Identification of serum biomarkers for the discrimination of movement disorders by antibody arrays in the screening cohort. (A) Representative picture of Raybiotech human cytokine antibody array showing the reactivity of pooled serum samples (10 PSP/CBS, 10 MSA, 20 PD and 30 controls) to arrays G series 2000 6, 7 and 8 (174 cytokines). Each protein was measured in duplicates. Signals were scanned with a GenePix 4000B scanner. Blue boxes: positive controls (upper left corner, high intense spots). Red box, negative controls (upper left and lower right corner, no spots). Purple boxes, internal controls IC1, IC and IC3 (lower right corner, spots with three different intensities). White and green colored boxes indicate the location of the detection of two proteins that were significantly different in both the microarray and validation experiment (white = PDGF-BB and green = prolactin). (B) Normalized array data of the 174 cytokines were analyzed by SAM to detect differences in their concentrations between pooled serum samples (PSP/CBS, one pool of 10 samples with three replicates; MSA, one pool of 10 samples with three replicates each; PD, two pools of 10 samples with two replicates each; and controls, three pools of 10 samples with two replicates each). The relative concentrations of the 12 cytokines that obtained a significant score (q-value <0.001%) are shown in a “heatmap”. Low concentrations are shown in blue, median concentrations in black and high concentrations in yellow.