Fig. 1.

PCA-DA distinguishes an IC/BPS participant subgroup by a) negative and b) positive ESI-MS. Score plots of PCA-DA analysis of urine from IC/BPS participants (red) were clustered separately from non-IC/BPS controls (gray). Quality control samples (black) were prepared by pooling equal aliquots from each IC/BPS and non-IC/BPS sample, and run at random intervals. Each data point represents the average of triplicate runs. (c) Loading plot of PCA components 1 and 2 determined by negative ESI-MS. (d) Distribution of values from the loadings plot indicates two distinct subgroups within the IC/BPS population. The D1 loadings values resolve two distinct IC/BPS subgroups, with 19 out of the 40 (47.5%) samples in subgroup 1 (red), and 21 out of the 40 (52.5%) in subgroup 2 (blue).