Microheterogeneity of some serum glycoproteins in neurodegenerative diseases

article Background: Participation of protein polymorphism is often considered in the pathogenesis of various diseases. Aberrant protein glycosylation has been recognized to play major roles in human disorders, including neurodegenerative diseases. Objective: The aim of the study was to examine possible involvement of protein genetic variants and degree of glycosylation of some serum glycoproteins in the manifestation of neurodegenerative disorders in a Czech population sample. Methods: Apolipoprotein (Apo) E and three main serum markers of glycosylation defects (transferrin, Tf, alpha1-antitrypsin, aAT and ApoCIII) in patients with Alzheimer's dementia (AD), Parkinson's disease (PD) and vascular dementia (n=62, 139 and 44, respectively) were analyzed by isoelectric focusing. Chil- dren with serious neurological symptoms (n=55) and three age-matched control groups (n=45, 45 and 42) were examined for comparison. Results: Of the supposedly pathognomonic protein variants Tf C2, aAT ZM and ApoE e4 only the latter was detected with higher frequency in AD patients; significant synergy of the C2/e4 allelic combination was not confirmed. The most prominent finding among PD adults was an increased appearance of Tf C2 allele and significant mean hypoglycosylation of ApoCIII, besides a C2/e4 positive correlation in PD seniors. Laboratory signs of Tf hypoglycosylation and a pattern of Tf/ApoCIII hyperglycosylation have been occasionally found.