Figure 2.

CTAD plasma TGFβ levels in normal donors and oncology patients. A) Relationship of platelet-activation markers in clinical samples. Dashed lines represent the upper limit of normal for both markers, %’s indicated fraction of all samples falling in each quadrant. The overall correlation between platelet activation markers was good across all samples (r² = 0.71, Pearson correlation coefficient), with agreement between PF4 and BTG in 85% of the samples. B) TGFβ levels in oncology patients related to platelet activation. Boxes represent the median and central 50th percentile of observations, whiskers represent the 10th and 90th percentiles with individual outliers noted, dashed line represents upper limit established in normal donors (1.7 ng/ml). A single sample with an extremely elevated TGFβ level (13.2 pg/ml, BTG/PF4 +ve) is not shown to improve scaling. Samples collected from oncology patients had significantly higher circulating TGFβ levels than those from normal donors (p < 0.05 students t-test for all groups when compared to normal donors). This was true regardless of platelet activation status, although TGFβ levels were higher in samples with evidence of platelet activation.

Abbreviations: BTG, beta-thromboglobulin; CTAD, citrate-theophylline-adenosine-dipyridamole; PF4, platelet factor 4; TGFβ, transforming growth factor beta.