Blood test for Alzheimer’s disease shows promise

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AUSTIN: Researchers have developed and validated a blood-based biomarker profile with high sensitivity and specificity for Alzheimer's disease (AD), according to a report published in the September issue of the Archives of Neurology.

Sid E. O'Bryant, PhD, from Texas Tech University Health Sciences Center in Lubbock, and colleagues in the Texas Alzheimer's Research Consortium analyzed serum protein-based multiplex biomarker data from 197 patients diagnosed with AD and 203 control patients without AD.

Using statistical analyses, the authors created a biomarker risk score, which included levels of numerous proteins, many of which have been associated with inflammation.

"The diagnostic accuracy of the blood test is very good," Dr. O'Bryant noted in a telephone interview with Medscape Medical News, with a sensitivity and specificity of 0.80 and 0.91, respectively, and an area under the curve of 0.91 in detecting AD. Dr. O'Bryant and several coauthors are listed on a pending patent on this biomarker algorithm.

When the investigators combined the biomarker risk score with the key clinical variables of age, sex, education, and apolipoprotein E status, the sensitivity, specificity, and area under the curve were 0.94, 0.84, and 0.95, respectively.

According to the investigators, a "disproportionate number" of inflammatory and vascular markers were weighted most heavily in their analyses, and these markers "consistently distinguished cases from controls."

This, they say, points to the existence of an inflammatory-related endophenotype of AD, "which could offer targeted therapeutic opportunities for this subgroup of patients."