Leukotriene B4 and 8-isoprostane in exhaled breath condensate of children with episodic and persistent asthma.

BACKGROUND: Leukotrienes and isoprostanes are biomarkers of airway inflammation and oxidative stress that can be detected in exhaled breath condensate (EBC). The aim of this study was to evaluate leukotriene B4 (LTB4) and 8-isoprostane levels in EBC of healthy and asthmatic children with episodic and moderate persistent asthma. METHODS: EBC was collected from 62 children aged 6 to 14 years: 22 healthy children, 30 patients with episodic asthma, and 10 patients with moderate persistent asthma, without preventive treatment at the time of enrolment. RESULTS: LTB concentrations were higher in children with asthma than in healthy controls (50.7 pg/mL vs. 13.68 pg/mL, P < .011). The same was true for children with moderate persistent asthma compared to children with episodic asthma (146.9 pg/mL vs. 18.85 pg/mL, P < .0001), children with moderate persistent asthma compared to healthy controls (146.9 pg/mL vs. 13.68 pg/mL, P < .0001), and children with episodic asthma compared to healthy controls (P, nonsignificant). EBC concentrations of 8-isoprostane were higher in asthmatic than in healthy children (18.3 pg/mL vs. 6.59 pg/mL, P < .026). They were also increased in children with moderate persistent asthma compared to those with episodic asthma (36.25 pg/mL and 12.28 pg/mL, P < .012), and in children with moderate persistent asthma and episodic asthma compared to healthy controls (36.25 pg/mL vs. 6.59 pg/mL [P < .0001] and 12.28 pg/mL versus 6.59 pg/mL [P < .0001], respectively). CONCLUSION: LTB4 and 8-isoprostane concentrations were increased in asthmatic children compared to healthy individuals, with differences detected for 2 degrees of asthma severity. Our findings suggest that EBC is a noninvasive method for airway inflammation and oxidative stress assessment.

Debate pro-con: uso de óxido nítrico en el manejo y seguimiento del asma. En contra / No disponible

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[Comparison of the rapidity of action of dry-powder inhaler vs pressurized aerosol terbutaline]. / Comparación de la rapidez de acción de terbutalino en inhalador de polvo seco con el aerosol presurizado.

The speed of bronchodilatation with terbutaline administered through the Turbuhaler system and the same drug administered through a pressurized liquid aerosol device was compared in 9 patients with reversible air flow obstruction. On 2 consecutive days, terbutaline 0.5 mg in aerosol or dry-powder form (Turbuhaler) was administered after baseline spirometric measurements were taken. Spirometry was repeated at 15, 45 and 90 s and at 3, 5, 10, 15, 30, 60 and 120 min after administration of the drug. Both forms of presentation produced approximately 50% of their maximum effect within the first 45 s; 80% of the patients in the dry-powder group reached the mean of maximum FEV1 increase at 10 min, while 83% in the pressurized-aerosol-device group did so. The maximum increase was reached at 52 (54) min with the Turbuhaler and at 69 (50) min for the aerosol. The difference in speed of effect for the two pharmaceutical forms were not statistically significant. The administration of terbutaline in powder form (Turbuhaler) was as fast and effective in achieving bronchodilatation as was the aerosol form.