Urinary and exhaled biomarkers of exercise‐induced bronchoconstriction in atopic asthmatic children

Abstract

Background Exercise‐induced bronchoconstriction (EIB) reflects poor asthma control. Assessing noninvasive biomarkers associated with EIB could help to monitor patients in the pediatric age. Aims To test exhaled and urinary biomarkers for assessing EIB in atopic asthmatic children. Methods In 45 atopic patients (11.1 ± 1.8 years, 25 males) we measured the fractional exhaled nitric oxide (FENO), its alveolar (CaNO), and bronchial (J’awNO) components corrected for the trumpet shape of the airways and axial NO diffusion (TMAD), concentrations of urinary adenosine and 8‐hydroxy‐2'‐deoxyguanosine (8‐OxodG), blood eosinophils count, total immunoglobulin E , skin prick tests, and baseline spirometry before a treadmill exercise challenge. Forty healthy control subjects participated solely to baseline measurements. Results Patients yielded higher FENO and urinary adenosine concentrations than healthy controls. After the challenge, 18 patients (40%) had EIB; these patients had higher levels of CaNO, CaNO TMAD, and urinary adenosine than patients without EIB. Baseline spirometry, FE NO, JawNO, JawNO TMAD, urinary 8‐OxodG, allergy, and blood eosinophil counts were found similar in both groups. In multiple linear regression, the fall in FEV 1 was explained by CaNO TMAD, urinary adenosine and blood eosinophil count, whereas the fall in FEF 25‐75 was explained by CaNO TMAD and blood eosinophil count. Both CaNO TMAD ≥10.5 ppb and urinary adenosine ≥406 nmol/mmol Cr predicted a fall in FEV 1 ≥10%, while only CaNO TMAD ≥10.5 ppb predicted a fall in FEF 25‐75 ≥26%. Conclusion Concentrations of peripheral airway NO are complementary with urinary adenosine for assessing EIB and promising tools of asthma control in pediatric patients with the atopic phenotype.

Effort-induced bronchospasm in athletes: modern views on pathogenesis and diagnosis in high-school teenagers

“…Similar inflammatory changes in the respiratory passages were revealed when examining long-distance runners [30]. A positive correlation was also detected between the exhaled NO index immediately after doing an exercise and the degree of bronchial inflammatory infiltration [24,33]. An independent pathogenetic factor in bronchial asthma and EIB development in athletes is the atopy and its severity.…”

“…It is now considered proven that bronchial asthma associated with EIB is accompanied by an increase in NO production associated with airway obstruction severity. At the same time, reduced NO production is associated with retrograded EIB clinical signs severity [24]. On the other hand, some literature sources present data showing that there is no identified association between the EIB severity and NO production [25].…”

Biomarkers of nucleic acid oxidation – A summary state-of-the-art

“…In addition to the urinary ranges for healthy adults, the urinary ranges of oxidative stress biomarkers in children have also been reported, although there are fewer of these studies in the literature. The reference urinary ranges are 2.63–4.61 ng/mg creatinine for 8-oxodGuo [ [278] , [279] , [280] ], 5.58–12.5 ng/mg creatinine for 8-oxoGuo [ [280] , [281] , [282] ], and 11.5–17.8 ng/mg creatinine for 8-oxoGua [ 281 , 283 ].…”

Pediatric pulmonology 2019 year in review: Asthma

“…Other biomarkers have also been postulated to identify patients with asthma. One group compared patients with atopic asthma to controls and found that both urinary adenosine and peripheral airway exhaled nitric oxide were significantly higher in the group with asthma 4 . Additionally, within the group of subjects with atopic asthma, those with exercise‐induced bronchoconstriction (EIB) had higher measurements of both noninvasive inflammatory biomarkers.…”