New tests may help predict Alzheimer's: conference

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - New tests involving blood and brain scans can detect symptoms of Alzheimer's disease, and brief appraisals of real-life functioning can predict who is likely to develop it, researchers said on Sunday.

The tests will be critical, experts told a meeting on Alzheimer's disease, because more than 26 million people now have the brain-wasting disease and this number will quadruple, to 106 million, by 2050.

"By 2050, 1 in 85 persons worldwide will have Alzheimer's disease," said Ron Brookmeyer of Johns Hopkins University, who led the study on how many people have the disease.

No drugs can significantly affect Alzheimer's disease, although four have a very modest impact if given early on.

The disease is very difficult to detect until it has progressed from mild memory loss to clear impairment. Patients eventually lose all ability to care for themselves.

Detecting the disease early can help patients and their families plan better for the future but can also help researchers develop drugs to treat and perhaps even prevent the disease.

Anders Lonneborg and colleagues of DiaGenic, a biotech company based in Oslo, Norway, found a set of 96 genes that look different in the blood of Alzheimer's patients when compared to the same genes in healthy people.

Their study of more than 100 older people, half from memory clinics and half from senior centers, found Alzheimer's accurately 85 percent of the time.

They identified genes related to the immune system, to inflammation and to cell division. The company has applied to regulators in the United States and Europe to approve the test, Lonneborg told a meeting of the Alzheimer's Association in Washington.

BRAIN SCANS

Christos Davatzikos and colleagues at the University of Pennsylvania used a combination of PET and MRI scans to diagnose Alzheimer's.

Positron emission tomography or PET scans can be used to measure blood flow in the brain in real time, while magnetic resonance imaging or MRI can clearly show the shape and size of physical structures in the brain.

This method correctly found all 15 cases of mild cognitive impairment -- a first step towards Alzheimer's -- and cleared 15 healthy volunteers.

"This abnormal pattern of brain structure and blood flow detected not only mild cognitive impairment but even earlier ... when they were clinically normal," Davatzikos told the news conference.

Deborah Barnes and colleagues at the University of California San Francisco developed a more low-tech approach that might be used by a family doctor.