Blood test probes the immune system to diagnose Alzheimer’s disease

Computer representation of an antibody (purple Y) binding to its target. [Image: ‘B0007277 Monoclonal antibodies’ from Wellcome Images]

What can our immune system tell us about brain health? Research from Rowan University suggests that the presence of particular antibodies, the means by which our bodies identify threats, can predict if mental decline is an early symptom of a neurodegenerative disease like Alzheimer’s. The research team discovered a set of 50 antibodies that, in a proof-of-concept study, predicted whether a patient exhibiting mild cognitive impairment (MCI) would eventually develop Alzheimer’s disease with 100% accuracy. Furthermore, the test can distinguish between cases of MCI caused by different stages of Alzheimer’s, Parkinson’s disease, and multiple sclerosis, among others.

In a field that has become littered with therapeutic disappointments, a simple and accurate diagnostic test would be a welcome reversal of fortune. Only 60% of MCI patients will develop Alzheimer’s, so identifying this subset is a critical challenge; the onset of Alzheimer’s disease can be slowed in some cases if it’s caught at an early stage. Also, antibody levels can be measured via a blood test, which is a significant improvement over imprecise, symptom-based diagnostic tests and invasive biopsies.

These promising results lay the groundwork for additional experiments that can more thoroughly examine this method’s diagnostic power. Future studies can be made more robust by including more patient samples, employing statistical methods that further mitigate the influence of bias and chance, and incorporating the inherent “randomness” that stems from non-standardized diagnoses of diverse sets of patients. They’re often taken for granted, but diagnostic procedures can be just as powerful as a new drug—knowing where to aim is often half the battle.

Acknowledgments: Many thanks to Adam Brown, a graduate student in the Biological and Biomedical Sciences Program at Harvard University, for providing his expertise and commentary on the topic.

Managing Correspondent: Christopher Gerry

Original Research: Detection of Alzheimer’s disease at mild cognitive impairment and disease progression using autoantibodies as blood-based biomarkers – Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring

Media Coverage: New blood test helps detect MCI stage of Alzheimer’s disease – News Medical