyzed on people in both the control and the AD groups. The researchers tested the blood of people who were “converters” twice, once at the beginning of the study and once after developing memory problems.

Using a technique to tell what was different between the blood samples, the researchers identified 10 compounds in the blood that were different in people with Alzheimer’s disease, compared to normal controls.

These compounds were lipid (fat) containing compounds, some amino acids (the building blocks of proteins) and some other chemicals, all of which play a role in the structure and function of normal cell membranes.

Their analysis also showed that, compared to the control group, six of these compounds were lower in people who started the study with normal memory, but experienced memory loss during the study.

The researchers tested a set of blood samples without knowing if the people had Alzheimer’s or not and were able to use the results of their testing to predict with 90 percent accuracy who had the disease.

A benefit of this type of testing, noted the authors is that, “Blood-based biomarkers are not routinely using in clinical practice, but may be more useful because they are easily obtained with less risk of complication in older adults.”

The authors stated that they believe this is the first report of a blood test with very high accuracy for predicting people who will get Alzheimer’s disease, but have no symptoms presently.

"Alzheimer’s disease is a very common and devastating cognitive debility with clinical symptoms of progressive memory difficulties over many years. Clinical symptoms are a result of ongoing cumulative injuries to the brain which are thought to be irreversible," said Sadat Shamim, MD, Director of Inpatient Neurology and Neurophysiology at the Baylor University Medical Center in Dallas.

"It is believed that many treatment strategies have had poor efficacy due to limitations in diagnosing the condition after cognitive function has already been irreparably affected. The search for accurate biomarkers has become increasingly important in determining patients in the preclinical phase of disease when they are most likely to benefit from novel treatments," Dr. Shamim told dailyRx News.

"Dr. Federoff and colleagues have developed a biomarker with the hopes of achieving accurate and easy preclinical diagnosis. If validated by further studies, this biomarker may help researchers target the disease while it is in cognitively salvageable phase," he said.

This study was published in the March issue of Nature Medicine.

Grants from the National Institutes of Health funded the research.

The authors disclosed no conflicts of interest.

Review Date: 
March 8, 2014