The Relationship between Oxidative Stress Markers in Exhaled Breath Condensate and Respiratory Problems in Patients with Repaired Esophageal Atresia.

To evaluate the relationship between respiratory problems and oxidative stress markers in exhaled breath condensate (EBC) of patients with esophageal atresia (EA).EA cases with respiratory problems were evaluated retrospectively for age, gender, the type of atresia, surgical treatment, outcome and respiratory symptoms. The results of gastroesophageal reflux (GER) treatment including the use of proton pump inhibitor (PPI) and fundoplication were also documented. EBC samples of 500-1000 μl were obtained by Ecoscreen machine in all cases. The levels of Glutathione (Glut), 8-isoprostane (8-iso), cysteinyl-leukotriene (Cys-LT) were measured with ELISA. Results were compared with healthy control subjects (CG, n = 26) and the relationship between oxidative stress markers and respiratory symptoms was evaluated. The results of GER treatment and oxidative stress markers in EBC were also correlated.Twenty-nine patients with a mean age of 8.8 years (3-14 years) were included. The male/female ratio was 16:13. The EA presented with distal fistula in 27 cases. While no fistula was observed in 1 case, both proximal and distal fistulae were present in another single case. Associated anomalies, most of which were cardiovascular anomalies, were observed in 65.5% (n = 19) of cases. The median Glut level was 1.03 mM/ml (0.93-1.15), iso-8 was 38.8 pg/mL (32.03-76.2) and Cys-LT was 0.44 pg/mL (20.17-61.3) in patients with EA. The median levels of oxidative markers in CG were 1.23 mM/mL (1.13-1.36), 66.3 pg/mL (33.5-106.7), and 56.9 pg/mL (27.4-80.1), respectively. Glut levels were significantly lower in EA cases compared to CG (p = 0.01). There was no significant difference between the groups regarding 8-iso and CYS-LT levels (p = 0.9, p = 1.0). Cys-LT levels were significantly lower in patients with PPI treatment [21.7 pg/mL (18.6-48.1)], when compared to patients without PPI treatment [41.1 pg/mL (22.5-83.1)] (p = 0.04) and healthy subjects [56.9 pg/mL (27.4-80.1)] (p = 0.017). The 8-iso levels were significantly decreased in cases with fundoplication compared to the patients without fundoplication (p = 0.02).Glut - an antioxidant agent - levels were significantly lower in EBC of EA cases. The decrease in Cys-LT levels in cases with PPI treatment and in 8-iso levels in patients with fundoplication suggests that the oxidative damage in EBC of EA cases may be correlated with GER and its management.Case control study LEVEL OF EVIDENCE: Level III.