Cytokine responses during exacerbation compared with stable phase in asthmatic children.

Bronchial asthma is a chronic inflammatory disorder of the airways. Balancing in Th1 and Th2 response is a target in the treatment. Recent studies show that interleukin-10 (IL-10) has an important role in the regulation of Th2 and allergic responses and its amount was found to decrease in asthmatic patients. This study was to focus on cytokine responses, including interferon-gamma (IFN- γ), IL-4 and IL-10 in asthmatic children during acute exacerbation compared to stable period. Peripheral blood mononuclear cells (PBMCs) from fourteen asth-matic children during exacerbation and stable phase were stimulated with phytohemagglutinin (PHA) and mite allergen (Der p) for 72 hours. Levels of IFN-γ, IL-4 and IL-10 in cell culture supernatants were measured using en-zyme-linked immunosorbent assay. The median level of IL-10 in PBMCs stimulated with PHA was significantly low-er in acute asthma exacerbation compared with stable phase (464 vs. 859.5 pg/ml, p= 0.03). However, there was no difference in the level of IL-10 in PBMCs stimulated with Der p. The level of IFN-γ and IL-4 were not different between exacerbation and stable phase both in PHA and Der p-stimulated PBMCs. The decrease of IL-10 production in asthmatic children during acute exacerbation may emphasize the role of IL-10 in immune regulation in allergic disease.

Serum TGF-beta1 in atopic asthma.

Asthma is a chronic inflammatory disease of the airway. Pathological repair of chronic inflammation leads to airway remodeling. Transforming growth factor-beta (TGF-beta), a profibrotic cytokine, plays an important role in promoting the structural changes of airway remodeling. TGF-beta effects on the proliferation, differentiation and extracellular matrix (ECM) metabolism of airway structural cells. This study assessed serum TGF-beta1 in different severity of atopic asthma compared to non-atopic controls. Thirty-one atopic asthmatic patients and 34 non-atopic controls, aged 7-18 years, were recruited as to the asthma severity: steroid naïve mild asthma, moderate asthma, and asthma in remission. Serum TGF-beta1 was measured by enzyme-linked immunosorbent assay. There was a significant difference between serum TGF-beta1 in asthmatic patients and that in control patients (39.59 ng/ml vs. 0.26 ng/ml, p < 0.001). Serum TGF-beta1 was highest in steroid naïve mild asthma group when compared to the moderate asthma and asthma in remission groups (47.44 ng/ml vs. 38.64 ng/ml and 47.44 ng/ml vs. 35.94 ng/ml, p = 0.013 and 0.001, respectively). There were no correlations among serum TGF-beta1 and pulmonary function test parameters, duration of asthma, and duration of inhaled corticosteroid treatment. These data support the role of TGF-beta1 in airway remodeling in asthma.

Impact of particulate air pollutants on allergic diseases, allergic skin reactivity and lung function.

Elevated levels of particulate matter can exacerbate existing asthma and atopy, while evidence that it can promote the induction of atopy and asthma is limited. A cross sectional study was taken to compare the prevalence of eye, nose, ear and airway allergic symptoms, allergic skin sensitivity and lung function in 290 high school students with a history of high 24 hour average exposure to particulate matter less than 10 microm in diameter (PM10) = 170 microg/m3 versus low PM10 of 36 microg/m3 in central Bangkok. Multivariate analysis revealed an increased risk of eye and airway symptoms in groups exposed to higher PM10 levels (p = 0.003, and 0.05, respectively). Positive skin prick tests and a history of having a lawn at home were associated with nasal symptoms (p = 0.008 and 0.04, respectively). Mean FEF(25-75%) (forced expiratory flow that occurs during the middle 50% of the forced expiratory effort) was significantly lower in those who were exposed to higher PM10 levels (3.89 +/- 1 vs 4.42 +/- 0.9 l/sec, p < 0.001). A significant increase in days of school absence and medical expenses was associated with high PM10 exposure. It is concluded that chronic exposure to high PM 10 levels was significantly associated with increased prevalence of eye and airway symptoms and a decrement of FEF(25-75%) resulting in increase of school absence and medical expense.