Using a new technology that relies on thousands of synthetic molecules to fish for disease-specific antibodies, researchers have developed a potential method for detecting Alzheimer’s disease with a simple blood test. The same methodology might lead to blood tests for many important diseases, according to the report published by Thomas Kodadek’s group at the Scripps Research Institute in the January 7th issue of the journal Cell.
The new method relies on the notion that many diseases lead to the production of modified proteins. At some point, the adaptive immune system might begin to recognize those proteins as foreign and mount a response. If tests could be developed to recognize those disease-specific proteins or the antibodies that recognize them, it could be the basis for early diagnosis. But in most cases, researchers have had little luck identifying those abnormal proteins.
Kodadek’s team decided to take a different tack. They used a large library of randomly selected, unnatural molecules known as “peptoids” to screen for antibodies found in the bloodstream of animals or patients with specific diseases and not in healthy controls.
Their method uncovered three peptoids that appear to discriminate between healthy and Alzheimer’s disease blood samples with high accuracy. Three of them reacted strongly to the blood of six patients with the condition, but not that of 16 healthy individuals used as controls. Although this is encouraging the findings must be corroborated by further studies to demonstrate that antibodies can indicate whether the attack opens a picture for diagnosing the disease.
* Reddy MM, Wilson R, Wilson J, Connell S, Gocke A, Hynan L, German D, Kodadek T. Identification of candidate IgG biomarkers for Alzheimer’s disease via combinatorial library screening. Cell 2011 January 7;144:132-142.