Diagnostic serum proteomic analysis in patients with active tuberculosis

Background: The diagnosis for smear-negative pulmonary tuberculosis (TB) is very difficult. Proteomic fingerprinting of sera is a potentially useful tool. Methods: This study analyzed the results of the proteomic fingerprinting in sera obtained from active TB patients and controls using the surface-enhanced laser desorption ionization time of flight mass spectrometry (SELDI-TOF-MS) and protein-chip technology. The peaks were detected and analyzed, and a diagnostic system was developed. The protein peak was identified using high performance liquid chromatography (HPLC)-tandem matrix-assisted laser desorption/ionization-TOF-MS (MALDI-TOF-MS). Results: Around 50 protein peaks were found significantly different between the TB patients and the controls (P<0.01). Three protein peaks at m/z 5643, 4486 and 4360 were selected for system classification and the development of a decision model. The model distinguished the TB patients from the controls with a sensitivity of 96.9% and a specificity of 97.8%, respectively. The diagnostic accuracy was up to 97.3%. The one most discrepant protein peak at m/z 5643 seen in sera of active TB patients was identified as orosomucoid. Conclusions: A diagnostic system for active TB was developed using mass spectrometry and protein chip technology and required only small-volume serum samples. One potential protein biomarker at m/z 5643 was identified as orosomucoid. (C) 2012 Published by Elsevier B.V.