We plotted crude plasma global protein expression profiles in a heat map (Figure 2 ) that shows spectra patterns from active TB patients and unhealthy controls. The most striking area of upregulation in TB patients is seen in the 11 kDa region where a series of protein peaks are seen in red amongst TB patients ( Figure 2) . A parallel area of up-regulation is seen at 5 kDa and a third smaller area seen at the 21 kDa region (Figure 2 ). Inspecting in more detail the spectra in the 5.8 and 11.5 kDa regions ( Figure 3 ) reveals a complex of peaks at both these regions, which is more abundant in patients with active TB. We assessed overall separability of patient groups by PCA of mass spectra from crude and pre-fractionated plasma (Figure 4 ab) . In figure 4 , each patient sample is plotted in a 3-dimensional space defined by the first 3 principal components. The spectra from patients with active TB (purple spheres) cluster relatively tightly together and are well separated from symptomatic control patients (blue and green spheres) regardless of LTBI. This analysis, however, does not clearly separate symptomatic controls with or without LTBI (blue and green spheres, respectively).