Edward Tufte encourages us to remove all unnecessary graphical elements from our presentation. When this is done, images can be reduced in size.  Perhaps the logical extension of this compacting of graphic representation is Tufte’s concept of sparklines, in which a graphical element serves almost as a word. These word-pictures can be placed in-line with text.

David Wagner, of the  University of Colorado School of Medicine, is studying the ways in which CD40 acts like a costimulatory molecule, similar to CD28. One way of approaching this investigation is to see whether or not stimulation with anti-CD40 yields different results than stimulation with anti-CD3, or the combination of anti-CD3 and anti-CD40.

Researchers in his lab used a Bender MedSystems human cytokine bead array to study differences in cytokine production in 19 donors (7 healthy controls, 12 with Type 1 Diabetes (T1D)). Four different experimental conditions—unstimulated, stimulated with anti-CD3, anti-CD40, and the combination of anti-CD3 and anti-CD40—were considered.

In considering response to stimulation, we want to take into account the baseline production of the cytokines for each donor. Thus, we might want to compute a fold change metric, equal to MFI-stim/MFI-unstim. The following graph illustrates these measurements for a particular donor, for all cytokines, for all treatment environments.

An illustration of sparklines follows:

In this study described above, Donor 101 shows a very different pattern of production of IFNg than of IL-8 in response to the 3 stimulation environments. Keep in mind that the order of the readouts is anti-CD3, anti-CD3 and anti-CD40, anti-CD40. Note that for IFNg, Donor 101 shows the largest response to the combination of CD3 and CD40, perhaps demonstrating co-stimulation.

In this case, the use of sparklines lets us easily integrate the graphical representation of the experimental results with the narrative.