This study evaluated the value of procalcitonin (PCT) levels in pleural effusion to differentiate the etiology of parapneumonic effusion (PPE). Forty-one consecutive PPE patients were enrolled and were divided into bacterial and non-bacterial PPE. Blood and pleural effusion samples were collected for PCT measurement on admission and analyzed for diagnostic evaluation. PCT of pleural fluid was significantly increased in the bacterial PPE group (0.24 ng/mL) compared to the non-bacterial PPE group (0.09 ng/mL), but there was no significant difference for serum PCT. A PCT concentration of pleural fluid >0.174 ng/mL (best cut-off value) was considered positive for a diagnosis of bacterial PPE (sensitivity, 80%; specificity, 76%; AUC, 0.84). Pleural effusion PCT in the bacterial PPE is significantly different from those of the non-bacterial PPE and control groups, so the diagnostic use of PCT still warrants further investigation.

T-lymphocyte (T-LC)-derived cytokines have been implicated in asthmatic pathogenesis. Proteomic technology is now widely accepted as a complementary technology to genetic profiling. We investigated the changes of proteins in T-LC of asthmatic patients from the no typical therapy (uncontrolled) to typical therapy (controlled) level by using standard proteome technology. Methods: The proteins of CD4+ T-LC were isolated from the whole blood of six asthmatic patients from uncontrolled to controlled levels over 3 months. Two-dimensional polyacrylamide gel electrophoresis was performed and coomassie blue stained protein spots were comparatively analyzed by using an image analyzer. Some differentially expressed spots were identified by liquid chromatography/mass spectrometry and database search. Our results showed that 13 proteins showed different expression. Six protein spots in the CD4+ T-LC of the uncontrolled asthmatic patients were increased and 7 spots were decreased compared to those of the controlled subjects. In conclusion, the proteomic examination of the CD4+ T-LC revealed some differentially expressed proteins in the uncontrolled and controlled asthmatic patients. The possibility of using the differentially expressed proteins as important biomarkers and therapeutic targets warrants further study.