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)

Study objective: To investigate the effects of segmental allergen challenge on the concentration of soluble CD86 (sCD86) in BAL fluids in patients with allergic asthma. Methods: BAL fluid and peripheral blood were collected at baseline, 24h after segmental saline solution or allergen challenge by fiberoptic bronchoscopy and venepuncture, respectively, from 10 patients with allergic asthma. Total and differential cell counts in BAL fluid were performed, and sCD86 levels in both BAL fluid and serum were measured by enzyme-linked immunosorbent assay. Results: In allergic asthmatics, there was no significant increase in BAL sCD86 concentrations after saline solution challenge (median, 2.0IU/L; 25th to 75th percentiles, 0 to 3.4) compared with baseline control subjects (median, 1.2IU/L; 25th to 75th percentiles, 0 to 3.6IU/mL; p 0.735); however, sCD86 concentrations were significantly elevated after allergen challenge (median, 8.1IU/L; 25th to 75th percentiles, 4.4 to 17.0IU/mL; p<0.001). The concentrations of sCD86 in BAL fluid after allergen challenge exceeded levels that could be accounted for passive transudation from the circulation, based on the magnitude of increases in BAL albumin concentrations. Conclusions: These data indicate that allergen challenge results in a significant local accumulation of sCD86 within the airways, and that the local release of sCD86 may play a role in allergen-induced inflammatory processes in the asthmatic airways.