title: Urinary leukotriene E4 in the assessment of nocturnal asthma.
abstract: BACKGROUND
  Urinary leukotriene E4 (LTE4) is a marker of the body's production of cysteinyl LTs, important mediators of airway inflammation. The role of the latter in nocturnal asthma is a topic of increasing interest.
  
  
  OBJECTIVE
  This investigation was aimed at determining whether nighttime attacks are associated with increased release of LTs, expressed by urinary LTE4, and the relationship between the two phenomena.
  
  
  METHODS
  Three groups were studied: group A, seven control subjects; group B, nine asthmatic patients without nocturnal attacks; and group C, nine asthmatic patients with a comparable daytime FEV1 but who were experiencing nocturnal exacerbations (morning dips in peak expiratory flow greater than 20%). Urine was collected over 24 hours in three samples (9:00 AM to 3:00 PM; 3:00 PM to 9:00 PM; and 9:00 PM to 9:00 AM). LTE4 was measured by high-performance liquid chromatography and radioimmunoassay and expressed as nanograms per millimole of creatinine.
  
  
  RESULTS
  No significant differences between urinary LTE4 were noticed within groups A and B. Conversely, in group C urinary LTE4 at night (geometric mean with 95% confidence interval; 35.16 with 28.77-42.85) was significantly higher than that of the other samples (respectively 23.12 with 17.78-30.06, p less than 0.05; and 25.18 with 21.03-30.13, p less than 0.02); it was also significantly higher than in all the samples of other groups. A significant (p less than 0.02) linear correlation was observed between morning dip in peak expiratory flow and the log urinary LTE4 in the nocturnal sample.
  
  
  CONCLUSIONS
  These results indicate the role of LTs in nocturnal asthma and suggest that urinary LTE4 may be a useful marker of this condition.
authors.affiliation: Istituto di Medicina Generale e Pneumologia-Universit¿a, Palermo, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Bellia
authors.forename: A
authors.initials: A
authors.lastname: Bonanno
authors.forename: F
authors.initials: F
authors.lastname: Cibella
authors.forename: G
authors.initials: G
authors.lastname: Cuttitta
authors.forename: A
authors.initials: A
authors.lastname: Mirabella
authors.forename: M
authors.initials: M
authors.lastname: Profita
authors.forename: A M
authors.initials: AM
authors.lastname: Vignola
authors.forename: G
authors.initials: G
authors.lastname: Bonsignore
mesh_terms: D000204:Activity Cycles / Q000276:immunology*; D000328:Adult; D000368:Aged; D001249:Asthma / Q000209:etiology / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D005260:Female; D006801:Humans; D017999:Leukotriene E4 / Q000652:urine*; D008297:Male; D008875:Middle Aged
chemical_list: D015415:Biomarkers; D017999:Leukotriene E4