Bronchopulmonary dysplasia (BPD), the chronic lung disease of prematurity, may be associated with long-term airflow limitation. Survivors of BPD may develop asthma-like symptoms in childhood, with a variable response to beta(2)-agonists. However, the pathologic pathways underlying these respiratory manifestations are still unknown. The aim of this study was to measure exhaled nitric oxide (FE(NO)) and lung function in a group of 31 school-age survivors of BPD. They showed variable degrees of airflow obstruction (mean FEV(1) 77.8 +/- 2.3% predicted) unresponsive to beta(2)-agonists in 72% of the subjects. Their FE(NO) values (geometric mean [95% confidence interval]: 7.7 [+/- 1.1] ppb) were significantly lower than in a group of healthy matched control subjects born at term (10.7 [+/- 1.1] ppb, p < 0.05) and a group of preterm children without BPD (9.9 [+/- 1.1] ppb, p < 0.05). The children with BPD were also compared with a group of 31 patients with asthma with a comparable airflow limitation (FEV(1) 80.2 +/- 2.1% predicted) and showed FE(NO) values four times lower than in those with asthma (24.9 [+/- 1.2] ppb, p < 0.001). In conclusion, unlike children with asthma, school-age survivors of BPD have airflow limitation associated with low FE(NO) values and lack of reversibility to beta(2)-agonists, probably as a result of mechanisms related to early life structural changes in the airways.

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Prematurity and its main respiratory complication, bronchopulmonary dysplasia (BPD), are potentially associated with lifelong respiratory morbidities and/or lung function abnormalities. The mechanisms behind these long-term respiratory problems are still unclear.We assessed airway oxidative stress in adolescents born very pre-term (f32 gestational weeks) by measuring 8-isoprostane concentration in exhaled breath condensate (EBC). In addition, the study protocol included spirometry and measurement of exhaled nitric oxide fraction (FeNO).The study groups included 34 ex-pre-term adolescents with BPD, 18 ex-pre-term adolescents without BPD and 34 healthy controls born at term.Regardless of a history of BPD, the ex-premature adolescents had higher EBC 8-isoprostane levels (median (interquartile range) BPD 9.5 (7.3-12.2) pg?mL -1 ; pre-term non-BPD 10 (8.1-16) pg?mL -1 ) than the controls (3.2 (1.9-6.5) pg?mL -1 ) (p,0.001). Forced expiratory volume in 1 s was lower in the BPD group (mean¡SD Z-score -2.1¡1.58) than in the pre-term non-BPD individuals (-1.13¡1.15), who showed in turn significantly lower values than the controls (0.18¡0.83; p,0.001). FeNO was similar in the three groups (p50.55).Our data show that, after premature birth, evidence of oxidative stress in the airways may be detected into adolescence, suggesting that long-term respiratory abnormalities after pre-term birth may be associated with an ongoing airway disease and not just a stabilised structural lung damage.

Children acutely exposed to chlorine in a swimming pool presented a substantial lung function impairment associated with biochemical exhaled breath alterations, represented mainly by an increase in LTB(4) and a reduction in Fe(NO). Although lung function and Fe(NO) improved within a few weeks, the increased levels of exhaled LTB(4) persisted for several months.