title: Cerebrospinal fluid levels of complement proteins C3, C4 and CR1 in Alzheimer's disease.
abstract: Alzheimer's disease (AD) is strongly associated with loss of synapses. The complement system has been shown to be involved in synaptic elimination. Several studies point to an association between AD and the complement system. The purpose of this study was to examine the association of cerebrospinal fluid (CSF) levels of complement components 3 and 4 (C3 and C4, respectively), and complement receptor 1 (CR1) with AD in 43 patients with AD plus dementia, 42 patients with mild cognitive impairment (MCI) who progressed to AD during follow-up (MCI-AD), 42 patients with stable MCI and 44 controls. Complement levels were also applied in a multivariate model to determine if they provided any added value to the core AD biomarkers Aβ42, T-tau and P-tau. We found elevated CSF levels of C3 and C4 in AD compared with MCI without progression to AD, and elevated CSF levels of CR1 in MCI-AD and AD when these groups were merged. These results provide support for aberrant complement regulation as a part in the AD process, but the changes are not diagnostically useful.
authors.affiliation: Department of Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 405 30, Gothenburg, Sweden. jonny.daborg@physiol.gu.se
authors.forename: Jonny
authors.initials: J
authors.lastname: Daborg
authors.forename: Ulf
authors.initials: U
authors.lastname: Andreasson
authors.forename: Marcela
authors.initials: M
authors.lastname: Pekna
authors.forename: Ronald
authors.initials: R
authors.lastname: Lautner
authors.forename: Eric
authors.initials: E
authors.lastname: Hanse
authors.forename: Lennart
authors.initials: L
authors.lastname: Minthon
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.forename: Oskar
authors.initials: O
authors.lastname: Hansson
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D060825:Cognitive Dysfunction / Q000134:cerebrospinal fluid*; D003176:Complement C3 / Q000134:cerebrospinal fluid*; D003181:Complement C4 / Q000134:cerebrospinal fluid*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000134:cerebrospinal fluid; D011951:Receptors, Complement / Q000378:metabolism*; D016875:tau Proteins / Q000134:cerebrospinal fluid
chemical_list: D016229:Amyloid beta-Peptides; D003176:Complement C3; D003181:Complement C4; D010446:Peptide Fragments; D011951:Receptors, Complement; C075222:amyloid beta-protein (1-42); D016875:tau Proteins