Alzheimer's disease is the most common form of dementia, characterized by the formation of plaques and tangles in the brain. Trouble is these plaques are not obvious on imaging tests until it is very late. Thus far there is no blood chemistry abnormality that signals the presence of Alzheimer's disease.

However all that could change if the blood test developed at the Stanford University School of Medicine is replicated and validated. The researchers conducted a detailed analysis of 259 blood samples, which were procured from people with and without Alzheimer's disease.

Led by Tony Wyss-Coray, an associate professor of neurology at the Stanford University School of Medicine, the team honed in on 120 plasma proteins, which were vital to cell signaling and communication.

Of these 120 proteins, 18 were found in abundance in people with Alzheimer's disease and could help distinguish these patients from those who do not have the neurological disease.

Researchers were able to correctly diagnose the presence of Alzheimer's disease in 90 percent of the cases using these 18-signalling proteins. Furthermore in 88 percent of the cases, they were also able to refute the presence of Alzheimer's disease.

However when applied to mild cognitive impairment, the protein panel was not so effective as it was able to predict the future development of Alzheimer's 81 percent accuracy. This prediction however was made 30 months in advance of the development of the symptoms.

Reporting in the October 14 online issue of Nature Medicine, the researchers said that the protein panel test was able to identify 20 of 22 patients with mild cognitive impairment who eventually developed Alzheimer's disease two to five years after the test.

The 18 proteins were also found to be involved in the generation of new blood cells and the development of immune processes. If this test is validated, then it could be a big help in protecting Alzheimer's patients from the progressive neurological damage late on in the disease. However all this depends on finding a palliative or a therapeutic treatment for the condition.

Alzheimer's disease: Facts and Figures

* Alzheimer’s disease is a neurological disorder named for German physician Dr Alois Alzheimer. He was the first one to describe the disease in 1906, according to the Alzheimer's Association.

* According to the World Health Organization, an estimated 37 million people worldwide live with dementia - with Alzheimer's disease causing the majority of cases.

* Alzheimer's disease is a degenerative brain syndrome characterized by a progressive decline in memory, thinking, comprehension, calculation, language, learning capacity and judgment.

* About 5% of men and 6% of women over 60 years of age are affected with Alzheimer's.

* The only treatment for Alzheimer's disease at present is supportive. The WHO says the main aim is to maintain the functioning of the individual; reduce disability due to lost mental functions; minimize symptoms such as depression, agitation, suspiciousness and provide support to the affected families

Source: Alzheimer's Association and World Health Organization