Biomarker selection and training/testing analysis.

<p>Before biomarker selection, our total sample pool was split into two randomized groups: the Training Set and Testing Set. <i>Prospector</i> and <i>PAM</i> statistical analyses were performed on the Training Set to identify the top 10 most significant autoantibody classifiers of PD and control. We then verified the diagnostic accuracy of these selected biomarkers by using <i>Random Forest</i> to predict sample classification in the Training Set, Testing Set, and then both sets combined.</p

Diagnostic Accuracies of Selected Biomarkers.

*<p><i>The biomarkers used for this classification are those of Table 5 in our previous work </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032383#pone.0032383-Nagele2" target="_blank">[<i>18</i>]</a><i>; all others are the biomarkers identified in </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032383#pone-0032383-t002" target="_blank"><i>Table 2</i></a>.</p

Identity and significance of 10 ad vs. Ndc diagnostic biomarkers.

<p>Identity and significance of 10 ad vs. Ndc diagnostic biomarkers.</p

Differential Expression of PTCD2 and FRMD8 autoantibodies in AD and NDC sera.

<p>Microarray fluorescence values reflecting individual serum autoantibody titers demonstrate a difference in the expression of anti-PTCD2 and anti-FRMD8 in AD (n = 50) and NDC (n = 40) sera (a,c). This difference was confirmed in independent dot blots that assessed AD and NDC sera reactivity to purified PTCD2 and FRMD8 protein antigens (b,d).</p

Diagnostic accuracies of selected biomarkers.

<p>*<i>The biomarkers used for this classification are those of </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0023112#pone-0023112-t005" target="_blank"><i>Table 5</i></a><i>; all others are the biomarkers identified in </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0023112#pone-0023112-t003" target="_blank"><i>Table 3</i></a><i>.</i></p

Differential expression of identified PD-specific autoantibody biomarkers in PD and control sera.

<p>Microarray fluorescence values reflecting individual serum autoantibody titers demonstrate the differences in the serum expression of the selected ten PD-specific autoantibody biomarkers in PD (n = 29) and control (n = 40) sera (A–I).</p

Demographics of Serum Donors.

<p>Demographics of Serum Donors.</p

Identity and significance of five AD vs. PD diagnostic biomarkers.

<p>Identity and significance of five AD vs. PD diagnostic biomarkers.</p

Estimate of autoantibodies per sample group.

<p>Estimate of autoantibodies per sample group.</p

Biomarker selection and Training / Testing Analysis.

<p>Before biomarker selection, our total sample pool was split into two randomized groups: the Training Set and Testing Set. <i>Prospector</i> and <i>PAM</i> statistical analyses were performed on the Training Set to identify the top 10 most significant autoantibody classifiers of AD and NDC. We then verified the diagnostic accuracy of these selected biomarkers by using <i>Random Forest</i> to predict sample classification in the Training Set, Testing Set, and then both sets combined.</p