New campus collaboration combines brain imaging techniques with saliva sampling to identify early indicators of cognitive decline in elderly populations

Beth Thomas Saliva

A new cross-campus collaboration at the University of California, Irvine would advance research aimed at improving the diagnosis, prevention and treatment of patients with neurodegenerative diseases.

The UCI Institute for Interdisciplinary Salivary Bioscience Research (IISBR) and the UCI Center for the Neurobiology of Learning and Memory (CNLM) have joined forces to investigate associations between salivary cytokines – proteins that influence interactions between cells – and imaging biomarkers in elderly participants who suffer from Alzheimer’s and dementia.

Alzheimer’s disease is the most common cause for dementia in older people, and currently over five million people suffer from this degenerative condition in America. Identifying early biomarkers, prior to the onset of overt disease symptoms, is of critical importance to the field. It is thought that early intervention during the pre-symptomatic stage will be more effective than later intervention, once the neurodegenerative cascade, or the decline of brain function, has begun.

While the causes of Alzheimer’s Disease are not fully understood, research shows that different cytokines play an active role in initiating neurodegeneration by producing different inflammatory responses.

Through collaborative, interdisciplinary research, we’re coming closer to understanding how potential salivary biomarkers of early cognitive decline could enhance future Alzheimer’s Disease screening efforts.”

Dr. Thomas

Pilot studies led by IISBR faculty member and researcher with the UCI Program in Public Health, Beth Thomas, PhD, and UCI Program in Public Health epidemiology postdoctoral fellow, Georgia Parkin PhD, have validated a salivary immunoassay to simultaneously measure ten different cytokines, including commonly studied interleukins (IL), IL-1B and IL-6, in the same sample.

“Saliva sampling is non-invasive and easy to collect, which makes it a great alternative to the traditional blood sampling methods that many elderly patients find uncomfortable and cumbersome,” Thomas said. “Through collaborative, interdisciplinary research, we’re coming closer to understanding how potential salivary biomarkers of early cognitive decline could enhance future Alzheimer’s Disease screening efforts.”

The next steps will look at the associations between levels of these salivary biomarkers and sensitive cognitive measures. Those findings would then be analyzed against the imaging data (MRI and PET scans) of 60 participants that have already been collected. “Exciting preliminary data has already been generated, which show correlations between salivary IL-6 and imaging markers (or white matter) in the cortex that are early signs of cognitive decline,” Thomas added.

“There is a great need, across disease indications, for non-invasive monitoring and biomarkers that are linked to neurocognitive dysfunction. We could not be more excited about our collaboration with IISBR to break new ground in space,” said Mike Yassa, PhD, Professor of Neurology and Director of CNLM.