Leaky Blood-Brain Barrier May Be Early Biomarker for Cognitive Dysfunction

In a study published in the journal Nature Medicine, researchers showed a correlation between damage of capillaries in the hippocampal region and early cognitive dysfunction, irrespective of differences in the Alzheimer’s disease biomarkers Aß and tau. In this study, capillary damage was examined with dynamic contrast-enhanced MRI and cerebrospinal fluid (CSF) levels of the putative marker for capillary damage, soluble platelet-derived growth factor receptor-ß (CSFPDGFRb). 

Both individuals who were cognitively normal and those who had early cognitive impairments, but not those with vascular cognitive impairments, were included in the study. Individuals with more cognitive impairments had higher levels of CSFPDGFRbcompared with those who had no cognitive impairment but did not have differences in CSF levels of Aß or tau. Regional blood-brain barrier (BBB) was also examined using gadolinium contrast in dynamic contrast-enhanced MRI to examine if capillary damage varied among specific brain regions. Individuals with cognitive impairments had increased BBB breakdown in the hippocampus, parahippocampal gyrus, but not in other areas of the brain that was also independent of Aß and tau levels. 

The study authors suggest that BBB breakdown could be an early, independent marker of cognitive impairment that should be studied along with Aß and tau.