Blood-brain barrier permeability correlates with medial temporal lobe atrophy but not with amyloid-beta protein transport across the blood-brain barrier in Alzheimer's disease

BACKGROUND/AIMS: Alterations in the blood-brain barrier (BBB) may play an important role in the pathogenesis and treatment of Alzheimer's disease (AD). We investigated BBB disturbance and its influence on the equilibrium of amyloid-beta protein (Abeta) between plasma and cerebrospinal fluid (CSF) in AD patients. METHODS: We analyzed albumin ratio as a marker of the BBB permeability and correlated it with the severity of dementia, brain atrophy on MRI, apolipoprotein E isoform, CSF levels of total tau, CSF and plasma levels of Abeta 1-40 (Abeta40) and 1-42 (Abeta42), and CSF/plasma ratios of Abeta40 and Abeta42 in 42 AD patients. RESULTS: The albumin ratio was positively correlated with the severity of medial temporal lobe atrophy but not with the other parameters including CSF/plasma ratios of Abeta40 or Abeta42. CONCLUSION: Our results suggest that progression of medial temporal lobe atrophy is associated with increased BBB permeability and that the transport of Abeta across the BBB is not influenced by the BBB alteration in AD.