Expression of soluble Toll-like receptors in pleural effusions / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The Toll-like receptors (TLRs) represent a group of single-pass transmembrane receptors expressed on sentinel cells that are central to innate immune responses.The aim of this study was to investigate the presence of soluble TLRs in pleural effusions, and the diagnostic values of TLRs for pleural effusion with various etiologies.</p><p><b>METHODS</b>Pleural effusion and serum samples were collected from 102 patients (36 with malignant pleural effusion, 36 with tuberculous pleural effusion, 18 with bacterial pleural effusion, and 12 with transudative pleural effusion). The concentrations of TLR1 to TLR10 were determined in effusion and serum samples by enzyme linked immunosorbent assay. Four classical parameters (protein, lactate dehydrogenase, glucose and C-reactive protein (CRP)) in the pleural fluid were also assessed. Receiver-operating characteristic curves were used to assess the sensitivity and specificity of pleural fluid TLRs and biochemical parameters for differentiating bacterial pleural effusion.</p><p><b>RESULTS</b>The concentrations of TLR1, TLR3, TLR4, TLR7 and TLR9 in bacterial pleural effusion were significantly higher than those in malignant, tuberculous, and transudative groups, respectively. Analysis of receiver operating characteristic curves revealed that the area under the curves of TLR1, TLR3, TLR4, TLR7 and TLR9 were 0.831, 0.843, 0.842, 0.883 and 0.786, respectively, suggesting that these TLRs play a role in the diagnosis of bacterial pleural effusion. Also, the diagnostic value of TLRs for bacterial pleural effusions was much better than that of biochemical parameters (protein, lactate dehydrogenase, glucose and CRP).</p><p><b>CONCLUSIONS</b>The concentrations of TLR1, TLR3, TLR4, TLR7 and TLR9 appeared to be increased in bacterial pleural effusion compared to non-bacterial pleural effusions. Determination of these pleural TLRs may improve the ability of clinicians to differentiate pleural effusion patients of bacterial origin from those with other etiologies.</p>

Effects of the TREM-1 pathway modulation during empyema in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The activation of triggering receptor expressed on myeloid cells-1 (TREM-1) in the presence of microbial components amplifies the inflammatory response. The aim of the present study was to investigate the effect of the modulation of the TREM-1 pathway during empyema in rats.</p><p><b>METHODS</b>Adult male Wistar rats were subjected to empyema induced by intrapleural injection of Pseudomonas aeruginosa and Staphylococcus aureus. The animals were treated with LP17 (a synthetic TREM-1 inhibitor), a control peptide, or a vehicle (normal saline). Differential cell count, flow cytometry and histological examination were performed to evaluate local inflammatory alterations. Concentrations of tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 in both pleural effusion and serum were measured by enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>Although differential counts of each type of leukocytes in pleural effusion were not affected by LP17, a marked reduction in neutrophil numbers was seen in LP17 treated rats due to the reduction of both pleural effusion volume and total cell numbers. LP17 administration impaired concentration elevation in tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 in both pleural effusion and serum. It was found that survival rate in LP17 treated rats was much higher than that in control rats.</p><p><b>CONCLUSION</b>The modulation of the TREM-1 pathway by the use of LP17 appears to be beneficial during empyema in rats in attenuating pleural and systemic inflammatory responses.</p>