Pittsburgh Compound-B and Alzheimer's Disease Biomarkers in CSF, Plasma and Urine: An Exploratory Study

Background: The positron emission tomography (PET) radiotracer Pittsburgh Compound-B (PIB) is an in vivo ligand for measuring beta-amyloid (A beta) load. Associations between PET PIB and cerebrospinal fluid (CSF) A beta 1-42 and apolipoprotein E epsilon 4 (APOE epsilon 4) have been observed in several studies, but the relations between PIB uptake and other biomarkers of Alzheimer's disease (AD) are less investigated. Method: PET PIB, PET 18Fluoro-2-deoxy-D-glucose and different AD biomarkers were measured twice in CSF, plasma and urine 12 months apart in 10 patients with a clinical diagnosis of mild to moderate AD. Results: PIB retention was constant over 1 year, inversely related to low CSF A beta 1-42 (p = 0.01) and correlated positively to the numbers of the APOE epsilon 4 allele (0, 1 or 2) (p = 0.02). There was a relation between mean PIB retention and CSF ApoE protein (r = -0.59, p = 0.07), and plasma cystatin C (r = -0.56, p = 0.09). Conclusion: PIB retention is strongly related to CSF A beta 1-42, and to the numbers of the APOE epsilon 4 allele. Copyright (C) 2010 S. Karger AG, Basel