Cerebrospinal fluid levels of complement proteins C3, C4 and CR1 in Alzheimer’s disease

• Published in: Journal of Neural Transmission Vol. 119; no. 7; pp. 789 - 797
• Main Authors: Daborg, Jonny, Andreasson, Ulf, Pekna, Marcela, Lautner, Ronald, Hanse, Eric, Minthon, Lennart, Blennow, Kaj, Hansson, Oskar, Zetterberg, Henrik
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.07.2012; Springer Nature B.V
• Subjects: 80 and over; Adult; Aged; Aged, 80 and over; Alzheimer Disease; Alzheimer Disease - cerebrospinal fluid; Alzheimer's disease; Amyloid beta-Peptides; Amyloid beta-Peptides - cerebrospinal fluid; beta -Amyloid; Biomarkers; Cerebrospinal fluid; Clinical Medicine; Cognitive ability; Cognitive Dysfunction - cerebrospinal fluid; Complement; Complement C3; Complement C3 - cerebrospinal fluid; Complement C4; Complement C4 - cerebrospinal fluid; Complement component C3; complement component C4; Complement receptors; CR1; Dementia disorders; Dementias - Original Article; Disease Progression; Female; Humans; Klinisk medicin; Male; Medical and Health Sciences; Medicin och hälsovetenskap; Medicine; Medicine & Public Health; metabolism; Middle Aged; Mild Cognitive Impairment; Neurodegenerative diseases; Neurologi; Neurology; Neurosciences; Peptide Fragments; Peptide Fragments - cerebrospinal fluid; Psychiatry; Receptors; Receptors, Complement - metabolism; Synapses; tau Proteins; tau Proteins - cerebrospinal fluid; C3; Biomarkers; C4; Complement; CR1; Alzheimer’s disease
• ISSN: 0300-9564; 1435-1463; 1435-1463
• DOI: 10.1007/s00702-012-0797-8

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.