September 16, 2010

Biomarkers In Blood Could Classify People With Alzheimer’s Disease

(Ivanhoe Newswire) -- Biomarkers in blood serum can be combined with clinical information to accurately classify patients with Alzheimer's disease.  If only biomarkers in blood serum could make our tax forms easier and more accurate.

"There is clearly a need for reliable and valid diagnostic and prognostic biomarkers of Alzheimer's disease, and in recent years, there has been an explosive increase of effort aimed at identifying such markers," which authors from the study are quoted as saying.  "It has been previously argued that, because of significant advantages, the ideal biomarkers would be gleaned from peripheral blood."

Sid E. O'Bryant, Ph.D., of Texas Tech University Health Sciences Center, Lubbock, and his colleagues in the Texas Alzheimer's Research Consortium analyzed proteins in the serum of 197 patients diagnosed with Alzheimer's disease and 203 controls without.  The researcher created a biomarker risk score, which included levels of a number of protein biomarkers, including fibrinogen (a clotting protein), interleukin-10 (associated with the immune system) and C-reactive protein (an inflammatory marker).

The concluding biomarker risk score accurately identified 80 percent of the individuals with Alzheimer's disease and correctly excluded 91 percent of the individuals without the disease.  When other factors were brought into the equation such as age, sex, education and whether or not the individual had the APOE gene, the score appropriately identified 94 percent of the individuals with Alzheimer's disease and correctly classified 84 percent of the individuals without the disease.

"In addition to offering more accessible, rapid and cost- and time-effective methods for assessment, biomarkers (or panels of biomarkers) also hold great potential for identification of endophenotypes within Alzheimer's disease populations that are associated with particular disease mechanisms," the authors from the study added.  In the current study, "a disproportionate number of inflammatory and vascular markers were weighed most heavily in the analyses."

"The identification of blood-based biomarker profiles with good diagnostic accuracy would have a profound impact worldwide and requires further validation," the authors concluded.  "Additionally, the identification of pathway-specific endophenotypes among patients with Alzheimer's disease would likewise have implications for targeted therapeutics as well as understanding differential progression among diagnostic cases.  With the rapidly evolving technology and the analytic techniques available, Alzheimer's disease researchers now have the tools to simultaneously analyze exponentially more information from a host of modalities, which is likely going to be necessary to understand this very complex disease."

SOURCE: Archives of Neurology, September 2010