%0 Journal Article
%T ¦Á-Synuclein and Anti-¦Á-Synuclein Antibodies in Parkinson¡¯s Disease, Atypical Parkinson Syndromes, REM Sleep Behavior Disorder, and Healthy Controls
%A Lynnae M. Smith
%A Mya C. Schiess
%A Mary P. Coffey
%A Andrea C. Klaver
%A David A. Loeffler
%J PLOS ONE
%D 2012
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0052285
%X ¦Á-synuclein is thought to play a key role in Parkinson¡¯s disease (PD) because it is the major protein in Lewy bodies, and because its gene mutations, duplication, and triplication are associated with early-onset PD. There are conflicting reports as to whether serum and plasma concentrations of ¦Á-synuclein and anti-¦Á-synuclein antibodies differ between PD and control subjects. The objectives of this study were to compare the levels of ¦Á-synuclein and its antibodies between individuals with typical PD (n = 14), atypical Parkinson syndromes (n = 11), idiopathic rapid eye movement sleep behavior disorder (n = 10), and healthy controls (n = 9), to assess the strength of association between these serum proteins, and to determine group sizes needed for a high probability (80% power) of detecting statistical significance for 25% or 50% differences between typical PD and control subjects for these measurements. Analysis of log-transformed data found no statistically significant differences between groups for either ¦Á-synuclein or its antibodies. The concentrations of these proteins were weakly correlated (Spearman rho = 0.16). In subjects with typical PD and atypical Parkinson syndromes, anti-¦Á-synuclein antibody levels above 1.5 ¦Ìg/ml were detected only in subjects with no more than four years of clinical disease. Power analysis indicated that 236 and 73 samples per group would be required for an 80% probability that 25% and 50% differences, respectively, in mean ¦Á-synuclein levels between typical PD and control subjects would be statistically significant; for anti-¦Á-synuclein antibodies, 283 and 87 samples per group would be required. Our findings are consistent with those previous studies which suggested that serum concentrations of ¦Á-synuclein and its antibodies are not significantly altered in PD.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0052285