Glycoproteins in cerebrospinal fluid (CSF) are altered in Alzheimer's Disease 
(AD) patients compared to control individuals. We have utilized albumin 
depletion prior to 2D gel electrophoresis to enhance glycoprotein concentration 
for image analysis as well as structural glycoprotein determination without 
glycan release using mass spectrometry (MS). The benefits of a direct 
glycoprotein analysis approach include minimal sample manipulation and retention 
of structural details. A quantitative comparison of gel-separated glycoprotein 
isoforms from twelve AD patients and twelve control subjects was performed with 
glycoprotein-specific and total protein stains. We have also compared glycoforms 
in pooled CSF obtained from AD patients and control subjects with mass 
spectrometry. One isoform of alpha1-antitrypsin showed decreased glycosylation 
in AD patients while another glycosylated isoform of an unassigned protein was 
up-regulated. Protein expression levels of alpha1-antitrypsin were decreased, 
while the protein levels of apolipoprotein E and clusterin were increased in AD. 
No specific glycoform could be specifically assigned to AD.