One TB patient profile (reporter ion at m/z 121) clustered with the control group, and review of the clinical data showed that although the Mycobacterium tuberculosis (M. tuberculosis) sputum culture was positive, the plasma C-reactive protein (CRP) level was normal and the chest x-ray showed no consolidation, suggesting very early disease, in contrast to all other patients who had lung inflammation. Here, CRP is linked to inflammatory response.