Affiliations: School of Chemical and Biomolecular Engineering,
Cornell University, Ithaca, NY 14853, USA
Note: [] Corresponding author: Kelvin H. Lee, 120 Olin Hall, Ithaca, NY
14853, USA. Tel.: +1 607 255 4215; Fax: +1 607 255 9166; E-mail:
KHL9@cornell.edu
Abstract: It has been suggested that the activation of the complement system
is involved in the pathogenesis of several neurodegenerative diseases including
Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis
(MS). Here, the CSF expression levels of complement proteins C3b, C4b, factor
B, and factor H were compared between normal subjects and patients diagnosed
with AD, PD, MS, and neurosyphilis. The CSF proteins were initially separated
using two-dimensional gel electrophoresis, which allowed the comparison of some
of the individual complement isoforms. Patients with AD, PD, and MS all showed
more than one complement isoform with a significant change (p < 0.05) in CSF
expression level compared to normal subjects. PD patients were found to have
the greatest number of significantly changed isoforms, all showing a decreased
expression level in PD CSF. The complement isoforms examined were able to
distinguish between some, but not all, of the diseases studied. The data
suggest that when investigating a protein as a possible biomarker, it may be
useful to compare individual protein isoform expression levels in addition to
the more commonly measured total protein expression level.
