Comparison of the prevalence of chronic obstructive pulmonary disease diagnosed by lower limit of normal and fixed ratio criteria.

The Global Initiative of Chronic Obstructive Lung Disease (GOLD) guidelines define chronic obstructive pulmonary disease (COPD) in subjects with FEV(1)/FVC <0.7. However, the use of this fixed ratio may result in over-diagnosis of COPD in the elderly, especially with mild degree of COPD. The lower limit of normal (LLN) can be used to minimize the potential misclassification. The aim of this study was to evaluate the impact of different definitions of airflow obstruction (LLN or fixed ratio of FEV(1)/FVC) on the estimated prevalence of COPD in a population-based sample. We compared the prevalence of COPD and its difference diagnosed by different methods using either fixed ratio (FEV(1)/FVC <0.7) or LLN criterion (FEV(1)/FVC below LLN). Among the 4,816 subjects who had performed spirometry, 2,728 subjects met new ATS/ERS spirometry criteria for acceptability and repeatability. The prevalence of COPD was 10.9% (14.7% in men, 7.2% in women) by LLN criterion and 15.5% (21.8% in men, 9.1% in women) by fixed ratio of FEV(1)/FVC among subjects older than 45 yr. The difference of prevalence between LLN and fixed ratio of FEV(1)/FVC was even higher among subjects with age >/=65, 14.9% and 31.1%, respectively. In conclusion, the prevalence of COPD by LLN criterion was significantly lower in elderly compared to fixed ratio of FEV(1)/FVC. Implementing LLN criterion instead of fixed ratio of FEV(1)/FVC may reduce the risk of over-diagnosis of COPD in elderly people.

Urinary excretion of 9α,11ß-prostaglandin F2 and leukotriene E4 in patients with exercise-induced bronchoconstriction.

BACKGROUND: Increased levels of mast cell-derived eicosanoids, such as prostaglandin (PG) D2 and cysteinyl leukotrienes (CysLTs), have been reported in patients with exercise-induced bronchoconstriction (EIB), suggesting that mast cell activation is involved in the mechanism of EIB. However, it is still controversial since these results have not been reproduced in other studies. The aim of this study was to evaluate the role of PGD2 and LTE4 in adult asthma with EIB, as measuring urinary levels of their metabolites-9α,11ß-PGF2 and LTE4 before and after an exercise challenge test. METHODS: Eight patients with asthma and EIB and five normal controls without EIB were enrolled. Exercise challenge tests comprised of 6 min of treadmill exercise or free running were performed in all study subjects, and urine samples before and 1 h after the challenge were collected. Urinary levels of 9α,11ß-PGF2 and LTE4 were measured by enzyme immunoassay (EIA). RESULTS: No significant differences were observed in 9α,11ß-PGF2 and LTE4 levels before/after the exercise challenge between patients with EIB and normal controls. No significant increases in urinary levels of 9α,11ß-PGF2 or LTE4 were detected during the exercise challenge in patients with EIB and normal controls. No significant correlations were observed between the percent decrease in forced expiratory volume in 1 s (FEV1) or percent changes in 9α,11ß-PGF2 and LTE4 levels after the exercise challenge. CONCLUSIONS: Urinary 9α,11ß-PGF2 and LTE4 levels did not increase after an exercise challenge in patients with EIB, suggesting that urinary excretion of 9α,11ß-PGF2 and LTE4 may not be a good marker of mast cell activation in patients with EIB.

Bronchoscopic ethanolamine injection therapy in patients with persistent air leak from chest tube drainage.

BACKGROUND: Chest tube drainage (CTD) is an indication for the treatment of pneumothorax, hemothroax and is used after a thoracic surgery. But, in the case of incomplete lung expansion, and/or persistent air leak from CTD, medical or surgical thoracoscopy or, if that is unavailable, limited thoracotomy, should be considered. We evaluate the efficacy of bronchoscopic injection of ethanolamine to control the persistent air leak in patients with CTD. METHODS: Patients who had persistent or prolonged air leak from CTD were included, consecutively. We directly injected 1.0 mL solution of 5% ethanolamine oleate into a subsegmental or its distal bronchus, where it is a probable air leakage site, 1 to 21 times using an injection needle through a fiberoptic bronchoscope. RESULTS: A total of 15 patients were enrolled; 14 cases of spontaneous pneumothorax [idiopathic 9, chronic obstructive pulmonary disease (COPD) 3, post-tuberculosis 2] and one case of empyema associated with broncho-pleural fistula. Of these, five were patients with persistent air leak from CTD, just after a surgical therapy, wedge resection with plication for blebs or bullae. With an ethanolamine injection therapy, 12 were successful but three (idiopathic, COPD and post-tuberculosis) failed, and were followed by a surgery (2 cases) or pleurodesis (1 case). Some adverse reactions, such as fever, chest pain and increased radiographic opacities occurred transiently, but resolved without any further events. With success, the time from the procedure to discharge was about 3 days (median). CONCLUSION: Bronchoscopic ethanolamine injection therapy may be partially useful in controlling air leakage, and reducing the hospital stay in patients with persistent air leak from CTD.

Clinical efficacy of direct DNA sequencing analysis on sputum specimens for early detection of drug-resistant Mycobacterium tuberculosis in a clinical setting.

BACKGROUND: Early detection of drug-resistant Mycobacterium tuberculosis is important for the control and prevention of disease transmission. However, conventional drug susceptibility tests for drug-resistant M tuberculosis take at least 3 to 8 weeks. Here, we report the clinical efficacy of direct DNA sequencing analysis for detecting drug-resistant TB on sputum specimens in a clinical setting. METHODS: A total of 113 sputum specimens from 111 patients, who were suspected of having drug-resistant TB by clinicians, were used for DNA sequencing of katG, rpoB, embB, and pncA genes for isoniazid (INH), rifampin (RIF), ethambutol (EMB), and pyrazinamide (PZA) resistance, respectively, and the results were compared with drug susceptibility tests. The optimization of antituberculosis drugs according to the results of DNA sequencing and the treatment outcomes of the patients were also analyzed. RESULTS: Turnaround time of the direct DNA sequencing analysis was 3.8 +/- 1.8 days. We found mutations related to drug resistance in 30 clinical specimens for katG, 39 for rpoB, 13 for embB, and 24 for pncA. The sensitivity and specificity of the assay were 63.6% and 94.6% for INH, 96.2 and 93.9% for RIF, 69.2% and 97.5% for EMB, and 100% and 92.6% for PZA, respectively. Of the patients with RIF resistance, including multidrug-resistant TB by the assay, 92.5% of the patients with initial first-line antituberculosis drugs were changed to second-line antituberculosis drugs, and treatment was successful in 61.9% of these cases. CONCLUSION: Direct DNA sequencing analysis of clinical sputum specimens is a rapid and useful method for the detection and treatment of drug-resistant TB.