Thomas Kodadek and co-workers, Scripps Research Institute, USA, team have used a general and unbiased approach to the identification of diagnostically useful antibodies that avoids the requirement for antigen identification. They used a large library of randomly selected peptoids to screen for antibodies in the bloodstream of animals or patients with specific diseases.

As a proof of concept, mice with experimental autoimmune encephalitis were tested. Several peptiods from the few thousand used could distinguish blood samples taken from healthy versus sick mice. The method also identified three peptoids that appear to discriminate between healthy and Alzheimer’s disease blood samples with high accuracy.

Development of a clinically useful test will depend on further validation and the team also plans to test their method in the context of diseases, such as pancreatic cancer, where early diagnosis could have significant implications for patient survival.

• Identification of Candidate IgG Biomarkers for Alzheimer’s Disease via Combinatorial Library Screening
  M. M. Reddy, R. Wilson, J. Wilson, S. Connell, A. Gocke, L. Hynan, D. German, T. Kodadek,
  Cell 2011, 144(1), 132-142.
  DOI: 10.1016/j.cell.2010.11.054