The aim of this study was to investigate the presence of epithelial neutrophil-activating peptide (ENA)-78 in pleural effusions, as well as the chemoattractant activity of pleural ENA-78 0n neutrophils. Pleural effusion and serum samples were collected from 75 patients who presented to the respiratory institute (19 with malignant pleural effusion, 21 with tuberculous pleural effusion, 18 with infectious pleural effusion and 17 with transudative pleural effusion). The concentrations of ENA-78, myeloperoxidase and neutrophil elastase were determined, and the chemoattractant activity of ENA-78 for neutrophils both in vitro and in vivo was also observed. The concentrations of ENA-78, myeloperoxidase and neutrophil elastase in infectious pleural effusion were significantly higher than those in malignant, tuberculous and transudative groups, respectively (all p<0.01). Infectious pleural fluid was chemotactic for neutrophils in vitro and anti-ENA-78 antibody could partly inhibit these chemotactic effects. Intrapleural administration of ENA-78 produced a marked progressive influx of neutrophils into pleural space. Compared with noninfectious pleural effusion, ENA-78 appeared to be increased in infectious pleural effusion. Our data suggested that ENA-78 was able to induce neutrophil infiltration into pleural space and might be responsible for pleural neutrophil degranulation.

Allergic asthma is characterized by airway hyper-responsiveness and chronic mucosal inflammation mediated by CD4+ Th2 lymphocytes. Regulatory CD4+CD25+ T cells are important components of the homeostasis of the immune system, as impaired CD4+CD25+ T cell activity can cause autoimmune diseases and allergy. The mechanism of suppression by CD4+CD25+ T cells remains controversial; different in vivo and in vitro studies raise possible roles for the immunosuppressive cytokines interleukin-10 and transforming growth factor-β, forkhead transcription factor Foxp3, glucocorticoid-induced tumor necrosis factor receptor, cytotoxic lymphocyte associated antigen-4, 4-1BB costimulator receptor, a CD4-related molecule LAG-3, and neuropilin-1. Current data suggest that Th2 responses to allergens are normally suppressed by CD4+CD25+ T cells. Suppression by CD4+CD25+ T cells is decreased in allergic individuals. Furthermore, CD4+CD25+ T cells play a key role in regulating airway eosinophilic inflammation. The immunomodulatory properties of CD4+CD25+ T cells do extend to Th2 responses, most notably by limiting the development of a proinflammatory CD4+ Th2 phenotype characterized by reduced cytokine production. An understanding of the roles of CD4+CD25+ T cells in vivo could provide better insight into the design of novel approaches to modulate the chronic airway inflammatory reaction evident in bronchial asthma.

Conventional tests are not always helpful in making a diagnosis of tuberculous pleurisy. Many studies have investigated the usefulness of interferon (IFN)-γ measurements in pleural fluid for the early diagnosis of tuberculous pleurisy. We conducted a metaanalysis to determine the accuracy of IFN-γ measurements in the diagnosis of tuberculous pleurisy. Methods: After a systematic review of English-language studies, sensitivity, specificity, and other measures of accuracy of IFN-γ concentrations in the diagnosis of pleural effusion were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize overall test performance. Results: Twenty-two studies met our inclusion criteria. The summary estimates for IFN-γ in the diagnosis of tuberculous pleurisy in the studies included were as follows: sensitivity, 0.89 (95% confidence interval [CI], 0.87 to 0.91); specificity, 0.97 (95% CI, 0.96 to 0.98); positive likelihood ratio, 23.45 (95% CI, 17.31 to 31.78); negative likelihood ratio, 0.11 (95% CI, 0.07 to 0.16); and diagnostic odds ratio, 272.7 (95% CI, 147.5 to 504.2). Conclusions: IFN-γ determination is a sensitive and specific test for the diagnosis of tuberculous pleurisy. The measurement of IFN-γ levels in pleural effusions is thus likely to be a useful tool for diagnosing tuberculous pleurisy. The results of IFN-γ assays should be interpreted in parallel with clinical findings and the results of conventional tests. (CHEST 2007; 131:1133–1141)