Fig. 4.

A heat map displaying the relative concentration of 19 mediators in samples with and without CSF/plasma discordance. Samples and mediators were organised via an unsupervised hierarchical clustering algorithm along the horizontal and vertical axes respectively. Twenty-one samples without discordance are labeled on the x-axis with the symbol “o”. Nineteen samples with discordance are indicated by the symbol “+”; discordant samples with CSF HIV-1 RNA >1log₁₀ plasma are labeled “+++” (n = 11), CSF 0.5–1log₁₀ plasma are labeled “++” (n = 5) and those with ultrasensitive discordance are labeled “+” (n = 3). Tile colour indicates relative mediator concentration: red, increased; green, decreased; black, at median concentration (for the samples). On the horizontal axis the samples segregated into two main clusters, cluster one and two, corresponding significantly to discordant and non-discordant samples respectively (p < 0.0001). Grouped in cluster one were all samples with CSF HIV-1 RNA >1log₁₀ plasma, all with CSF HIV-1 RNA 0.5–1log₁₀ plasma, and two of the three with ultrasensitive discordance. One subject with ultrasensitive discordance (CSF HIV-1 RNA 74, plasma <7 copies/ml) was grouped in cluster two. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)