title: Inflammatory mediators in exhaled breath condensate of children with obstructive sleep apnea syndrome.
abstract: BACKGROUND
  Upper airway inflammation is now recognized in adults with obstructive sleep apnea (OSA) syndrome. However, the role played by eicosanoids such as leukotrienes and prostaglandins is unclear.
  
  
  OBJECTIVE
  To investigate whether eicosanoids are measurable in exhaled breath condensate (EBC), and to determine whether differences in these inflammatory mediators emerge among children with and without sleep-disordered breathing (SDB).
  
  
  METHODS
  EBC was collected from 50 consecutive snoring children undergoing overnight polysomnography for suspected SDB, and from 12 nonsnoring control subjects. Prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and cysteinyl leukotrienes (cys-LTs: leukotriene C4 [LTC4]/leukotriene D4 [LTD4]/leukotriene E4 [LTE4]) EBC levels were analyzed using enzyme-linked immunosorbent assay.
  
  
  RESULTS
  LTB4 levels were elevated in children with an apnea-hypopnea index (AHI) > 5/h (SDB; 97.6 +/- 6.3 pg/mL) compared to children with an AHI < 5/h (mild SDB; 66.4 +/- 19.1 pg/mL; p < 0.01) and control subjects (27.8 +/- 3.7 pg/mL; p < 0.01). Similarly, cys-LT (LTC4/LTD4/LTE4) concentrations were also increased in SDB (45.1 +/- 10.6 pg/mL in SDB vs 27.6 +/- 8.3 pg/mL in mild SDB, and 15.7 +/- 7.6 pg/mL in control subjects; p < 0.01). In contrast, PGE2 concentrations were similar among the three groups.
  
  
  CONCLUSIONS
  Inflammatory mediators such as leukotrienes and prostaglandins can be readily quantified in EBC collected from the upper airway of children. Disease severity-dependent increases in leukotriene concentrations (LTB4 and LTC4/LTD4/LTE4) emerge among children and may serve as a noninvasive tool in the clinical assessment of these children.
authors.affiliation: Kosair Children's Hospital Research Institute, University of Louisville, 570 South Preston St, Suite 321, Louisville, KY 40202, USA.
authors.forename: Aviv D
authors.initials: AD
authors.lastname: Goldbart
authors.forename: Jyoti
authors.initials: J
authors.lastname: Krishna
authors.forename: Richard C
authors.initials: RC
authors.lastname: Li
authors.forename: Laura D
authors.initials: LD
authors.lastname: Serpero
authors.forename: David
authors.initials: D
authors.lastname: Gozal
mesh_terms: D000293:Adolescent; D001944:Breath Tests / Q000295:instrumentation / Q000379:methods*; D002648:Child; D015777:Eicosanoids / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D017286:Polysomnography; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000145:classification* / Q000378:metabolism; D012913:Snoring
chemical_list: D015777:Eicosanoids