Proteomic Analysis of Plasma in Adult Active Pulmonary Tuberculosis Patients with Diabetes Mellitus

Background: There is a high burden of both diabetes and tuberculosis in China. Diabetes depresses the immunologic response that facilitates the development of infectious diseases, including infection by Mycobacterium tuberculosis, the agent of tuberculosis. Tuberculosis is the third cause of death among subjects with non-communicable diseases, and among the non-communicable diseases, diabetes is one of the most important. The relationship between diabetes and tuberculosis has already been object of many investigations but the association between these two diseases is not fully understood. The aim of this study was to determine whether relative qualitative and quantitative differences in protein expression of plasma could be related to active pulmonary tuberculosis complicated with diabetes. Methods: Biological parameters are useful tools for understanding and monitoring complicated disease processes. Our study employed two-dimensional gel electrophoresis and mass spectrometry to analyze the proteins associated with active pulmonary tuberculosis complicated with diabetes. Results: Under the baseline condition, we found that the levels of alpha-1 antitrypsin precursor, vitamin D-binding protein precursor, CD5 antigen like precursor, clusterin precursor, apolipoprotein A-I precursor, haptoglobin, and fibrinogen gamma-chain differed between patients with active pulmonary tuberculosis and active pulmonary tuberculosis complicated with diabetes subjects. Western blotting results confirmed differential expression of clusterin. Conclusions: We identified active pulmonary tuberculosis complicated with diabetes-associated proteins in plasma. C-terminal haptoglobin is a possible candidate protein of interest, which might be a link between active pulmonary tuberculosis and diabetes. The dynamics of protein expression during disease progression may improve our understanding of the pathogenesis of active pulmonary tuberculosis complicated with diabetes.