July 2011

Summer Bulletin Online Now
The Summer issue of our Section Bulletin is up on the SECTION WEB SITE now, with a review of a new CLSI guideline on pulse oximetry, plus an article on exercise and long term oxygen therapy from the diagnostician’s perspective.

Lung-Homing of Endothelial Progenitor Cells Following Allergen Challenge
Canadian researchers who previously showed that inhibiting allergen (Ag)-induced recruitment of endothelial progenitor cells (EPC) in sensitized mice attenuated increased bronchial vascularity and development of airway hyppresponsiveness have extended their study to reveal that increased lung-homing of EPC may promote bronchial vascularity in allergic asthmatic responses. What’s more, the recruitment of these progenitors may be orchestrated by CXCR2 chemokines. The investigators arrived at those conclusions after measuring sputum levels of EPC via multi-gating flow cytometry, and lung vascularity by immunostaining with von Willenbrand factor, in 13 mild atopic asthmatics with an FEV1 ≥70%, methacholine PC20 ≤ 16 mg/ml, and a dual response to Ag. The study was published ahead of print on June 30 by the American Journal of Respiratory and Critical Care Medicine. READ ABSTRACT

Air Pollution Worsens Lung Function in Wheezing Children
Air pollution leads to decreased lung function in wheezing children, report Portuguese investigators publishing ahead of print in the European Respiratory Journal on June 30. They assessed respiratory status in 51 children four times over the course of two years, then compared pulmonary function outcomes with air pollution levels. Results showed:

• Increasing total exposure to PM10, NO2, benzene, toluene, and ethylbenzene was significantly associated with a decrease in FEV1 and an increase in ΔFEV1.
• Increasing exposure to NO2 and benzene was related to a significant decrease in FEV1/FVC.
• Increasing exposure to PM10, NO2, benzene, and ethylbenzene was associated with acidity of EBC.

READ ABSTRACT

NOx Measurements May Have a Role in Asthma
After validating methods for the collection, storage, and analysis of exhaled breath condensate (EBC), researchers measured nitrogen oxides (NOx) levels in the EBC of patients with asthma and healthy controls, finding significantly higher NOx levels in the asthmatics. The patients had higher levels of exhaled nitric oxide (FeNO) as well. The authors believe these findings suggest NOx may complement the measurement of FeNO in this patient population. The study was published ahead of print in BMC Research Notes on June 16. READ ABSTRACT

Obese Have Impaired Response to Deep Inspiration
Deep inspirations (DIs) are impaired in people with asthma. Noting the association between asthma and obesity, researchers from Mount Sinai Medical Center decided to find out if they are also impaired in people with obesity. The study was conducted among 17 obese and 19 non-obese subjects who underwent methacholine challenge (Mch). Thirty of the 36 participants also underwent a modified bronchoprovocation in the absence of DIs. Results showed a consistently greater response to Mch in the obese subjects, but between-group differences were smaller in the modified challenge, suggesting a reduced DI effect in obesity. From there, the investigators assessed the bronchodilatory and bronchoprotective effects of DI separately, finding DI prior to Mch enhanced Mch-induced bronchoconstriction in the obese subjects, but DI after Mch resulted in bronchodilation similar to that seen in the non-obese subjects. The authors write, “We conclude that obesity is characterized by increased Mch responsiveness, predominantly of the small airways, due to a DI effect that renders the airways more sensitive to the stimulus.” The investigators published their findings ahead of print in the Journal of Applied Physiology on June 23. READ ABSTRACT