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 (A beta) 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 A beta 1-40 (A beta(40)) and 1-42 (A beta(42)), and CSF/plasma ratios of A beta(40) and A beta(42) 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 A beta(40) or A beta(42). Conclusion: Our results suggest that progression of medial temporal lobe atrophy is associated with increased BBB permeability and that the transport of A beta across the BBB is not influenced by the BBB alteration in AD. Copyright (C) 2007 S. Karger AG, Basel.