A role for Leukotriene B4 in the induction of airway hyper-responsiveness was explored through the use of transgenic mice deficient in the BLT1 receptor for LTB4 . Ovalbumin challenge of sensitized wild-type mice resulted in the usual features of experimental asthma, including goblet cell hyperplasia, hyper-responsiveness to inhaled methacholine and elevated BAL fluid concentrations of the Th2 cytokine IL-13. In contrast, BLT1 –/– mice (i.e. genetically modified mice lacking the gene coding for the BLT1 receptor) exhibited significantly lower responses. BLT1 –/– mice also exhibited lower numbers of IL-13-positive T lymphocytes of both the helper (CD4 T Cells) and cytotoxic/suppressor (CD8 + ) types. (more…)

Some features seem to be common to severe asthma and Chronic Obstructive Pulmonary Disease with reversibility of airflow limitation. The neutrophil chemoattractant leukotriene B 4 (LTB 4) may play a role in Chronic Obstructive Pulmonary Disease and in some forms of asthma. In this study, 55 smokers with no disease, Chronic Obstructive Pulmonary Disease (with or without bronchodilator reversibility of airflow limitation) or asthma underwent measurement of LTB 4 in sputum supernatants and exhaled breath condensate asthma (EBC). Both Chronic Obstructive Pulmonary Disease and asthma patients had higher levels of LTB 4 than control subjects; patients with asthma or reversible Chronic Obstructive Pulmonary Disease exhibited significantly higher levels of LTB 4 than those with irreversible Chronic Obstructive Pulmonary Disease. (more…)

Leukotrienes are present in increased amounts in exhaled breath condensate (EBC) in patients with asthma. So far, no data have been reported about leukotriene levels in non-asthmatic patients with Seasonal Allergic Rhinitis. The aim of the study was to find out whether the leukotriene levels in exhaled breath condensate were increased in the non-asthmatic adult patients with Seasonal Allergic Rhinitis both during and after the pollen season in comparison with healthy controls, and to assess changes in leukotriene levels after the pollen season. Twentynine non-asthmatic adult patients with Seasonal Allergic Rhinitis and 50 healthy non-smoking controls underwent measurement of exhaled leukotrienes in the exhaled breath condensate during and after the pollen season. Spirometry, skin-prick tests and total IgE were also evaluated. (more…)