Figure 1

PBMC matrix - peptide level analysis. PCA score plot (upper) and loading plot (bottom) after median normalisation. In the PCA plot, B-ALS (blue) displays a higher degree of variability in the peptide profile compared to the L-ALS (red). The plot also shows a separation of the two clusters along the PC1 (x-axis) which is represented mostly by the site of disease onset as illustrated by the arrows in the loading plot. The loading plot confirms an anticorrelation between the B-ALS group and the L-ALS group, as indicated by the opposite direction of the corresponding vectors. A strong anticorrelation was also observed between B-ALS fast and L-ALS fast, as suggested by the lenght of the vectors.